<?xml version="1.0"encoding="utf-8"?> <!-- name="GENERATOR" content="github.com/mmarkdown/mmark Mmark Markdown Processor - mmark.miek.nl" -->encoding="UTF-8"?> <!DOCTYPE rfc [ <!ENTITY nbsp " "> <!ENTITY zwsp "​"> <!ENTITY nbhy "‑"> <!ENTITY wj "⁠"> ]> <rfc version="3" ipr="trust200902" docName="draft-ietf-cellar-matroska-21"sortRefs="true" tocDepth="4"number="9559" submissionType="IETF" category="std" consensus="true" tocInclude="true" sortRefs="true" symRefs="true" tocDepth="4" xml:lang="en" xmlns:xi="http://www.w3.org/2001/XInclude"indexInclude="true" consensus="true">updates="8794" obsoletes=""> <!-- [rfced] We added "Updates: 8794" to the document header per the text in the Abstract and Section 4.2. Please review and let us know any concerns. --> <!-- [rfced] Should "Specifications" (plural) in the document title be updated to "Specification" (singular)? Or is the current correct? Original: Matroska Media Container Format Specifications Perhaps: Matroska Media Container Format Specification --> <front> <title abbrev="Matroska Format">Matroska Media Container FormatSpecifications</title><seriesInfo value="draft-ietf-cellar-matroska-21" stream="IETF" status="standard" name="Internet-Draft"></seriesInfo>Specifications</title> <seriesInfo name="RFC" value="9559"/> <author initials="S." surname="Lhomme" fullname="SteveLhomme"><organization></organization><address><postal><street></street> </postal><email>slhomme@matroska.org</email> </address></author><authorLhomme"> <organization></organization> <address> <postal> <street></street> </postal> <email>slhomme@matroska.org</email> </address> </author> <author initials="M." surname="Bunkus" fullname="MoritzBunkus"><organization></organization><address><postal><street></street> </postal><email>moritz@bunkus.org</email> </address></author><authorBunkus"> <organization></organization> <address> <postal> <street></street> </postal> <email>moritz@bunkus.org</email> </address> </author> <author initials="D." surname="Rice" fullname="DaveRice"><organization></organization><address><postal><street></street> </postal><email>dave@dericed.com</email> </address></author><date year="2023" month="October" day="22"></date>Rice"> <organization></organization> <address> <postal> <street></street> </postal> <email>dave@dericed.com</email> </address> </author> <date year="2024" month="April" /> <area>art</area><workgroup>CELLAR Group</workgroup><workgroup>cellar</workgroup> <keyword>binary</keyword> <keyword>storage</keyword> <keyword>matroska</keyword> <keyword>ebml</keyword> <keyword>webm</keyword> <abstract> <t>This document defines the Matroska audiovisual data container structure, including definitions of its structural elements,as well as itsterminology, vocabulary, and application.</t> <t>This document updates<xref target="RFC8794"></xref>RFC 8794 to permit the use of a previously reservedEBMLExtensible Binary Meta Language (EBML) Element ID.</t> </abstract> </front> <middle> <section anchor="introduction"><name>Introduction</name> <t>Matroska is an audiovisual data container format. It was derived from a project called <xreftarget="MCF"></xref>,target="MCF"></xref> but diverges from it significantly because it is based on EBML (Extensible Binary Meta Language) <xref target="RFC8794"></xref>, a binary derivative of XML. EBML provides significant advantages in terms of future format extensibility, without breaking file support in parsers reading the previous versions.</t><t>First,<t>To avoid any misunderstandings, it is essential to clarify exactly"Whatwhat anAudio/Videoaudio/video containeris", to avoid any misunderstandings:</t> <ul spacing="compact">is:</t> <ul> <li>It is NOT a video or audio compression format(codec)</li>(codec).</li> <li>It is an envelope in which there can be many audio, video, and subtitles streams, allowing the user to store a complete movie or CD in a single file.</li> </ul> <t>Matroska is designed with the future in mind. It incorporates features such as:</t><ul spacing="compact"><ul> <li>Fast seeking in the file</li> <li>Chapter entries</li> <li>Full metadata (tags) support</li> <li>Selectable subtitle/audio/video streams</li> <li>Modularly expandable</li> <li>Error resilience (can recover playback even when the stream is damaged)</li> <li>Streamable over theinternetInternet and local networks (HTTP <xref target="RFC9110"></xref>, FTP <xref target="RFC0959"></xref>, SMB <xref target="SMB-CIFS"></xref>, etc.)</li> <li>Menus (like menus that DVDs have <xref target="DVD-Video"></xref>)</li> </ul> </section> <section anchor="status-of-this-document"><name>Status ofthis document</name>This Document</name> <t>This document covers Matroska versions 1, 2,33, and 4. Matroskav4version 4 is the current version. Matroska versions 1 to 3 are no longer maintained. No new elements are expected in files with version numbers 1, 2, or 3.</t> </section> <section anchor="notation-and-conventions"><name>Notation and Conventions</name><t>The<t> The key words"<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>","<bcp14>MUST</bcp14>", "<bcp14>MUST NOT</bcp14>", "<bcp14>REQUIRED</bcp14>", "<bcp14>SHALL</bcp14>", "<bcp14>SHALL NOT</bcp14>", "<bcp14>SHOULD</bcp14>", "<bcp14>SHOULD NOT</bcp14>", "<bcp14>RECOMMENDED</bcp14>", "<bcp14>NOT RECOMMENDED</bcp14>", "<bcp14>MAY</bcp14>", and"<bcp14>OPTIONAL</bcp14>""<bcp14>OPTIONAL</bcp14>" in this document are to be interpreted as described inBCP 14BCP 14 <xreftarget="RFC2119"></xref>target="RFC2119"/> <xreftarget="RFC8174"></xref>target="RFC8174"/> when, and only when, they appear in all capitals, as shownhere.</t>here. </t> <t>This document definesspecificthe following terms in order to define the format and application of<tt>Matroska</tt>. Specific terms are defined below:</t> <dl spacing="compact"><tt>Matroska</tt>: </t> <dl> <dt><tt>Matroska</tt>:</dt> <dd>A multimedia container format based on EBML (Extensible Binary Meta Language).</dd> <dt><tt>Matroska Reader</tt>:</dt> <dd>A data parser that interprets the semantics of a Matroska document and creates a way for programs to use <tt>Matroska</tt>.</dd> <dt><tt>Matroska Player</tt>:</dt> <dd>A <tt>Matroska Reader</tt> withathe primary purpose of playing audiovisual files, including <tt>Matroska</tt> documents.</dd> <dt><tt>Matroska Writer</tt>:</dt> <dd>A data writer that creates <tt>Matroska</tt> documents.</dd> </dl> </section> <section anchor="matroska-overview"><name>Matroska Overview</name> <section anchor="principles"><name>Principles</name> <t>Matroska is a Document Type ofEBML (Extensible Binary Meta Language).EBML. This specification is dependent on the EBMLSpecificationspecification <xref target="RFC8794"></xref>. For an understanding of Matroska's EBML Schema, see in particular the sections of the EBMLSpecification coveringspecification that cover EBML Element Types (Section7),<xref target="RFC8794" sectionFormat="bare" section="7"/>), EBML Schema (Section11.1),<xref target="RFC8794" sectionFormat="bare" section="11.1"/>), and EBML Structure (Section3).</t><xref target="RFC8794" sectionFormat="bare" section="3"/>).</t> </section> <section anchor="updates-to-rfc-8794"><name>Updates to RFC 8794</name> <t>Because of an oversight, <xref target="RFC8794"></xref> reserved EBML ID 0x80, which is used by deployed Matroska implementations. For this reason, this specification updates <xref target="RFC8794"></xref> to make 0x80 a legal EBML ID.Specifically,Additionally, this specification makes the followingare changed inupdates:</t> <ul> <li><t><xref target="RFC8794" sectionFormat="of" section="17.1"/> (per Erratum ID #7189 <xreftarget="RFC8794"></xref>:</t> <ul spacing="compact"> <li>From Errata 7189</li> </ul> <t>In Section 17.1,</t>target="Err7189"/>)</t> <t>OLD:</t> <blockquote> <t>One-octet Element IDsMUST<bcp14>MUST</bcp14> be between 0x81 and 0xFE. These items are valuable because they are short, and they need to be used for commonly repeated elements. Element IDs are to be allocated within this range according to the"RFC Required""RFC Required" policy[RFC8126].</t><xref target="RFC8126"/>.</t> <t>The following one-octet Element IDs are RESERVED: 0xFF and 0x80.</t> </blockquote> <t>NEW:</t> <blockquote> <t>One-octet Element IDsMUST<bcp14>MUST</bcp14> be between 0x80 and 0xFE. These items are valuable because they are short, and they need to be used for commonly repeated elements. Element IDs are to be allocated within this range according to the"RFC Required""RFC Required" policy[RFC8126].</t><xref target="RFC8126"/>.</t> <t>The following one-octet Element ID is RESERVED: 0xFF.</t><ul spacing="compact"> <li>From Errata 7191</li> </ul> <t>In Section 5,</t></blockquote> </li> <li><t><xref target="RFC8794" sectionFormat="of" section="5"/> (per Erratum ID #7191 <xref target="Err7191"/>)</t> <t>OLD:</t> <artwork> +=========================+================+=================+ | Element ID Octet Length | Range of Valid | Number of Valid | | | Element IDs | Element IDs | +=========================+================+=================+ | 1 | 0x81 - 0xFE | 126 | +-------------------------+----------------+-----------------+ </artwork> <t>NEW:</t> <artwork> +=========================+================+=================+ | Element ID Octet Length | Range of Valid | Number of Valid | | | Element IDs | Element IDs | +=========================+================+=================+ | 1 | 0x80 - 0xFE | 127 | +-------------------------+----------------+-----------------+ </artwork> </li> </ul> </section> <section anchor="added-ebml-constraints"><name>Added EBML Constraints</name> <t>As an EBML Document Type, Matroska adds the following constraints to the EBMLspecification.</t> <ul spacing="compact">specification <xref target="RFC8794"></xref>:</t> <ul> <li>The <tt>docType</tt> of the <tt>EBML Header</tt> <bcp14>MUST</bcp14> be"matroska".</li>"matroska".</li> <li>The <tt>EBMLMaxIDLength</tt> of the <tt>EBML Header</tt> <bcp14>MUST</bcp14> be 4.</li> <li>The <tt>EBMLMaxSizeLength</tt> of the <tt>EBML Header</tt> <bcp14>MUST</bcp14> be between 1 and88, inclusive.</li> </ul> </section> <section anchor="design-rules"><name>Design Rules</name> <t>The Root Element and allTop-LevelsTop-Level Elements <bcp14>MUST</bcp14> use 4 octets for their EBML Element ID --i.e.i.e., Segment and direct children of Segment.</t> <t>Legacy EBML/Matroska parsers did not handle Empty Elementsproperly,properly; elements were present in the file butwithhad a length ofzero.0. They always assumed the value was 0 for integers/dates or 0x0p+0, the textual expression of floats using the format in <xreftarget="ISO9899"></xref> format,target="ISO9899"></xref>, no matter the default value of the elementwhichthat should have been used instead. Therefore, MatroskawritersWriters <bcp14>MUST NOT</bcp14> use EBML EmptyElements,Elements if the element has a default value that is not 0 for integers/dates and 0x0p+0 for floats.</t> <t>When adding new elements to Matroska, these rules apply:</t><ul spacing="compact"><ul> <li>A non-mandatory integer/date Element <bcp14>MUST NOT</bcp14> have a default value other than 0.</li> <li>A non-mandatory float Element <bcp14>MUST NOT</bcp14> have a default value other than 0x0p+0.</li> <li>A non-mandatory string Element <bcp14>MUST NOT</bcp14> have a default value, as emptystringstrings cannot be defined in the XML Schema.</li> </ul> </section> <section anchor="data-layout"><name>Data Layout</name> <t>A Matroska file <bcp14>MUST</bcp14> be composed of at least one <tt>EBML Document</tt> using the <tt>Matroska Document Type</tt>. Each <tt>EBML Document</tt> <bcp14>MUST</bcp14> start with an <tt>EBML Header</tt> and <bcp14>MUST</bcp14> be followed by the <tt>EBML Root Element</tt>, defined as <tt>Segment</tt> in Matroska. Matroska defines several <tt>Top-Level Elements</tt>whichthat may occur within the <tt>Segment</tt>.</t> <t>As an example, a simple Matroska file consisting of a single <tt>EBML Document</tt> could be represented like this:</t> <ul spacing="compact"> <li><tt>EBML Header</tt></li> <li><tt>Segment</tt></li> </ul> <t>A more complex Matroska file consisting of an <tt>EBML Stream</tt> (consisting of two <tt>EBML Documents</tt>) could be represented like this:</t> <ul spacing="compact"> <li><tt>EBML Header</tt></li> <li><tt>Segment</tt></li> <li><tt>EBML Header</tt></li> <li><tt>Segment</tt></li> </ul> <t>The following diagram represents a simple Matroska file, comprised of an <tt>EBML Document</tt> with an <tt>EBML Header</tt>, a <tt>Segment Element</tt> (the <tt>Root Element</tt>), and all eight Matroska <tt>Top-Level Elements</tt>. In thefollowingdiagramsofin this section, horizontal spacing expresses a parent-child relationship between Matroska Elements (e.g., the <tt>Info Element</tt> is contained within the <tt>SegmentElement</tt>)Element</tt>), whereas vertical alignment represents the storage order within the file.</t> <figure><name>BasiclayoutLayout of a Matroskafile. </name> <artwork>+-------------+File</name> <artwork> +-------------+ | EBML Header | +---------------------------+ | Segment | SeekHead | | |-------------| | | Info | | |-------------| | | Tracks | | |-------------| | | Chapters | | |-------------| | | Cluster | | |-------------| | | Cues | | |-------------| | | Attachments | | |-------------| | | Tags | +---------------------------+ </artwork> </figure> <t>The Matroska <tt>EBML Schema</tt> defines eight <tt>Top-Level Elements</tt>:</t><ul spacing="compact"><ul> <li><tt>SeekHead</tt> (<xreftarget="seekhead"></xref>),</li>target="seekhead"></xref>)</li> <li><tt>Info</tt> (<xreftarget="info"></xref>),</li>target="info"></xref>)</li> <li><tt>Tracks</tt> (<xreftarget="track-flags"></xref>),</li>target="track-flags"></xref>)</li> <li><tt>Chapters</tt> (<xreftarget="chapters"></xref>),</li>target="chapters"></xref>)</li> <li><tt>Cluster</tt> (<xreftarget="cluster-blocks"></xref>),</li>target="cluster-blocks"></xref>)</li> <li><tt>Cues</tt> (<xreftarget="cues"></xref>),</li>target="cues"></xref>)</li> <li><tt>Attachments</tt> (<xreftarget="attachments-1"></xref>),</li> <li>and <tt>Tags</tt>target="attachments-1"></xref>)</li> <li><tt>Tags</tt> (<xreftarget="tags"></xref>).</li>target="tags"></xref>)</li> </ul> <t>The <tt>SeekHead Element</tt> (also known as <tt>MetaSeek</tt>) contains an index of <tt>Top-Level Elements</tt> locations within the <tt>Segment</tt>. Use of the <tt>SeekHead Element</tt> is <bcp14>RECOMMENDED</bcp14>. Without a <tt>SeekHead Element</tt>, a Matroska parser would have to search the entire file to find all of the other <tt>Top-Level Elements</tt>. This is due to Matroska's flexible ordering requirements; for instance, it is acceptable for the <tt>Chapters Element</tt> to be stored after the <tt>ClusterElements</tt>.</t>Element</tt>.</t> <figure><name>Representation of a <tt>SeekHeadElement</tt>.Element</tt> </name><artwork>+--------------------------------+<artwork> +--------------------------------+ | SeekHead | Seek | SeekID | | | |--------------| | | | SeekPosition | +--------------------------------+ </artwork> </figure> <t>The <tt>Info Element</tt> contains vital information for identifying the whole <tt>Segment</tt>. This includes the title for the <tt>Segment</tt>, a randomly generated uniqueidentifier,identifier (UID), and theunique identifier(s)UID(s) of any linked <tt>Segment Elements</tt>.</t> <figure><name>Representation of an <tt>Info Element</tt> anditsIts <tt>ChildElements</tt>.Elements</tt> </name><artwork>+-------------------------+<artwork> +-------------------------+ | Info | SegmentUUID | | |------------------| | | SegmentFilename | | |------------------| | | PrevUUID | | |------------------| | | PrevFilename | | |------------------| | | NextUUID | | |------------------| | | NextFilename | | |------------------| | | SegmentFamily | | |------------------| | | ChapterTranslate | | |------------------| | | TimestampScale | | |------------------| | | Duration | | |------------------| | | DateUTC | | |------------------| | | Title | | |------------------| | | MuxingApp | | |------------------| | | WritingApp | |-------------------------| </artwork> </figure> <t>The <tt>Tracks Element</tt> defines the technical details for each track and can store the name, number,unique identifier,UID, language, and type (audio, video, subtitles, etc.) of each track. For example, the <tt>Tracks Element</tt> <bcp14>MAY</bcp14> store information about the resolution of a video track or sample rate of an audio track.</t> <t>The <tt>Tracks Element</tt> <bcp14>MUST</bcp14> identify all the data needed by the codec to decode the data of the specified track. However, the data required is contingent on the codec used for the track. For example, a <tt>Track Element</tt> for uncompressed audio only requires the audio bit rate to be present. A codec such as AC-3 would require that the <tt>CodecID Element</tt> be present for all tracks, as it is the primary way to identify which codec to use to decode the track.</t> <figure><name>Representation of the <tt>Tracks Element</tt> and aselectionSelection ofitsIts <tt>DescendantElements</tt>.Elements</tt> </name><artwork>+------------------------------------+<artwork> +------------------------------------+ | Tracks | TrackEntry | TrackNumber | | | |--------------| | | | TrackUID | | | |--------------| | | | TrackType | | | |--------------| | | | Name | | | |--------------| | | | Language | | | |--------------| | | | CodecID | | | |--------------| | | | CodecPrivate | | | |--------------| | | | CodecName | | | |----------------------------------+ | | | Video | FlagInterlaced | | | | |-------------------| | | | | FieldOrder | | | | |-------------------| | | | | StereoMode | | | | |-------------------| | | | | AlphaMode | | | | |-------------------| | | | | PixelWidth | | | | |-------------------| | | | | PixelHeight | | | | |-------------------| | | | | DisplayWidth | | | | |-------------------| | | | | DisplayHeight | | | | |-------------------| | | | | AspectRatioType | | | | |-------------------| | | | | Color | | | |----------------------------------| | | | Audio | SamplingFrequency | | | | |-------------------| | | | | Channels | | | | |-------------------| | | | | BitDepth | |--------------------------------------------------------| </artwork> </figure> <t>The <tt>Chapters Element</tt> lists all of the chapters. Chapters are a way to set predefined points to jump to in video or audio.</t> <figure><name>Representation of the <tt>Chapters Element</tt> and aselectionSelection ofitsIts <tt>DescendantElements</tt>.Elements</tt> </name><artwork>+-----------------------------------------+<artwork> +-----------------------------------------+ | Chapters | Edition | EditionUID | | | Entry |--------------------| | | | EditionFlagDefault | | | |--------------------| | | | EditionFlagOrdered | | | |---------------------------------+ | | | ChapterAtom | ChapterUID | | | | |-------------------| | | | | ChapterStringUID | | | | |-------------------| | | | | ChapterTimeStart | | | | |-------------------| | | | | ChapterTimeEnd | | | | |-------------------| | | | | ChapterFlagHidden | | | | |-------------------------------+ | | | | ChapterDisplay | ChapString | | | | | |--------------| | | | | | ChapLanguage | +------------------------------------------------------------------+ </artwork> </figure> <t><tt>Cluster Elements</tt> contain the content for each track, e.g., video frames. A Matroska file <bcp14>SHOULD</bcp14> contain at least one <tt>Cluster Element</tt>. <!-- [rfced] How may we clarify "a form of Segment linking with other Segments"? Original: In the rare case it doesn't, there should be a form of Segment linking with other Segments, possibly using Chapters, see Section 17. Perhaps: In the rare case it doesn't, there should be a method for Segments to link together, possibly using Chapters; see Section 17. --> In the rare case it doesn't, there should be a form of Segment linking with other Segments, possibly using Chapters; see <xref target="linked-segments"></xref>.</t> <t>The <tt>Cluster Element</tt> helps to break up <tt>SimpleBlock</tt> or <tt>BlockGroup Elements</tt> and helps with seeking and error protection. Every <tt>Cluster Element</tt> <bcp14>MUST</bcp14> contain a <tt>Timestamp Element</tt>. This <bcp14>SHOULD</bcp14> be the <tt>Timestamp Element</tt> used to play the first <tt>Block</tt> in the <tt>Cluster Element</tt>, unless a different value is needed to accommodate for moreBlocks,Blocks; see <xref target="block-timestamps"></xref>.</t> <t><tt>Cluster Elements</tt> contain one or more block element, such as <tt>BlockGroup</tt> or <tt>SimpleBlock</tt> elements. In some situations, a <tt>Cluster Element</tt> <bcp14>MAY</bcp14> contain no block element, forexampleexample, in a live recording when no data has been collected.</t> <t>A <tt>BlockGroup Element</tt> <bcp14>MAY</bcp14> contain a <tt>Block</tt> of data and any information relating directly to that <tt>Block</tt>.</t> <figure><name>Representation of a <tt>Cluster Element</tt> andits immediateIts Immediate <tt>ChildElements</tt>.Elements</tt> </name><artwork>+--------------------------+<artwork> +--------------------------+ | Cluster | Timestamp | | |----------------| | | Position | | |----------------| | | PrevSize | | |----------------| | | SimpleBlock | | |----------------| | | BlockGroup | +--------------------------+ </artwork> </figure> <figure><name>Representation of the <tt>Block Element</tt>structure.Structure </name><artwork>+----------------------------------+<artwork> +----------------------------------+ | Block | Portion of | Data Type | | | a Block | - Bit Flag | | |--------------------------+ | | Header | TrackNumber | | | |-------------| | | | Timestamp | | | |-------------| | | | Flags | | | | - Gap | | | | - Lacing | | | | - Reserved | | |--------------------------| | | Optional | FrameSize | | |--------------------------| | | Data | Frame | +----------------------------------+ </artwork> </figure> <t>Each <tt>Cluster</tt> <bcp14>MUST</bcp14> contain exactly one <tt>Timestamp Element</tt>. The <tt>Timestamp Element</tt> value <bcp14>MUST</bcp14> be stored once per <tt>Cluster</tt>. The <tt>Timestamp Element</tt> in the <tt>Cluster</tt> is relative to the entire <tt>Segment</tt>. The <tt>Timestamp Element</tt> <bcp14>SHOULD</bcp14> be the first <tt>Element</tt> in the <tt>Cluster</tt> it belongsto,to or the second <tt>Element</tt> if that Cluster contains a CRC-32 element (<xref target="crc-32"></xref>)</t> <t>Additionally, the <tt>Block</tt> contains an offset that, when added to the <tt>Cluster</tt>'s <tt>Timestamp Element</tt> value, yields the <tt>Block</tt>'s effective timestamp. Therefore, the timestamp in the <tt>Block</tt> itself is relative to the <tt>Timestamp Element</tt> in the <tt>Cluster</tt>. For example, if the <tt>Timestamp Element</tt> in the <tt>Cluster</tt> is set to 10 seconds and a <tt>Block</tt> in that <tt>Cluster</tt> is supposed to be played 12 seconds into the clip, the timestamp in the <tt>Block</tt> would be set to 2 seconds.</t> <t>The <tt>ReferenceBlock</tt> in the <tt>BlockGroup</tt> is used instead of the basic"P-frame"/"B-frame""P-frame"/"B-frame" description. Instead of simply saying that this <tt>Block</tt> depends on the <tt>Block</tt> directlybefore,before or directlyafterwards,after, the <tt>Timestamp</tt> of the necessary <tt>Block</tt> is used. Because there can be as many <tt>ReferenceBlock Elements</tt> as necessary for a <tt>Block</tt>, it allows for some extremely complex referencing.</t> <t>The <tt>Cues Element</tt> is used to seek when playing back a file by providing a temporal index for some of the <tt>Tracks</tt>. It is similar to the <tt>SeekHeadElement</tt>,Element</tt> but is used for seeking to a specific time when playing back the file. It is possible to seek without this element, but it is much more difficult because a <tt>Matroska Reader</tt> would have to'hunt"hunt andpeck'peck" through the filelookingto look for the correct timestamp.</t> <t>The <tt>Cues Element</tt> <bcp14>SHOULD</bcp14> contain at least one <tt>CuePoint Element</tt>. Each <tt>CuePoint Element</tt> stores the position of the <tt>Cluster</tt> that contains the <tt>BlockGroup</tt> or <tt>SimpleBlock Element</tt>. The timestamp is stored in the <tt>CueTimeElement</tt>Element</tt>, and the location is stored in the <tt>CueTrackPositions Element</tt>.</t> <t>The <tt>Cues Element</tt> is flexible. For instance, the <tt>Cues Element</tt> can be used to index every single timestamp of every <tt>Block</tt> or they can be indexed selectively.</t> <figure><name>Representation of a <tt>Cues Element</tt> andtwo levelsTwo Levels ofitsIts <tt>DescendantElements</tt>.Elements</tt> </name><artwork>+-------------------------------------+<artwork> +-------------------------------------+ | Cues | CuePoint | CueTime | | | |-------------------| | | | CueTrackPositions | | |------------------------------| | | CuePoint | CueTime | | | |-------------------| | | | CueTrackPositions | +-------------------------------------+ </artwork> </figure> <t>The <tt>Attachments Element</tt> is for attaching files to a Matroskafilefile, such as pictures, fonts,webpages,web pages, etc.</t> <figure><name>Representation of an <tt>AttachmentsElement</tt>.Element</tt> </name><artwork>+------------------------------------------------+<artwork> +------------------------------------------------+ | Attachments | AttachedFile | FileDescription | | | |-------------------| | | | FileName | | | |-------------------| | | | FileMediaType | | | |-------------------| | | | FileData | | | |-------------------| | | | FileUID | | | |-------------------| | | | FileName | | | |-------------------| | | | FileReferral | | | |-------------------| | | | FileUsedStartTime | | | |-------------------| | | | FileUsedEndTime | +------------------------------------------------+ </artwork> </figure> <t>The <tt>Tags Element</tt> contains metadata that describes the <tt>Segment</tt> and potentially its <tt>Tracks</tt>, <tt>Chapters</tt>, and <tt>Attachments</tt>. Each <tt>Track</tt> or <tt>Chapter</tt> that those tags applies to has its UID listed in the <tt>Tags</tt>. The <tt>Tags</tt> contain all extra information about the file:scriptwriter, singer,scriptwriters, singers, actors, directors, titles, edition, price, dates, genre, comments, etc. Tags can contain their values in multiple languages. <!-- [rfced] May we update "the title it was released as in Germany" in one of the following ways to improve readability? Original: For example, a movie's "title" Tag might contain both the original English title as well as the title it was released as in Germany. Perhaps: For example, a movie's "title" Tag might contain both the original English title as well as the German title. Or: For example, a movie's "title" Tag might contain both the original English title as well as the title used when it was released in Germany. --> For example, a movie's"title""title" <tt>Tag</tt> might contain both the original English title as well as the title it was released as in Germany.</t> <figure><name>Representation of a <tt>Tags Element</tt> andthree levelsThree Levels ofitsIts <tt>ChildrenElements</tt>.Elements</tt> </name><artwork>+-------------------------------------------+<artwork> +-------------------------------------------+ | Tags | Tag | Targets | TargetTypeValue | | | | |------------------| | | | | TargetType | | | | |------------------| | | | | TagTrackUID | | | | |------------------| | | | | TagEditionUID | | | | |------------------| | | | | TagChapterUID | | | | |------------------| | | | | TagAttachmentUID | | | |------------------------------| | | | SimpleTag | TagName | | | | |------------------| | | | | TagLanguage | | | | |------------------| | | | | TagDefault | | | | |------------------| | | | | TagString | | | | |------------------| | | | | TagBinary | | | | |------------------| | | | | SimpleTag | +-------------------------------------------+ </artwork> </figure> </section> </section> <section anchor="matroska-schema"><name>Matroska Schema</name><t>This<!-- [rfced] We are having trouble understanding the second sentence below. Is it redundant with the first sentence? Should it be either deleted or rephrased? Original: This specification includes an<tt>EBML Schema</tt>,EBML Schema, which defines the Elements and structure of Matroska using the EBML Schema elements and attributes defined in Section 11.1 of [RFC8794]. The EBML Schema defines every valid Matroska element in a manner defined by the EBML specification. Perhaps (delete second sentence): This specification includes an EBML Schema that defines the Elements and structure of Matroska using the EBML Schema elements and attributes defined in Section 11.1 of [RFC8794]. Or (rephrase second sentence): This specification includes an EBML Schema that defines the Elements and structure of Matroska using the EBML Schema elements and attributes defined in Section 11.1 of [RFC8794]. The EBML Schema in this document defines every valid Matroska element in a manner defined by the EBML specification [RFC8794]. --> <t>This specification includes an <tt>EBML Schema</tt> that defines the Elements and structure of Matroska using the EBML Schema elements and attributes defined in <xreftarget="RFC8794"></xref>.target="RFC8794" sectionFormat="of" section="11.1"/>. The EBML Schema defines every valid Matroska element in a manner defined by the EBMLspecification.</t>specification <xref target="RFC8794"></xref>.</t> <t>Attributes using their default valuelike(like <tt>minOccurs</tt>, <tt>minver</tt>,etc.etc.) or attributes with undefined valueslike(like <tt>length</tt>, <tt>maxver</tt>,etc.etc.) are omitted.</t><t>Here the definition of<t>The definitions for each Matroska Elementis provided.</t>are provided below.</t> <section anchor="segment-element"><name>Segment Element</name> <!-- [rfced] FYI - To make the definition lists in Section 5.1 consistent (especially when definitions appear after a table), we moved the tables out of the definition lists. --> <!-- [rfced] The following sections include paragraphs that are not part of the <dl>. Should these paragraphs be nested under "definition:"? 5.1.3.5.5 5.1.4.1.28.44 5.1.4.1.28.45 5.1.4.1.28.46 --> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x18538067 / master</dd></dl> <t>unknownsizeallowed: True</t> <dl spacing="compact"><dt>unknownsizeallowed:</dt> <dd>True</dd> <dt>path:</dt> <dd><tt>\Segment</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The Root Element that contains all other Top-Level Elements; see <xref target="data-layout"></xref>.</dd> </dl> <section anchor="seekhead-element"><name>SeekHead Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x114D9B74 / master</dd> <dt>path:</dt> <dd><tt>\Segment\SeekHead</tt></dd> <dt>maxOccurs:</dt> <dd>2</dd> <dt>definition:</dt> <dd>Contains seeking information of Top-Level Elements; see <xref target="data-layout"></xref>.</dd> </dl> <section anchor="seek-element"><name>Seek Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4DBB / master</dd> <dt>path:</dt> <dd><tt>\Segment\SeekHead\Seek</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Contains a single seek entry to an EBML Element.</dd> </dl> <section anchor="seekid-element"><name>SeekID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x53AB / binary</dd> <dt>length:</dt> <dd>4</dd> <dt>path:</dt> <dd><tt>\Segment\SeekHead\Seek\SeekID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The binary EBML ID of a Top-Level Element.</dd> </dl> </section> <section anchor="seekposition-element"><name>SeekPosition Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x53AC / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\SeekHead\Seek\SeekPosition</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The Segment Position (<xref target="segment-position"></xref>) of a Top-Level Element.</dd> </dl> </section> </section> </section> <section anchor="info-element"><name>Info Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1549A966 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Info</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd></dl> <t>recurring: True</t> <dl spacing="compact"><dt>recurring:</dt><dd>True</dd> <dt>definition:</dt> <dd>Contains general information about the Segment.</dd> </dl> <section anchor="segmentuuid-element"><name>SegmentUUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x73A4 / binary</dd> <dt>length:</dt> <dd>16</dd> <dt>path:</dt> <dd><tt>\Segment\Info\SegmentUUID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A randomly generatedunique ID to identifyUID that identifies the Segment amongst many others (128 bits). It is equivalent to aUUIDUniversally Unique Identifier (UUID) v4 <xref target="RFC4122"></xref> with all bits randomly (orpseudo-randomly)pseudorandomly) chosen. An actual UUID v4 value, where some bits are not random, <bcp14>MAY</bcp14> also be used.</dd> <dt>usage notes:</dt> <dd>If the Segment is a part of a Linked Segment, then this Element is <bcp14>REQUIRED</bcp14>. The value of theunique IDUID <bcp14>MUST</bcp14> contain at least one bit set to 1.</dd> </dl> </section> <section anchor="segmentfilename-element"><name>SegmentFilename Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x7384 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Info\SegmentFilename</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A filename corresponding to this Segment.</dd> </dl> </section> <section anchor="prevuuid-element"><name>PrevUUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x3CB923 / binary</dd> <dt>length:</dt> <dd>16</dd> <dt>path:</dt> <dd><tt>\Segment\Info\PrevUUID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>An IDto identifythat identifies the previous Segment of a Linked Segment.</dd> <dt>usage notes:</dt> <dd>If the Segment is a part of a Linked Segment that uses Hard Linking (<xref target="hard-linking"></xref>), then either the PrevUUID or the NextUUID Element is <bcp14>REQUIRED</bcp14>. If a Segment contains a PrevUUID but not a NextUUID, then it <bcp14>MAY</bcp14> be considered as the last Segment of the Linked Segment. The PrevUUID <bcp14>MUST NOT</bcp14> be equal to the SegmentUUID.</dd> </dl> </section> <section anchor="prevfilename-element"><name>PrevFilename Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x3C83AB / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Info\PrevFilename</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A filename corresponding to the file of the previous Linked Segment.</dd> <dt>usage notes:</dt> <dd>Provision of the previous filename is for display convenience, but PrevUUID <bcp14>SHOULD</bcp14> be considered authoritative for identifying the previous Segment in a Linked Segment.</dd> </dl> </section> <section anchor="nextuuid-element"><name>NextUUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x3EB923 / binary</dd> <dt>length:</dt> <dd>16</dd> <dt>path:</dt> <dd><tt>\Segment\Info\NextUUID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>An IDto identifythat identifies the next Segment of a Linked Segment.</dd> <dt>usage notes:</dt> <dd>If the Segment is a part of a Linked Segment that uses Hard Linking (<xref target="hard-linking"></xref>), then either the PrevUUID or the NextUUID Element is <bcp14>REQUIRED</bcp14>. If a Segment contains a NextUUID but not a PrevUUID, then it <bcp14>MAY</bcp14> be considered as the first Segment of the Linked Segment. The NextUUID <bcp14>MUST NOT</bcp14> be equal to the SegmentUUID.</dd> </dl> </section> <section anchor="nextfilename-element"><name>NextFilename Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x3E83BB / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Info\NextFilename</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A filename corresponding to the file of the next Linked Segment.</dd> <dt>usage notes:</dt> <dd>Provision of the next filename is for display convenience, but NextUUID <bcp14>SHOULD</bcp14> be considered authoritative for identifying the Next Segment.</dd> </dl> </section> <section anchor="segmentfamily-element"><name>SegmentFamily Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4444 / binary</dd> <dt>length:</dt> <dd>16</dd> <dt>path:</dt> <dd><tt>\Segment\Info\SegmentFamily</tt></dd> <dt>definition:</dt> <dd>Aunique IDUID that all Segments of a Linked Segment <bcp14>MUST</bcp14> share (128 bits). It is equivalent to a UUID v4 <xref target="RFC4122"></xref> with all bits randomly (orpseudo-randomly)pseudorandomly) chosen. An actual UUID v4 value, where some bits are not random, <bcp14>MAY</bcp14> also be used.</dd> <dt>usage notes:</dt> <dd>If the Segment Info contains a <tt>ChapterTranslate</tt> element, this Element is <bcp14>REQUIRED</bcp14>.</dd> </dl> </section> <section anchor="chaptertranslate-element"><name>ChapterTranslate Element</name> <!-- [rfced] Does "they" refer to "Chapter Codec" in these sentences? If so, we will updated "Chapter Codec" to "Chapter Codecs". Original: rationale: Chapter Codec may need to address different segments, but they may not know of the way to identify such segment when stored in Matroska. rationale: Chapter Codec may need to address content in specific track, but they may not know of the way to identify tracks in Matroska. Perhaps: rationale: Chapter Codecs may need to address different segments, but they may not know of the way to identify such segments when stored in Matroska. rationale: Chapter Codecs may need to address content in specific track, but they may not know of the way to identify tracks in Matroska. --> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6924 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Info\ChapterTranslate</tt></dd> <dt>definition:</dt> <dd>The mapping between this <tt>Segment</tt> and a segment value in the given Chapter Codec.</dd> <dt>rationale:</dt> <dd>Chapter Codec may need to address different segments, but they may not know of the way to identify suchsegmentsegments when stored in Matroska. This element and its child elements add a way to map the internal segments known to the Chapter Codec to the Segment IDs in Matroska. This allows remuxing a file with the Chapter Codec without changing the content of the codec data, just the Segment mapping.</dd> </dl> <section anchor="chaptertranslateid-element"><name>ChapterTranslateID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x69A5 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Info\ChapterTranslate\ChapterTranslateID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The binary value used to represent this Segment in the chapter codec data. The format depends on the ChapProcessCodecID used; see <xref target="chapprocesscodecid-element"></xref>.</dd> </dl> </section> <section anchor="chaptertranslatecodec-element"><name>ChapterTranslateCodec Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x69BF / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Info\ChapterTranslate\ChapterTranslateCodec</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>This <tt>ChapterTranslate</tt> applies to this chapter codec of the given chapter edition(s); see <xref target="chapprocesscodecid-element"></xref>.</dd> <dt>defined values:</dt> <dd>See <xref target="ChapterTranslateCodecValues"/>.</dd> </dl><t>defined values:</t><table anchor="ChapterTranslateCodecValues"><name>ChapterTranslateCodecvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">Matroska Script</td> <td align="left">Chapter commands using the Matroska Script codec.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">DVD-menu</td> <td align="left">Chapter commands using the DVD-like codec.</td> </tr> </tbody></table></section></table> </section> <section anchor="chaptertranslateeditionuid-element"><name>ChapterTranslateEditionUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x69FC / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Info\ChapterTranslate\ChapterTranslateEditionUID</tt></dd> <dt>definition:</dt> <dd>Specify a chapter edition UIDonto which this <tt>ChapterTranslate</tt> applies.</dd> <dt>usage notes:</dt> <dd>When no <tt>ChapterTranslateEditionUID</tt> is specified in the <tt>ChapterTranslate</tt>, the <tt>ChapterTranslate</tt> applies to all chapter editions found in the Segment using the given <tt>ChapterTranslateCodec</tt>.</dd> </dl> </section> </section> <section anchor="timestampscale-element"><name>TimestampScale Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x2AD7B1 / uinteger / 1000000</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Info\TimestampScale</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Base unit for Segment Ticks and Track Ticks, in nanoseconds. A TimestampScale value of 1000000 means scaled timestamps in the Segment are expressed in milliseconds; see <xref target="timestamps"></xref> on how to interpret timestamps.</dd> </dl> </section> <section anchor="duration-element"><name>Duration Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4489 / float</dd> <dt>range:</dt> <dd>> 0x0p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Info\Duration</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Duration of the Segment, expressed in SegmentTicksTicks, whichisare based on TimestampScale; see <xref target="timestamp-ticks"></xref>.</dd> </dl> </section> <section anchor="dateutc-element"><name>DateUTC Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4461 / date</dd> <dt>path:</dt> <dd><tt>\Segment\Info\DateUTC</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>The date and time that the Segment was created by the muxing application or library.</dd> </dl> </section> <section anchor="title-element"><name>Title Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x7BA9 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Info\Title</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>General name of the Segment.</dd> </dl> </section> <section anchor="muxingapp-element"><name>MuxingApp Element</name> <!-- [rfced] Will readers know what "libmatroska" is? Would a citation be helpful or is the current okay? Original: definition: Muxing application or library (example: "libmatroska- 0.4.3"). ... definition: Bogus StereoMode value used in old versions of libmatroska. ... usage notes: This Element MUST NOT be used. It was an incorrect value used in libmatroska up to 0.9.0. ... There was also a bug in libmatroska prior to 0.9.0 that would save/read it as 0x53B9 instead of 0x53B8; see OldStereoMode (Section 5.1.4.1.28.5). --> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4D80 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Info\MuxingApp</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Muxing application or library (example:"libmatroska-0.4.3").</dd>"libmatroska-0.4.3").</dd> <dt>usage notes:</dt> <dd>Include the full name of the application or library followed by the version number.</dd> </dl> </section> <section anchor="writingapp-element"><name>WritingApp Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x5741 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Info\WritingApp</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Writing application (example:"mkvmerge-0.3.3").</dd>"mkvmerge-0.3.3").</dd> <dt>usage notes:</dt> <dd>Include the full name of the application followed by the version number.</dd> </dl> </section> </section> <section anchor="cluster-element"><name>Cluster Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1F43B675 / master</dd></dl> <t>unknownsizeallowed: True</t> <dl spacing="compact"><dt>unknownsizeallowed:</dt> <dd>True</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster</tt></dd> <dt>definition:</dt> <dd>The Top-Level Element containing the (monolithic) Block structure.</dd> </dl> <section anchor="timestamp-element"><name>Timestamp Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE7 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\Timestamp</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Absolute timestamp of the cluster, expressed in SegmentTicksTicks, whichisare based on TimestampScale; see <xref target="timestamp-ticks"></xref>.</dd> <dt>usage notes:</dt> <dd>This element <bcp14>SHOULD</bcp14> be the first child element of the Cluster it belongsto,to or the second if that Cluster contains a CRC-32 element (<xref target="crc-32"></xref>).</dd> </dl> </section> <section anchor="position-element"><name>Position Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA7 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\Position</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>maxver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The Segment Position of the Cluster in the Segment (0 in live streams). It might help toresynchroniseresynchronize the offset on damaged streams.</dd> </dl> </section> <section anchor="prevsize-element"><name>PrevSize Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xAB / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\PrevSize</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Size of the previous Cluster, in octets. Can be useful for backward playing.</dd> </dl> </section> <section anchor="simpleblock-element"><name>SimpleBlock Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA3 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\SimpleBlock</tt></dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>Similar toBlock, seeBlock (see <xreftarget="block-structure"></xref>,target="block-structure"></xref>) but without all the extrainformation, mostlyinformation. Mostly used toreducedreduce overhead when no extra feature is needed; see <xref target="simpleblock-structure"></xref> on SimpleBlock Structure.</dd> </dl> </section> <section anchor="blockgroup-element"><name>BlockGroup Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA0 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup</tt></dd> <dt>definition:</dt> <dd>Basic container of information containing a single Block and information specific to that Block.</dd> </dl> <section anchor="block-element"><name>Block Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA1 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Block</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Block containing the actual data to be rendered and a timestamp relative to the Cluster Timestamp; see <xref target="block-structure"></xref> on Block Structure.</dd> </dl> </section> <section anchor="blockadditions-element"><name>BlockAdditions Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x75A1 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\BlockAdditions</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt><dd>Contain<!-- [rfced] Will readers understand "the main one" here? Original: definition: Contain additional binary data to complete the main one; see Codec BlockAdditions section of [MatroskaCodec] for more information. Perhaps: definition: Contain additional binary data to complete the Block element; see Section 4.1.5 of [MatroskaCodec] for more information. --> <dd>Contains additional binary data to complete the main one; see <xreftarget="MatroskaCodec"></xref>target="I-D.ietf-cellar-codec" sectionFormat="of" section="4.1.5" ></xref> for more information. An EBML parser that has no knowledge of the Block structure could still see and use/skip these data.</dd> </dl> <section anchor="blockmore-element"><name>BlockMore Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA6 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\BlockAdditions\BlockMore</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt><dd>Contain<dd>Contains the BlockAdditional and some parameters.</dd> </dl> </section> <section anchor="blockadditional-element"><name>BlockAdditional Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA5 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\BlockAdditions\BlockMore\BlockAdditional</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Interpreted by the codec as it wishes (using the BlockAddID).</dd> </dl> </section> <section anchor="blockaddid-element"><name>BlockAddID Element</name> <!-- [rfced] Section 5.1.3.5.2.3 ("BlockAddID Element") has two "usage notes". Would you like to combine these or leave as is? Original: usage notes: Each BlockAddID value MUST be unique between all BlockMore elements found in a BlockAdditions. usage notes: To keep MaxBlockAdditionID as low as possible, small values SHOULD be used. Perhaps: usage notes: Each BlockAddID value MUST be unique between all BlockMore elements found in a BlockAdditions. To keep MaxBlockAdditionID as low as possible, small values SHOULD be used. --> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0xEE / uinteger / 1</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\BlockAdditions\BlockMore\BlockAddID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>An IDto identifythat identifies how to interpret the BlockAdditional data; seeCodec BlockAdditions section of<xreftarget="MatroskaCodec"></xref>target="I-D.ietf-cellar-codec" sectionFormat="of" section="4.1.5" ></xref> for more information. <!-- [rfced] Please review "the meaning of the BlockAdditional data" in the following sentences. Will this be clear? Original: A value of 1 indicates that the meaning of the BlockAdditional data is defined by the codec. Any other value indicates the meaning of the BlockAdditional data is found in the BlockAddIDType found in the TrackEntry. Perhaps: A value of 1 indicates that the BlockAdditional data is defined by the codec. Any other value indicates that the BlockAdditional data should be handled according to the BlockAddIDType that is located in the TrackEntry. --> A value of 1 indicates that the meaning of the BlockAdditional data is defined by the codec. Any other value indicates the meaning of the BlockAdditional data is found in the BlockAddIDType found in the TrackEntry.</dd> <dt>usage notes:</dt> <dd>Each BlockAddID value <bcp14>MUST</bcp14> be unique between all BlockMore elements found in a BlockAdditions.</dd> <dt>usage notes:</dt> <dd>To keep MaxBlockAdditionID as low as possible, small values <bcp14>SHOULD</bcp14> be used.</dd> </dl> </section> </section> <section anchor="blockduration-element"><name>BlockDuration Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x9B / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\BlockDuration</tt></dd> <dt>minOccurs / maxOccurs:</dt> <!-- [rfced] For elements containing "see implementation notes", would it be helpful to direct the reader to the corresponding table? Or is the current okay? Here is one example: Original (BlockDuration Element): minOccurs / maxOccurs: see implementation notes / 1 Perhaps (BlockDuration Element): minOccurs / maxOccurs: see Table 2 / 1 --> <dd>see implementation notes / 1</dd> <dt>definition:</dt> <dd>The duration of the Block, expressed in Track Ticks; see <xref target="timestamp-ticks"></xref>. The BlockDuration Element can be useful at the end of a Track to define the duration of the last frame (as there is no subsequent Blockavailable),available) or when there is a break in a track like for subtitle tracks.</dd> <dt>notes:</dt> <dd>See <xref target="BlockDurationNotes"/>.</dd> </dl><t>notes:</t><table anchor="BlockDurationNotes"><name>BlockDurationimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">minOccurs</td> <td align="left">BlockDuration <bcp14>MUST</bcp14> be set (minOccurs=1) if the associated TrackEntry stores a DefaultDuration value.</td> </tr> <tr> <td align="left">default</td> <!-- [rfced] How may we clarity "When not written and with no DefaultDuration"? Original: When not written and with no DefaultDuration, the value is assumed to be the difference between the timestamp of this Block and the timestamp of the next Block in "display" order (not coding order). Perhaps: If a value is not specified and no DefaultDuration is present, the value is assumed to be the difference between the timestamp of this Block and the timestamp of the next Block in "display" order (not coding order). --> <td align="left">When not written and with no DefaultDuration, the value is assumed to be the difference between the timestamp of this Block and the timestamp of the next Block in"display""display" order (not coding order).</td> </tr> </tbody></table></section></table> </section> <section anchor="referencepriority-element"><name>ReferencePriority Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0xFA / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\ReferencePriority</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>This frame is referenced and has the specified cache priority. Incachethe cache, only a frame of the same or higher priority can replace this frame. A value of 0 means the frame is not referenced.</dd> </dl> </section> <section anchor="referenceblock-element"><name>ReferenceBlock Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xFB / integer</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\ReferenceBlock</tt></dd> <dt>definition:</dt> <dd>A timestamp value, relative to the timestamp of the Block in this BlockGroup, expressed in Track Ticks; see <xref target="timestamp-ticks"></xref>. This is used to reference other frames necessary to decode this frame. The relative value <bcp14>SHOULD</bcp14> correspond to a valid <tt>Block</tt> that this <tt>Block</tt> depends on.HistoricallyHistorically, MatroskaWriterWriters didn't write the actual <tt>Block(s)</tt> that this <tt>Block</tt> depends on, but they did write <em>some</em><tt>Block</tt><tt>Block(s)</tt> in the past.</dd> </dl> <!-- [rfced] How may we rephrase the part of this sentence starting with "but without..." for clarity? Original: The value "0" MAY also be used to signify this Block cannot be decoded on its own, but without knownledge of which Block is necessary. Perhaps: The value "0" MAY also be used to signify that this Block cannot be decoded on its own but the necessary Block is unknown. --> <t>The value"0""0" <bcp14>MAY</bcp14> also be used to signify that this <tt>Block</tt> cannot be decoded on its own, but withoutknownledgeknowledge of which <tt>Block</tt> is necessary. In this case, other <tt>ReferenceBlock</tt> Elements <bcp14>MUST NOT</bcp14> be found in the same <tt>BlockGroup</tt>.</t> <t>If the <tt>BlockGroup</tt> doesn't haveanya <tt>ReferenceBlock</tt> element, then the <tt>Block</tt> it contains can be decoded without using any other <tt>Block</tt> data.</t> </section> <section anchor="codecstate-element"><name>CodecState Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xA4 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\CodecState</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>The new codec state to use. Data interpretation is private to the codec. This information <bcp14>SHOULD</bcp14> always be referenced by a seek entry.</dd> </dl> </section> <section anchor="discardpadding-element"><name>DiscardPadding Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x75A2 / integer</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\DiscardPadding</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Duration of the silent data added to the Block, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref> (padding at the end of the Block for positivevalue,values and at the beginning of the Block for negativevalue).values). The duration of DiscardPadding is not calculated in the duration of the TrackEntry and <bcp14>SHOULD</bcp14> be discarded during playback.</dd> </dl> </section> </section> </section> <section anchor="tracks-element"><name>Tracks Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1654AE6B / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd></dl> <t>recurring: True</t> <dl spacing="compact"><dt>recurring:</dt><dd>True</dd> <dt>definition:</dt> <dd>A Top-Level Element of information with many tracks described.</dd> </dl> <section anchor="trackentry-element"><name>TrackEntry Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xAE / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Describes a track with all Elements.</dd> </dl> <section anchor="tracknumber-element"><name>TrackNumber Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xD7 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackNumber</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The track number as used in the Block Header.</dd> </dl> </section> <section anchor="trackuid-element"><name>TrackUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x73C5 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackUID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Aunique ID to identifyUID that identifies the Track.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="tracktype-element"><name>TrackType Element</name> <!-- [rfced] May we rephrase the following in Table 3 (last column)? Original: A mix of different other TrackType. Perhaps: A mix of other TrackType Elements. --> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x83 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackType</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The <tt>TrackType</tt> defines the type of each frame found in the Track. The value <bcp14>SHOULD</bcp14> be stored on 1 octet.</dd> <dt>defined values:</dt> <dd>See <xref target="TrackTypeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="TrackTypeValues"><name>TrackTypevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <thalign="left">each frame contains</th>align="left">contents of each frame</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>1</tt></td> <td align="left">video</td> <td align="left">An image.</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">audio</td> <td align="left">Audio samples.</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">complex</td> <td align="left">A mix of different other TrackType. The codec needs to define how the <tt>Matroska Player</tt> should interpret such data.</td> </tr> <tr> <td align="left"><tt>16</tt></td> <td align="left">logo</td> <td align="left">An image to be rendered over the video track(s).</td> </tr> <tr> <td align="left"><tt>17</tt></td> <td align="left">subtitle</td> <td align="left">Subtitle or closed caption data to be rendered over the video track(s).</td> </tr> <tr> <td align="left"><tt>18</tt></td> <td align="left">buttons</td> <td align="left">Interactive button(s) to be rendered over the video track(s).</td> </tr> <tr> <td align="left"><tt>32</tt></td> <td align="left">control</td> <td align="left">Metadata used to control the player of the <tt>Matroska Player</tt>.</td> </tr> <tr> <td align="left"><tt>33</tt></td> <td align="left">metadata</td> <td align="left">Timed metadata that can be passed on to the <tt>Matroska Player</tt>.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="flagenabled-element"><name>FlagEnabled Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0xB9 / uinteger / 1</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagEnabled</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>Set to 1 if the track is usable. It is possible to turn a track that is not usabletrackinto a usable track using chapter codecs or control tracks.</dd> </dl> </section> <section anchor="flagdefault-element"><name>FlagDefault Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x88 / uinteger / 1</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagDefault</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt><dd>Set<!-- [rfced] Should "subs" here be updated to "subtitle"? Original: definition: Set if that track (audio, video or subs) is eligible for automatic selection by the player; see Section 19 for more details. --> <!-- [rfced] For the definitions of "FlagDefault Element" and "FlagForced Element", should the following sentences be rephrased to clarify the values that should be set? We note that surrounding elements use the phrase "Set to 1..." consistently. Original: Set if that track (audio, video or subs) is eligible for automatic selection by the player; see Section 19 for more details. ... Set if that track is eligible for automatic selection by the player if it matches the user's language preference... Perhaps: Set to 1 if the track (audio, video, or subs) is eligible for automatic selection by the player; see Section 19 for more details. ... Set to 1 if the track is eligible for automatic selection by the player if it matches the user's language preference... --> <dd>Set if the track (audio, video, or subs) is eligible for automatic selection by the player; see <xref target="default-track-selection"></xref> for more details.</dd> </dl> </section> <section anchor="flagforced-element"><name>FlagForced Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55AA / uinteger / 0</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagForced</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Applies only to subtitles. Set ifthatthe track is eligible for automatic selection by the player if it matches the user's language preference, even if the user's preferences wouldnormallynot normally enable subtitles with the selected audio track; this can be used for tracks containing only translations offoreign-languageaudio in foreign languages oronscreenon-screen text. See <xref target="default-track-selection"></xref> for more details.</dd> </dl> </section> <section anchor="flaghearingimpaired-element"><name>FlagHearingImpaired Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55AB / uinteger</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagHearingImpaired</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Set to 1 if and only ifthatthe track is suitable for users with hearing impairments.</dd> </dl> </section> <section anchor="flagvisualimpaired-element"><name>FlagVisualImpaired Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55AC / uinteger</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagVisualImpaired</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Set to 1 if and only ifthatthe track is suitable for users with visual impairments.</dd> </dl> </section> <section anchor="flagtextdescriptions-element"><name>FlagTextDescriptions Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55AD / uinteger</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagTextDescriptions</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Set to 1 if and only ifthatthe track contains textual descriptions of video content.</dd> </dl> </section> <section anchor="flagoriginal-element"><name>FlagOriginal Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55AE / uinteger</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagOriginal</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Set to 1 if and only ifthatthe track is in the content's original language.</dd> </dl> </section> <section anchor="flagcommentary-element"><name>FlagCommentary Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55AF / uinteger</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagCommentary</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Set to 1 if and only ifthatthe track contains commentary.</dd> </dl> </section> <section anchor="flaglacing-element"><name>FlagLacing Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x9C / uinteger / 1</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\FlagLacing</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Set to 1 if the track <bcp14>MAY</bcp14> contain blocksusingthat use lacing. When set to00, all blocks <bcp14>MUST</bcp14> have their lacing flags set toNo lacing;"no lacing"; see <xref target="block-lacing"></xref> on Block Lacing.</dd> </dl> </section> <section anchor="defaultduration-element"><name>DefaultDuration Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x23E383 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\DefaultDuration</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Number of nanoseconds per frame, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>(frame("frame" in the Matroska sense -- one Element put into a (Simple)Block).</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="defaultdecodedfieldduration-element"><name>DefaultDecodedFieldDuration Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x234E7A / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\DefaultDecodedFieldDuration</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The period between two successive fields at the output of the decoding process, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>.seeSee <xref target="defaultdecodedfieldduration"></xref> for more information</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="tracktimestampscale-element"><name>TrackTimestampScale Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x23314F / float / 0x1p+0</dd> <dt>range:</dt> <dd>> 0x0p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackTimestampScale</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>maxver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>The scale to apply on this track to work at normal speed in relation with other tracks (mostly used to adjust video speed when the audio length differs).</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="maxblockadditionid-element"><name>MaxBlockAdditionID Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55EE / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\MaxBlockAdditionID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The maximum value of BlockAddID (<xref target="blockaddid-element"></xref>). A value of 0 means there is no BlockAdditions (<xref target="blockadditions-element"></xref>) for this track.</dd> </dl> </section> <section anchor="blockadditionmapping-element"><name>BlockAdditionMapping Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x41E4 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\BlockAdditionMapping</tt></dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Contains elements that extend the trackformat,format by adding content either to each frame, with BlockAddID (<xref target="blockaddid-element"></xref>), or to the track as a whole with BlockAddIDExtraData.</dd> </dl> <section anchor="blockaddidvalue-element"><name>BlockAddIDValue Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x41F0 / uinteger</dd> <dt>range:</dt> <dd>>=2</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\BlockAdditionMapping\BlockAddIDValue</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>If the track format extension needs content beside frames, the value refers to the BlockAddID (<xreftarget="blockaddid-element"></xref>),target="blockaddid-element"></xref>) value being described.</dd> <dt>usage notes:</dt> <dd>To keep MaxBlockAdditionID as low as possible, small values <bcp14>SHOULD</bcp14> be used.</dd> </dl> </section> <section anchor="blockaddidname-element"><name>BlockAddIDName Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x41A4 / string</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\BlockAdditionMapping\BlockAddIDName</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>A human-friendly name describing the type of BlockAdditional data, as defined by the associated Block Additional Mapping.</dd> </dl> </section> <section anchor="blockaddidtype-element"><name>BlockAddIDType Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x41E7 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\BlockAdditionMapping\BlockAddIDType</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Stores the registered identifier of the Block Additional Mapping to define how the BlockAdditional data should be handled.</dd> <dt>usage notes:</dt> <dd>If BlockAddIDType is 0, the BlockAddIDValue and corresponding BlockAddID values <bcp14>MUST</bcp14> be 1.</dd> </dl> </section> <section anchor="blockaddidextradata-element"><name>BlockAddIDExtraData Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x41ED / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\BlockAdditionMapping\BlockAddIDExtraData</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Extra binary data that the BlockAddIDType can use to interpret the BlockAdditional data. The interpretation of the binary data depends on the BlockAddIDType value and the corresponding Block Additional Mapping.</dd> </dl> </section> </section> <section anchor="name-element"><name>Name Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x536E / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Name</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A human-readable track name.</dd> </dl> </section> <section anchor="language-element"><name>Language Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x22B59C / string / eng</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Language</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The language of the track, in the Matroska languages form; see <xref target="language-codes"></xref> on language codes. This Element <bcp14>MUST</bcp14> be ignored if the LanguageBCP47 Element is used in the same TrackEntry.</dd> </dl> </section> <section anchor="languagebcp47-element"><name>LanguageBCP47 Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x22B59D / string</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\LanguageBCP47</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The language of the track, in the form defined in <xreftarget="BCP47"></xref> form;target="RFC5646"></xref>; see <xref target="language-codes"></xref> on language codes. If this Element is used, then any Language Elements used in the same TrackEntry <bcp14>MUST</bcp14> be ignored.</dd> </dl> </section> <section anchor="codecid-element"><name>CodecID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x86 / string</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>An ID corresponding to thecodec,codec; see <xreftarget="MatroskaCodec"></xref>target="I-D.ietf-cellar-codec"></xref> for more info.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="codecprivate-element"><name>CodecPrivate Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x63A2 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecPrivate</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Private data only known to the codec.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="codecname-element"><name>CodecName Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x258688 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecName</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A human-readable string specifying the codec.</dd> </dl> </section> <section anchor="attachmentlink-element"><name>AttachmentLink Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x7446 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\AttachmentLink</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>maxver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>The UID of an attachment that is used by this codec.</dd> <dt>usage notes:</dt> <dd>The value <bcp14>MUST</bcp14> match the <tt>FileUID</tt> value of an attachment found in this Segment.</dd> </dl> </section> <section anchor="codecdelay-element"><name>CodecDelay Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x56AA / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecDelay</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt><dd>CodecDelay is The codec-built-in delay,<dd>The built-in delay for the codec, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>. It represents theamountnumber of codec samples that will be discarded by the decoder during playback. This timestamp value <bcp14>MUST</bcp14> be subtracted from each frame timestamp in order to get the timestamp that will be actually played. The value <bcp14>SHOULD</bcp14> be small so the muxing of tracks with the same actual timestamp are in the same Cluster.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="seekpreroll-element"><name>SeekPreRoll Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x56BB / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\SeekPreRoll</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>After a discontinuity,SeekPreRoll isthe duration of the data that the decoder <bcp14>MUST</bcp14> decode before the decoded data is valid, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="tracktranslate-element"><name>TrackTranslate Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6624 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackTranslate</tt></dd> <dt>definition:</dt> <dd>The mapping between this <tt>TrackEntry</tt> and a track value in the given Chapter Codec.</dd> <dt>rationale:</dt> <dd>Chapter Codec may need to address content in a specific track, but they may not know of the way to identify tracks in Matroska. This element and its child elements add a way to map the internal tracks known to the Chapter Codec to the track IDs in Matroska. This allows remuxing a file with Chapter Codec without changing the content of the codec data, just the track mapping.</dd> </dl> <section anchor="tracktranslatetrackid-element"><name>TrackTranslateTrackID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x66A5 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackTranslate\TrackTranslateTrackID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The binary value used to represent this <tt>TrackEntry</tt> in the chapter codec data. The format depends on the <tt>ChapProcessCodecID</tt> used; see <xref target="chapprocesscodecid-element"></xref>.</dd> </dl> </section> <section anchor="tracktranslatecodec-element"><name>TrackTranslateCodec Element</name> <!-- [rfced] Would updating "This TrackTranslate applies" in one of the following ways improve readability and maintain consistency with other definition?? Original: definition: This TrackTranslate applies to this chapter codec of the given chapter edition(s); see Section 5.1.7.1.4.15. Perhaps: definition: Applies to the chapter codec of the given chapter edition(s); see Section 5.1.7.1.4.15. Or: definition: Indicates that this TrackTranslate applies to the chapter codec of the given chapter edition(s); see Section 5.1.7.1.4.15. --> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x66BF / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackTranslate\TrackTranslateCodec</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>This <tt>TrackTranslate</tt> applies tothisthe chapter codec of the given chapter edition(s); see <xref target="chapprocesscodecid-element"></xref>.</dd> <dt>defined values:</dt> <dd>See <xref target="TrackTranslateCodecValues"/>.</dd> </dl><t>defined values:</t><table anchor="TrackTranslateCodecValues"><name>TrackTranslateCodecvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">Matroska Script</td> <td align="left">Chapter commands using the Matroska Script codec.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">DVD-menu</td> <td align="left">Chapter commands using the DVD-like codec.</td> </tr> </tbody></table></section></table> </section> <section anchor="tracktranslateeditionuid-element"><name>TrackTranslateEditionUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x66FC / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackTranslate\TrackTranslateEditionUID</tt></dd> <dt>definition:</dt><dd>Specify<dd>Specifies a chapter edition UIDonto which this <tt>TrackTranslate</tt> applies.</dd> <dt>usage notes:</dt> <dd>When no <tt>TrackTranslateEditionUID</tt> is specified in the <tt>TrackTranslate</tt>, the <tt>TrackTranslate</tt> applies to all chapter editions found in the Segment using the given <tt>TrackTranslateCodec</tt>.</dd> </dl> </section> </section> <section anchor="video-element"><name>Video Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE0 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Video settings.</dd> </dl> <section anchor="flaginterlaced-element"><name>FlagInterlaced Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x9A / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\FlagInterlaced</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt><dd>Specify<dd>Specifies whether the video frames in this track are interlaced.</dd> <dt>defined values:</dt> <dd>See <xref target="FlagInterlacedValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="FlagInterlacedValues"><name>FlagInterlacedvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">undetermined</td> <td align="left">Unknownstatus.Thisstatus. This value <bcp14>SHOULD</bcp14> be avoided.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">interlaced</td> <td align="left">Interlaced frames.</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">progressive</td> <td align="left">No interlacing.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="fieldorder-element"><name>FieldOrder Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x9D / uinteger / 2</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\FieldOrder</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt><dd>Specify<dd>Specifies the field ordering of video frames in this track.</dd> <dt>defined values:</dt> <dd>See <xref target="FieldOrderValues"/>.</dd> <dt>usage notes:</dt> <dd>If FlagInterlaced is not set to 1, this Element <bcp14>MUST</bcp14> be ignored.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="FieldOrderValues"><name>FieldOrdervalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">progressive</td> <td align="left">Interlacedframes.Thisframes. This value <bcp14>SHOULD</bcp14> beavoided,avoided; setting FlagInterlaced to 2 is sufficient.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">tff</td> <td align="left">Top field displayed first. Top field stored first.</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">undetermined</td> <td align="left">Unknown fieldorder.Thisorder. This value <bcp14>SHOULD</bcp14> be avoided.</td> </tr> <tr> <td align="left"><tt>6</tt></td> <td align="left">bff</td> <td align="left">Bottom field displayed first. Bottom field stored first.</td> </tr> <tr> <td align="left"><tt>9</tt></td> <td align="left">bff(swapped)</td> <td align="left">Top field displayed first. Fields are interleaved in storage with the top line of the top field stored first.</td> </tr> <tr> <td align="left"><tt>14</tt></td> <td align="left">tff(swapped)</td> <td align="left">Bottom field displayed first. Fields are interleaved in storage with the top line of the top field stored first.</td> </tr> </tbody> </table><dl spacing="compact"> <dt>usage notes:</dt> <dd>If FlagInterlaced is not set to 1, this Element <bcp14>MUST</bcp14> be ignored.</dd> </dl> <t>stream copy: True (<xref target="stream-copy"></xref>)</t></section> <section anchor="stereomode-element"><name>StereoMode Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x53B8 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\StereoMode</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>Stereo-3D video mode.There are someSee <xref target="multi-planar-and-3d-videos"></xref> for moredetails indetails.</dd> <dt>restrictions:</dt> <dd>See <xreftarget="multi-planar-and-3d-videos"></xref>.</dd>target="StereoModeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="StereoModeValues"><name>StereoModevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">mono</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">side by side (left eye first)</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">top - bottom (right eye is first)</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">top - bottom (left eye is first)</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">checkboard (right eye is first)</td> </tr> <tr> <td align="left"><tt>5</tt></td> <td align="left">checkboard (left eye is first)</td> </tr> <tr> <td align="left"><tt>6</tt></td> <td align="left">row interleaved (right eye is first)</td> </tr> <tr> <td align="left"><tt>7</tt></td> <td align="left">row interleaved (left eye is first)</td> </tr> <tr> <td align="left"><tt>8</tt></td> <td align="left">column interleaved (right eye is first)</td> </tr> <tr> <td align="left"><tt>9</tt></td> <td align="left">column interleaved (left eye is first)</td> </tr> <tr> <td align="left"><tt>10</tt></td> <td align="left">anaglyph (cyan/red)</td> </tr> <tr> <td align="left"><tt>11</tt></td> <td align="left">side by side (right eye first)</td> </tr> <tr> <td align="left"><tt>12</tt></td> <td align="left">anaglyph (green/magenta)</td> </tr> <tr> <td align="left"><tt>13</tt></td> <td align="left">both eyes laced in one Block (left eye is first)</td> </tr> <tr> <td align="left"><tt>14</tt></td> <td align="left">both eyes laced in one Block (right eye is first)</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="alphamode-element"><name>AlphaMode Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x53C0 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\AlphaMode</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>3</dd> <!-- [rfced] Please clarify the parenthetical in the second sentence below, i.e., "(considered either as 0 or 1)". Also, we updated "by to" to "by" in the first sentence. Please review. Original: definition: Indicate whether the BlockAdditional Element with BlockAddID of "1" contains Alpha data as defined by to the Codec Mapping for the CodecID. Undefined values SHOULD NOT be used, as the behavior of known implementations is different (considered either as 0 or 1). Perhaps: definition: Indicates whether the BlockAdditional Element with BlockAddID of "1" contains Alpha data as defined by the Codec Mapping for the CodecID. Undefined values (i.e., values other than 0 or 1) SHOULD NOT be used, as the behavior of known implementations is different. --> <dt>definition:</dt><dd>Indicate<dd>Indicates whether the BlockAdditional Element with BlockAddID of"1""1" contains Alpha data, as defined bytothe Codec Mapping for the <tt>CodecID</tt>. Undefined values <bcp14>SHOULD NOT</bcp14> beusedused, as the behavior of known implementations is different (considered either as 0 or 1).</dd> <dt>defined values:</dt> <dd>See <xref target="AlphaModeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="AlphaModeValues"><name>AlphaModevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">none</td> <td align="left">The BlockAdditional Element with BlockAddID of"1""1" does not exist or <bcp14>SHOULD NOT</bcp14> be considered as containing such data.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">present</td> <td align="left">The BlockAdditional Element with BlockAddID of"1""1" contains alpha channel data.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="oldstereomode-element"><name>OldStereoMode Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x53B9 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\OldStereoMode</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>maxver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>Bogus StereoMode value used in old versions of libmatroska.</dd> <dt>restrictions:</dt> <dd>See <xref target="OldStereoModeValues"/>.</dd> <dt>usage notes:</dt> <dd>This Element <bcp14>MUST NOT</bcp14> be used. It was an incorrect value used in libmatroska up to 0.9.0.</dd> </dl><t>restrictions:</t><table anchor="OldStereoModeValues"><name>OldStereoModevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">mono</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">right eye</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">left eye</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">both eyes</td> </tr> </tbody> </table><dl spacing="compact"> <dt>usage notes:</dt> <dd>This Element <bcp14>MUST NOT</bcp14> be used. It was an incorrect value used in libmatroska up to 0.9.0.</dd> </dl></section> <section anchor="pixelwidth-element"><name>PixelWidth Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xB0 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\PixelWidth</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Width of the encoded video frames in pixels.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="pixelheight-element"><name>PixelHeight Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xBA / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\PixelHeight</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Height of the encoded video frames in pixels.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="pixelcropbottom-element"><name>PixelCropBottom Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x54AA / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\PixelCropBottom</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The number of video pixels to remove at the bottom of the image.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="pixelcroptop-element"><name>PixelCropTop Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x54BB / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\PixelCropTop</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The number of video pixels to remove at the top of the image.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="pixelcropleft-element"><name>PixelCropLeft Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x54CC / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\PixelCropLeft</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The number of video pixels to remove on the left of the image.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="pixelcropright-element"><name>PixelCropRight Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x54DD / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\PixelCropRight</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The number of video pixels to remove on the right of the image.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="displaywidth-element"><name>DisplayWidth Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x54B0 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\DisplayWidth</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Width of the video frames to display. Applies to the video frame after cropping (PixelCrop* Elements).</dd> <dt>notes:</dt> <dd>See <xref target="DisplayWidthNotes"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>notes:</t><table anchor="DisplayWidthNotes"><name>DisplayWidthimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">default</td> <td align="left">If the DisplayUnit of the same TrackEntry is 0, then the default value for DisplayWidth is equaltoPixelWidthto PixelWidth - PixelCropLeft -PixelCropRight, elsePixelCropRight; else, there is no default value.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="displayheight-element"><name>DisplayHeight Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x54BA / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\DisplayHeight</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Height of the video frames to display. Applies to the video frame after cropping (PixelCrop* Elements).</dd> <dt>notes:</dt> <dd>See <xref target="DisplayHeightNotes"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>notes:</t><table anchor="DisplayHeightNotes"><name>DisplayHeightimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">default</td> <td align="left">If the DisplayUnit of the same TrackEntry is 0, then the default value for DisplayHeight is equaltoPixelHeightto PixelHeight - PixelCropTop -PixelCropBottom, elsePixelCropBottom; else, there is no default value.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="displayunit-element"><name>DisplayUnit Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x54B2 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\DisplayUnit</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>How DisplayWidth&and DisplayHeight are interpreted.</dd> <dt>restrictions:</dt> <dd>See <xref target="DisplayUnitValues"/>.</dd> </dl><t>restrictions:</t><table anchor="DisplayUnitValues"><name>DisplayUnitvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">pixels</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">centimeters</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">inches</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">display aspect ratio</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">unknown</td> </tr> </tbody></table></section></table> </section> <section anchor="uncompressedfourcc-element"><name>UncompressedFourCC Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x2EB524 / binary</dd> <dt>length:</dt> <dd>4</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\UncompressedFourCC</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>see implementation notes / 1</dd> <dt>definition:</dt><dd>Specify<dd>Specifies the uncompressed pixel format used for the Track's data as a FourCC. This value is similar in scope to the biCompression value of AVI's <tt>BITMAPINFO</tt> <xref target="AVIFormat"></xref>. There isnoneither a definitive list of FourCCvalues,values nor an official registry. Some common values for YUV pixel formats can be found at <xref target="MSYUV8"></xref>, <xreftarget="MSYUV16"></xref>target="MSYUV16"></xref>, and <xref target="FourCC-YUV"></xref>. Some common values for uncompressed RGB pixel formats can be found at <xref target="MSRGB"></xref> and <xref target="FourCC-RGB"></xref>.</dd> <dt>notes:</dt> <dd>See <xref target="UncompressedFourCCNotes"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>notes:</t><table anchor="UncompressedFourCCNotes"><name>UncompressedFourCCimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">minOccurs</td> <td align="left">UncompressedFourCC <bcp14>MUST</bcp14> be set (minOccurs=1) inTrackEntry,TrackEntry when the CodecID Element of the TrackEntry is set to"V_UNCOMPRESSED".</td>"V_UNCOMPRESSED".</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="colour-element"><name>Colour Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55B0 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Settings describing the colour format.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="matrixcoefficients-element"><name>MatrixCoefficients Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55B1 / uinteger / 2</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MatrixCoefficients</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The Matrix Coefficients of the video used to derive luma and chroma values from red, green, and blue color primaries. For clarity, the value and meanings for MatrixCoefficients are adopted from Table 4 of <xref target="ITU-H.273"></xref>.</dd> <dt>restrictions:</dt> <dd>See <xref target="MatrixCoefficientsValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="MatrixCoefficientsValues"><name>MatrixCoefficientsvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">Identity</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">ITU-R BT.709</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">unspecified</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">reserved</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">US FCC 73.682</td> </tr> <tr> <td align="left"><tt>5</tt></td> <td align="left">ITU-R BT.470BG</td> </tr> <tr> <td align="left"><tt>6</tt></td> <td align="left">SMPTE 170M</td> </tr> <tr> <td align="left"><tt>7</tt></td> <td align="left">SMPTE 240M</td> </tr> <tr> <td align="left"><tt>8</tt></td> <td align="left">YCoCg</td> </tr> <tr> <td align="left"><tt>9</tt></td> <td align="left">BT2020 Non-constant Luminance</td> </tr> <tr> <td align="left"><tt>10</tt></td> <td align="left">BT2020 Constant Luminance</td> </tr> <tr> <td align="left"><tt>11</tt></td> <td align="left">SMPTE ST 2085</td> </tr> <tr> <td align="left"><tt>12</tt></td> <td align="left">Chroma-derived Non-constant Luminance</td> </tr> <tr> <td align="left"><tt>13</tt></td> <td align="left">Chroma-derived Constant Luminance</td> </tr> <tr> <td align="left"><tt>14</tt></td> <td align="left">ITU-R BT.2100-0</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="bitsperchannel-element"><name>BitsPerChannel Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55B2 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\BitsPerChannel</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Number of decoded bits per channel. A value of 0 indicates that the BitsPerChannel is unspecified.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="chromasubsamplinghorz-element"><name>ChromaSubsamplingHorz Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55B3 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\ChromaSubsamplingHorz</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Theamountnumber of pixels to remove in the Cr and Cb channels for every pixel not removed horizontally. Example: For video with 4:2:0 chroma subsampling, the ChromaSubsamplingHorz <bcp14>SHOULD</bcp14> be set to1.</dd> </dl> <t>stream copy: True1. </dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t> </section>target="stream-copy"></xref>)</dd> </dl></section> <section anchor="chromasubsamplingvert-element"><name>ChromaSubsamplingVert Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55B4 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\ChromaSubsamplingVert</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Theamountnumber of pixels to remove in the Cr and Cb channels for every pixel not removed vertically. Example: For video with 4:2:0 chroma subsampling, the ChromaSubsamplingVert <bcp14>SHOULD</bcp14> be set to1.</dd> </dl> <t>stream copy: True1. </dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="cbsubsamplinghorz-element"><name>CbSubsamplingHorz Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55B5 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\CbSubsamplingHorz</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Theamountnumber of pixels to remove in the Cb channel for every pixel not removed horizontally. This is additive with ChromaSubsamplingHorz. Example: For video with 4:2:1 chroma subsampling, the ChromaSubsamplingHorz <bcp14>SHOULD</bcp14> be set to11, and CbSubsamplingHorz <bcp14>SHOULD</bcp14> be set to1.</dd> </dl> <t>stream copy: True1. </dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t> </section>target="stream-copy"></xref>)</dd> </dl></section> <section anchor="cbsubsamplingvert-element"><name>CbSubsamplingVert Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55B6 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\CbSubsamplingVert</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Theamountnumber of pixels to remove in the Cb channel for every pixel not removed vertically. This is additive with ChromaSubsamplingVert.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="chromasitinghorz-element"><name>ChromaSitingHorz Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55B7 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\ChromaSitingHorz</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>How chroma is subsampled horizontally.</dd> <dt>restrictions:</dt> <dd>See <xref target="ChromaSitingHorzValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="ChromaSitingHorzValues"><name>ChromaSitingHorzvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">unspecified</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">left collocated</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">half</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="chromasitingvert-element"><name>ChromaSitingVert Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55B8 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\ChromaSitingVert</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>How chroma is subsampled vertically.</dd> <dt>restrictions:</dt> <dd>See <xref target="ChromaSitingVertValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="ChromaSitingVertValues"><name>ChromaSitingVertvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">unspecified</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">top collocated</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">half</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="range-element"><name>Range Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55B9 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\Range</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Clipping of the color ranges.</dd> <dt>restrictions:</dt> <dd>See <xref target="RangeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="RangeValues"><name>Rangevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">unspecified</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">broadcast range</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">full range (no clipping)</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">defined by MatrixCoefficients / TransferCharacteristics</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="transfercharacteristics-element"><name>TransferCharacteristics Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55BA / uinteger / 2</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\TransferCharacteristics</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The transfer characteristics of the video. For clarity, the value and meanings for TransferCharacteristics are adopted from Table 3 of <xref target="ITU-H.273"></xref>.</dd> <dt>restrictions:</dt> <dd>See <xref target="TransferCharacteristicsValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="TransferCharacteristicsValues"><name>TransferCharacteristicsvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">reserved</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">ITU-R BT.709</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">unspecified</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">reserved2</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">Gamma 2.2 curve - BT.470M</td> </tr> <tr> <td align="left"><tt>5</tt></td> <td align="left">Gamma 2.8 curve - BT.470BG</td> </tr> <tr> <td align="left"><tt>6</tt></td> <td align="left">SMPTE 170M</td> </tr> <tr> <td align="left"><tt>7</tt></td> <td align="left">SMPTE 240M</td> </tr> <tr> <td align="left"><tt>8</tt></td> <td align="left">Linear</td> </tr> <tr> <td align="left"><tt>9</tt></td> <td align="left">Log</td> </tr> <tr> <td align="left"><tt>10</tt></td> <td align="left">Log Sqrt</td> </tr> <tr> <td align="left"><tt>11</tt></td> <td align="left">IEC 61966-2-4</td> </tr> <tr> <td align="left"><tt>12</tt></td> <td align="left">ITU-R BT.1361 Extended Colour Gamut</td> </tr> <tr> <td align="left"><tt>13</tt></td> <td align="left">IEC 61966-2-1</td> </tr> <tr> <td align="left"><tt>14</tt></td> <td align="left">ITU-R BT.2020 10 bit</td> </tr> <tr> <td align="left"><tt>15</tt></td> <td align="left">ITU-R BT.2020 12 bit</td> </tr> <tr> <td align="left"><tt>16</tt></td> <td align="left">ITU-R BT.2100 Perceptual Quantization</td> </tr> <tr> <td align="left"><tt>17</tt></td> <td align="left">SMPTE ST 428-1</td> </tr> <tr> <td align="left"><tt>18</tt></td> <td align="left">ARIB STD-B67 (HLG)</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="primaries-element"><name>Primaries Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x55BB / uinteger / 2</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\Primaries</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The colour primaries of the video. For clarity, the value and meanings for Primaries are adopted from Table 2 of <xref target="ITU-H.273"></xref>.</dd> <dt>restrictions:</dt> <dd>See <xref target="PrimariesValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="PrimariesValues"><name>Primariesvalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">reserved</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">ITU-R BT.709</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">unspecified</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">reserved2</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">ITU-R BT.470M</td> </tr> <tr> <td align="left"><tt>5</tt></td> <td align="left">ITU-R BT.470BG - BT.601 625</td> </tr> <tr> <td align="left"><tt>6</tt></td> <td align="left">ITU-R BT.601 525 - SMPTE 170M</td> </tr> <tr> <td align="left"><tt>7</tt></td> <td align="left">SMPTE 240M</td> </tr> <tr> <td align="left"><tt>8</tt></td> <td align="left">FILM</td> </tr> <tr> <td align="left"><tt>9</tt></td> <td align="left">ITU-R BT.2020</td> </tr> <tr> <td align="left"><tt>10</tt></td> <td align="left">SMPTE ST 428-1</td> </tr> <tr> <td align="left"><tt>11</tt></td> <td align="left">SMPTE RP 432-2</td> </tr> <tr> <td align="left"><tt>12</tt></td> <td align="left">SMPTE EG 432-2</td> </tr> <tr> <td align="left"><tt>22</tt></td> <td align="left">EBU Tech. 3213-E - JEDEC P22 phosphors</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="maxcll-element"><name>MaxCLL Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55BC / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MaxCLL</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Maximum brightness of a single pixel (Maximum Content Light Level) in candelas per square meter (cd/m<sup>2</sup>).</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="maxfall-element"><name>MaxFALL Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55BD / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MaxFALL</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Maximum brightness of a single full frame (Maximum Frame-Average Light Level) in candelas per square meter (cd/m<sup>2</sup>).</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="masteringmetadata-element"><name>MasteringMetadata Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D0 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>SMPTE 2086 mastering data.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="primaryrchromaticityx-element"><name>PrimaryRChromaticityX Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D1 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\PrimaryRChromaticityX</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Red X chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="primaryrchromaticityy-element"><name>PrimaryRChromaticityY Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D2 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\PrimaryRChromaticityY</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Red Y chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="primarygchromaticityx-element"><name>PrimaryGChromaticityX Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D3 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\PrimaryGChromaticityX</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Green X chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="primarygchromaticityy-element"><name>PrimaryGChromaticityY Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D4 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\PrimaryGChromaticityY</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Green Y chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="primarybchromaticityx-element"><name>PrimaryBChromaticityX Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D5 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\PrimaryBChromaticityX</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Blue X chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="primarybchromaticityy-element"><name>PrimaryBChromaticityY Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D6 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\PrimaryBChromaticityY</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Blue Y chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="whitepointchromaticityx-element"><name>WhitePointChromaticityX Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D7 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\WhitePointChromaticityX</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>White X chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="whitepointchromaticityy-element"><name>WhitePointChromaticityY Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D8 / float</dd> <dt>range:</dt> <dd>0x0p+0-0x1p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\WhitePointChromaticityY</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>White Y chromaticity coordinate, as defined by <xref target="CIE-1931"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="luminancemax-element"><name>LuminanceMax Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55D9 / float</dd> <dt>range:</dt> <dd>>= 0x0p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\LuminanceMax</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Maximum luminance. Represented in candelas per square meter (cd/m<sup>2</sup>).</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="luminancemin-element"><name>LuminanceMin Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x55DA / float</dd> <dt>range:</dt> <dd>>= 0x0p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Colour\MasteringMetadata\LuminanceMin</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Minimum luminance. Represented in candelas per square meter (cd/m<sup>2</sup>).</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="projection-element"><name>Projection Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x7670 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Projection</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <!-- [rfced] We updated this sentence as follows. Please review and let us know any concerns. Original: Used to render spherical, VR videos or flipping videos horizontally/vertically. Updated: Used to render spherical or VR videos or to flip videos horizontally or vertically. --> <dd>Describes the video projection details. Used to renderspherical,spherical or VR videos orflippingto flip videoshorizontally/vertically.</dd> </dl> <t>stream copy: Truehorizontally or vertically.</dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t> </section>target="stream-copy"></xref>)</dd> </dl></section> <section anchor="projectiontype-element"><name>ProjectionType Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x7671 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Projection\ProjectionType</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Describes the projection used for this video track.</dd> <dt>restrictions:</dt> <dd>See <xref target="ProjectionTypeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="ProjectionTypeValues"><name>ProjectionTypevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">rectangular</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">equirectangular</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">cubemap</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">mesh</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="projectionprivate-element"><name>ProjectionPrivate Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x7672 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Projection\ProjectionPrivate</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt><dd>Private<dd><t>Private data that only applies to a specificprojection.</dd> </dl>projection.</t> <ul spacing="compact"> <li>If <tt>ProjectionType</tt> equals 0(Rectangular),(rectangular), then this element <bcp14>MUST NOT</bcp14> be present.</li> <li>If <tt>ProjectionType</tt> equals 1(Equirectangular),(equirectangular), then this element <bcp14>MUST</bcp14> be present and contain the same binary data that would be stored inside an ISOBMFF Equirectangular Projection Box('equi').</li>("equi").</li> <li>If <tt>ProjectionType</tt> equals 2(Cubemap),(cubemap), then this element <bcp14>MUST</bcp14> be present and contain the same binary data that would be stored inside an ISOBMFF Cubemap Projection Box('cbmp').</li>("cbmp").</li> <li>If <tt>ProjectionType</tt> equals 3(Mesh),(mesh), then this element <bcp14>MUST</bcp14> be present and contain the same binary data that would be stored inside an ISOBMFF Mesh Projection Box('mshp').</li>("mshp").</li> </ul><dl spacing="compact"></dd> <dt>usage notes:</dt> <dd>ISOBMFF box size and fourcc fields are not included in the binary data, but the FullBox version and flag fields are. This is to avoid redundant framing information while preserving versioning and semantics between the two container formats.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <!-- [rfced] Please review "both included" in Sections 5.1.4.1.28.44 through 5.1.4.1.28.46. Is the meaning here "inclusive"? Original: The value of this element MUST be in the -180 to 180 degree range, both included. ... The value of this element MUST be in the -90 to 90 degree range, both included. ... The value of this element MUST be in the -180 to 180 degree range, both included. Perhaps: The value of this element MUST be in the -180 to 180 (inclusive) degree range. ... The value of this element MUST be in the -90 to 90 (inclusive) degree range. ... The value of this element MUST be in the -180 to 180 (inclusive) degree range. --> <section anchor="projectionposeyaw-element"><name>ProjectionPoseYaw Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x7673 / float / 0x0p+0</dd> <dt>range:</dt> <dd>>= -0xB4p+0, <= 0xB4p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Projection\ProjectionPoseYaw</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Specifies a yaw rotation to the projection.</dd> </dl> <t>Value represents a clockwise rotation, in degrees, around the up vector. This rotation must be applied before any <tt>ProjectionPosePitch</tt> or <tt>ProjectionPoseRoll</tt> rotations. The value of this element <bcp14>MUST</bcp14> be in the -180 to 180 degree range, both included.</t> <t>Setting <tt>ProjectionPoseYaw</tt> to 180 or -180degrees,degrees withthe<tt>ProjectionPoseRoll</tt> and <tt>ProjectionPosePitch</tt> set to 0 degrees flips the image horizontally.</t><t>stream copy: True<dl spacing="compact"> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="projectionposepitch-element"><name>ProjectionPosePitch Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x7674 / float / 0x0p+0</dd> <dt>range:</dt> <dd>>= -0x5Ap+0, <= 0x5Ap+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Projection\ProjectionPosePitch</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Specifies a pitch rotation to the projection.</dd> </dl> <t>Value represents a counter-clockwise rotation, in degrees, around the right vector. This rotation must be applied after the <tt>ProjectionPoseYaw</tt> rotation and before the <tt>ProjectionPoseRoll</tt> rotation. The value of this element <bcp14>MUST</bcp14> be in the -90 to 90 degree range, both included.</t><t>stream copy: True<dl spacing="compact"> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="projectionposeroll-element"><name>ProjectionPoseRoll Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x7675 / float / 0x0p+0</dd> <dt>range:</dt> <dd>>= -0xB4p+0, <= 0xB4p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\Projection\ProjectionPoseRoll</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Specifies a roll rotation to the projection.</dd> </dl> <t>Value represents a counter-clockwise rotation, in degrees, around the forward vector. This rotation must be applied after the <tt>ProjectionPoseYaw</tt> and <tt>ProjectionPosePitch</tt> rotations. The value of this element <bcp14>MUST</bcp14> be in the -180 to 180 degree range, both included.</t> <t>Setting <tt>ProjectionPoseRoll</tt> to 180 or -180degrees, thedegrees and <tt>ProjectionPoseYaw</tt> to 180 or -180 degrees with <tt>ProjectionPosePitch</tt> set to 0 degrees flips the image vertically.</t> <t>Setting <tt>ProjectionPoseRoll</tt> to 180 or -180degrees,degrees withthe<tt>ProjectionPoseYaw</tt> and <tt>ProjectionPosePitch</tt> set to 0 degrees flips the image horizontally and vertically.</t><t>stream copy: True<dl spacing="compact"> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> </section> <section anchor="audio-element"><name>Audio Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE1 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Audio</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Audio settings.</dd> </dl> <section anchor="samplingfrequency-element"><name>SamplingFrequency Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0xB5 / float / 0x1.f4p+12</dd> <dt>range:</dt> <dd>> 0x0p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Audio\SamplingFrequency</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Sampling frequency in Hz.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="outputsamplingfrequency-element"><name>OutputSamplingFrequency Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x78B5 / float</dd> <dt>range:</dt> <dd>> 0x0p+0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Audio\OutputSamplingFrequency</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Real output sampling frequency in Hz (used for SBR techniques).</dd> <dt>notes:</dt> <dd>See <xref target="OutputSamplingFrequencyNotes"/>.</dd> </dl><t>notes:</t><table anchor="OutputSamplingFrequencyNotes"><name>OutputSamplingFrequencyimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">default</td> <td align="left">The default value for OutputSamplingFrequency of the same TrackEntry is equal to the SamplingFrequency.</td> </tr> </tbody></table></section></table> </section> <section anchor="channels-element"><name>Channels Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x9F / uinteger / 1</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Audio\Channels</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Numbers of channels in the track.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="bitdepth-element"><name>BitDepth Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6264 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Audio\BitDepth</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Bits per sample, mostly used for PCM.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> </section> <section anchor="trackoperation-element"><name>TrackOperation Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE2 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>Operation that needs to be applied on tracks to create this virtual track. For moredetails look atdetails, see <xref target="track-operation"></xref>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> <section anchor="trackcombineplanes-element"><name>TrackCombinePlanes Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE3 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation\TrackCombinePlanes</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>Contains the list of all video plane tracks that need to be combined to create this 3Dtrack</dd> </dl> <t>stream copy: Truetrack.</dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="trackplane-element"><name>TrackPlane Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE4 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation\TrackCombinePlanes\TrackPlane</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>Contains a video plane track thatneedneeds to be combined to create this 3Dtrack</dd> </dl> <t>stream copy: Truetrack.</dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="trackplaneuid-element"><name>TrackPlaneUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE5 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation\TrackCombinePlanes\TrackPlane\TrackPlaneUID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>The trackUID number of the track representing the plane.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="trackplanetype-element"><name>TrackPlaneType Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE6 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation\TrackCombinePlanes\TrackPlane\TrackPlaneType</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>The kind of plane this track corresponds to.</dd> <dt>restrictions:</dt> <dd>See <xref target="TrackPlaneTypeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="TrackPlaneTypeValues"><name>TrackPlaneTypevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">left eye</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">right eye</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">background</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="trackjoinblocks-element"><name>TrackJoinBlocks Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xE9 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation\TrackJoinBlocks</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>Contains the list of all tracks whose Blocks need to be combined to create this virtualtrack</dd> </dl> <t>stream copy: Truetrack.</dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="trackjoinuid-element"><name>TrackJoinUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xED / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOperation\TrackJoinBlocks\TrackJoinUID</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>The trackUID number of a track whose blocks are used to create this virtual track.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> </section> <section anchor="contentencodings-element"><name>ContentEncodings Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6D80 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Settings for several content encoding mechanisms like compression or encryption.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> <section anchor="contentencoding-element"><name>ContentEncoding Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6240 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Settings for one content encoding like compression or encryption.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="contentencodingorder-element"><name>ContentEncodingOrder Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x5031 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncodingOrder</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <!-- [rfced] May we rephrase the first sentence of this definition as follows for clarity? Original: Tell in which order to apply each ContentEncoding of the ContentEncodings. Perhaps: Defines the order to apply to each ContentEncoding of the ContentEncodings. --> <dd>Tell in which order to apply each <tt>ContentEncoding</tt> of the <tt>ContentEncodings</tt>. The decoder/demuxer <bcp14>MUST</bcp14> start with the <tt>ContentEncoding</tt> with the highest <tt>ContentEncodingOrder</tt> and work its way down to the <tt>ContentEncoding</tt> with the lowest <tt>ContentEncodingOrder</tt>. This value <bcp14>MUST</bcp14> be uniqueoverfor each <tt>ContentEncoding</tt> found in the <tt>ContentEncodings</tt> of this <tt>TrackEntry</tt>.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="contentencodingscope-element"><name>ContentEncodingScope Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x5032 / uinteger / 1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncodingScope</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>A bit field that describes which Elements have been modified in this way. Values (big-endian) can be OR'ed.</dd> <dt>defined values:</dt> <dd>See <xref target="ContentEncodingScopeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="ContentEncodingScopeValues"><name>ContentEncodingScopevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>1</tt></td> <td align="left">Block</td> <td align="left">All frame contents, excluding lacing data.</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">Private</td> <td align="left">The track's <tt>CodecPrivate</tt> data.</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">Next</td> <td align="left">The next ContentEncoding (next<tt>ContentEncodingOrder</tt>. Either<tt>ContentEncodingOrder</tt>; the data inside <tt>ContentCompression</tt> and/or<tt>ContentEncryption</tt>).This<tt>ContentEncryption</tt>). This value <bcp14>SHOULD NOT</bcp14> beusedused, as it's not supported by players.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="contentencodingtype-element"><name>ContentEncodingType Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x5033 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncodingType</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>A value describingwhatthe kind of transformation that is applied.</dd> <dt>restrictions:</dt> <dd>See <xref target="ContentEncodingTypeValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>restrictions:</t><table anchor="ContentEncodingTypeValues"><name>ContentEncodingTypevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">Compression</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">Encryption</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="contentcompression-element"><name>ContentCompression Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x5034 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentCompression</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Settings describing the compression used. This Element <bcp14>MUST</bcp14> be present if the value of ContentEncodingType is 0 and absent otherwise. Each block <bcp14>MUST</bcp14> bedecompressabledecompressable, even if no previous block is available in ordernotto not prevent seeking.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="contentcompalgo-element"><name>ContentCompAlgo Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x4254 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentCompression\ContentCompAlgo</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The compression algorithm used.</dd> <dt>defined values:</dt> <dd>See <xref target="ContentCompAlgoValues"/>.</dd> <dt>usage notes:</dt> <dd>Compression method "1" (bzlib) and "2" (lzo1x) lack proper documentation on the format, which limits implementation possibilities. Due to licensing conflicts on commonly available libraries' compression methods, "2" (lzo1x) does not offer widespread interoperability. A Matroska Writer <bcp14>SHOULD NOT</bcp14> use these compression methods by default. A Matroska Reader <bcp14>MAY</bcp14> support methods "1" and "2" as possible and <bcp14>SHOULD</bcp14> support other methods.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="ContentCompAlgoValues"><name>ContentCompAlgovalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">zlib</td> <td align="left">zlib compression <xref target="RFC1950"></xref>.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">bzlib</td> <td align="left">bzip2 compression <xreftarget="BZIP2"></xref>,target="BZIP2"></xref> <bcp14>SHOULD NOT</bcp14> be used; see usage notes.</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">lzo1x</td> <td align="left">Lempel-Ziv-Oberhumer compression <xref target="LZO"></xref>, <bcp14>SHOULD NOT</bcp14> be used; see usage notes.</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">Header Stripping</td> <td align="left">Octets in <tt>ContentCompSettings</tt> (<xref target="contentcompsettings-element"></xref>) have been stripped from each frame.</td> </tr> </tbody> </table><dl spacing="compact"> <dt>usage notes:</dt> <dd>Compression method "1" (bzlib) and "2" (lzo1x) are lacking proper documentation on the format which limits implementation possibilities. Due<!-- [rfced] Please review "as possible" here. Is this phrase needed? If it is needed, should it be updated tolicensing conflicts on commonly available libraries compression"if possible"? Original: A Matroska Reader MAY support methods"2" (lzo1x) does not offer widespread interoperability."1" and "2" as possible, and SHOULD support other methods. Perhaps (deleted "as possible"): A MatroskaWriter <bcp14>SHOULD NOT</bcp14> use these compressionReader MAY support methodsby default."1" and "2" and SHOULD support other methods. Or (use "if possible"): A Matroska Reader<bcp14>MAY</bcp14>MAY support methods"1""1" and"2" as possible,"2" if possible and<bcp14>SHOULD</bcp14>SHOULD support othermethods.</dd> </dl> <t>stream copy: True (<xref target="stream-copy"></xref>)</t>methods. --> </section> <section anchor="contentcompsettings-element"><name>ContentCompSettings Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4255 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentCompression\ContentCompSettings</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Settings that might be needed by the decompressor. For Header Stripping (<tt>ContentCompAlgo</tt>=3), the bytes that were removed from the beginning of eachframesframe of the track.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="contentencryption-element"><name>ContentEncryption Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x5035 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Settings describing the encryption used. This Element <bcp14>MUST</bcp14> be present if the value of <tt>ContentEncodingType</tt> is 1 (encryption) and <bcp14>MUST</bcp14> be ignored otherwise. A Matroska Player <bcp14>MAY</bcp14> support encryption.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="contentencalgo-element"><name>ContentEncAlgo Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x47E1 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentEncAlgo</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The encryption algorithm used.</dd> <dt>defined values:</dt> <dd>See <xref target="ContentEncAlgoValues"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="ContentEncAlgoValues"><name>ContentEncAlgovalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">Not encrypted</td> <td align="left">The data are not encrypted.</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">DES</td> <td align="left">Data Encryption Standard (DES) <xreftarget="FIPS.46-3"></xref>.Thistarget="FIPS46-3"></xref>. This value <bcp14>SHOULD</bcp14> be avoided.</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">3DES</td> <td align="left">Triple Data Encryption Algorithm <xreftarget="SP.800-67"></xref>.Thistarget="SP800-67"></xref>. This value <bcp14>SHOULD</bcp14> be avoided.</td> </tr> <tr> <td align="left"><tt>3</tt></td> <td align="left">Twofish</td> <td align="left">Twofish Encryption Algorithm <xref target="Twofish"></xref>.</td> </tr> <tr> <td align="left"><tt>4</tt></td> <td align="left">Blowfish</td> <td align="left">Blowfish Encryption Algorithm <xreftarget="Blowfish"></xref>.Thistarget="Blowfish"></xref>. This value <bcp14>SHOULD</bcp14> be avoided.</td> </tr> <tr> <td align="left"><tt>5</tt></td> <td align="left">AES</td> <td align="left">Advanced Encryption Standard (AES) <xreftarget="FIPS.197"></xref>.</td>target="FIPS197"></xref>.</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="contentenckeyid-element"><name>ContentEncKeyID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x47E2 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentEncKeyID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>For public keyalgorithms this isalgorithms, the ID of the public key that the data was encrypted with.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="contentencaessettings-element"><name>ContentEncAESSettings Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x47E7 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentEncAESSettings</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>Settings describing the encryption algorithm used.</dd> <dt>notes:</dt> <dd>See <xref target="ContentEncAESSettingsNotes"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>notes:</t><table anchor="ContentEncAESSettingsNotes"><name>ContentEncAESSettingsimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">maxOccurs</td> <td align="left">ContentEncAESSettings <bcp14>MUST NOT</bcp14> be set (maxOccurs=0) if ContentEncAlgo is not AES (5).</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> <section anchor="aessettingsciphermode-element"><name>AESSettingsCipherMode Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x47E8 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentEncAESSettings\AESSettingsCipherMode</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The AES cipher mode used in the encryption.</dd> <dt>defined values:</dt> <dd>See <xref target="AESSettingsCipherModeValues"/>.</dd> <dt>notes:</dt> <dd>See <xref target="AESSettingsCipherModeNotes"/>.</dd> <dt>stream copy:</dt> <dd>True (<xref target="stream-copy"></xref>)</dd> </dl><t>defined values:</t><table anchor="AESSettingsCipherModeValues"><name>AESSettingsCipherModevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>1</tt></td> <td align="left">AES-CTR</td> <td align="left">Counter <xreftarget="SP.800-38A"></xref>.</td>target="SP800-38A"></xref></td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">AES-CBC</td> <td align="left">Cipher Block Chaining <xreftarget="SP.800-38A"></xref>.</td>target="SP800-38A"></xref></td> </tr> </tbody></table><t>notes:</t></table> <table anchor="AESSettingsCipherModeNotes"><name>AESSettingsCipherModeimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">maxOccurs</td> <td align="left">AESSettingsCipherMode <bcp14>MUST NOT</bcp14> be set (maxOccurs=0) if ContentEncAlgo is not AES (5).</td> </tr> </tbody></table><t>stream copy: True (<xref target="stream-copy"></xref>)</t></table> </section> </section> </section> </section> <section anchor="cues-element"><name>Cues Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1C53BB6B / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cues</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>see implementation notes / 1</dd> <dt>definition:</dt> <dd>A Top-Level Element to speed seeking access. All entries are local to the Segment.</dd> <dt>notes:</dt> <dd>See <xref target="CuesNotes"/>.</dd> </dl><t>notes:</t><table anchor="CuesNotes"><name>Cuesimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">minOccurs</td> <td align="left">This Element <bcp14>SHOULD</bcp14> be set when the Segment is not transmitted as a live stream; see <xref target="livestreaming"></xref>.</td> </tr> </tbody> </table> <section anchor="cuepoint-element"><name>CuePoint Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xBB / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Contains all information relative to a seek point in the Segment.</dd> </dl> <section anchor="cuetime-element"><name>CueTime Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xB3 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTime</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Absolute timestamp of the seek point, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>.</dd> </dl> </section> <section anchor="cuetrackpositions-element"><name>CueTrackPositions Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xB7 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt><dd>Contain<dd>Contains positions for different tracks corresponding to the timestamp.</dd> </dl> <section anchor="cuetrack-element"><name>CueTrack Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xF7 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueTrack</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The track for which a position is given.</dd> </dl> </section> <section anchor="cueclusterposition-element"><name>CueClusterPosition Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xF1 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueClusterPosition</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The Segment Position (<xref target="segment-position"></xref>) of the Cluster containing the associated Block.</dd> </dl> </section> <section anchor="cuerelativeposition-element"><name>CueRelativePosition Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xF0 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueRelativePosition</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The relative position inside the Cluster of the referenced SimpleBlock or BlockGroup with 0 being the first possible position for an Element inside that Cluster.</dd> </dl> </section> <section anchor="cueduration-element"><name>CueDuration Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xB2 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueDuration</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The duration of the block, expressed in SegmentTicksTicks, whichisare based on TimestampScale; see <xref target="timestamp-ticks"></xref>. If missing, the track's DefaultDuration does not apply and no duration information is available in terms of the cues.</dd> </dl> </section> <section anchor="cueblocknumber-element"><name>CueBlockNumber Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x5378 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueBlockNumber</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Number of the Block in the specified Cluster.</dd> </dl> </section> <section anchor="cuecodecstate-element"><name>CueCodecState Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0xEA / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueCodecState</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>The Segment Position (<xref target="segment-position"></xref>) of the Codec State corresponding to this Cue Element. 0 means that the data is taken from the initial Track Entry.</dd> </dl> </section> <section anchor="cuereference-element"><name>CueReference Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xDB / master</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueReference</tt></dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>The Clusters containing the referenced Blocks.</dd> </dl> </section> <section anchor="cuereftime-element"><name>CueRefTime Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x96 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueReference\CueRefTime</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>minver:</dt> <dd>2</dd> <dt>definition:</dt> <dd>Timestamp of the referenced Block, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>.</dd> </dl> </section> </section> </section> </section> <section anchor="attachments-element"><name>Attachments Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1941A469 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt><dd>Contain<dd>Contains attached files.</dd> </dl> <section anchor="attachedfile-element"><name>AttachedFile Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x61A7 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>An attached file.</dd> </dl> <section anchor="filedescription-element"><name>FileDescription Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x467E / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileDescription</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A human-friendly name for the attached file.</dd> </dl> </section> <section anchor="filename-element"><name>FileName Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x466E / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileName</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Filename of the attached file.</dd> </dl> </section> <section anchor="filemediatype-element"><name>FileMediaType Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4660 / string</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileMediaType</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Media type of the file following the format described in <xreftarget="RFC6838"></xref> format.</dd> </dl> <t>stream copy: Truetarget="RFC6838"></xref>.</dd> <dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="filedata-element"><name>FileData Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x465C / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileData</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The data of the file.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="fileuid-element"><name>FileUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x46AE / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileUID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt><dd>Unique ID<dd>UID representing the file, as random as possible.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> </section> </section> <section anchor="chapters-element"><name>Chapters Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1043A770 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd></dl> <t>recurring: True</t> <dl spacing="compact"><dt>recurring:</dt><dd>True</dd> <dt>definition:</dt> <dd>A system to define basic menus and partition data. For more detailed information,look at the Chapters explanation insee <xref target="chapters"></xref>.</dd> </dl> <section anchor="editionentry-element"><name>EditionEntry Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x45B9 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Contains all information about a Segment edition.</dd> </dl> <section anchor="editionuid-element"><name>EditionUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x45BC / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\EditionUID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>Aunique IDUID to identify the edition. It's useful for tagging an edition.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="editionflagdefault-element"><name>EditionFlagDefault Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x45DB / uinteger / 0</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\EditionFlagDefault</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Set to 1 if the edition <bcp14>SHOULD</bcp14> be used as the default one.</dd> </dl> </section> <section anchor="editionflagordered-element"><name>EditionFlagOrdered Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x45DD / uinteger / 0</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\EditionFlagOrdered</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Set to 1 if the chapters can be defined multiple times and the order to play them is enforced; see <xref target="editionflagordered"></xref>.</dd> </dl> </section> <section anchor="chapteratom-element"><name>ChapterAtom Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0xB6 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom</tt></dd> <dt>minOccurs:</dt> <dd>1</dd></dl> <t>recursive: True</t> <dl spacing="compact"><dt>recursive:</dt><dd>True</dd> <dt>definition:</dt> <dd>Contains the atom information to use as the chapter atom(apply(applies to all tracks).</dd> </dl> <section anchor="chapteruid-element"><name>ChapterUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x73C4 / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterUID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Aunique IDUID to identify the Chapter.</dd></dl> <t>stream copy: True<dt>stream copy:</dt><dd>True (<xreftarget="stream-copy"></xref>)</t>target="stream-copy"></xref>)</dd> </dl> </section> <section anchor="chapterstringuid-element"><name>ChapterStringUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x5654 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterStringUID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>3</dd> <dt>definition:</dt> <dd>A unique string ID to identify the Chapter. Forexampleexample, it is used as the storage for<xref target="WebVTT"></xref>cue identifiervalues.</dd>values <xref target="WebVTT"></xref>.</dd> </dl> </section> <section anchor="chaptertimestart-element"><name>ChapterTimeStart Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x91 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterTimeStart</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Timestamp of the start of Chapter, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>.</dd> </dl> </section> <section anchor="chaptertimeend-element"><name>ChapterTimeEnd Element</name> <!-- [rfced] Please clarify "Timestamp of the end of Chapter timestamp excluded". Original: definition: Timestamp of the end of Chapter timestamp excluded, expressed in Matroska Ticks - i.e., in nanoseconds; see Section 11.1. --> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x92 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterTimeEnd</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>see implementation notes / 1</dd> <dt>definition:</dt> <dd>Timestamp of the end of Chapter timestamp excluded, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>. The value <bcp14>MUST</bcp14> be greater than or equal to the <tt>ChapterTimeStart</tt> of the same <tt>ChapterAtom</tt>.</dd> <dt>usage notes:</dt><dd>The<dd>With the <tt>ChapterTimeEnd</tt> timestamp value being excluded, it <bcp14>MUST</bcp14> takeininto account the duration of the last frame it includes, especially for the <tt>ChapterAtom</tt> using the last frames of the <tt>Segment</tt>.</dd> <dt>notes:</dt> <dd>See <xref target="ChapterTimeEndNotes"/>.</dd> </dl><t>notes:</t><table anchor="ChapterTimeEndNotes"><name>ChapterTimeEndimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">minOccurs</td> <td align="left">ChapterTimeEnd <bcp14>MUST</bcp14> be set (minOccurs=1) if the Edition is an ordered edition; see <xreftarget="editionflagordered"></xref>, unlesstarget="editionflagordered"></xref>. If it's a <tt>ParentChapter</tt>;Chapter</tt>, see <xreftarget="nested-chapters"></xref></td>target="nested-chapters"></xref>.</td> </tr> </tbody></table></section></table> </section> <section anchor="chapterflaghidden-element"><name>ChapterFlagHidden Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x98 / uinteger / 0</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterFlagHidden</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Set to 1 if a chapter is hidden. <!-- [rfced] How may we rephrase the parenthetical in the following sentence for clarity? Original: Hidden chapters SHOULD NOT be available to the user interface (but still to Control Tracks; see Section 20.2.5 on Chapter flags). Perhaps: Hidden chapters SHOULD NOT be available to the user interface (but still be available to Control Tracks); see Section 20.2.5 on Chapter flags. --> Hidden chapters <bcp14>SHOULD NOT</bcp14> be available to the user interface (but still to Control Tracks; see <xref target="chapterflaghidden"></xref> on Chapter flags).</dd> </dl> </section> <section anchor="chaptersegmentuuid-element"><name>ChapterSegmentUUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6E67 / binary</dd> <dt>length:</dt> <dd>16</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterSegmentUUID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>see implementation notes / 1</dd> <dt>definition:</dt> <dd>The SegmentUUID of another Segment to play during this chapter.</dd> <dt>usage notes:</dt> <dd>The value <bcp14>MUST NOT</bcp14> be the <tt>SegmentUUID</tt> value of the <tt>Segment</tt> it belongs to.</dd> <dt>notes:</dt> <dd>See <xref target="ChapterSegmentUUIDNotes"/>.</dd> </dl><t>notes:</t><table anchor="ChapterSegmentUUIDNotes"><name>ChapterSegmentUUIDimplementation notes</name>Implementation Notes</name> <thead> <tr> <th align="left">attribute</th> <th align="left">note</th> </tr> </thead> <tbody> <tr> <td align="left">minOccurs</td> <td align="left">ChapterSegmentUUID <bcp14>MUST</bcp14> be set (minOccurs=1) if ChapterSegmentEditionUID is used; see <xref target="medium-linking"></xref> onmedium-linkingMedium-Linking Segments.</td> </tr> </tbody></table></section></table> </section> <section anchor="chaptersegmenteditionuid-element"><name>ChapterSegmentEditionUID Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6EBC / uinteger</dd> <dt>range:</dt> <dd>not 0</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterSegmentEditionUID</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>The EditionUID to play from the Segment linked in ChapterSegmentUUID. If ChapterSegmentEditionUID is undeclared, then no Edition of the linked Segment is used; see <xref target="medium-linking"></xref> onmedium-linkingMedium-Linking Segments.</dd> </dl> </section> <section anchor="chapterphysicalequiv-element"><name>ChapterPhysicalEquiv Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x63C3 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterPhysicalEquiv</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt><dd>Specify<dd>Specifies the physical equivalent of thisChapterAtom like "DVD"ChapterAtom, e.g., "DVD" (60) or"SIDE""SIDE" (50); see <xref target="physical-types"></xref> for a complete list of values.</dd> </dl> </section> <section anchor="chapterdisplay-element"><name>ChapterDisplay Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x80 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterDisplay</tt></dd> <dt>definition:</dt> <dd>Contains all possible strings to use for the chapter display.</dd> </dl> </section> <section anchor="chapstring-element"><name>ChapString Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x85 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterDisplay\ChapString</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Contains the string to use as the chapter atom.</dd> </dl> </section> <section anchor="chaplanguage-element"><name>ChapLanguage Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x437C / string / eng</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterDisplay\ChapLanguage</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A language corresponding to the string, in the Matroska languages form; see <xref target="language-codes"></xref> on language codes. This Element <bcp14>MUST</bcp14> be ignored if a ChapLanguageBCP47 Element is used within the same ChapterDisplay Element.</dd> </dl> </section> <section anchor="chaplanguagebcp47-element"><name>ChapLanguageBCP47 Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x437D / string</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterDisplay\ChapLanguageBCP47</tt></dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>A language corresponding to the ChapString, in the form defined in <xreftarget="BCP47"></xref> form;target="RFC5646"></xref>; see <xref target="language-codes"></xref> on language codes. If a ChapLanguageBCP47 Element is used, then any ChapLanguage and ChapCountry Elements used in the same ChapterDisplay <bcp14>MUST</bcp14> be ignored.</dd> </dl> </section> <section anchor="chapcountry-element"><name>ChapCountry Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x437E / string</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapterDisplay\ChapCountry</tt></dd> <dt>definition:</dt> <dd>A country corresponding to the string, in the Matroska countries form; see <xref target="country-codes"></xref> on country codes. This Element <bcp14>MUST</bcp14> be ignored if a ChapLanguageBCP47 Element is used within the same ChapterDisplay Element.</dd> </dl> </section> <section anchor="chapprocess-element"><name>ChapProcess Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6944 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapProcess</tt></dd> <dt>definition:</dt> <dd>Contains all the commands associated to the Atom.</dd> </dl> </section> <section anchor="chapprocesscodecid-element"><name>ChapProcessCodecID Element</name> <!-- [rfced] We have two questions about the definition below: a) Does "to be defined" need further clarification, perhaps "to be defined in future specifications"? b) Section 20.3 defines value 0 as "matroska script" and value 1 as "menu borrowed from the DVD [DVD-Video]". Should the definitions match? Or is the current okay? Original: definition: Contains the type of the codec used for the processing. A value of 0 means built-in Matroska processing (to be defined), a value of 1 means the DVD command set is used; see Section 20.3 on DVD menus. --> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x6955 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapProcess\ChapProcessCodecID</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Contains the type of the codec used fortheprocessing. A value of 0 means built-in Matroska processing (to be defined), and a value of 1 means the DVD command set is used; see <xref target="menu-features"></xref> on DVD menus. More codec IDs can be added later.</dd> </dl> </section> <section anchor="chapprocessprivate-element"><name>ChapProcessPrivate Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x450D / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapProcess\ChapProcessPrivate</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt><dd>Some optional<dd>Optional data attached to the ChapProcessCodecID information. For ChapProcessCodecID = 1, it is the"DVD level""DVD level" equivalent; see <xref target="menu-features"></xref> on DVD menus.</dd> </dl> </section> <section anchor="chapprocesscommand-element"><name>ChapProcessCommand Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6911 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapProcess\ChapProcessCommand</tt></dd> <dt>definition:</dt> <dd>Contains all the commands associatedtowith the Atom.</dd> </dl> </section> <section anchor="chapprocesstime-element"><name>ChapProcessTime Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6922 / uinteger</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapProcess\ChapProcessCommand\ChapProcessTime</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Defines when the process command <bcp14>SHOULD</bcp14> behandled</dd>handled.</dd> <dt>restrictions:</dt> <dd>See <xref target="ChapProcessTimeValues"/>.</dd> </dl><t>restrictions:</t><table anchor="ChapProcessTimeValues"><name>ChapProcessTimevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>0</tt></td> <td align="left">during the whole chapter</td> </tr> <tr> <td align="left"><tt>1</tt></td> <td align="left">before starting playback</td> </tr> <tr> <td align="left"><tt>2</tt></td> <td align="left">after playback of the chapter</td> </tr> </tbody></table></section></table> </section> <section anchor="chapprocessdata-element"><name>ChapProcessData Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x6933 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Chapters\EditionEntry\+ChapterAtom\ChapProcess\ChapProcessCommand\ChapProcessData</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Contains the command information. The data <bcp14>SHOULD</bcp14> be interpreted depending on the ChapProcessCodecID value. For ChapProcessCodecID = 1, the data correspond to the binary DVD cell pre/post commands; see <xref target="menu-features"></xref> on DVD menus.</dd> </dl> </section> </section> </section> </section> <section anchor="tags-element"><name>Tags Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x1254C367 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tags</tt></dd> <dt>definition:</dt> <dd>Element containing metadata describing Tracks, Editions, Chapters, Attachments, or the Segment as a whole. A list of valid tags can be found in <xreftarget="MatroskaTags"></xref>.</dd>target="I-D.ietf-cellar-tags"></xref>.</dd> </dl> <section anchor="tag-element"><name>Tag Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x7373 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag</tt></dd> <dt>minOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>A single metadata descriptor.</dd> </dl> <section anchor="targets-element"><name>Targets Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x63C0 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Specifies which other elements the metadata represented by the Tag applies to. If empty or omitted, then the Tag describes everything in the Segment.</dd> </dl> <section anchor="targettypevalue-element"><name>TargetTypeValue Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x68CA / uinteger / 50</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets\TargetTypeValue</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>A number to indicate the logical level of the target.</dd> <dt>defined values:</dt> <dd>See <xref target="TargetTypeValueValues"/>.</dd> </dl><t>defined values:</t><table anchor="TargetTypeValueValues"><name>TargetTypeValuevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> <th align="left">definition</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>70</tt></td> <td align="left">COLLECTION</td> <td align="left">The highest hierarchical level that tags can describe.</td> </tr> <tr> <td align="left"><tt>60</tt></td> <td align="left">EDITION / ISSUE / VOLUME / OPUS / SEASON / SEQUEL</td> <td align="left">A list of lower levels grouped together.</td> </tr> <tr> <td align="left"><tt>50</tt></td> <td align="left">ALBUM / OPERA / CONCERT / MOVIE / EPISODE</td> <td align="left">The most common grouping level of music and video(equals to(e.g., an episode for TV series).</td> </tr> <tr> <td align="left"><tt>40</tt></td> <td align="left">PART / SESSION</td> <td align="left">When an album or episode has different logical parts.</td> </tr> <tr> <td align="left"><tt>30</tt></td> <td align="left">TRACK / SONG / CHAPTER</td> <td align="left">The common parts of an album or movie.</td> </tr> <tr> <td align="left"><tt>20</tt></td> <td align="left">SUBTRACK / MOVEMENT / SCENE</td> <td align="left">Corresponds to parts of a track foraudio likeaudio, such as amovement,movement orascene in a movie.</td> </tr> <tr> <td align="left"><tt>10</tt></td> <td align="left">SHOT</td> <td align="left">The lowest hierarchy found in music or movies.</td> </tr> </tbody></table></section></table> </section> <section anchor="targettype-element"><name>TargetType Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x63CA / string</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets\TargetType</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>An informational string that can be used to display the logical level of thetarget like "ALBUM", "TRACK", "MOVIE", "CHAPTER",target, such as "ALBUM", "TRACK", "MOVIE", "CHAPTER", etc.</dd> <dt>restrictions:</dt> <dd>See <xref target="TargetTypeValues"/>.</dd> </dl><t>restrictions:</t><table anchor="TargetTypeValues"><name>TargetTypevalues</name>Values</name> <thead> <tr> <th align="left">value</th> <th align="left">label</th> </tr> </thead> <tbody> <tr> <td align="left"><tt>COLLECTION</tt></td> <td align="left">TargetTypeValue 70</td> </tr> <tr> <td align="left"><tt>EDITION</tt></td> <td align="left">TargetTypeValue 60</td> </tr> <tr> <td align="left"><tt>ISSUE</tt></td> <td align="left">TargetTypeValue 60</td> </tr> <tr> <td align="left"><tt>VOLUME</tt></td> <td align="left">TargetTypeValue 60</td> </tr> <tr> <td align="left"><tt>OPUS</tt></td> <td align="left">TargetTypeValue 60</td> </tr> <tr> <td align="left"><tt>SEASON</tt></td> <td align="left">TargetTypeValue 60</td> </tr> <tr> <td align="left"><tt>SEQUEL</tt></td> <td align="left">TargetTypeValue 60</td> </tr> <tr> <td align="left"><tt>ALBUM</tt></td> <td align="left">TargetTypeValue 50</td> </tr> <tr> <td align="left"><tt>OPERA</tt></td> <td align="left">TargetTypeValue 50</td> </tr> <tr> <td align="left"><tt>CONCERT</tt></td> <td align="left">TargetTypeValue 50</td> </tr> <tr> <td align="left"><tt>MOVIE</tt></td> <td align="left">TargetTypeValue 50</td> </tr> <tr> <td align="left"><tt>EPISODE</tt></td> <td align="left">TargetTypeValue 50</td> </tr> <tr> <td align="left"><tt>PART</tt></td> <td align="left">TargetTypeValue 40</td> </tr> <tr> <td align="left"><tt>SESSION</tt></td> <td align="left">TargetTypeValue 40</td> </tr> <tr> <td align="left"><tt>TRACK</tt></td> <td align="left">TargetTypeValue 30</td> </tr> <tr> <td align="left"><tt>SONG</tt></td> <td align="left">TargetTypeValue 30</td> </tr> <tr> <td align="left"><tt>CHAPTER</tt></td> <td align="left">TargetTypeValue 30</td> </tr> <tr> <td align="left"><tt>SUBTRACK</tt></td> <td align="left">TargetTypeValue 20</td> </tr> <tr> <td align="left"><tt>MOVEMENT</tt></td> <td align="left">TargetTypeValue 20</td> </tr> <tr> <td align="left"><tt>SCENE</tt></td> <td align="left">TargetTypeValue 20</td> </tr> <tr> <td align="left"><tt>SHOT</tt></td> <td align="left">TargetTypeValue 10</td> </tr> </tbody></table></section></table> </section> <section anchor="tagtrackuid-element"><name>TagTrackUID Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x63C5 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets\TagTrackUID</tt></dd> <dt>definition:</dt> <dd>Aunique IDUID to identify the Track(s) that the tags belong to.</dd> <dt>usage notes:</dt> <dd>If the value is 0 at this level, the tags apply to all tracks in the Segment. If set to any other value, it <bcp14>MUST</bcp14> match the <tt>TrackUID</tt> value of a track found in this Segment.</dd> </dl> </section> <section anchor="tageditionuid-element"><name>TagEditionUID Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x63C9 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets\TagEditionUID</tt></dd> <dt>definition:</dt> <dd>Aunique IDUID to identify the EditionEntry(s) that the tags belong to.</dd> <dt>usage notes:</dt> <dd>If the value is 0 at this level, the tags apply to all editions in the Segment. If set to any other value, it <bcp14>MUST</bcp14> match the <tt>EditionUID</tt> value of an edition found in this Segment.</dd> </dl> </section> <section anchor="tagchapteruid-element"><name>TagChapterUID Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x63C4 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets\TagChapterUID</tt></dd> <dt>definition:</dt> <dd>Aunique IDUID to identify the Chapter(s) that the tags belong to.</dd> <dt>usage notes:</dt> <dd>If the value is 0 at this level, the tags apply to all chapters in the Segment. If set to any other value, it <bcp14>MUST</bcp14> match the <tt>ChapterUID</tt> value of a chapter found in this Segment.</dd> </dl> </section> <section anchor="tagattachmentuid-element"><name>TagAttachmentUID Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x63C6 / uinteger / 0</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\Targets\TagAttachmentUID</tt></dd> <dt>definition:</dt> <dd>Aunique IDUID to identify the Attachment(s) that the tags belong to.</dd> <dt>usage notes:</dt> <dd>If the value is 0 at this level, the tags apply to all the attachments in the Segment. If set to any other value, it <bcp14>MUST</bcp14> match the <tt>FileUID</tt> value of an attachment found in this Segment.</dd> </dl> </section> </section> <section anchor="simpletag-element"><name>SimpleTag Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x67C8 / master</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag</tt></dd> <dt>minOccurs:</dt> <dd>1</dd></dl> <t>recursive: True</t> <dl spacing="compact"><dt>recursive:</dt><dd>True</dd> <dt>definition:</dt> <dd>Contains general information about the target.</dd> </dl> <section anchor="tagname-element"><name>TagName Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x45A3 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagName</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>The name of the Tag that is going to be stored.</dd> </dl> </section> <section anchor="taglanguage-element"><name>TagLanguage Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x447A / string / und</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagLanguage</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>Specifies the language of the specified tagspecified,in the Matroska languages form; see <xref target="language-codes"></xref> on language codes. This Element <bcp14>MUST</bcp14> be ignored if the TagLanguageBCP47 Element is used within the same SimpleTag Element.</dd> </dl> </section> <section anchor="taglanguagebcp47-element"><name>TagLanguageBCP47 Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x447B / string</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagLanguageBCP47</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>minver:</dt> <dd>4</dd> <dt>definition:</dt> <dd>The language used in the TagString, in the form defined in <xreftarget="BCP47"></xref> form;target="RFC5646"></xref>; see <xref target="language-codes"></xref> on language codes. If this Element is used, then any TagLanguage Elements used in the same SimpleTag <bcp14>MUST</bcp14> be ignored.</dd> </dl> </section> <section anchor="tagdefault-element"><name>TagDefault Element</name> <dl spacing="compact"> <dt>id / type / default:</dt> <dd>0x4484 / uinteger / 1</dd> <dt>range:</dt> <dd>0-1</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagDefault</tt></dd> <dt>minOccurs / maxOccurs:</dt> <dd>1 / 1</dd> <dt>definition:</dt> <dd>A boolean value to indicate if this is the default/original language to use for the given tag.</dd> </dl> </section> <section anchor="tagstring-element"><name>TagString Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4487 / utf-8</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagString</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>The value of the Tag.</dd> </dl> </section> <section anchor="tagbinary-element"><name>TagBinary Element</name> <dl spacing="compact"> <dt>id / type:</dt> <dd>0x4485 / binary</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagBinary</tt></dd> <dt>maxOccurs:</dt> <dd>1</dd> <dt>definition:</dt> <dd>The values of theTag,Tag if it is binary. Note that this cannot be used in the same SimpleTag as TagString.</dd> </dl> </section> </section> </section> </section> </section> </section> <section anchor="matroska-element-ordering"><name>Matroska Element Ordering</name><t>Except for<t>With the exceptions of the <tt>EBML Header</tt> and the <tt>CRC-32 Element</tt>, the EBML specification <xref target="RFC8794"></xref> does not require any particular storage order for <tt>Elements</tt>.ThisHowever, this specificationhoweverdefines mandates and recommendations for ordering certain <tt>Elements</tt>in orderto facilitate better playback, seeking, and editing efficiency. This section describes and offers rationale for ordering requirements and recommendations for Matroska.</t> <section anchor="top-level-elements"><name>Top-Level Elements</name> <t>The <tt>Info Element</tt> is the only <bcp14>REQUIRED</bcp14> <tt>Top-Level Element</tt> in a Matroska file. To be playable, Matroska <bcp14>MUST</bcp14> also contain at least one <tt>Tracks Element</tt> and <tt>Cluster Element</tt>. The first <tt>Info Element</tt> and the first <tt>Tracks Element</tt><bcp14>MUST</bcp14>either <bcp14>MUST</bcp14> be stored before the first <tt>Cluster Element</tt> orboth<bcp14>SHALL</bcp14> both be referenced by a <tt>SeekHead Element</tt> occurring before the first <tt>Cluster Element</tt>.</t> <t>All <tt>Top-Level Elements</tt> <bcp14>MUST</bcp14> use a 4-octetlongEBML Element ID.</t> <t>When using Medium Linking, chapters are used to reference other Segments to play in a given order (see <xreftarget="medium-linking"></xref>.target="medium-linking"></xref>). A Segment containing theselinkedLinked Chapters does not require a <tt>Track</tt> Element or a <tt>Cluster</tt> Element.</t> <t>It is possible to edit a Matroska file after it has been created. For example, chapters, tags, or attachments can be added. When new <tt>Top-Level Elements</tt> are added to a Matroska file, the <tt>SeekHead</tt> Element(s) <bcp14>MUST</bcp14> be updated so that the <tt>SeekHead</tt> Element(s)itemizeitemizes the identity and position of all <tt>Top-Level Elements</tt>.</t> <t>Editing, removing, or adding <tt>Elements</tt> to a Matroska file often requires that some existing <tt>Elements</tt> be voided or extended. Transforming the existing <tt>Elements</tt> into <tt>Void Elements</tt> as padding can be used as a method to avoid moving large amounts of data around.</t> </section> <section anchor="crc-32"><name>CRC-32</name> <t>As noted by the EBMLspecification,specification <xref target="RFC8794"></xref>, if a <tt>CRC-32 Element</tt> is used, then the <tt>CRC-32 Element</tt> <bcp14>MUST</bcp14> be the first ordered <tt>Element</tt> within its <tt>Parent Element</tt>.</t> <t>InMatroskaMatroska, all <tt>Top-Level Elements</tt> of an EBML Document <bcp14>SHOULD</bcp14> include a <tt>CRC-32 Element</tt> as their first <tt>Child Element</tt>. The <tt>Segment Element</tt>, which is the <tt>Root Element</tt>, <bcp14>SHOULD NOT</bcp14> have a <tt>CRC-32 Element</tt>.</t> </section> <section anchor="seekhead"><name>SeekHead</name> <t>If used, the first <tt>SeekHead Element</tt> <bcp14>MUST</bcp14> be the first non-<tt>CRC-32 Child Element</tt> of the <tt>Segment Element</tt>. If a second <tt>SeekHead Element</tt> is used, then the first <tt>SeekHead Element</tt> <bcp14>MUST</bcp14> reference the identity and position of the second<tt>SeekHead</tt>.</t><tt>SeekHead Element</tt>.</t> <t>Additionally, the second <tt>SeekHead Element</tt> <bcp14>MUST</bcp14> only reference <tt>Cluster</tt> Elements and not any other <tt>Top-Level Element</tt> already contained within the first <tt>SeekHead Element</tt>.</t> <t>The second <tt>SeekHead Element</tt> <bcp14>MAY</bcp14> be stored in any order relative to the other <tt>Top-Level Elements</tt>. Whether one or two <tt>SeekHeadElement(s)</tt>Elements</tt> are used, the <tt>SeekHead Element(s)</tt> <bcp14>MUST</bcp14> collectively reference the identity and position of all <tt>Top-Level Elements</tt> except for the first <tt>SeekHead Element</tt>.</t> </section> <section anchor="cues-index"><name>Cues(index)</name>(Index)</name> <t>The <tt>Cues Element</tt> is <bcp14>RECOMMENDED</bcp14> to optimize seeking access in Matroska. It is programmatically simpler to add the <tt>Cues Element</tt> after all <tt>Cluster Elements</tt> have been written because this does not require a prediction of how much space to reserve before writing the <tt>Cluster Elements</tt>. However, storing the <tt>Cues Element</tt> before the <tt>Cluster Elements</tt> can provide some seeking advantages. If the <tt>Cues Element</tt> is present, then it <bcp14>SHOULD</bcp14> either be stored before the first <tt>Cluster Element</tt> or be referenced by a <tt>SeekHead Element</tt>.</t> </section> <section anchor="info"><name>Info</name> <t>The first <tt>Info Element</tt> <bcp14>SHOULD</bcp14> occur before the first <tt>Tracks Element</tt> and first <tt>Cluster Element</tt> except when referenced by a <tt>SeekHead Element</tt>.</t> </section> <section anchor="chapters-element-1"><name>Chapters Element</name> <t>The <tt>Chapters Element</tt> <bcp14>SHOULD</bcp14> be placed before the <tt>Cluster Element(s)</tt>. The <tt>Chapters Element</tt> can be used during playback even if the user does not need to seek. It immediately gives the user information about what section is being read and what other sections are available. In the case of OrderedChaptersChapters, it is <bcp14>RECOMMENDED</bcp14> to evaluate the logical linkingevenbefore playing. The <tt>Chapters Element</tt> <bcp14>SHOULD</bcp14> be placed before the first <tt>Tracks Element</tt> and after the first <tt>Info Element</tt>.</t> </section> <section anchor="attachments"><name>Attachments</name> <t>The <tt>Attachments Element</tt> is not intended to be used by default when playing thefile,file but could contain information relevant to the content, such as cover art or fonts. Cover art is useful even before the file isplayedplayed, and fonts could be needed before playback starts for the initialization of subtitles. The <tt>Attachments Element</tt> <bcp14>MAY</bcp14> be placed before the first <tt>Cluster Element</tt>; however, if the <tt>Attachments Element</tt> is likely to be edited, then it <bcp14>SHOULD</bcp14> be placed after the last <tt>Cluster Element</tt>.</t> </section> <section anchor="tags"><name>Tags</name> <t>The <tt>Tags Element</tt> is most subject to changes after the file was originally created. For easier editing, the <tt>Tags Element</tt> can be placed at the end of the <tt>Segment Element</tt>, even after the <tt>Attachments Element</tt>. On the other hand, it is inconvenient to have to seek in the <tt>Segment</tt> for tags, especially for networkstreams. Sostreams; thus, it's better if the <tt>Tags Element</tt> is found early in the stream. When editing the <tt>Tags Element</tt>, the original <tt>Tags Element</tt> at the beginning can be overwritten with a <tt>Void Element</tt> and a new <tt>Tags Element</tt> written at the end of the <tt>Segment Element</tt>. The file and Segment sizes will only marginally change.</t> </section> </section> <section anchor="matroska-versioning"><name>Matroskaversioning</name>Versioning</name> <t>Matroska is baseduponon the principle that a reading application does not have to support 100% of the specifications in order to be able to play the file.ATherefore, a Matroska filethereforecontains version indicators that tell a reading application what to expect.</t> <t>It is possible and valid to have the version fields indicate that the file contains Matroska <tt>Elements</tt> from a higher specification version number while signaling that a reading application <bcp14>MUST</bcp14> only support a lower version number properly in order to play it back (possibly with a reduced feature set).</t> <t>The <tt>EBML Header</tt> of each Matroska document informs the reading application on what version of Matroska to expect. The <tt>Elements</tt> within the <tt>EBML Header</tt> with jurisdiction over this information are <tt>DocTypeVersion</tt> and <tt>DocTypeReadVersion</tt>.</t> <t><tt>DocTypeVersion</tt> <bcp14>MUST</bcp14> be equal to or greater than the highest Matroska version number of any <tt>Element</tt> present in the Matroska file. For example, a file using the <tt>SimpleBlock Element</tt> (<xref target="simpleblock-element"></xref>) <bcp14>MUST</bcp14> have a <tt>DocTypeVersion</tt> equal to or greater than 2. A file containing <tt>CueRelativePosition</tt> Elements (<xref target="cuerelativeposition-element"></xref>) <bcp14>MUST</bcp14> have a <tt>DocTypeVersion</tt> equal to or greater than 4.</t> <t>The <tt>DocTypeReadVersion</tt> <bcp14>MUST</bcp14> contain the minimum version number that a reading application can minimally support in order to play the file back -- optionally with a reduced feature set. For example, if a file contains only <tt>Elements</tt> of version 2 or lower except for <tt>CueRelativePosition</tt> (which is a version 4 Matroska <tt>Element</tt>), then <tt>DocTypeReadVersion</tt> <bcp14>SHOULD</bcp14> still be set to 2 and not 4 because evaluating <tt>CueRelativePosition</tt> is not necessary for standard playback -- it makes seeking more precise if used.</t> <t>A reading application supporting Matroska version <tt>V</tt> <bcp14>MUST NOT</bcp14> refuse to read a file with <tt>DocReadTypeVersion</tt> equal to or lower than<tt>V</tt><tt>V</tt>, even if <tt>DocTypeVersion</tt> is greater than <tt>V</tt>.</t> <t>A reading application supporting at least Matroska version <tt>V</tt> and reading a file whose <tt>DocTypeReadVersion</tt> field is equal to or lower than <tt>V</tt> <bcp14>MUST</bcp14> skip Matroska/EBML <tt>Elements</tt> it encounters but does not know about if that unknown element fits into the size constraints set by the current <tt>Parent Element</tt>.</t> </section> <section anchor="stream-copy"><name>Stream Copy</name> <t>It is sometimes necessary to create a Matroska file from another Matroska file, forexampleexample, to add subtitles in a language or to edit out a portion of the content. Some values from the original Matroska file need to be kept the same in the destination file. For example, the SamplingFrequency of an audio track wouldn't change between the two files. Some other values may change between the two files, forexampleexample, the TrackNumber of an audio track when another track has been added.</t> <!-- [rfced] Please clarify "with a property: stream copy: True when". Original: An Element is marked with a property: stream copy: True when the values of that Element need to be kept identical between the source and destination file. Perhaps: An Element is marked with the property "stream copy: True" when the values of that Element need to be kept identical between the source and destination files. --> <t>An Element is marked with a property: <tt>stream copy: True</tt> when the values of that Element need to be kept identical between the source and destinationfile.files. If that property is not set, elements may or may not keep the same value between the source anddestination.</t>destination files.</t> </section> <section anchor="defaultdecodedfieldduration"><name>DefaultDecodedFieldDuration</name> <t>The <tt>DefaultDecodedFieldDuration Element</tt> can signal to the displaying application how often fields of a video sequence will be available for displaying. It can be used for both interlaced and progressive content.</t> <t>If the video sequence is signaled as interlaced<xref target="flaginterlaced-element"></xref>,(<xref target="flaginterlaced-element"></xref>), then <tt>DefaultDecodedFieldDuration</tt> equals the period between two successive fields at the output of the decoding process. For video sequences signaled as progressive, <tt>DefaultDecodedFieldDuration</tt> is half of the period between two successive frames at the output of the decoding process.</t> <t>These values are valid at the end of the decoding process before post-processing (such as deinterlacing or inverse telecine) is applied.</t> <t>Examples:</t><ul spacing="compact"><ul> <li>Blu-ray movie: 1000000000 ns/(48/1.001) = 20854167 ns</li> <li>PAL broadcast/DVD: 1000000000 ns/(50/1.000) = 20000000 ns</li> <li>N/ATSC broadcast: 1000000000 ns/(60/1.001) = 16683333 ns</li><li>hard-telecined<li>Hard-telecined DVD: 1000000000 ns/(60/1.001) = 16683333 ns (60 encoded interlaced fields per second)</li><li>soft-telecined<li>Soft-telecined DVD: 1000000000 ns/(60/1.001) = 16683333 ns (48 encoded interlaced fields per second, with"repeat_first_field"repeat_first_field =1")</li>1")</li> </ul> </section> <section anchor="cluster-blocks"><name>Cluster Blocks</name> <t>Frames using references <bcp14>SHOULD</bcp14> be stored in"coding order". That means"coding order" (i.e., the referencesfirst,first and then the frames referencingthem.them). A consequence is that timestamps might not be consecutive.ButHowever, a frame with a past timestamp <bcp14>MUST</bcp14> reference a frame alreadyknown, otherwise it'sknown; otherwise, it is considered bad/void.</t> <t>Matroska has two similar ways to store frames in a block:</t><ul spacing="compact"><ul> <li>in a <tt>Block</tt>whichthat is contained inside a<tt>BlockGroup</tt>,</li> <li>or in<tt>BlockGroup</tt></li> <li>in a <tt>SimpleBlock</tt>whichthat is directly in the<tt>Cluster</tt>.</li><tt>Cluster</tt></li> </ul> <t>The <tt>SimpleBlock</tt> is usually preferred unless some extra elements of the <tt>BlockGroup</tt> need to be used. A Matroska Reader <bcp14>MUST</bcp14> support both types of blocks.</t> <t>Each block contains the same parts in the following order:</t><ul spacing="compact"><ul> <li>avariable length header,</li> <li>optionally thevariable-length header</li> <li>the lacinginformation,</li>information (optional)</li> <li>the consecutive frame(s)</li> </ul> <!-- [rfced] Is "on up to" correct here? Original: The value can be coded on up to 8 octets. Perhaps: The value can be coded up to 8 octets. --> <t>The block header starts with the number of the Track it corresponds to. The value <bcp14>MUST</bcp14>correspondingcorrespond to the <tt>TrackNumber</tt> (<xref target="tracknumber-element"></xref>) of a <tt>TrackEntry</tt> of the <tt>Segment</tt>.</t> <t>The <tt>TrackNumber</tt> is coded using theVINTVariable-Size Integer (VINT) mechanism described inSection 4 of<xreftarget="RFC8794"></xref>.target="RFC8794" sectionFormat="of" section="4"></xref>. To save space, the shortest VINT form <bcp14>SHOULD</bcp14> be used. The value can be coded on up to 8 octets. This is the only element with a variable size in the block header.</t> <t>The timestamp is expressed in Track Ticks; see <xref target="timestamp-ticks"></xref>. The value is stored as a signed value on 16 bits.</t> <section anchor="block-structure"><name>Block Structure</name> <t>This section describes the binary data contained in the <tt>Block</tt> Element<xref target="block-element"></xref>.(<xref target="block-element"></xref>). Bit 0 is the most significant bit.</t> <t>As the <tt>TrackNumber</tt> size can vary between 1 and 8 octets, there are 8 different sizes for the <tt>Block</tt> header.We only provide theThe definitions for <tt>TrackNumber</tt> sizes of 1 and2. The2 are provided; the other variants can be deduced by extending the size of the <tt>TrackNumber</tt> by multiples of 8 bits.</t> <figure><name>Block Header with1 octet1-Octet TrackNumber </name> <artwork> 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | |I|LAC|U| | Track Number | Timestamp | Rsvrd |N|ING|N| | | | |V| |U| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ </artwork> </figure> <figure><name>Block Header with2 octets2-Octet TrackNumber </name> <artwork> 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Track Number | Timestamp | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |I|LAC|U| | Rsvrd |N|ING|N| ... | |V| |U| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ </artwork> </figure> <t>where:</t> <dlnewline="true"newline="false" spacing="normal"> <dt>TrackNumber: 8,Number:</dt><dd>8, 16, 24, 32, 40,4848, or 64bits</dt> <dd>anbits. An EBMLVINT codedVINT-coded tracknumber</dd> <dt>Timestamp: 16 bits</dt> <dd>signednumber.</dd> <dt>Timestamp:</dt><dd>16 bits. Signed timestamp in TrackTicks</dd> <dt>Rsvrd: 4 bits</dt> <dd>ReservedTicks.</dd> <dt>Rsvrd:</dt><dd>4 bits. Reserved bits <bcp14>MUST</bcp14> be set to0</dd> <dt>INV: 1 bit</dt> <dd>Invisible, the0.</dd> <dt>INV:</dt><dd>1 bit. Invisible. The codec <bcp14>SHOULD</bcp14> decode this frame but not displayit</dd> <dt>LACING: 2 bits</dt> <dd><t>usingit.</dd> <dt>LACING:</dt><dd><t>2 bits. Uses lacingmode</t> <ulmode.</t> <dl spacing="compact"><li>00b : no<dt>00b:</dt><dd>no lacing (<xreftarget="no-lacing"></xref>)</li> <li>01b : Xiphtarget="no-lacing"></xref>)</dd> <dt>01b:</dt><dd>Xiph lacing (<xreftarget="xiph-lacing"></xref>)</li> <li>11b : EBMLtarget="xiph-lacing"></xref>)</dd> <dt>11b:</dt><dd>EBML lacing (<xreftarget="ebml-lacing"></xref>)</li> <li>10b : fixed-sizetarget="ebml-lacing"></xref>)</dd> <dt>10b:</dt><dd>fixed-size lacing (<xreftarget="fixed-size-lacing"></xref>)</li> </ul></dd> <dt>UNU: 1 bit</dt> <dd>unused bit</dd>target="fixed-size-lacing"></xref>)</dd> </dl></dd> <dt>UNU:</dt><dd>1 bit. Unused bit.</dd> </dl> <t>The following data in the <tt>Block</tt>correspondcorresponds to the lacing data and frames usage as described in each respective lacing mode.</t> </section> <section anchor="simpleblock-structure"><name>SimpleBlock Structure</name> <t>This section describes the binary data contained in the <tt>SimpleBlock</tt> Element<xref target="simpleblock-element"></xref>.(<xref target="simpleblock-element"></xref>). Bit 0 is the most significant bit.</t> <t>The <tt>SimpleBlock</tt> structure is inspired by the Block structure; see <xref target="block-structure"></xref>. The main differences are the added Keyframe flag and Discardable flag. Otherwise, everything is the same.</t> <t>As the <tt>TrackNumber</tt> size can vary between 1 and 8 octets, there are 8 different sizes for the <tt>SimpleBlock</tt> header.We only provide theThe definitions for <tt>TrackNumber</tt> sizes of 1 and2. The2 are provided; the other variants can be deduced by extending the size of the <tt>TrackNumber</tt> by multiples of 8 bits.</t> <figure><name>SimpleBlock Header with1 octet1-Octet TrackNumber </name> <artwork> 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | |K| |I|LAC|D| | Track Number | Timestamp |E|Rsvrd|N|ING|I| | | |Y| |V| |S| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ </artwork> </figure> <figure><name>SimpleBlock Header with2 octets2-Octet TrackNumber </name> <artwork> 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Track Number | Timestamp | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |K| |I|LAC|D| |E|Rsvrd|N|ING|I| ... |Y| |V| |S| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ </artwork> </figure> <t>where:</t> <dlnewline="true"newline="false" spacing="normal"> <dt>TrackNumber: 8,Number:</dt><dd>8, 16, 24, 32, 40,4848, or 64bits</dt> <dd>anbits. An EBMLVINT codedVINT-coded tracknumber</dd> <dt>Timestamp: 16 bits</dt> <dd>signednumber.</dd> <dt>Timestamp:</dt><dd>16 bits. Signed timestamp in TrackTicks</dd> <dt>KEY: 1 bit</dt> <dd>Keyframe, setTicks.</dd> <dt>KEY:</dt><dd>1 bit. Keyframe. Set when the Block contains onlykeyframes</dd> <dt>Rsvrd: 3 bits</dt> <dd>Reservedkeyframes.</dd> <dt>Rsvrd:</dt><dd>3 bits. Reserved bits <bcp14>MUST</bcp14> be set to0</dd> <dt>INV: 1 bit</dt> <dd>Invisible, the0.</dd> <dt>INV:</dt><dd>1 bit. Invisible. The codec <bcp14>SHOULD</bcp14> decode this frame but not displayit</dd> <dt>LACING: 2 bits</dt> <dd><t>usingit.</dd> <dt>LACING:</dt><dd><t>2 bits. Uses lacingmode</t> <ulmode.</t> <dl spacing="compact"><li>00b : no<dt>00b:</dt><dd>no lacing (<xreftarget="no-lacing"></xref>)</li> <li>01b : Xiphtarget="no-lacing"></xref>)</dd> <dt>01b:</dt><dd>Xiph lacing (<xreftarget="xiph-lacing"></xref>)</li> <li>11b : EBMLtarget="xiph-lacing"></xref>)</dd> <dt>11b:</dt><dd>EBML lacing (<xreftarget="ebml-lacing"></xref>)</li> <li>10b : fixed-sizetarget="ebml-lacing"></xref>)</dd> <dt>10b:</dt><dd>fixed-size lacing (<xreftarget="fixed-size-lacing"></xref>)</li> </ul></dd> <dt>DIS: 1 bit</dt> <dd>Discardable, thetarget="fixed-size-lacing"></xref>)</dd> </dl></dd> <dt>DIS:</dt><dd>1 bit. Discardable. The frames of the Block can be discarded during playing ifneeded</dd>needed.</dd> </dl> <!-- [rfced] Please clarify "The following data" in these similar sentences. Is the intended meaning "The remaining data", or something else? Would a pointer to Section 10.3 be helpful? Original: The following data in the Block correspond to the lacing data and frames usage as described in each respective lacing mode. ... The following data in the SimpleBlock correspond to the lacing data and frames usage as described in each respective lacing mode. Perhaps: The remaining data in the Block corresponds to the lacing data and frames usage as described in each respective lacing mode (see Section 10.3). ... The remaining data in the SimpleBlock corresponds to the lacing data and frames usage as described in each respective lacing mode (see Section 10.3). --> <t>The following data in the <tt>SimpleBlock</tt>correspondcorresponds to the lacing data and frames usage as described in each respective lacing mode.</t> </section> <section anchor="block-lacing"><name>Block Lacing</name> <t>Lacing is a mechanism to save space when storing data. It is typically used for small blocks of data (referred to as frames in Matroska). It packs multiple frames into a single <tt>Block</tt> or <tt>SimpleBlock</tt>.</t> <t>Lacing <bcp14>MUST NOT</bcp14> be used to store a single frame in a <tt>Block</tt> or <tt>SimpleBlock</tt>.</t> <t>There are3three types of lacing:</t><ol spacing="compact"><ul> <li>Xiph, which is inspired by what is found in the Ogg container <xref target="RFC3533"></xref></li> <li>EBML, which is the same with sizes coded differently</li><li>fixed-size,<li>Fixed-size, where the size is not coded</li></ol> <t>When</ul> <!-- [rfced] We have two questions about the sentences below. a) Please confirm that "bits 5 and 6" and "bits 5-6" are correct in the text below. Or should this be "bits 6-7" per Figures 11-14? Or possibly just "The LACING bits"? b) The sentences below have "0b00", "0b01", "0b11", and "0b10", but Sections 10.1 and 10.2 have "00b", "01b", "11b", and "10b" for the LACING bits. Please review and let us know if any updates are needed. Original: When lacing is not used, i.e. to store a single frame, the lacing bits 5 and 6 of the Block or SimpleBlock MUST be set to zero. The bits 5-6 of the Block Header flags are set to 0b00. The bits 5-6 of the Block Header flags are set to 0b01. The bits 5-6 of the Block Header flags are set to 0b11. The bits 5-6 of the Block Header flags are set to 0b10. Perhaps: When lacing is not used, i.e. to store a single frame, the lacing bits 6 and 7 of the Block or SimpleBlock MUST be set to zero. Bits 6-7 of the Block Header flags are set to 00b. Bits 6-7 of the Block Header flags are set to 01b. Bits 6-7 of the Block Header flags are set to 11b. Bits 6-7 of the Block Header flags are set to 10b. Or: When lacing is not used, i.e. to store a single frame, the lacing bits (bits 6 and 7) of the Block or SimpleBlock MUST be set to zero. The LACING bits of the Block Header flags are set to 00b. The LACING bits of the Block Header flags are set to 01b. The LACING bits of the Block Header flags are set to 11b. The LACING bits of the Block Header flags are set to 10b. --> <t>When lacing is not used, i.e., to store a single frame, lacing bits 5 and 6 of the <tt>Block</tt> or <tt>SimpleBlock</tt> <bcp14>MUST</bcp14> be set tozero.</t>0.</t> <t>For example, a user wants to store3three frames of the same track. The first frame is 800 octets long, the second is 500 octetslonglong, and the third is 1000 octets long. <!-- [rfced] We updated "these data" to "frames". Please let us know any objections. Original: As these data are small, they can be stored in a lace to save space. Current: Because these frames are small, they can be stored in a lace to save space. --> Because these frames are small, they can be stored in a lace to save space.</t> <t>It is possiblenotto not use lacing at all and just store a single frame without any extra data. When the FlagLacing-- <xref target="flaglacing-element"></xref> --(<xref target="flaglacing-element"></xref>) is set to"0"0, all blocks of that track <bcp14>MUST NOT</bcp14> use lacing.</t> <section anchor="no-lacing"><name>Nolacing</name>Lacing</name> <t>When no lacing is used, the number of frames in the lace isommittedommitted, and only one frame can be stored in the Block.The bits 5-6Bits 5 and 6 of the Block Header flags are set to <tt>0b00</tt>.</t> <t>The Block for an800 octets800-octet frame is as follows:</t> <table anchor="blockNoLacing"><name>Nolacing</name>Lacing</name> <thead> <tr> <th align="left">BlockOctets</th>Octet</th> <th align="left">Value</th> <th align="left">Description</th> </tr> </thead> <tbody> <tr> <td align="left">4-803</td> <td align="left"><frame></td> <td align="left">Single frame data</td> </tr> </tbody></table><t>When</table> <t>When a Block contains a single frame, it <bcp14>MUST</bcp14> use thisNo lacing"no lacing" mode.</t> </section> <section anchor="xiph-lacing"><name>Xiphlacing</name>Lacing</name> <t>The Xiph lacing uses the same coding of size as found in the Ogg container <xref target="RFC3533"></xref>.The bits 5-6Bits 5 and 6 of the Block Header flags are set to <tt>0b01</tt>.</t> <t>The Block data with laced frames is stored as follows:</t><ul spacing="compact"> <li>Lacing<ul> <!-- [rfced] Will readers understand the following? Note that this text appears in three locations in the document. Original: * Lacing Head on 1 Octet: Number of frames in the lace minus 1. --> <li>Lacing Head on 1 octet: Number of frames in the lace minus 1.</li> <li>Lacing size of each frame except the last one.</li> <li>Binary data of each frame consecutively.</li> </ul> <t>The lacing size is split into 255 values, stored as unsigned octets -- for example, 500 is coded 255;245 or [0xFF 0xF5]. A frame with a size multiple of 255 is coded with a 0 at the end of the size -- for example, 765 is coded 255;255;255;0 or [0xFF 0xFF 0xFF 0x00].</t> <t>The size of the last frame is deduced from the size remaining in the Block after the other frames.</t> <t>Because large sizes result in large coding of the sizes, it is <bcp14>RECOMMENDED</bcp14> to use Xiph lacing only with small frames.</t> <t>In our example, the800, 500800-, 500-, and10001000-octet frames are stored with Xiph lacing in a Block as follows:</t> <table anchor="blockXiphLacing"><name>Xiphlacing example</name>Lacing Example</name> <thead> <tr> <th align="left">BlockOctet</th>Octets</th> <th align="left">Value</th> <th align="left">Description</th> </tr> </thead> <tbody> <tr> <td align="left">4</td> <td align="left">0x02</td> <td align="left">Number of frames minus 1</td> </tr> <tr> <td align="left">5-8</td> <td align="left">0xFF 0xFF 0xFF 0x23</td> <td align="left">Size of the first frame (255;255;255;35)</td> </tr> <tr> <td align="left">9-10</td> <td align="left">0xFF 0xF5</td> <td align="left">Size of the second frame (255;245)</td> </tr> <tr> <td align="left">11-810</td> <td align="left"></td> <td align="left">First frame data</td> </tr> <tr> <td align="left">811-1310</td> <td align="left"></td> <td align="left">Second frame data</td> </tr> <tr> <td align="left">1311-2310</td> <td align="left"></td> <td align="left">Third frame data</td> </tr> </tbody> </table><t>The Block is 2311octets largeoctets, and the last frame starts at 1311, so we can deduce that the size of the last frame is 2311 - 1311 = 1000.</t> </section> <section anchor="ebml-lacing"><name>EBMLlacing</name>Lacing</name> <t>The EBML lacing encodes the frame size with an EBML-like encoding <xref target="RFC8794"></xref>.The bits 5-6Bits 5 and 6 of the Block Header flags are set to <tt>0b11</tt>.</t> <t>The Block data with laced frames is stored as follows:</t><ul spacing="compact"><ul> <li>Lacing Head on 1 Octet: Number of frames in the lace minus 1.</li> <li>Lacing size of each frame except the last one.</li> <li>Binary data of each frame consecutively.</li> </ul> <t>The first frame size is encoded as an EBMLVariable-Size Integer value, also known asVINTin <xref target="RFC8794"></xref>.value. The remaining frame sizes are encoded as signed values using the difference between the frame size and the previous frame size. These signed values are encoded as VINT, with a mapping from signed to unsigned numbers. Decoding the unsigned number stored in the VINT to a signed number is done by subtracting 2<sup>((7*n)-1)</sup>-1, where <tt>n</tt> is the octet size of the VINT.</t> <table anchor="ebmlLacingBits"><name>EBML LacingsignedSigned VINTbits usage</name>Bits Usage</name> <thead> <tr> <th align="left">Bit Representation ofsignedSigned VINT</th> <th align="left">Possible Value Range</th> </tr> </thead> <tbody> <tr> <td align="left">1xxx xxxx</td> <td align="left">2^7 values from -(2<sup>6</sup>-1) to 2<sup>6</sup></td> </tr> <tr> <td align="left">01xx xxxx xxxx xxxx</td> <td align="left">2^14 values from -(2<sup>13</sup>-1) to 2<sup>13</sup></td> </tr> <tr> <td align="left">001x xxxx xxxx xxxx xxxx xxxx</td> <td align="left">2^21 values from -(2<sup>20</sup>-1) to 2<sup>20</sup></td> </tr> <tr> <td align="left">0001 xxxx xxxx xxxx xxxx xxxx xxxx xxxx</td> <td align="left">2^28 values from -(2<sup>27</sup>-1) to 2<sup>27</sup></td> </tr> <tr> <td align="left">0000 1xxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx xxxx</td> <td align="left">2^35 values from -(2<sup>34</sup>-1) to 2<sup>34</sup></td> </tr> </tbody> </table><t>In our example, the800, 500800-, 500- and10001000-octet frames are stored with EBML lacing in a Block as follows:</t> <table anchor="blockEbmlLacing"><name>EBMLlacing example</name>Lacing Example</name> <thead> <tr> <th align="left">Block Octets</th> <th align="left">Value</th> <th align="left">Description</th> </tr> </thead> <tbody> <tr> <td align="left">4</td> <td align="left">0x02</td> <td align="left">Number of frames minus 1</td> </tr> <tr> <td align="left">5-6</td> <td align="left">0x43 0x20</td> <td align="left">Size of the first frame (800 = 0x320 + 0x4000)</td> </tr> <tr> <td align="left">7-8</td> <td align="left">0x5E 0xD3</td> <td align="left">Size of the second frame (500 - 800 = -300 = - 0x12C + 0x1FFF + 0x4000)</td> </tr> <tr> <td align="left">8-807</td> <td align="left"><frame1></td> <td align="left">First frame data</td> </tr> <tr> <td align="left">808-1307</td> <td align="left"><frame2></td> <td align="left">Second frame data</td> </tr> <tr> <td align="left">1308-2307</td> <td align="left"><frame3></td> <td align="left">Third frame data</td> </tr> </tbody> </table><t>The Block is 2308octets largeoctets, and the last frame starts at 1308, so we can deduce that the size of the last frame is 2308 - 1308 = 1000.</t> </section> <section anchor="fixed-size-lacing"><name>Fixed-sizelacing</name> <t>The Fixed-sizeLacing</name> <t>Fixed-size lacing doesn't store the framesize,size; rather, it only stores the number of frames in the lace. Each frame <bcp14>MUST</bcp14> have the same size. The frame size of each frame is deduced from the total size of the Block.The bits 5-6Bits 5 and 6 of the Block Header flags are set to <tt>0b10</tt>.</t> <t>The Block data with laced frames is stored as follows:</t><ul spacing="compact"><ul> <li>Lacing Head on 1 Octet: Number of frames in the lace minus 1.</li> <li>Binary data of each frame consecutively.</li> </ul> <t>For example, for3three framesofthat are 800 octets each:</t> <tableanchor="blockFixedSizeLacing"><name>Fixed-size lacing example</name>anchor="blockFixedSizeLacing"><name>Fixed-Size Lacing Example</name> <thead> <tr> <th align="left">Block Octets</th> <th align="left">Value</th> <th align="left">Description</th> </tr> </thead> <tbody> <tr> <td align="left">4</td> <td align="left">0x02</td> <td align="left">Number of frames minus 1</td> </tr> <tr> <td align="left">5-804</td> <td align="left"><frame1></td> <td align="left">First frame data</td> </tr> <tr> <td align="left">805-1604</td> <td align="left"><frame2></td> <td align="left">Second frame data</td> </tr> <tr> <td align="left">1605-2404</td> <td align="left"><frame3></td> <td align="left">Third frame data</td> </tr> </tbody> </table><t>This gives a Block of 2405 octets. When reading theBlockBlock, we find that there are3three frames (Octet 4). The data start at Octet 5, so the size of each frame is (2405 - 5) / 3 = 800.</t> </section> <section anchor="laced-frames-timestamp"><name>Laced Frames Timestamp</name> <t>A Block only contains a single timestamp value. But when lacing is used, it contains more than one frame. Each frame originally has its own timestamp, or Presentation Timestamp (PTS). That timestamp applies to the first frame in the lace.</t> <t>In the lace, each frame after the first one has an underdetermined timestamp.ButHowever, each of these frames <bcp14>MUST</bcp14> be contiguous --i.e.i.e., the decoded data <bcp14>MUST NOT</bcp14> contain any gap between them. If there is a gap in the stream, the frames around the gap <bcp14>MUST NOT</bcp14> be in the same Block.</t> <t>Lacing is only useful for small contiguous data to save space. This is usually the case for audio tracks and not the case for video-- which(which use a lot ofdata --data) or subtitle tracks-- which(which have longgaps.gaps). For audio, there is usually a fixed output sampling frequency for the wholetrack. Sotrack, so the decoder should be able to recover the timestamp of each sample, knowing each output sample is contiguous with a fixed frequency. Forsubtitlessubtitles, this is usually not thecasecase, so lacing <bcp14>SHOULD NOT</bcp14> be used.</t> </section> </section> <section anchor="random-access-points"><name>Random Access Points</name> <t>Random Access Points(RAP)(RAPs) are positions where the parser can seek to and start playback without decodingofwhat was before. InMatroskaMatroska, <tt>BlockGroups</tt> and <tt>SimpleBlocks</tt> can be RAPs. <!-- [rfced] Is RAP read as "rap" or "R-A-P"? We ask for guidance in order to choose the appropriate indefinite article for it to follow (i.e., a or an). We see both "an RAP" and "a RAP" in the document.--> To seek to theseelementselements, it is still necessary to seek to the <tt>Cluster</tt> containing them, read the ClusterTimestampTimestamp, and start playback from the <tt>BlockGroup</tt> or <tt>SimpleBlock</tt> that is a RAP.</t> <t>Because a Matroska File is usually composed of multiple tracks playing at the same time -- video,audioaudio, and subtitles -- to seek properly to a RAP, each selected track must be taken in account.UsuallyUsually, all audio and subtitle<tt>BlockGroup</tt><tt>BlockGroups</tt> or<tt>SimpleBlock</tt><tt>SimpleBlocks</tt> areRAP.RAPs. They are independent of each other and can be played randomly.</t><t>Video tracks on<t>On the otherhandhand, video tracks often use references to previous and future frames for better coding efficiency. Frames with suchreferencereferences <bcp14>MUST</bcp14> either contain one or more <tt>ReferenceBlock</tt> Elements in their <tt>BlockGroup</tt> or <bcp14>MUST</bcp14> be marked as non-keyframe in a <tt>SimpleBlock</tt>; see <xref target="simpleblock-structure"></xref>.</t><ul spacing="compact"> <li>BlockGroup<!-- [rfced] In Section 10.4, would you like to change the text introducing the XML examples to be figure titles (would appear under the XML and also include a figure number)? Or do you prefer the current? Current: BlockGroup with a frame that references another frame, with the EBML tree shown asXML:</li> </ul>XML: Perhaps (below XML example): Figure 15: Blockgroup with a Frame That References Another Frame, with the EBML Tree Shown as XML --> <t>BlockGroup with a frame that references another frame, with the EBML tree shown as XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <BlockGroup> <!-- References a Block 40 Track Ticks before this one --> <ReferenceBlock>-40</ReferenceBlock> <Block/> </BlockGroup> ... </Cluster> </sourcecode><ul spacing="compact"> <li>SimpleBlock<t>SimpleBlock with a frame that references another frame, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <SimpleBlock/> (octet 3 bit 0 not set) ... </Cluster> </sourcecode> <t>Frames that areRAP -- i.e. theyRAPs (i.e., frames that don't depend on otherframes --frames) <bcp14>MUST</bcp14> set the keyframe flag if they are in a <tt>SimpleBlock</tt> or their parent <tt>BlockGroup</tt> <bcp14>MUST NOT</bcp14> contain a <tt>ReferenceBlock</tt>.</t><ul spacing="compact"> <li>BlockGroup<t>BlockGroup with a frame that references no other frame, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <BlockGroup> <!-- No ReferenceBlock allowed in this BlockGroup --> <Block/> </BlockGroup> ... </Cluster> </sourcecode><ul spacing="compact"> <li>SimpleBlock<t>SimpleBlock with a frame that references no other frame, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <SimpleBlock/> (octet 3 bit 0 set) ... </Cluster> </sourcecode> <t>There may be cases where the use of <tt>BlockGroup</tt> is necessary, as the frame may need a <tt>BlockDuration</tt>, <tt>BlockAdditions</tt>,<tt>CodecState</tt><tt>CodecState</tt>, ora<tt>DiscardPadding</tt> element. For thosescasescases, a <tt>SimpleBlock</tt> <bcp14>MUST NOT</bcp14> beused,used; the reference information <bcp14>SHOULD</bcp14> be recovered for non-RAP frames.</t><ul spacing="compact"> <li>SimpleBlock<t>SimpleBlock with a frame that references another frame, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <SimpleBlock/> (octet 3 bit 0 not set) ... </Cluster> </sourcecode><ul spacing="compact"> <li>Same<!-- [rfced] We updated the end tag as follows in two blocks of XML in Section 10.4. Please review. Original: <BlockDuration>20<BlockDuration> Perhaps: <BlockDuration>20</BlockDuration> --> <t>Same frame that references another frame put inside a BlockGroup to add <tt>BlockDuration</tt>, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <BlockGroup> <!-- ReferenceBlock value recovered based on the codec --> <ReferenceBlock>-40</ReferenceBlock><BlockDuration>20<BlockDuration><BlockDuration>20</BlockDuration> <Block/> </BlockGroup> ... </Cluster> </sourcecode> <t>When a frame in a <tt>BlockGroup</tt> is not a RAP, the <tt>BlockGroup</tt> <bcp14>MUST</bcp14> contain at least a <tt>ReferenceBlock</tt>. The <tt>ReferenceBlock</tt>s <bcp14>MUST</bcp14> be used in one of the following ways:</t><ul spacing="compact"><ul> <li>each reference frame listed as a <tt>ReferenceBlock</tt>,</li> <li>some referencedframeframes listed as a <tt>ReferenceBlock</tt>, even if the timestamp value isaccurate,</li> <li>or oneaccurate, or</li> <li>one <tt>ReferenceBlock</tt> with the timestamp value"0""0" corresponding to a self or unknown reference.</li> </ul> <t>The lack of <tt>ReferenceBlock</tt> would mean such a frame is aRAPRAP, and seeking on that frame that actually depends on other frames may create a bogus output or even crash.</t><ul spacing="compact"> <li>Same<t>Same frame that references another frame put inside aBlockGroupBlockGroup, but the reference could not be recovered, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <BlockGroup> <!-- ReferenceBlock value not recovered from the codec --> <ReferenceBlock>0</ReferenceBlock><BlockDuration>20<BlockDuration><BlockDuration>20</BlockDuration> <Block/> </BlockGroup> ... </Cluster> </sourcecode><ul spacing="compact"> <li>BlockGroup<t>BlockGroup with a frame that references two other frames, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <BlockGroup> <!-- References a Block 80 Track Ticks before this one --> <ReferenceBlock>-80</ReferenceBlock> <!-- References a Block 40 Track Ticks after this one --> <ReferenceBlock>40</ReferenceBlock> <Block/> </BlockGroup> ... </Cluster> </sourcecode> <t>Intra-only video frames, such as the ones found in AV1 or VP9, can be decoded without any other frame, but they don't reset the codec state.SoThus, seeking to these frames is notpossiblepossible, as the next frames may need frames that are not known from this seeking point. Such intra-only frames <bcp14>MUST NOT</bcp14> be considered askeyframeskeyframes, so the keyframe flag <bcp14>MUST NOT</bcp14> be set in the <tt>SimpleBlock</tt> or a <tt>ReferenceBlock</tt> <bcp14>MUST</bcp14> be used to signify the frame is not a RAP. The timestamp value of the <tt>ReferenceBlock</tt> <bcp14>MUST</bcp14> be"0","0", meaning it's referencing itself.</t><ul spacing="compact"> <li>Intra-only<t>Intra-only frame not an RAP, with the EBML tree shown asXML:</li> </ul>XML:</t> <sourcecode type="xml"><Cluster> <Timestamp>123456</Timestamp> <BlockGroup> <!-- References itself to mark it should not be used as RAP --> <ReferenceBlock>0</ReferenceBlock> <Block/> </BlockGroup> ... </Cluster> </sourcecode> <t>Because a video <tt>SimpleBlock</tt> has lessreferencesinformation on references than a video <tt>BlockGroup</tt>, it is possible to remux a video track using <tt>BlockGroup</tt> into a <tt>SimpleBlock</tt>, as long as it doesn't use any other <tt>BlockGroup</tt> features than <tt>ReferenceBlock</tt>.</t> </section> </section> <section anchor="timestamps"><name>Timestamps</name><t>Historically<t>Historically, timestamps in Matroska were mistakenly called timecodes. The <tt>Timestamp Element</tt> was called Timecode, the <tt>TimestampScale Element</tt> was called TimecodeScale, the <tt>TrackTimestampScale Element</tt> was calledTrackTimecodeScaleTrackTimecodeScale, and the <tt>ReferenceTimestamp Element</tt> was called ReferenceTimeCode.</t> <section anchor="timestamp-ticks"><name>Timestamp Ticks</name> <t>All timestamp values in Matroska are expressed in multiples of a tick. They are usually stored as integers. There are three types of tickspossible:</t>possible: Matroska Ticks, Segment Ticks, and Track Ticks.</t> <section anchor="matroska-ticks"><name>Matroska Ticks</name> <!-- [rfced] Will readers know what "For such elements" refers to in this first sentence of Section 11.1.1?? Original: For such elements, the timestamp value is stored directly in nanoseconds. --> <t>For such elements, the timestamp value is stored directly in nanoseconds.</t> <t>The elements storing values in Matroska Ticks/nanoseconds are:</t><ul spacing="compact"><ul> <li><tt>TrackEntry\DefaultDuration</tt>; defined in <xref target="defaultduration-element"></xref></li> <li><tt>TrackEntry\DefaultDecodedFieldDuration</tt>; defined in <xref target="defaultdecodedfieldduration-element"></xref></li> <li><tt>TrackEntry\SeekPreRoll</tt>; defined in <xref target="seekpreroll-element"></xref></li> <li><tt>TrackEntry\CodecDelay</tt>; defined in <xref target="codecdelay-element"></xref></li> <li><tt>BlockGroup\DiscardPadding</tt>; defined in <xref target="discardpadding-element"></xref></li> <li><tt>ChapterAtom\ChapterTimeStart</tt>; defined in <xref target="chaptertimestart-element"></xref></li> <li><tt>ChapterAtom\ChapterTimeEnd</tt>; defined in <xref target="chaptertimeend-element"></xref></li> <li><tt>CuePoint\CueTime</tt>; defined in <xref target="cuetime-element"></xref></li> <li><tt>CueReference\CueRefTime</tt>; defined in <xref target="cuetime-element"></xref></li> </ul> </section> <section anchor="segment-ticks"><name>Segment Ticks</name> <t>Elements in Segment Ticks involve the use of the <tt>TimestampScale Element</tt> of the Segment to get the timestamp in nanoseconds of the element, with the following formula:</t> <artwork>timestamp in nanosecond = element value * TimestampScale </artwork> <t>This allowsstoringfor storage of smaller integer values in the elements.</t> <t>When using the default value of<tt>TimestampScale</tt> of "1,000,000","1,000,000" for <tt>TimestampScale</tt>, one Segment Tick represents one millisecond.</t> <t>The elements storing values in Segment Ticks are:</t><ul spacing="compact"><ul> <li><tt>Cluster\Timestamp</tt>; defined in <xref target="timestamp-element"></xref></li> <li><tt>Info\Duration</tt> is stored as afloating-pointfloating-point, but the same formula applies; defined in <xref target="duration-element"></xref></li> <li><tt>CuePoint\CueTrackPositions\CueDuration</tt>; defined in <xref target="cueduration-element"></xref></li> </ul> </section> <section anchor="track-ticks"><name>Track Ticks</name> <t>Elements in Track Ticks involve the use of the <tt>TimestampScale Element</tt> of the Segment and the <tt>TrackTimestampScale Element</tt> of the Track to get the timestamp in nanoseconds of the element, with the following formula:</t> <artwork>timestamp in nanoseconds = element value * TrackTimestampScale * TimestampScale </artwork> <t>This allowsstoringfor storage of smaller integer values in the elements. The resulting floating-point values of the timestamps are still expressed in nanoseconds.</t> <t>When using the default values of "1,000,000" for <tt>TimestampScale</tt> and<tt>TrackTimestampScale</tt> of "1,000,000" and of "1.0" respectively,"1.0" for <tt>TrackTimestampScale</tt>, one Track Tick represents one millisecond.</t> <t>The elements storing values in Track Ticks are:</t><ul spacing="compact"><ul> <li><tt>Cluster\BlockGroup\Block</tt> and <tt>Cluster\SimpleBlock</tt> timestamps; detailed in <xref target="block-timestamps"></xref></li> <li><tt>Cluster\BlockGroup\BlockDuration</tt>; defined in <xref target="blockduration-element"></xref></li> <li><tt>Cluster\BlockGroup\ReferenceBlock</tt>; defined in <xref target="referenceblock-element"></xref></li> </ul> <t>When the <tt>TrackTimestampScale</tt> is interpreted as"1.0","1.0", Track Ticks are equivalent to Segment Ticks and give an integer value in nanoseconds. This is the most common case as <tt>TrackTimestampScale</tt> is usually omitted.</t> <t>A value of <tt>TrackTimestampScale</tt> other than"1.0""1.0" <bcp14>MAY</bcp14> be used to scale the timestamps more in tune with each Track sampling frequency. For historical reasons, a lot of MatroskareadersReaders don't take the <tt>TrackTimestampScale</tt> valueininto account.SoThus, using a value other than"1.0""1.0" might not work in many places.</t> </section> </section> <section anchor="block-timestamps"><name>Block Timestamps</name> <t>A <tt>Block Element</tt> and <tt>SimpleBlock Element</tt> timestamp is the time when the decoded data of the first frame in the Block/SimpleBlock <bcp14>MUST</bcp14> bepresented,presented if the track of that Block/SimpleBlock is selected for playback. This is also known as the Presentation Timestamp (PTS).</t> <t>The <tt>Block Element</tt> and <tt>SimpleBlock Element</tt> store their timestamps as signed integers, relative to the <tt>Cluster\Timestamp</tt> value of the <tt>Cluster</tt> they are stored in. To get the timestamp of a <tt>Block</tt> or <tt>SimpleBlock</tt> innanoseconds you have to usenanoseconds, the followingformula:</t>formula is used:</t> <artwork>( Cluster\Timestamp + ( block timestamp * TrackTimestampScale ) ) * TimestampScale </artwork> <t>The <tt>Block Element</tt> and <tt>SimpleBlock Element</tt> store their timestamps as16bit16-bit signed integers, allowing a range from"-32768""-32768" to"+32767""+32767" Track Ticks. Although these values can be negative, when added to the <tt>Cluster\Timestamp</tt>, the resulting frame timestamp <bcp14>SHOULD NOT</bcp14> be negative.</t> <t>When a <tt>CodecDelay Element</tt> is set, its value <bcp14>MUST</bcp14> be substracted from each Block timestamp of that track. To get the timestamp in nanoseconds of the first frame in a <tt>Block</tt> or <tt>SimpleBlock</tt>, the formula becomes:</t> <artwork>( ( Cluster\Timestamp + ( block timestamp * TrackTimestampScale ) ) * TimestampScale ) - CodecDelay </artwork> <t>The resulting frame timestamp <bcp14>SHOULD NOT</bcp14> be negative.</t> <t>During playback, when a frame has a negative timestamp, the content <bcp14>MUST</bcp14> be decoded by the decoder but not played to the user.</t> </section> <section anchor="timestampscale-rounding"><name>TimestampScale Rounding</name> <t>The default Track Tick duration is one millisecond.</t> <t>The <tt>TimestampScale</tt> is a floating-pointvalue, whichvalue that is usually1.0."1.0". But when it's not, the multiplied Block Timestamp is a floating-point value in nanoseconds. The <tt>Matroska Reader</tt> <bcp14>SHOULD</bcp14> use the nearest rounding value innanosecondnanoseconds to get the proper nanosecond timestamp of a Block. This allows some clever <tt>TimestampScale</tt> values to have a more refined timestamp precision per frame.</t> </section> </section> <section anchor="language-codes"><name>Language Codes</name> <t>Matroskafrom versionversions 1 through 3usesuse language codes that can be either the3 lettersthree-letter bibliographicISO-639-2ISO 639-2 form <xref target="ISO639-2"></xref> (like"fre""fre" forFrench),French) or such a language code followed by a dash and a country code for specialities in languages (like"fre-ca""fre-ca" for Canadian French). The <tt>ISO 639-2 Language Elements</tt> are"Language Element", "TagLanguage Element","Language Element", "TagLanguage Element", and"ChapLanguage Element".</t>"ChapLanguage Element".</t> <t>Starting in Matroska version 4, either <xref target="ISO639-2"></xref> or <xreftarget="BCP47"></xref>target="RFC5646"></xref> <bcp14>MAY</bcp14> be used, although <tt>BCP 47</tt> is <bcp14>RECOMMENDED</bcp14>. The <tt>BCP 47 Language Elements</tt> are"LanguageBCP47 Element", "TagLanguageBCP47 Element","LanguageBCP47 Element", "TagLanguageBCP47 Element", and"ChapLanguageBCP47 Element"."ChapLanguageBCP47 Element". If a <tt>BCP 47 Language Element</tt> and an <tt>ISO 639-2 Language Element</tt> are used within the same <tt>Parent Element</tt>, then the <tt>ISO 639-2 Language Element</tt> <bcp14>MUST</bcp14> be ignored and precedence given to the <tt>BCP 47 Language Element</tt>.</t> </section> <section anchor="country-codes"><name>Country Codes</name> <t>Country codes are the <xreftarget="BCP47"></xref>target="RFC5646"></xref> two-letter regionsubtag,subtags, without the UK exception.</t> </section> <section anchor="encryption"><name>Encryption</name> <!-- [rfced] How may we update "to provide authorization" to create parallel structure for the list in this sentence? The other items in the list are nouns (i.e., confidentiality, integrity, authenticity). Original: This Matroska specification provides no interoperable solution for securing the data container with any assurances of confidentiality, integrity, authenticity, or to provide authorization. Perhaps: This Matroska specification provides no interoperable solution for securing the data container with any assurances of confidentiality, integrity, authenticity, or authorization. --> <t>This Matroska specification provides no interoperable solution for securing the data container with any assurances of confidentiality, integrity, authenticity, or to provide authorization. The <tt>ContentEncryption Element</tt> (<xref target="contentencryption-element"></xref>) and associated sub-fields (<xref target="contentencalgo-element"></xref> to <xref target="aessettingsciphermode-element"></xref>) are defined only for the benefit of implementers to construct their own proprietary solution or as the basis for further standardization activities. How to use these fields to secure a Matroska data container is out of scope, as are any related issues such as key management and distribution.</t> <t>A <tt>Matroska Reader</tt> who encounters containers that use the fields defined in this section <bcp14>MUST</bcp14> rely on out-of-scope guidance to decode the associated content.</t> <t>Because encryption occurs within the <tt>Block Element</tt>, it is possible to manipulate encrypted streams without decrypting them. The streams could potentially be copied, deleted, cut, appended, or any number of other possible editing techniques without decryption. The data can be used without having to expose it or go through the decrypting process.</t> <t>Encryption can also be layered within Matroska. This means that two completely different types of encryption can be used, requiring two separate keys to be able to decrypt a stream.</t> <t>Encryption information is stored in the <tt>ContentEncodings Element</tt> under the <tt>ContentEncryption Element</tt>.</t> <t>For encryption systems sharing public/private keys, the creation of the keys and the exchange of keys are not covered by this document. They have to be handled by the system using Matroska.</t> <t>The algorithms described in <xref target="ContentEncAlgoValues"></xref> support different modes of operations and key sizes. The specification of these parameters is required for a completesolution,solution but is out of scope of this document and left to the proprietary implementations using them or subsequent profiles of this document.</t> <t>The <tt>ContentEncodingScope Element</tt> gives an idea of which part of the trackare encrypted. Butis encrypted, but each <tt>ContentEncAlgo Element</tt> and itssub elements like <tt>AESSettingsCipherMode</tt> reallysub-elements (like <tt>AESSettingsCipherMode</tt>) define exactly how the encrypted track should beexactlyinterpreted.</t> <t>An example of an extension that builds upon these security-related fields in this specification is <xref target="WebM-Enc"></xref>. It uses AES-CTR, <tt>ContentEncAlgo</tt> = 5 (<xreftarget="contentencalgo-element"></xref>)target="contentencalgo-element"></xref>), and <tt>AESSettingsCipherMode</tt> = 1 (<xref target="aessettingsciphermode-element"></xref>).</t> <t>A <tt>Matroska Writer</tt> <bcp14>MUST NOT</bcp14> use insecure cryptographic algorithms to create new archives or streams, but a <tt>Matroska Reader</tt> <bcp14>MAY</bcp14> support these algorithms to read previously made archives orstream.</t>streams.</t> </section> <section anchor="image-presentation"><name>Image Presentation</name> <section anchor="cropping"><name>Cropping</name> <t>The <tt>PixelCrop Elements</tt> (<tt>PixelCropTop</tt>, <tt>PixelCropBottom</tt>, <tt>PixelCropRight</tt>, and <tt>PixelCropLeft</tt>) indicate when, and by how much, encodedvideosvideo frames <bcp14>SHOULD</bcp14> be cropped for display. These Elements allow edges of the frame that are not intended fordisplay, suchdisplay (such as the sprockets of a full-frame film scan or the VANC area of a digitized analogvideotape,videotape) to be stored but hidden. <tt>PixelCropTop</tt> and <tt>PixelCropBottom</tt> store an integer of how many rows of pixels <bcp14>SHOULD</bcp14> be cropped from the top and bottom of theimage (respectively).image, respectively. <tt>PixelCropLeft</tt> and <tt>PixelCropRight</tt> store an integer of how many columns of pixels <bcp14>SHOULD</bcp14> be cropped from the left and right of theimage (respectively).</t>image, respectively.</t> <t>For example, a pillar-boxed video that stores a 1440x1080 visual image within the center of a padded 1920x1080 encoded image may set both <tt>PixelCropLeft</tt> and <tt>PixelCropRight</tt> to"240","240", sothata <tt>Matroska Player</tt> should crop off 240 columns of pixels from the left and right of the encoded image to present the image with the pillar-boxes hidden.</t> <t>Cropping has to be performed before resizing and the display dimensions given by <tt>DisplayWidth</tt>,<tt>DisplayHeight</tt><tt>DisplayHeight</tt>, and <tt>DisplayUnit</tt> apply to thealready croppedalready-cropped image.</t> </section> <section anchor="rotation"><name>Rotation</name> <t>The ProjectionPoseRoll Element(see <xref(<xref target="projectionposeroll-element"></xref>) can be used to indicate that the image from the associated video track <bcp14>SHOULD</bcp14> be rotated for presentation. For instance, the followingrepresentationexample of the Projection Element<xref(<xref target="projection-element"></xref>) and the ProjectionPoseRoll Element represents a video track where the image <bcp14>SHOULD</bcp14> be presented with a 90-degree counter-clockwise rotation, with the EBML tree shown asXML :</t>XML:</t> <figure><name>Rotationexample.Example </name> <sourcecode type="xml"><Projection> <ProjectionPoseRoll>90</ProjectionPoseRoll> </Projection> </sourcecode> </figure> </section> </section> <section anchor="segment-position"><name>Segment Position</name> <t>The <tt>Segment Position</tt> of an <tt>Element</tt> refers to the position of the first octet of the <tt>Element ID</tt> of that <tt>Element</tt>, measured in octets, from the beginning of the <tt>Element Data</tt> section of the containing <tt>Segment Element</tt>. In other words, the <tt>Segment Position</tt> of an <tt>Element</tt> is the distance in octets from the beginning of its containing <tt>Segment Element</tt> minus the size of the <tt>Element ID</tt> and <tt>Element Data Size</tt> of that <tt>Segment Element</tt>. The <tt>Segment Position</tt> of the first <tt>Child Element</tt> of the <tt>Segment Element</tt> is 0. An <tt>Element</tt>whichthat is not stored within a <tt>Segment Element</tt>, such as the <tt>Elements</tt> of the <tt>EBML Header</tt>, do not have a <tt>Segment Position</tt>.</t> <section anchor="segment-position-exception"><name>Segment Position Exception</name> <t><tt>Elements</tt> that are defined to store a <tt>Segment Position</tt> <bcp14>MAY</bcp14> define reserved values to indicate a special meaning.</t> </section> <section anchor="example-of-segment-position"><name>Example of Segment Position</name> <t>This table presents an example of <tt>Segment Position</tt> by showing a hexadecimal representation of a very small Matroska file with labels to show the offsets in octets. The file contains a <tt>Segment Element</tt> with an <tt>Element ID</tt> of"0x18538067""0x18538067" and a <tt>MuxingApp Element</tt> with an <tt>Element ID</tt> of"0x4D80".</t>"0x4D80".</t> <artwork> 0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ 0 |1A|45|DF|A3|8B|42|82|88|6D|61|74|72|6F|73|6B|61| ^ EBML Header 0 | |18|53|80|67| ^ Segment ID 20 |93| ^ Segment Data Size 20 | |15|49|A9|66|8E|4D|80|84|69|65|74|66|57|41|84|69|65|74|66| ^ Start of Segment data 20 | |4D|80|84|69|65|74|66|57|41|84|69|65|74|66| ^ MuxingApp start </artwork> <t>In the above example, the <tt>Element ID</tt> of the <tt>Segment Element</tt> is stored at offset 16, the <tt>Element Data Size</tt> of the <tt>Segment Element</tt> is stored at offset 20, and the <tt>Element Data</tt> of the <tt>Segment Element</tt> is stored at offset 21.</t> <t>The <tt>MuxingApp Element</tt> is stored at offset 26. Since the <tt>Segment Position</tt> of an <tt>Element</tt> is calculated by subtracting the position of the <tt>Element Data</tt> of the containing <tt>Segment Element</tt> from the position of that <tt>Element</tt>, the <tt>Segment Position</tt> of the <tt>MuxingApp Element</tt> in the above example is'26"26 -21'21" or'5'.</t>"5".</t> </section> </section> <section anchor="linked-segments"><name>Linked Segments</name> <t>Matroska provides several methods to link two or more <tt>Segment Elements</tt> together to create a <tt>Linked Segment</tt>. A <tt>Linked Segment</tt> is a set of multiple <tt>Segments</tt> linked together into a single presentation by using Hard Linking or Medium Linking.</t> <t>All <tt>Segments</tt> within a <tt>Linked Segment</tt> <bcp14>MUST</bcp14> have a <tt>SegmentUUID</tt>.</t> <t>All <tt>Segments</tt> within a <tt>Linked Segment</tt> <bcp14>SHOULD</bcp14> be stored within the same directory or beaccessiblequickly accessible based on their <tt>SegmentUUID</tt> in order to have a seamless transition between segments.</t> <t>All <tt>Segments</tt> within a <tt>Linked Segment</tt> <bcp14>MAY</bcp14> set a <tt>SegmentFamily</tt> with a common value to make it easier for a <tt>Matroska Player</tt> to know which <tt>Segments</tt> are meant to be played together.</t> <t>The <tt>SegmentFilename</tt>,<tt>PrevFilename</tt><tt>PrevFilename</tt>, and <tt>NextFilename</tt> elements <bcp14>MAY</bcp14> also give hints on the original filenames that were used when the Segment links were created, in case some<tt>SegmentUUID</tt><tt>SegmentUUIDs</tt> are damaged.</t> <section anchor="hard-linking"><name>Hard Linking</name> <t>Hard Linking, also calledsplitting,"splitting", is the process of creating a <tt>Linked Segment</tt> by linking multiple <tt>Segment Elements</tt> using the <tt>NextUUID</tt> and <tt>PrevUUID</tt> Elements.</t> <t>All <tt>Segments</tt> within a <tt>Hard Linked Segment</tt> <bcp14>MUST</bcp14> use the same <tt>Tracks</tt> list and <tt>TimestampScale</tt>.</t> <t>Within a <tt>Linked Segment</tt>, the timestamps of <tt>Block</tt> and <tt>SimpleBlock</tt> <bcp14>MUST</bcp14>followconsecutively follow the timestamps of <tt>Block</tt> and <tt>SimpleBlock</tt> from the previous <tt>Segment</tt> in linking order.</t> <t>With Hard Linking, the chapters of any <tt>Segment</tt> within the <tt>Linked Segment</tt> <bcp14>MUST</bcp14> only reference the current <tt>Segment</tt>. The <tt>NextUUID</tt> and <tt>PrevUUID</tt> reference the respective <tt>SegmentUUID</tt> values of the next and previous <tt>Segments</tt>.</t> <t>The first <tt>Segment</tt> of a <tt>Linked Segment</tt> <bcp14>MUST NOT</bcp14> have a <tt>PrevUUID Element</tt>. The last <tt>Segment</tt> of a <tt>Linked Segment</tt> <bcp14>MUST NOT</bcp14> have a <tt>NextUUID Element</tt>.</t> <t>For each node of the chain of <tt>Segments</tt> of a <tt>LinkedSegment</tt>Segment</tt>, at least one <tt>Segment</tt> <bcp14>MUST</bcp14> reference the other <tt>Segment</tt> within the chain.</t> <t>In a chain of <tt>Segments</tt> of a <tt>LinkedSegment</tt>Segment</tt>, the <tt>NextUUID</tt> always takes precedence over the <tt>PrevUUID</tt>.SoThus, if SegmentA has a <tt>NextUUID</tt> to SegmentB and SegmentB has a <tt>PrevUUID</tt> to SegmentC, the link to use is <tt>NextUUID</tt> between SegmentA and SegmentB, and SegmentC is not part of the Linked Segment.</t> <t>If SegmentB has a <tt>PrevUUID</tt> toSegmentASegmentA, but SegmentA has no <tt>NextUUID</tt>, then the Matroska Player <bcp14>MAY</bcp14> consider these two Segments linked as SegmentA followed by SegmentB.</t> <t>As an example, three <tt>Segments</tt> can be Hard Linked as a <tt>Linked Segment</tt> through cross-referencing each other with <tt>SegmentUUID</tt>, <tt>PrevUUID</tt>, and<tt>NextUUID</tt>,<tt>NextUUID</tt> as shown in this table:</t> <table anchor="hardLinkingUIDs"><name>Usual Hard Linking UIDs</name> <thead> <tr> <th align="left">file name</th> <th align="left"><tt>SegmentUUID</tt></th> <th align="left"><tt>PrevUUID</tt></th> <th align="left"><tt>NextUUID</tt></th> </tr> </thead> <tbody> <tr> <td align="left"><tt>start.mkv</tt></td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">Invalid</td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> </tr> <tr> <td align="left"><tt>middle.mkv</tt></td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> </tr> <tr> <td align="left"><tt>end.mkv</tt></td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> <td align="left">Invalid</td> </tr> </tbody> </table><t>Anotherexample where only the <tt>NextUUID</tt> Element is used:</t> <table anchor="hardLinkingWoPrevUUID"><name>Hard Linking without PrevUUID</name> <thead> <tr> <th align="left">file name</th> <th align="left"><tt>SegmentUUID</tt></th> <th align="left"><tt>PrevUUID</tt></th> <th align="left"><tt>NextUUID</tt></th> </tr> </thead> <tbody> <tr> <td align="left"><tt>start.mkv</tt></td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">Invalid</td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> </tr> <tr> <td align="left"><tt>middle.mkv</tt></td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> <td align="left">n/a</td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> </tr> <tr> <td align="left"><tt>end.mkv</tt></td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> <td align="left">n/a</td> <td align="left">Invalid</td> </tr> </tbody> </table><t>An example where only the <tt>PrevUUID</tt> Element is used:</t> <table anchor="hardLinkingWoNextUUID"><name>Hard Linking without NextUUID</name> <thead> <tr> <th align="left">file name</th> <th align="left"><tt>SegmentUUID</tt></th> <th align="left"><tt>PrevUUID</tt></th> <th align="left"><tt>NextUUID</tt></th> </tr> </thead> <tbody> <tr> <td align="left"><tt>start.mkv</tt></td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">Invalid</td> <td align="left">n/a</td> </tr> <tr> <td align="left"><tt>middle.mkv</tt></td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">n/a</td> </tr> <tr> <td align="left"><tt>end.mkv</tt></td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> <td align="left">Invalid</td> </tr> </tbody></table><t>In this</table><t>An example where only the <tt>middle.mkv</tt> is using the <tt>PrevUUID</tt> and <tt>NextUUID</tt> Elements:</t> <table anchor="hardLinkingMixedUIDs"><name>Hard Linking withmixedMixed UIDlinks</name>Links</name> <thead> <tr> <th align="left">file name</th> <th align="left"><tt>SegmentUUID</tt></th> <th align="left"><tt>PrevUUID</tt></th> <th align="left"><tt>NextUUID</tt></th> </tr> </thead> <tbody> <tr> <td align="left"><tt>start.mkv</tt></td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">Invalid</td> <td align="left">n/a</td> </tr> <tr> <td align="left"><tt>middle.mkv</tt></td> <td align="left">a77b3598941cb803 eac0fcdafe44fac9</td> <td align="left">71000c23cd310998 53fbc94dd984a5dd</td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> </tr> <tr> <td align="left"><tt>end.mkv</tt></td> <td align="left">6c92285fa6d3e827 b198d120ea3ac674</td> <td align="left">n/a</td> <td align="left">Invalid</td> </tr> </tbody> </table></section> <section anchor="medium-linking"><name>Medium Linking</name> <t>Medium Linking creates relationships between <tt>Segments</tt> using Ordered Chapters (<xref target="editionflagordered"></xref>) and the <tt>ChapterSegmentUUID Element</tt>. A <tt>Chapter Edition</tt> with Ordered Chapters <bcp14>MAY</bcp14> contain Chapter elements that reference timestamp ranges from other <tt>Segments</tt>. The <tt>Segment</tt> referenced by the Ordered Chapter via the <tt>ChapterSegmentUUID Element</tt> <bcp14>SHOULD</bcp14> be played as part of a Linked Segment.</t> <t>The timestamps of Segment content referenced by Ordered Chapters <bcp14>MUST</bcp14> be adjusted according to the cumulative duration of the previous Ordered Chapters.</t> <t>As anexampleexample, a file named <tt>intro.mkv</tt> could have a <tt>SegmentUUID</tt> of"0xb16a58609fc7e60653a60c984fc11ead"."0xb16a58609fc7e60653a60c984fc11ead". Another file called <tt>program.mkv</tt> could use a Chapter Edition that contains two Ordered Chapters. The first chapter references the <tt>Segment</tt> of <tt>intro.mkv</tt> with the use of a <tt>ChapterSegmentUUID</tt>, <tt>ChapterSegmentEditionUID</tt>, <tt>ChapterTimeStart</tt>, andoptionally aan optional <tt>ChapterTimeEnd</tt> element. The second chapter references content within the <tt>Segment</tt> of <tt>program.mkv</tt>. A <tt>Matroska Player</tt> <bcp14>SHOULD</bcp14> recognize the <tt>Linked Segment</tt> created by the use of <tt>ChapterSegmentUUID</tt> in an enabled <tt>Edition</tt> and present the reference content of the two <tt>Segments</tt> as a single presentation.</t> <t>The <tt>ChapterSegmentUUID</tt> represents the Segment that holds the content to play in place of the <tt>Linked Chapter</tt>. The <tt>ChapterSegmentUUID</tt> <bcp14>MUST NOT</bcp14> be the <tt>SegmentUUID</tt> of its own <tt>Segment</tt>.</t> <t>There are2two ways to use a chapter link:</t> <ul> <li><t>Linked-Durationlinking,</t>linking</t> </li> <li><t>Linked-Edition linking</t> </li> </ul> <section anchor="linked-duration"><name>Linked-Duration</name> <t>A <tt>Matroska Player</tt> <bcp14>MUST</bcp14> play the content of the linked Segment from the <tt>ChapterTimeStart</tt> until the <tt>ChapterTimeEnd</tt> timestamp in place of the <tt>Linked Chapter</tt>.</t> <t><tt>ChapterTimeStart</tt> and <tt>ChapterTimeEnd</tt> represent timestamps in the Linked Segment matching the value of <tt>ChapterSegmentUUID</tt>. Their values <bcp14>MUST</bcp14> be in the range of the linked Segment duration.</t> <t>The <tt>ChapterTimeEnd</tt> value <bcp14>MUST</bcp14> be set when usinglinked-durationLinked-Duration chapter linking. <tt>ChapterSegmentEditionUID</tt> <bcp14>MUST NOT</bcp14> be set.</t> </section> <section anchor="linked-edition"><name>Linked-Edition</name> <t>A <tt>Matroska Player</tt> <bcp14>MUST</bcp14> play the wholelinkedLinked <tt>Edition</tt> of the linked Segment in place of the <tt>Linked Chapter</tt>.</t> <t><tt>ChapterSegmentEditionUID</tt> represents a valid Edition from the Linked Segment matching the value of <tt>ChapterSegmentUUID</tt>.</t> <t>When usinglinked-editionLinked-Edition chapterlinking.linking, <tt>ChapterTimeEnd</tt> is <bcp14>OPTIONAL</bcp14>.</t> </section> </section> </section> <section anchor="track-flags"><name>Track Flags</name> <!-- [rfced] In Sections 18 and 19, would it be helpful for the names of the flags to align more closely with those in Sections 5.1.4.1.4 to 5.1.4.1.11? Or is the current okay? We are specifically asking about the following flags (the others match). Original (in Sections 18 and 19): hearing-impaired flag visual-impaired flag descriptions flag Current: Hearing-Impaired flag Visual-Impaired flag Descriptions flag Perhaps: HearingImpaired flag VisualImpaired flag TextDescriptions flag Note that we see both "default track flag" and "Default flag" in the text. We updated to "Default flag" for consistency. --> <section anchor="default-flag"><name>Defaultflag</name>Flag</name> <t>The"default track"Default flag is a hint for a <tt>Matroska Player</tt> indicating that a given track <bcp14>SHOULD</bcp14> be eligible to be automatically selected as the default track for a given language. If no tracks in a given language have thedefault trackDefault flag set, then all tracks in that language are eligible for automatic selection. This can be used to indicate that a track provides"regular service""regular service" that is suitable for users with default settings, as opposed to specialized services, such as commentary,hearing-impaired captions,captions for users with hearing impairments, or descriptive audio.</t> <t>The <tt>Matroska Player</tt> <bcp14>MAY</bcp14> override the"default track"Default flag for any reason, including user preferences to prefer tracks providing accessibility services.</t> </section> <section anchor="forced-flag"><name>Forcedflag</name>Flag</name> <t>The"forced"Forced flag tells the <tt>Matroska Player</tt> that it <bcp14>SHOULD</bcp14> display this subtitle track, even if user preferences usually would not call for any subtitles to be displayed alongside thecurrent selectedaudiotrack.track that is currently selected. This can be used to indicate that a track contains translations ofonscreen text,on-screen text orofdialogue spoken in a different language than the track's primaryone.</t>language.</t> </section> <sectionanchor="hearing-impaired-flag"><name>Hearing-impaired flag</name>anchor="hearing-impaired-flag"><name>Hearing-Impaired Flag</name> <t>The"hearing impaired"Hearing-Impaired flag tells the <tt>Matroska Player</tt> that it <bcp14>SHOULD</bcp14> prefer this track when selecting a default track for ahearing-impaired user,user with a hearing impairment and that it <bcp14>MAY</bcp14> prefer to select a different track when selecting a default track for anon-hearing-impaired user.</t>user that is not hearing-impaired.</t> </section> <sectionanchor="visual-impaired-flag"><name>Visual-impaired flag</name>anchor="visually-impaired-flag"><name>Visual-Impaired Flag</name> <t>The"visual impaired"Visual-Impaired flag tells the <tt>Matroska Player</tt> that it <bcp14>SHOULD</bcp14> prefer this track when selecting a default track for avisually-impaired user,user with a visual impairment and that it <bcp14>MAY</bcp14> prefer to select a different track when selecting a default track for anon-visually-impaired user.</t>user that is not visually impaired.</t> </section> <section anchor="descriptions-flag"><name>Descriptionsflag</name>Flag</name> <t>The"descriptions"Descriptions flag tells the <tt>Matroska Player</tt> that this track is suitable to play via a text-to-speech system for avisually-impaired user,user with a visual impairment and that it <bcp14>SHOULD NOT</bcp14> automatically select this track when selecting a default track for anon-visually-impaired user.</t>user that is not visually impaired.</t> </section> <section anchor="original-flag"><name>Originalflag</name>Flag</name> <t>The"original"Original flag tells the <tt>Matroska Player</tt> that this track is in the originallanguage,language and that it <bcp14>SHOULD</bcp14> preferitthe original language if configured to prefer original-language tracks of this track's type.</t> </section> <section anchor="commentary-flag"><name>Commentaryflag</name>Flag</name> <t>The"commentary"Commentary flag tells the <tt>Matroska Player</tt> that this track contains commentary on the content.</t> </section> <section anchor="track-operation"><name>Track Operation</name> <t><tt>TrackOperation</tt> allowscombiningfor the combination of multiple tracks to make a virtual one. It uses two separate system to combine tracks. One to create a 3D"composition""composition" (left/right/background planes) and one to simplify join two tracks together to make a single track.</t> <t>A track created with <tt>TrackOperation</tt> is a proper track with a UID and all its flags. However, the codec ID is meaningless because each"sub""sub" track needs to be decoded by its own decoder before the"operation""operation" is applied. The <tt>Cues Elements</tt> corresponding to such a virtual track <bcp14>SHOULD</bcp14> be the union of the <tt>Cues Elements</tt> for each of the tracks it's composed of (when the <tt>Cues</tt> are defined per track).</t> <t>In the case of <tt>TrackJoinBlocks</tt>, the <tt>Block Elements</tt> (from <tt>BlockGroup</tt> and <tt>SimpleBlock</tt>) of all the tracks <bcp14>SHOULD</bcp14> be used as if they were defined for this new virtual <tt>Track</tt>. When two <tt>Block Elements</tt> have overlapping start or end timestamps, it's up to the underlying system to either drop some of these frames or render them the way they overlap. This situation <bcp14>SHOULD</bcp14> be avoided when creating suchtrackstracks, as you can never be sure of the end result on different platforms.</t> </section> <section anchor="overlay-track"><name>Overlay Track</name> <!-- [rfced] The noun ("tracks") is plural, but the pronoun ("it's") is singular. Which of the following options is the best way to fix this agreement issue? Original: Overlay tracks SHOULD be rendered in the same channel as the track it's linked to. Perhaps (both plural): Overlay tracks SHOULD be rendered in the same channel as the track they are linked to. Or (both singular): An overlay track SHOULD be rendered in the same channel as the track it's linked to. --> <t>Overlay tracks <bcp14>SHOULD</bcp14> be rendered in the same channel as the track it's linked to. When content is found in such a track, it <bcp14>SHOULD</bcp14> be played on the rendering channel instead of the original track.</t> </section> <section anchor="multi-planar-and-3d-videos"><name>Multi-planar and 3Dvideos</name>Videos</name> <t>There are two different ways to compress 3D videos: have each eye track in a separate track and have one track have both eyes combined inside (which is moreefficient,efficient compression-wise). Matroska supports both ways.</t> <t>For thesingle tracksingle-track variant, there is the <tt>StereoMode Element</tt>, which defines how planes are assembled in the track (mono or left-right combined). Odd values of StereoMode means the left plane comes first for more convenient reading. The pixel count of the track (<tt>PixelWidth</tt>/<tt>PixelHeight</tt>) is the rawamountnumber ofpixels, for examplepixels (for example, 3840x1080 for full HD side byside,side), and the <tt>DisplayWidth</tt>/<tt>DisplayHeight</tt> in pixels is theamountnumber of pixels for one plane (1920x1080 for that full HD stream). <!-- [rfced] Would it be helpful to update "Old stereo 3D" to "Old stereo 3D movies" or something similar? Original: Old stereo 3D were displayed using anaglyph (cyan and red colors separated).For compatibility with such movies, there is a value of the StereoModePerhaps: Old stereo 3D movies were displayed using anaglyph (cyan and red colors separated). --> Old stereo 3D were displayed using anaglyph (cyan and red colors separated). For compatibility with such movies, there is a value of the StereoMode that corresponds to AnaGlyph.</t> <t>There is also a"packed""packed" mode (values 13 and 14)whichthat consists of packing two frames together in a <tt>Block</tt>usingthat uses lacing. The first frame is the left eye and the other frame is the right eye (or vice versa). The frames <bcp14>SHOULD</bcp14> be decoded in that order and are possibly dependent on each other (P and B frames).</t> <t>For separate tracks, Matroska needs to define exactly which track does what. <tt>TrackOperation</tt> with <tt>TrackCombinePlanes</tt>dodoes that. For moredetails look atdetails, see <xref target="track-operation"></xref> on how TrackOperation works.</t> <t>The 3D support is still in infancy and may evolve to support more features.</t> <t>The StereoMode used to be part of Matroskav2v2, but it didn't meet the requirement for multiple tracks. There was also a bug in libmatroska prior to 0.9.0 that would save/read it as <tt>0x53B9</tt> instead of <tt>0x53B8</tt>; see OldStereoMode (<xref target="oldstereomode-element"></xref>). <tt>Matroska Readers</tt> <bcp14>MAY</bcp14> support these legacy files by checking Matroska v2 or <tt>0x53B9</tt>. The older values of StereoMode were0: mono, 1: right eye, 2: left eye, 3: both eyes,0 (mono), 1 (right eye), 2 (left eye), and 3 (both eyes); these are the only values that can be found in OldStereoMode. They are not compatible with the StereoMode values found in Matroska v3 and above.</t> </section> </section> <section anchor="default-track-selection"><name>Defaulttrack selection</name>Track Selection</name> <t>This section provides some example sets of Tracks and hypothetical user settings, along with indications of which ones asimilarly-configuredsimilarly configured <tt>Matroska Player</tt> <bcp14>SHOULD</bcp14> automatically select for playback by default in such a situation. A player <bcp14>MAY</bcp14> provide additional settings with more detailed controls for more nuanced scenarios. These examples are provided as guidelines to illustrate the intended usages of the various supported Trackflags,flags and their expected behaviors.</t> <t>Track names are shown in English for illustrative purposes; actual files may have titles in the language of eachtrack,track or provide titles in multiple languages.</t> <section anchor="audio-selection"><name>Audio Selection</name> <t>Example track set:</t> <table anchor="audioTrackSelection"><name>Audio Tracks fordefault selection</name>Default Selection</name> <thead> <tr> <th>No.</th> <th>Type</th> <th>Lang</th> <th>Layout</th> <th>Original</th> <th>Default</th> <th>Otherflags</th>Flags</th> <th>Name</th> </tr> </thead> <tbody> <tr> <td>1</td> <td>Video</td> <td>und</td> <td>N/A</td> <td>N/A</td> <td>N/A</td> <td>None</td> <td></td> </tr> <tr> <td>2</td> <td>Audio</td> <td>eng</td> <td>5.1</td> <td>1</td> <td>1</td> <td>None</td> <td></td> </tr> <tr> <td>3</td> <td>Audio</td> <td>eng</td> <td>2.0</td> <td>1</td> <td>1</td> <td>None</td> <td></td> </tr> <tr> <td>4</td> <td>Audio</td> <td>eng</td> <td>2.0</td> <td>1</td> <td>0</td><td>Visual-impaired</td><td>Visual-Impaired</td> <td>Descriptive audio</td> </tr> <tr> <td>5</td> <td>Audio</td> <td>esp</td> <td>5.1</td> <td>0</td> <td>1</td> <td>None</td> <td></td> </tr> <tr> <td>6</td> <td>Audio</td> <td>esp</td> <td>2.0</td> <td>0</td> <td>0</td><td>Visual-impaired</td><td>Visual-Impaired</td> <td>Descriptive audio</td> </tr> <tr> <td>7</td> <td>Audio</td> <td>eng</td> <td>2.0</td> <td>1</td> <td>0</td> <td>Commentary</td> <td>Director's Commentary</td> </tr> <tr> <td>8</td> <td>Audio</td> <td>eng</td> <td>2.0</td> <td>1</td> <td>0</td> <td>None</td> <td>Karaoke</td> </tr> </tbody></table><t>Here we have</table><t>The table above shows a file with7seven audiotracks, of which 5 aretracks -- five in English and2 aretwo in Spanish.</t> <t>The English tracks all have the Original flag, indicating that English is the original content language.</t><t>Generally<t>Generally, the player will first consider the tracklanguages: iflanguages. If the player has an option to prefer original-language audio and the user has enabled it, then it should prefer one of theOriginal-flagged tracks.tracks with the Original flag. <!-- [rfced] Please review "If configured to specifically prefer" here. What is configured? Original: If configured to specifically prefer audio tracks in English or Spanish, the player should select one of the tracks in the corresponding language. Perhaps: If the user has configured to specifically prefer audio tracks in English or Spanish, the player should select one of the tracks in the corresponding language. --> If configured to specifically prefer audio tracks in English or Spanish, the player should select one of the tracks in the corresponding language. The player may also wish to preferan Original-flaggeda track with the Original flag if no tracks matching any of the user'sexplicitly-preferredexplicitly preferred languages are available.</t> <t>Two of the tracks have theVisual-impairedVisual-Impaired flag. If the player has been configured to prefer such tracks, it should select one; otherwise, it should avoid them if possible.</t> <t>If selecting an English track, when other settings have left multiple possible options, it may be useful to exclude the tracks that lack the Defaultflag: here,flag. Here, one provides descriptive service forthe visually impairedindividuals with visual impairments (which has its own flag and may be automatically selected by userconfiguration,configuration but is unsuitable for users with default-configured players), one is a commentary track (which has its ownflag, whichflag and the player may or may not have specialized handling for), and the last contains karaoke versions of the music that plays during thefilm, whichfilm (which is an unusual specialized audio service that Matroska has no built-in support for indicating, so it's indicated in the track nameinstead.instead). By not setting the Default flag on these specialized tracks, the file's author hints that they should not be automatically selected by a default-configured player.</t> <t>Having narrowed its choices down,ourthe example player now may have to select between tracks 2 and 3. The only difference between these tracks is their channel layouts: 2 is 5.1 surround, while 3 is stereo. If the player is aware that the output device is a pair of headphones or stereo speakers, it may wish to prefer the stereo mix automatically. On the other hand, if it knows that the device is a surround system, it may wish to prefer the surround mix.</t> <t>If the player finishes analyzing all of the available audio tracks and finds thatmultiple seemsmore than one seem equally and maximally preferable, it <bcp14>SHOULD</bcp14> default to the first of the group.</t> </section> <section anchor="subtitle-selection"><name>Subtitleselection</name>Selection</name> <t>Example track set:</t> <table anchor="subtitleTrackSelection"><name>Subtitle Tracks fordefault selection</name>Default Selection</name> <thead> <tr> <th>No.</th> <th>Type</th> <th>Lang</th> <th>Original</th> <th>Default</th> <th>Forced</th> <th>Other flags</th> <th>Name</th> </tr> </thead> <tbody> <tr> <td>1</td> <td>Video</td> <td>und</td> <td>N/A</td> <td>N/A</td> <td>N/A</td> <td>None</td> <td></td> </tr> <tr> <td>2</td> <td>Audio</td> <td>fra</td> <td>1</td> <td>1</td> <td>N/A</td> <td>None</td> <td></td> </tr> <tr> <td>3</td> <td>Audio</td> <td>por</td> <td>0</td> <td>1</td> <td>N/A</td> <td>None</td> <td></td> </tr> <tr> <td>4</td> <td>Subtitles</td> <td>fra</td> <td>1</td> <td>1</td> <td>0</td> <td>None</td> <td></td> </tr> <tr> <td>5</td> <td>Subtitles</td> <td>fra</td> <td>1</td> <td>0</td> <td>0</td><td>Hearing-impaired</td><td>Hearing-Impaired</td> <td>Captions forthe hearing-impaired</td>users with hearing impairments</td> </tr> <tr> <td>6</td> <td>Subtitles</td> <td>por</td> <td>0</td> <td>1</td> <td>0</td> <td>None</td> <td></td> </tr> <tr> <td>7</td> <td>Subtitles</td> <td>por</td> <td>0</td> <td>0</td> <td>1</td> <td>None</td> <td>Signs</td> </tr> <tr> <td>8</td> <td>Subtitles</td> <td>por</td> <td>0</td> <td>0</td> <td>0</td><td>Hearing-impaired</td><td>Hearing-Impaired</td> <td>SDH</td> </tr> </tbody></table><t>Here we have 2</table><t>The table above shows two audio tracks and5five subtitle tracks. As we can see, French is the original language.</t> <t>We'll start by discussing the case where the user prefers French (orOriginal-language)original-language) audio (or has explicitly selected the French audiotrack),track) and also prefers French subtitles.</t> <t>In this case, if the player isn't configured to display captions when the audio matches their preferred subtitle languages, the player doesn't need to select a subtitle track at all.</t> <t>If the user <em>has</em> indicated that they want captions to be displayed, the selection simply comes down to whetherHearing-impairedhearing-impaired subtitles are preferred.</t> <t>The situation for a user who prefers Portuguese subtitles starts out somewhat analogous. If they select the original French audio (either by explicit audio language preference, preference forOriginal-languageoriginal-language tracks, orbyexplicitly selecting that track), then the selection once again comes down to the hearing-impaired preference.</t> <t>However, the case where the Portuguese audio track is selected has an important catch: a Forced track in Portuguese is present. This may contain translations ofonscreenon-screen text from the videotrack,track or of portions of the audio that are not translated (music, for instance). This means that even if the user's preferences wouldn't normally call for captions here, the Forced track should be selected nonetheless, rather than selecting no track at all. On the other hand, if the user's preferences <em>do</em> call for captions, the non-Forced tracks should be preferred, as the Forced track will not contain captioning for the dialogue.</t> </section> </section> <section anchor="chapters"><name>Chapters</name> <t>The Matroska Chapters system can have multiple<tt>Editions</tt><tt>Editions</tt>, and each <tt>Edition</tt> can consist of <tt>Simple Chapters</tt> where a chapter start time is used as a marker in the timeline only. An <tt>Edition</tt> can be more complex with <tt>Ordered Chapters</tt> where a chapter endtime stamptimestamp is additionally used or much more complex with <tt>Linked Chapters</tt>. The Matroska Chapters system can also have a menustructure,structure borrowed from theDVD menuDVD-menu system <xreftarget="DVD-Video"></xref>,target="DVD-Video"></xref> or have its own built-in Matroska menu structure.</t> <section anchor="editionentry"><name>EditionEntry</name> <t>The <tt>EditionEntry</tt> is also called an <tt>Edition</tt>. An <tt>Edition</tt> contains a set of <tt>Edition</tt> flags and <bcp14>MUST</bcp14> contain at least one <tt>ChapterAtom Element</tt>. Chapters are always inside an <tt>Edition</tt> (or a Chapter itself is part of an <tt>Edition</tt>). Multiple Editions are allowed. Some of these Editions <bcp14>MAY</bcp14> be ordered and others not.</t> <section anchor="editionflagdefault"><name>EditionFlagDefault</name> <t>Only one <tt>Edition</tt> <bcp14>SHOULD</bcp14> have an <tt>EditionFlagDefault</tt> flag set to <tt>true</tt>.</t> </section> <section anchor="default-edition"><name>Default Edition</name> <t>The <tt>Default Edition</tt> is the <tt>Edition</tt> that a <tt>Matroska Player</tt> <bcp14>SHOULD</bcp14> use for playback by default.</t> <t>The first <tt>Edition</tt> with the <tt>EditionFlagDefault</tt> flag set to <tt>true</tt> is the <tt>Default Edition</tt>.</t> <t>When all <tt>EditionFlagDefault</tt> flags are set to <tt>false</tt>, then the first <tt>Edition</tt> is the <tt>Default Edition</tt>.</t> <table anchor="defaultEditionAllDefault"><name>Defaultedition, all default</name>Edition, All Default</name> <thead> <tr> <th align="left">Edition</th> <th align="left">FlagDefault</th> <th align="left">Default Edition</th> </tr> </thead> <tbody> <tr> <td align="left">Edition 1</td> <td align="left">true</td> <td align="left">X</td> </tr> <tr> <td align="left">Edition 2</td> <td align="left">true</td> <td align="left"></td> </tr> <tr> <td align="left">Edition 3</td> <td align="left">true</td> <td align="left"></td> </tr> </tbody> </table><table anchor="defaultEditionNoDefault"><name>Defaultedition, no default</name>Edition, No Default</name> <thead> <tr> <th align="left">Edition</th> <th align="left">FlagDefault</th> <th align="left">Default Edition</th> </tr> </thead> <tbody> <tr> <td align="left">Edition 1</td> <td align="left">false</td> <td align="left">X</td> </tr> <tr> <td align="left">Edition 2</td> <td align="left">false</td> <td align="left"></td> </tr> <tr> <td align="left">Edition 3</td> <td align="left">false</td> <td align="left"></td> </tr> </tbody> </table><table anchor="defaultEditionWithDefault"><name>Defaultedition, with default</name>Edition, With Default</name> <thead> <tr> <th align="left">Edition</th> <th align="left">FlagDefault</th> <th align="left">Default Edition</th> </tr> </thead> <tbody> <tr> <td align="left">Edition 1</td> <td align="left">false</td> <td align="left"></td> </tr> <tr> <td align="left">Edition 2</td> <td align="left">true</td> <td align="left">X</td> </tr> <tr> <td align="left">Edition 3</td> <td align="left">false</td> <td align="left"></td> </tr> </tbody> </table></section> <section anchor="editionflagordered"><name>EditionFlagOrdered</name> <t>The<tt>EditionFlagOrdered Flag</tt><tt>EditionFlagOrdered</tt> flag is a significantfeaturefeature, as it enables an <tt>Edition</tt> of <tt>Ordered Chapters</tt>whichthat defines and arranges a virtual timeline rather than simply labeling points within the timeline. For example, with <tt>Editions</tt> of <tt>OrderedChapters</tt>Chapters</tt>, a single <tt>Matroska file</tt> can present multiple edits of a film without duplicating content. Alternatively, if a videotape is digitized in full, one <tt>Ordered Edition</tt> could present the full content (including colorbars, countdown, slate, a feature presentation, and black frames), while another <tt>Edition</tt> of <tt>Ordered Chapters</tt> can use <tt>Chapters</tt> that only mark the intended presentation with the colorbars and other ancillary visual information excluded. If an <tt>Edition</tt> of <tt>Ordered Chapters</tt> is enabled, then the <tt>Matroska Player</tt> <bcp14>MUST</bcp14> play those Chapters in their stored order from the timestamp marked in the <tt>ChapterTimeStart Element</tt> to the timestamp marked in to <tt>ChapterTimeEnd Element</tt>.</t> <t>If the<tt>EditionFlagOrdered Flag</tt><tt>EditionFlagOrdered</tt> flag evaluates to"0","0", <tt>Simple Chapters</tt> are used and only the <tt>ChapterTimeStart</tt> of a <tt>Chapter</tt> is used as a chapter mark to jump to the predefined point in the timeline. With <tt>Simple Chapters</tt>, a <tt>Matroska Player</tt> <bcp14>MUST</bcp14> ignore certain <tt>Chapter Elements</tt>. In thatcasecase, these elements are informational only.</t> <t>The following list shows the different Chapter elements only found in <tt>Ordered Chapters</tt>.</t><table anchor="orderedOnly"><name>elements only found in ordered chapters</name> <thead> <tr> <th align="left">Ordered Chapter elements</th> </tr> </thead> <tbody> <tr> <td align="left">ChapterAtom/ChapterSegmentUUID</td> </tr> <tr> <td align="left">ChapterAtom/ChapterSegmentEditionUID</td> </tr> <tr> <td align="left">ChapterAtom/ChapterTrack</td> </tr> <tr> <td align="left">ChapterAtom/ChapProcess</td> </tr> <tr> <td align="left">Info/ChapterTranslate</td> </tr> <tr> <td align="left">TrackEntry/TrackTranslate</td> </tr> </tbody> </table><t>Furthermore,<ul> <li>ChapterAtom/ChapterSegmentUUID</li> <li>ChapterAtom/ChapterSegmentEditionUID</li> <li>ChapterAtom/ChapterTrack</li> <li>ChapterAtom/ChapProcess</li> <li>Info/ChapterTranslate</li> <li>TrackEntry/TrackTranslate</li> </ul> <t>Furthermore, there are other EBML <tt>Elements</tt>whichthat could be used if the <tt>EditionFlagOrdered</tt> evaluates to"1".</t>"1".</t> <section anchor="ordered-edition-and-matroska-segment-linking"><name>Ordered-Edition and MatroskaSegment-Linking</name> <ul> <li><t>Hard Linking: <tt>Ordered-Chapters</tt> supersedesSegment Linking</name> <dl> <dt>Hard Linking:</dt><dd><tt>Ordered Chapters</tt> supersede the <tt>HardLinking</tt>.</t> </li> <li><t>Medium Linking: <tt>OrderedLinking</tt>.</dd> <dt>Medium Linking:</dt><dd><tt>Ordered Chapters</tt> are used in a normal way and can be combined with the <tt>ChapterSegmentUUID</tt>elementelement, which establishes a link to anotherSegment.</t> </li> </ul>Segment.</dd> </dl> <t>See <xref target="linked-segments"></xref> ontheLinked Segments for more information about <tt>Hard Linking</tt> and <tt>Medium Linking</tt>.</t> </section> </section> </section> <section anchor="chapteratom"><name>ChapterAtom</name> <t>The <tt>ChapterAtom</tt> is also called a <tt>Chapter</tt>.</t> <section anchor="chaptertimestart"><name>ChapterTimeStart</name><t>The<t><tt>ChapterTimeStart</tt> is the timestamp of the start of <tt>Chapter</tt> with nanosecondaccuracy,accuracy and is not scaled by TimestampScale. For <tt>SimpleChapters</tt>Chapters</tt>, this is the position of the chapter markers in the timeline.</t> </section> <section anchor="chaptertimeend"><name>ChapterTimeEnd</name><t>The<t><tt>ChapterTimeEnd</tt> is the timestamp of the end of <tt>Chapter</tt> with nanosecondaccuracy,accuracy and is not scaled by TimestampScale. The timestamp defined by the <tt>ChapterTimeEnd</tt> is not part of the <tt>Chapter</tt>. A <tt>Matroska Player</tt> calculates the duration of this <tt>Chapter</tt> using the difference between the <tt>ChapterTimeEnd</tt> and <tt>ChapterTimeStart</tt>. The end timestamp <bcp14>MUST</bcp14> be greater than or equal to the start timestamp.</t> <t>When the <tt>ChapterTimeEnd</tt> timestamp is equal to the <tt>ChapterTimeStart</tt> timestamp, thetimestampstimestamp is included in the <tt>Chapter</tt>. It can be useful to put markers in a file or add chapter commands with ordered chapter commands without having to play anything; see <xref target="chapprocess-element"></xref>.</t> <table anchor="ChapterTimeEndUsage"><name>ChapterTimeEndusage possibilities</name>Usage Possibilities</name> <thead> <tr> <th align="left">Chapter</th> <th align="left">Start timestamp</th> <th align="left">End timestamp</th> <th align="left">Duration</th> </tr> </thead> <tbody> <tr> <td align="left">Chapter 1</td> <td align="left">0</td> <td align="left">1000000000</td> <td align="left">1000000000</td> </tr> <tr> <td align="left">Chapter 2</td> <td align="left">1000000000</td> <td align="left">5000000000</td> <td align="left">4000000000</td> </tr> <tr> <td align="left">Chapter 3</td> <td align="left">6000000000</td> <td align="left">6000000000</td> <td align="left">0</td> </tr> <tr> <td align="left">Chapter 4</td> <td align="left">9000000000</td> <td align="left">8000000000</td> <td align="left">Invalid (-1000000000)</td> </tr> </tbody> </table></section> <section anchor="nested-chapters"><name>Nested Chapters</name> <t>A <tt>ChapterAtom</tt> element can contain other <tt>ChapterAtom</tt> elements. That element is a <tt>ParentChapter</tt>Chapter</tt>, and the <tt>ChapterAtom</tt> elements it contains are <tt>Nested Chapters</tt>.</t> <t>Nested Chapters can be useful to tag small parts of a Segment that already have tags or add Chapter Codec commands on smaller parts of a Segment that already have Chapter Codec commands.</t> <t>The <tt>ChapterTimeStart</tt> of a <tt>Nested Chapter</tt> <bcp14>MUST</bcp14> be greater than or equal to the <tt>ChapterTimeStart</tt> of its <tt>Parent Chapter</tt>.</t> <t>If the <tt>Parent Chapter</tt> of a <tt>Nested Chapter</tt> has a <tt>ChapterTimeEnd</tt>, the <tt>ChapterTimeStart</tt> of that <tt>Nested Chapter</tt> <bcp14>MUST</bcp14> be smaller than or equal to the <tt>ChapterTimeEnd</tt> of the <tt>Parent Chapter</tt>.</t> </section> <section anchor="nested-chapters-in-ordered-chapters"><name>Nested Chapters in Ordered Chapters</name> <t>The <tt>ChapterTimeEnd</tt> of the lowest level of <tt>Nested Chapters</tt> <bcp14>MUST</bcp14> be set for Ordered Chapters.</t> <t>When used with Ordered Chapters, the <tt>ChapterTimeEnd</tt> value of a <tt>Parent Chapter</tt> is useless forplaybackplayback, as the proper playback sections are described in its <tt>Nested Chapters</tt>. The <tt>ChapterTimeEnd</tt> <bcp14>SHOULD NOT</bcp14> be set in <tt>Parent Chapters</tt> and <bcp14>MUST</bcp14> be ignored for playback.</t> </section> <section anchor="chapterflaghidden"><name>ChapterFlagHidden</name><t>Each<!-- [rfced] Please review "Chapter ChapterFlagHidden flag" and "Parent Chapter<tt>ChapterFlagHidden</tt>ChapterFlagHidden flag". Will these be clear for readers? Would updating to use a possessive be helpful? Original: Each Chapter ChapterFlagHidden flag works independently of parent chapters. A Nested Chapter with a ChapterFlagHidden that evaluates to "0" remains visible in the user interface even if the Parent Chapter ChapterFlagHidden flag is set to "1". Perhaps: Each Chapter's ChapterFlagHidden flag works independently of Parent Chapters. A Nested Chapter with a ChapterFlagHidden flag that evaluates to "0" remains visible in the user interface even if the Parent Chapter's ChapterFlagHidden flag is set to "1". --> <t>Each Chapter <tt>ChapterFlagHidden</tt> flag works independently of Parent Chapters. A <tt>Nested Chapter</tt> with a <tt>ChapterFlagHidden</tt> flag that evaluates to"0""0" remains visible in the user interface even if the <tt>Parent Chapter</tt> <tt>ChapterFlagHidden</tt> flag is set to"1".</t>"1".</t> <table anchor="ChapterFlagHiddenNested"><name>ChapterFlagHiddennested visibility</name>Nested Visibility</name> <thead> <tr> <th align="left">Chapter + Nested Chapter</th> <th align="left">ChapterFlagHidden</th> <th align="left">visible</th> </tr> </thead> <tbody> <tr> <td align="left">Chapter 1</td> <td align="left">0</td> <td align="left">yes</td> </tr> <tr> <td align="left">Nested Chapter 1.1</td> <td align="left">0</td> <td align="left">yes</td> </tr> <tr> <td align="left">Nested Chapter 1.2</td> <td align="left">1</td> <td align="left">no</td> </tr> <tr> <td align="left">Chapter 2</td> <td align="left">1</td> <td align="left">no</td> </tr> <tr> <td align="left">Nested Chapter 2.1</td> <td align="left">0</td> <td align="left">yes</td> </tr> <tr> <td align="left">Nested Chapter 2.2</td> <td align="left">1</td> <td align="left">no</td> </tr> </tbody> </table></section> </section> <section anchor="menu-features"><name>Menufeatures</name>Features</name> <t>The menu features are handled like a <tt>chapter codec</tt>. That means each codec has a type, some privatedatadata, and some data in the chapters.</t> <t>The type of the menu system is defined by the <tt>ChapProcessCodecID</tt> parameter. <!-- [rfced] Will readers understand the use of "idem" here? Would it be helpful to update as follows (or something similar)? Original: The private data depend on the type of menu system (stored in ChapProcessPrivate), idem for the data in the chapters (stored in ChapProcessData). Perhaps: The private data depend on the type of menu system (stored in ChapProcessPrivate), which is the same for the data in the chapters (stored in ChapProcessData). Or: The private data depend on the type of menu system (stored in ChapProcessPrivate); the same is true for the data in the chapters (stored in ChapProcessData). --> For now, only2two values aresupported :supported: 0matroska script,(Matroska Script) and 1menu(menu borrowed from the DVD <xreftarget="DVD-Video"></xref>.target="DVD-Video"></xref>). The private data depend on the type of menu system (stored in <tt>ChapProcessPrivate</tt>), idem for the data in the chapters (stored in <tt>ChapProcessData</tt>).</t> <t>The menu system, as well as Chapter Codecs in general, candoperform actions on the <tt>MatroskaPlayer</tt> likePlayer</tt>, such as jumping to another Chapter or Edition, selecting differenttrackstracks, and possibly more. The scope of all the possibilities of Chapter Codecs is not covered in thisdocumentdocument, as it depends on the Chapter Codec features and its integration in a <tt>Matroska Player</tt>.</t> </section> <section anchor="physical-types"><name>Physical Types</name> <t>Each level can have different meanings for audio and video. The <tt>ORIGINAL_MEDIA_TYPE</tt> tag <xreftarget="MatroskaTags"></xref>target="I-D.ietf-cellar-tags"></xref> can be used to specify a string for ChapterPhysicalEquiv = 60. Here is the list of possible levels for both audio and video:</t> <table anchor="ChapterPhysicalEquivMeaning"><name>ChapterPhysicalEquivmeaningMeaning pertrack type</name>Track Type</name> <thead> <tr> <th align="left">Value</th> <th align="left">Audio</th> <th align="left">Video</th> <th align="left">Comment</th> </tr> </thead> <tbody> <tr> <td align="left">70</td> <td align="left">SET / PACKAGE</td> <td align="left">SET / PACKAGE</td> <td align="left">the collection of different media</td> </tr> <tr> <td align="left">60</td> <td align="left">CD /12"12" /10"10" /7"7" / TAPE / MINIDISC / DAT</td> <td align="left">DVD / VHS / LASERDISC</td> <td align="left">the physical medium like a CD or a DVD</td> </tr> <tr> <td align="left">50</td> <td align="left">SIDE</td> <td align="left">SIDE</td> <td align="left">when the original medium (LP/DVD) has different sides</td> </tr> <tr> <td align="left">40</td> <td align="left">-</td> <td align="left">LAYER</td> <td align="left">another physical level on DVDs</td> </tr> <tr> <td align="left">30</td> <td align="left">SESSION</td> <td align="left">SESSION</td> <td align="left">as found on CDs and DVDs</td> </tr> <tr> <td align="left">20</td> <td align="left">TRACK</td> <td align="left">-</td> <td align="left">as found on audio CDs</td> </tr> <tr> <td align="left">10</td> <td align="left">INDEX</td> <td align="left">-</td> <td align="left">the first logical level of the side/medium</td> </tr> </tbody> </table></section> <section anchor="chapter-examples"><name>Chapter Examples</name> <section anchor="example-1-basic-chaptering"><name>Example1 : basic chaptering</name>1: Basic Chaptering</name> <t>In thisexampleexample, a movie is split in different chapters. It could also just be an audio file (album)onin which each track corresponds to a chapter.</t> <ul spacing="compact"> <li>00000 ms - 05000ms :ms: Intro</li> <li>05000 ms - 25000ms :ms: Before the crime</li> <li>25000 ms - 27500ms :ms: The crime</li> <li>27500 ms - 38000ms :ms: The killer arrested</li> <li>38000 ms - 43000ms :ms: Credits</li> </ul><t>This<!-- [rfced] How may we clarify this sentence? Note that this sentence appears twice in the document. Original: This would translate in the following matroska form, with the EBML tree shown as XML:</t>: Perhaps: This translates to Matroska form, with the EBML tree shown as follows in XML: --> <!-- [rfced] We see "The killer arrested" in the bulleted list below but not in the XML following this list. The XML has "After the crime" (in both English and French). Please review and let us know if any updates are needed. Current: * 00000 ms - 05000 ms: Intro * 05000 ms - 25000 ms: Before the crime * 25000 ms - 27500 ms: The crime * 27500 ms - 38000 ms: The killer arrested * 38000 ms - 43000 ms: Credits --> <t>This would translate in the following Matroska form, with the EBML tree shown as XML:</t> <figure><name>Basic ChaptersExample.Example </name> <sourcecode type="xml"><Chapters> <EditionEntry> <EditionUID>16603393396715046047</EditionUID> <ChapterAtom> <ChapterUID>1193046</ChapterUID> <ChapterTimeStart>0</ChapterTimeStart> <ChapterTimeEnd>5000000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Intro</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>2311527</ChapterUID> <ChapterTimeStart>5000000000</ChapterTimeStart> <ChapterTimeEnd>25000000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Before the crime</ChapString> </ChapterDisplay> <ChapterDisplay> <ChapString>Avant le crime</ChapString> <ChapLanguage>fra</ChapLanguage> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>3430008</ChapterUID> <ChapterTimeStart>25000000000</ChapterTimeStart> <ChapterTimeEnd>27500000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>The crime</ChapString> </ChapterDisplay> <ChapterDisplay> <ChapString>Le crime</ChapString> <ChapLanguage>fra</ChapLanguage> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>4548489</ChapterUID> <ChapterTimeStart>27500000000</ChapterTimeStart> <ChapterTimeEnd>38000000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>After the crime</ChapString> </ChapterDisplay> <ChapterDisplay> <ChapString>Apres le crime</ChapString> <ChapLanguage>fra</ChapLanguage> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>5666960</ChapterUID> <ChapterTimeStart>38000000000</ChapterTimeStart> <ChapterTimeEnd>43000000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Credits</ChapString> </ChapterDisplay> <ChapterDisplay> <ChapString>Generique</ChapString> <ChapLanguage>fra</ChapLanguage> </ChapterDisplay> </ChapterAtom> </EditionEntry> </Chapters> </sourcecode> </figure> </section> <section anchor="example-2-nested-chapters"><name>Example2 : nested chapters</name>2: Nested Chapters</name> <t>In thisexampleexample, an (existing) album is split into different chapters, and one of them contains another splitting.</t> <section anchor="the-micronauts-bleep-to-bleep"><name>The Micronauts"Bleep"Bleep ToBleep"</name>Bleep"</name> <ul spacing="compact"> <li><t>00:00 -12:28 :12:28: BabyWants Towants to Bleep/Rock</t> <ul spacing="compact"> <li>00:00 -04:38 :04:38: Baby wants to bleep (pt.1)</li> <li>04:38 -07:12 :07:12: Baby wants to rock</li> <li>07:12 -10:33 :10:33: Baby wants to bleep (pt.2)</li> <li>10:33 -12:28 :12:28: Baby wants to bleep (pt.3)</li> </ul></li> <li>12:30 -19:38 :19:38: Bleeper_O+2</li> <li>19:40 -22:20 :22:20: Baby wants to bleep (pt.4)</li> <li>22:22 -25:18 :25:18: Bleep to bleep</li> <li>25:20 -33:35 :33:35: Baby wants to bleep (k)</li> <li>33:37 -44:28 :44:28: Bleeper</li> </ul> <t>This would translate in the followingmatroskaMatroska form, with the EBML tree shown asXML :</t>XML:</t> <figure><name>Nested ChaptersExample.Example </name> <sourcecode type="xml"><Chapters> <EditionEntry> <EditionUID>1281690858003401414</EditionUID> <ChapterAtom> <ChapterUID>1</ChapterUID> <ChapterTimeStart>0</ChapterTimeStart> <ChapterTimeEnd>748000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to Bleep/Rock</ChapString> </ChapterDisplay> <ChapterAtom> <ChapterUID>2</ChapterUID> <ChapterTimeStart>0</ChapterTimeStart> <ChapterTimeEnd>278000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to bleep (pt.1)</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>3</ChapterUID> <ChapterTimeStart>278000000</ChapterTimeStart> <ChapterTimeEnd>432000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to rock</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>4</ChapterUID> <ChapterTimeStart>432000000</ChapterTimeStart> <ChapterTimeEnd>633000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to bleep (pt.2)</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>5</ChapterUID> <ChapterTimeStart>633000000</ChapterTimeStart> <ChapterTimeEnd>748000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to bleep (pt.3)</ChapString> </ChapterDisplay> </ChapterAtom> </ChapterAtom> <ChapterAtom> <ChapterUID>6</ChapterUID> <ChapterTimeStart>750000000</ChapterTimeStart> <ChapterTimeEnd>1178500000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Bleeper_O+2</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>7</ChapterUID> <ChapterTimeStart>1180500000</ChapterTimeStart> <ChapterTimeEnd>1340000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to bleep (pt.4)</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>8</ChapterUID> <ChapterTimeStart>1342000000</ChapterTimeStart> <ChapterTimeEnd>1518000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Bleep to bleep</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>9</ChapterUID> <ChapterTimeStart>1520000000</ChapterTimeStart> <ChapterTimeEnd>2015000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Baby wants to bleep (k)</ChapString> </ChapterDisplay> </ChapterAtom> <ChapterAtom> <ChapterUID>10</ChapterUID> <ChapterTimeStart>2017000000</ChapterTimeStart> <ChapterTimeEnd>2668000000</ChapterTimeEnd> <ChapterDisplay> <ChapString>Bleeper</ChapString> </ChapterDisplay> </ChapterAtom> </EditionEntry> </Chapters> </sourcecode> </figure> </section> </section> </section> </section> <section anchor="attachments-1"><name>Attachments</name> <t>Matroska supports storage of related files and data in the <tt>Attachments Element</tt> (a <tt>Top-Level Element</tt>). <tt>Attachment Elements</tt> can be used to store related cover art, font files, transcripts, reports, error recovery files,picture, orpictures, text-based annotations, copies of specifications, or other ancillary files related to the <tt>Segment</tt>.</t> <t><tt>Matroska Readers</tt> <bcp14>MUST NOT</bcp14> execute files stored as <tt>Attachment Elements</tt>.</t> <section anchor="cover-art"><name>Cover Art</name> <t>This section defines a set of guidelines for the storage of cover art in Matroska files. A <tt>Matroska Reader</tt> <bcp14>MAY</bcp14> use embedded cover art to display a representational still-image depiction of the multimedia contents of the Matroska file.</t> <t>Only <xref target="JPEG"></xref> and PNG <xref target="RFC2083"></xref> image formats <bcp14>SHOULD</bcp14> be used for cover art pictures.</t> <t>There can be two different covers for a movie/album: a portrait style (e.g., a DVD case) and a landscape style (e.g., a wide banner ad).</t> <t>There can be two versions of the samecover,cover: the <tt>normal cover</tt> and the <tt>small cover</tt>. The dimension of the <tt>normal cover</tt> <bcp14>SHOULD</bcp14> be 600 pixels on the smallest side-- for example,(e.g., 960x600 for landscape, 600x800 for portrait, or 600x600 forsquare.square). The dimension of the <tt>small cover</tt> <bcp14>SHOULD</bcp14> be 120 pixels on the smallest side-- for example,(e.g., 192x120 or120x160.</t>120x160).</t> <t>Versions of cover art can be differentiated by the filename, which is stored in the <tt>FileName Element</tt>. The default filename of the <tt>normal cover</tt> in square or portrait mode is <tt>cover.(jpg|png)</tt>. When stored, the <tt>normal cover</tt> <bcp14>SHOULD</bcp14> be the first Attachment in storage order. The <tt>small cover</tt> <bcp14>SHOULD</bcp14> be prefixed with"small_","small_", such as <tt>small_cover.(jpg|png)</tt>. The landscape variant <bcp14>SHOULD</bcp14> be suffixed with"_land","_land", such as <tt>cover_land.(jpg|png)</tt>. The filenames are case-sensitive.</t> <t>The following table provides examples of file names for cover art in Attachments.</t> <table anchor="coverartFilenames"><name>Cover Art Filenames</name> <thead> <tr><th>FileName</th><th>File Name</th> <th>Image Orientation</th> <th>Pixel Length of Smallest Side</th> </tr> </thead> <tbody> <tr> <td>cover.jpg</td> <td>Portrait or square</td> <td>600</td> </tr> <tr> <td>small_cover.png</td> <td>Portrait or square</td> <td>120</td> </tr> <tr> <td>cover_land.png</td> <td>Landscape</td> <td>600</td> </tr> <tr> <td>small_cover_land.jpg</td> <td>Landscape</td> <td>120</td> </tr> </tbody> </table></section> <section anchor="font-files"><name>Fontfiles</name>Files</name> <t>Font files <bcp14>MAY</bcp14> be added to a Matroska file as Attachments so that the font file may be used to display an associated subtitle track. This allows the presentation of a Matroska file to be consistent in various environments where the needed fonts might not be available on the local system.</t> <t>Depending on the font format in question, each font file can contain multiple font variants. Each font variant has a namewhichthat will be referred to as Font Name from now on. This Font Name can be different from the Attachment's <tt>FileName</tt>, even when disregarding the extension. In order to select a font for display, a MatroskaplayerPlayer <bcp14>SHOULD</bcp14> consider both the Font Name and the base name of the Attachment's FileName, preferring the former when there are multiple matches.</t><t>Subtitle<!-- [rfced] FYI - We updated "SubStation Alpha (SSA/ASS)" as follows. Please let us know any concerns. Original: Subtitle codecs, such as SubStation Alpha (SSA/ASS), usually refer to a font by its Font Name, not by its filename. Perhaps: Subtitle codecs, such as SubStation Alpha (SSA) and Advanced SubStation Alpha (ASS), usually refer to a font by its Font Name, not by its filename. --> <t>Subtitle codecs, such as SubStation Alpha (SSA) and Advanced SubStation Alpha (ASS), usually refer to a font by its Font Name, not by its filename. If none of the Attachments are a match for the Font Name, the MatroskaplayerPlayer <bcp14>SHOULD</bcp14> attempt to find a system font whose Font Name matches the one used in the subtitle track.</t> <t>Since loading fonts temporarily can take a while, a MatroskaplayerPlayer usually loads or installs all the fonts found in attachments so they are ready to be used during playback. Failure to use the font attachment might result in incorrect rendering of the subtitles.</t> <t>If a selected subtitle track has some <tt>AttachmentLink</tt> elements, the player <bcp14>MAY</bcp14> restrict its font rendering to use only these fonts.</t> <t>A MatroskaplayerPlayer <bcp14>SHOULD</bcp14> handle the official font media types from <xref target="RFC8081"></xref> when the system can handle the type:</t> <ul><li><t><tt>font/sfnt</tt>:<li>font/sfnt: Generic SFNT FontType,</t> </li> <li><t><tt>font/ttf</tt>: TTFType</li> <li>font/ttf: TrueType FontType,</t> </li> <li><t><tt>font/otf</tt>:(TTF) Font Type</li> <li>font/otf: OpenType Layout (OTF) FontType,</t> </li> <li><t><tt>font/collection</tt>:Type</li> <li>font/collection: Collection FontType,</t> </li> <li><t><tt>font/woff</tt>:Type</li> <li>font/woff: WOFF1.0,</t> </li> <li><t><tt>font/woff2</tt>:1.0</li> <li>font/woff2: WOFF2.0.</t> </li>2.0</li> </ul> <t>Fonts in Matroska existed long before <xref target="RFC8081"></xref>. A few unofficial media types for fonts were used in existing files. Therefore, it is <bcp14>RECOMMENDED</bcp14> for a MatroskaplayerPlayer to support the following legacy media types for font attachments:</t> <ul><li><t><tt>application/x-truetype-font</tt>: Truetype<li>application/x-truetype-font: TrueType fonts, equivalent to <tt>font/ttf</tt> and sometimes<tt>font/otf</tt>,</t> </li> <li><t><tt>application/x-font-ttf</tt>: TTF<tt>font/otf</tt></li> <li>application/x-font-ttf: TrueType fonts, equivalent to<tt>font/ttf</tt>,</t> </li> <li><t><tt>application/vnd.ms-opentype</tt>:<tt>font/ttf</tt></li> <li>application/vnd.ms-opentype: OpenType Layout fonts, equivalent to<tt>font/otf</tt></t> </li> <li><t><tt>application/font-sfnt</tt>:<tt>font/otf</tt></li> <li>application/font-sfnt: Generic SFNT Font Type, equivalent to<tt>font/sfnt</tt></t> </li> <li><t><tt>application/font-woff</tt>:<tt>font/sfnt</tt></li> <li>application/font-woff: WOFF 1.0, equivalent to<tt>font/woff</tt></t> </li><tt>font/woff</tt></li> </ul> <t>There may also be some font attachments with the <tt>application/octet-stream</tt> media type. In thatcasecase, the MatroskaplayerPlayer <bcp14>MAY</bcp14> try to guess the font type by checking the file extension of the <tt>AttachedFile\FileName</tt> string. Common file extensions for fonts are:</t> <ul> <li><t><tt>.ttf</tt> forTruetypeTrueType fonts, equivalent to<tt>font/ttf</tt>,</t><tt>font/ttf</tt></t> </li> <li><t><tt>.otf</tt> for OpenType Layout fonts, equivalent to<tt>font/otf</tt>,</t><tt>font/otf</tt></t> </li> <li><t><tt>.ttc</tt> for Collection fonts, equivalent to <tt>font/collection</tt></t> </li> </ul> <t>The file extension check <bcp14>MUST</bcp14> be case-insensitive.</t> <t>MatroskawritersWriters <bcp14>SHOULD</bcp14> use a valid font media type from <xref target="RFC8081"></xref> in the <tt>AttachedFile\FileMediaType</tt> of the font attachment. They <bcp14>MAY</bcp14> use the media types found in older files when compatibility with older players is necessary.</t> </section> </section> <section anchor="cues"><name>Cues</name> <t>The <tt>Cues Element</tt> provides an index of certain <tt>Cluster Elements</tt> to allow for optimized seeking to absolute timestamps within the <tt>Segment</tt>. The <tt>Cues Element</tt> contains one or many <tt>CuePointElements</tt> whichElements</tt>, each of which <bcp14>MUST</bcp14> reference an absolute timestamp (via the <tt>CueTime Element</tt>), a <tt>Track</tt> (via the <tt>CueTrack Element</tt>), and a <tt>Segment Position</tt> (via the <tt>CueClusterPosition Element</tt>). Additional non-mandated Elements are part of the <tt>CuePointElement</tt>Element</tt>, such as <tt>CueDuration</tt>, <tt>CueRelativePosition</tt>,<tt>CueCodecState</tt><tt>CueCodecState</tt>, and otherswhichthat provide any <tt>Matroska Reader</tt> with additional information to use in the optimization of seeking performance.</t> <section anchor="recommendations"><name>Recommendations</name> <t>The following recommendations are provided to optimize Matroska performance.</t> <ul> <li><t>Unless Matroska is used as a live stream, it <bcp14>SHOULD</bcp14> contain a <tt>Cues Element</tt>.</t> </li> <li><t>For each video track, each keyframe <bcp14>SHOULD</bcp14> be referenced by a <tt>CuePoint Element</tt>.</t> </li> <li><t>It is <bcp14>RECOMMENDED</bcp14> to not reference non-keyframes of video tracks in <tt>Cues</tt> unless it references a <tt>Cluster Element</tt>whichthat contains a <tt>CodecState Element</tt> but no keyframes.</t> </li> <li><t>For each subtitle track present, each subtitle frame <bcp14>SHOULD</bcp14> be referenced by a <tt>CuePoint Element</tt> with a <tt>CueDuration Element</tt>.</t> </li> <li><t>References to audio tracks <bcp14>MAY</bcp14> be skipped in <tt>CuePoint Elements</tt> if a video track is present. Whenincludedincluded, the <tt>CuePoint Elements</tt> <bcp14>SHOULD</bcp14> reference audio keyframesat mostonce every 500milliseconds.</t>milliseconds at most.</t> </li> <li><t>If the referenced frame is not stored within the first<tt>SimpleBlock</tt>,<tt>SimpleBlock</tt> or first <tt>BlockGroup</tt> within its <tt>Cluster Element</tt>, then the <tt>CueRelativePosition Element</tt> <bcp14>SHOULD</bcp14> be written to reference where in the <tt>Cluster</tt> the reference frame is stored.</t> </li> <li><t>If a <tt>CuePoint Element</tt> references a <tt>Cluster Element</tt> that includes a <tt>CodecState Element</tt>, then that <tt>CuePoint Element</tt> <bcp14>MUST</bcp14> use a <tt>CueCodecState Element</tt>.</t> </li> <li><t><tt>CuePoint Elements</tt> <bcp14>SHOULD</bcp14> be numerically sorted in storage order by the value of the <tt>CueTime Element</tt>.</t> </li> </ul> </section> </section> <section anchor="matroska-streaming"><name>Matroska Streaming</name> <t>In Matroska, there are two kinds of streaming: file access and livestreaming.</t> <section anchor="file-access"><name>File Access</name> <t>File access can simply be reading a file located on your computer, but it also includes accessing a file from an HTTP (web) server orCIFSCommon Internet File System (CIFS) (Windows share) server. These protocols are usually safe from readingerrorserrors, and seeking in the stream is possible. However, when a file is stored far away or on a slow server, seeking can be an expensive operation and should be avoided. <!-- [rfced] Would it be helpful to rephrase the text starting with "without a lot of data..."? Original: The guidelines in<xref target="implementation-recommendations"></xref>,Section 25, when followed, help reduce the number of seeking operations for regular playback and also have the playback start quickly without a lot of data needed to read first (like a Cues Element, Attachment Element or SeekHead Element). Perhaps: When followed, the guidelines in Section 25 help reduce the number of seeking operations for regular playback and also have the playback start quickly without needing to read lot of data first (like a Cues Element, Attachment Element, or SeekHead Element). --> When followed, the guidelines in <xref target="implementation-recommendations"></xref> help reduce the number of seeking operations for regular playback and also have the playback start quickly without a lot of data needed to read first (like a <tt>Cues Element</tt>, <tt>AttachmentElement</tt>Element</tt>, or <tt>SeekHead Element</tt>).</t> <t>Matroska, having a small overhead, is well suited for storing music/videos on file servers without a big impact on the bandwidth used. Matroska does not require the index to be loaded before playing, which allows playback to start very quickly. The index can be loaded only when seeking is requested the first time.</t> </section> <section anchor="livestreaming"><name>Livestreaming</name> <t>Livestreaming is the equivalent of television broadcasting on theinternet.Internet. There are2two families of servers for livestreaming:RTP/RTSPRTP / Real-Time Streaming Protocol (RTSP) and HTTP. Matroska is not meant to be used over RTP. RTP already has timing and channel mechanisms that would be wasted if doubled in Matroska. Additionally, having the same information at the RTP and Matroska level would be a source of confusion if they do not match. Livestreaming of Matroska over file-like protocols like HTTP, QUIC,etc.etc., is possible.</t> <t>A live Matroska stream is different from a file because it usually has no known end (only ending when the client disconnects). For this, all bits of the"size""size" portion of the <tt>Segment Element</tt> <bcp14>MUST</bcp14> be set to 1. Another option is to concatenate <tt>Segment Elements</tt> with known sizes, one after the other. This solution allows a change of codec/resolution between each segment. For example, this allows for a switch between 4:3 and 16:9 in a television program.</t> <t>When <tt>Segment Elements</tt> are continuous, certain<tt>Elements</tt>, like<tt>Elements</tt> (like <tt>SeekHead</tt>, <tt>Cues</tt>, <tt>Chapters</tt>, and<tt>Attachments</tt>,<tt>Attachments</tt>) <bcp14>MUST NOT</bcp14> be used.</t> <t>It is possible for a <tt>Matroska Player</tt> to detect that a stream is not seekable. If the stream has neither a <tt>SeekHead</tt> list nor a <tt>Cues</tt> list at the beginning of the stream, it <bcp14>SHOULD</bcp14> be considered non-seekable. Even though it is possible to seek forward in the stream, it is <bcp14>NOT RECOMMENDED</bcp14>.</t> <t>In the context of live radio or web TV, it is possible to"tag""tag" the content while it is playing. The <tt>Tags Element</tt> can be placed between <tt>Clusters</tt> each time it is necessary. In that case, the new <tt>Tags Element</tt> <bcp14>MUST</bcp14> reset the previously encountered <tt>Tags Elements</tt> and use the new values instead.</t> </section> </section> <section anchor="tags-1"><name>Tags</name> <section anchor="tags-precedence"><name>Tags Precedence</name> <!-- [rfced] Should "Track Name" here be updated to "Name" per Section 5.1.4.1.18? Or is the original okay? Original: Some Matroska elements also contain their own string value like the Track Name (Section 5.1.4.1.18) or the Chapter String (Section 5.1.7.1.4.10). ... * The Track Name Element (Section 5.1.4.1.18) corresponds to a tag with the TagTrackUID (Section 5.1.8.1.1.3) set to the given track, --> <!-- [rfced] Similar to the question above, should "Chapter String" be updated to "ChapString" per Section 5.1.7.1.4.10? Original: Some Matroska elements also contain their own string value like the Track Name (Section 5.1.4.1.18) or the Chapter String (Section 5.1.7.1.4.10). ... * The Chapter String Element (Section 5.1.7.1.4.10) corresponds to a tag with the TagChapterUID --> <t>Tags allow tagging all kinds of Matroska parts with very detailed metadata in multiple languages.</t> <t>Some Matroska elements also contain their own stringvaluevalue, like the Track Name (<xref target="name-element"></xref>) or the Chapter String (<xref target="chapstring-element"></xref>).</t> <t>The following Matroska elements can also be defined with tags:</t> <ul> <li><t>The Track Name Element (<xref target="name-element"></xref>) corresponds to a tag with the TagTrackUID (<xref target="tagtrackuid-element"></xref>) set to the given track, a TagName of <tt>TITLE</tt> (<xreftarget="tagname-element"></xref>)target="tagname-element"></xref>), and a TagLanguage (<xref target="taglanguage-element"></xref>) or TagLanguageBCP47 (<xref target="taglanguagebcp47-element"></xref>) of"und".</t>"und".</t> </li> <li><t>The Chapter String Element (<xref target="chapstring-element"></xref>) corresponds to a tag with the TagChapterUID (<xref target="tagchapteruid-element"></xref>) set to the same chapter UID, a TagName of <tt>TITLE</tt> (<xreftarget="tagname-element"></xref>)target="tagname-element"></xref>), and a TagLanguage (<xref target="taglanguage-element"></xref>) or TagLanguageBCP47 (<xref target="taglanguagebcp47-element"></xref>) matching the ChapLanguage (<xref target="chaplanguage-element"></xref>) or ChapLanguageBCP47 (<xreftarget="chaplanguagebcp47-element"></xref>)target="chaplanguagebcp47-element"></xref>), respectively.</t> </li> <li><t>The FileDescription Element (<xref target="filedescription-element"></xref>) of an attachment corresponds to a tag with the TagAttachmentUID (<xref target="tagattachmentuid-element"></xref>) set to the given attachment, a TagName of <tt>TITLE</tt> (<xreftarget="tagname-element"></xref>)target="tagname-element"></xref>), and a TagLanguage (<xref target="taglanguage-element"></xref>) or TagLanguageBCP47 (<xref target="taglanguagebcp47-element"></xref>) of"und".</t>"und".</t> </li> </ul> <t>When both values exist in the file, the value found in Tags takes precedence over the value found in the original location of the element. For example, if you have a <tt>TrackEntry\Name</tt> element and Tag <tt>TITLE</tt> for that track in a Matroska Segment, the Tag string <bcp14>SHOULD</bcp14> be usedand notinstead of the <tt>TrackEntry\Name</tt> string to identify the track.</t> <t>As the Tag element is optional, a lot of <tt>Matroska Readers</tt> do not handle it and will not use the tags value when it's found.SoThus, for maximum compatibility, it's usually better to put the strings in the <tt>TrackEntry</tt>,<tt>ChapterAtom</tt><tt>ChapterAtom</tt>, and <tt>Attachment</tt> and keep the tags matching these values if tags are also used.</t> </section> <section anchor="tag-levels"><name>Tag Levels</name> <t>Tag elements allow tagging information on multiple levels, with each level having a <tt>TargetTypeValue</tt> <xref target="targettypevalue-element"></xref>. An element for a given <tt>TargetTypeValue</tt> also applies to the lower levels denoted by smaller <tt>TargetTypeValue</tt> values. If an upper value doesn't apply to a level but the actual value to use is not known, an empty <tt>TagString</tt> (<xref target="tagstring-element"></xref>) or an empty <tt>TagBinary</tt> (<xref target="tagbinary-element"></xref>)element<bcp14>MUST</bcp14> be used as the tag value for this level.</t> <t>See <xreftarget="MatroskaTags"></xref>target="I-D.ietf-cellar-tags"></xref> for more details on common tag names,typestypes, and descriptions.</t> </section> </section> <section anchor="implementation-recommendations"><name>Implementation Recommendations</name> <section anchor="cluster"><name>Cluster</name> <t>It is <bcp14>RECOMMENDED</bcp14> that each individual <tt>Cluster Element</tt>containscontain no more than5five seconds or5five megabytes of content.</t> </section> <section anchor="seekhead-1"><name>SeekHead</name> <t>It is <bcp14>RECOMMENDED</bcp14> that the first <tt>SeekHead Element</tt> be followed by a <tt>Void Element</tt> to allow for the <tt>SeekHead Element</tt> to be expanded to cover new <tt>Top-Level Elements</tt> that could be added to the Matroska file, such as <tt>Tags</tt>, <tt>Chapters</tt>, and <tt>Attachments</tt> Elements.</t> <!-- [rfced] How may we clarify the text starting with "depending on the..."? Original: The size of this Void Element should be adjusted depending on the Matroska file already having Tags, Chapters, and Attachments Elements. Perhaps: The size of this Void Element should be adjusted depending on the Tags, Chapters, and Attachments Elements in the Matroska file. --> <t>The size of this <tt>Void Element</tt> should be adjusted depending on the Matroska file already having <tt>Tags</tt>, <tt>Chapters</tt>, and <tt>Attachments</tt> Elements.</t> </section> <section anchor="optimum-layouts"><name>Optimum Layouts</name> <t>While there can be <tt>Top-Level Elements</tt> in any order, someorderingorderings of Elements are better than others.Here are fewThe following subsections detail optimum layouts for different usecase:</t>cases.</t> <section anchor="optimum-layout-for-a-muxer"><name>OptimumlayoutLayout for amuxer</name>Muxer</name> <t>This is the basic layout muxers should be using for an efficient playbackexperience.</t>experience:</t> <ul spacing="compact"> <li>SeekHead</li> <li>Info</li> <li>Tracks</li> <li>Chapters</li> <li>Attachments</li> <li>Tags</li> <li>Clusters</li> <li>Cues</li> </ul> </section> <section anchor="optimum-layout-after-editing-tags"><name>OptimumlayoutLayout afterediting tags</name>Editing Tags</name> <t>When tags from the previous layout need to be extended, they are moved to the end with the extra information. The location where the old tags were located is voided.</t> <ul spacing="compact"> <li>SeekHead</li> <li>Info</li> <li>Tracks</li> <li>Chapters</li> <li>Attachments</li> <li>Void</li> <li>Clusters</li> <li>Cues</li> <li>Tags</li> </ul> </section> <section anchor="optimum-layout-with-cues-at-the-front"><name>OptimumlayoutLayout with Cues at thefront</name>Front</name> <t>Cues are usually a big chunk of data referencing a lot of locations in the file.For playersPlayers that want to seek in the filetheyneed to seek to the end of the file to access these locations. It is often better if they are placed early in the file. On the otherhandhand, that means players that don't intend to seek will have to read/skip these data no matter what.</t> <t>Because the Cues reference locations further in the file, it's often complicated to allocate the proper space for that element before all the locations are known. Therefore, this layout is rarelyused.</t>used:</t> <ul spacing="compact"> <li>SeekHead</li> <li>Info</li> <li>Tracks</li> <li>Chapters</li> <li>Attachments</li> <li>Tags</li> <li>Cues</li> <li>Clusters</li> </ul> </section> <section anchor="optimum-layout-for-livestreaming"><name>OptimumlayoutLayout forlivestreaming</name>Livestreaming</name> <t>InLivestreaminglivestreaming (<xreftarget="livestreaming"></xref>)target="livestreaming"></xref>), only a few elements make sense. For example, SeekHead and Cues areuseless for example.useless. All elements other than the Clusters <bcp14>MUST</bcp14> be placed before the Clusters.</t> <ul spacing="compact"> <li>Info</li> <li>Tracks</li> <li>Attachments (rare)</li> <li>Tags</li> <li>Clusters</li> </ul> </section> </section> </section> <section anchor="security-considerations"><name>Security Considerations</name> <!-- [rfced] Would it be helpful to include "[RFC8794]" in this sentence in the Security Considerations section? Original: Matroska inherits security considerations from EBML. Perhaps: Matroska inherits security considerations from EBML [RFC8794]. --> <t>Matroska inherits security considerations from EBML.</t> <t>Attacks on a <tt>Matroska Reader</tt> could include:</t> <ul> <li><t>Storage of an arbitrary and potentially executable data within an <tt>Attachment Element</tt>. <tt>Matroska Readers</tt> that extract or use data from Matroska Attachments <bcp14>SHOULD</bcp14> check that the data adheres to expectations or not use theattachement.</t>attachment.</t> </li> <li><t>A <tt>Matroska Attachment</tt> with an inaccurate media type.</t> </li> <li><t>Damage to the Encryption and Compression fields (<xref target="encryption"></xref>) that would result in bogus binary data interpreted by the decoder.</t> </li> <li><t>Chapter Codecs running unwanted commands on the host system.</t> </li> </ul> <!-- [rfced] How may we rephrase this sentence to make it more concise and clear? Original: It is up to the decision of the Matroska Readers on how to handle the errors if they are recoverable in their code or not. Perhaps: Matroska Readers decide how to handle the errors whether or not they are recoverable in their code. --> <t>The same error handling done for EBML applies to Matroska files. Particular error handling is not covered in thisspecificationspecification, as this is depends on the goal of the <tt>Matroska Readers</tt>. It is up to the decision of the <tt>Matroska Readers</tt> on how to handle the errors if they are recoverable in their code or not. For example, if the checksum of the <tt>\Segment\Tracks</tt> isinvalidinvalid, some could decide to try to read the data anyway, some will just reject the file, and most will not even check it.</t> <t><tt>Matroska Reader</tt> implementations need to be robust against malicious payloads. Those related to denial of service are outlined inSection 2.1 of [RFC4732].<br /> Although<xref target="RFC4732" sectionFormat="of" section="2.1"/>.</t> <t>Although rarer, the same may apply to a <tt>Matroska Writer</tt>. Malicious stream data must not cause the Matroska Writer to misbehave, as this might allow an attacker access to transcoding gateways.</t> <t>As an audio and visual container format, a Matroska file or stream will potentially encapsulate numerous byte streams created with a variety of codecs. Implementers will need to consider the security considerations of these encapsulated formats.</t> </section> <section anchor="iana-considerations"><name>IANA Considerations</name> <!-- [rfced] We moved "28. Annex A: Historic Deprecated Elements" to be "Appendix A. Historic Deprecated Elements" (appears after the references section). If no objections, we will ask IANA to update the section pointers in the registry defined in Section 27.1 accordingly. However, if you wish to retain this as Section 28, we will update to "28. Historic Deprecated Elements" (no "Annex A"). Link to registry: https://www.iana.org/assignments/matroska/matroska.xhtml --> <!-- [rfced] We have included some specific questions about the IANA text in the document. In addition to responding to those questions, please review all of the IANA-related updates carefully and let us know if any updates are needed. a) Section 27.1: Should the list in this sentence include an "Element Name"? Also, does IANA assign the Element ID? If so, should the sentence be updated per the "Or" text below to include "Element Name" but not "Element ID"? Also, please confirm that the Reference is optional. Original: To register a new Element ID in this registry, one needs an Element ID, a Change Controller (IETF or email of registrant) and an optional Reference to a document describing the Element ID. Perhaps (both Element ID and Element Name in list): To register a new Element ID in this registry, one needs an Element ID, an Element Name, a Change Controller (IETF or email of registrant), and an optional Reference to a document describing the Element ID. Or (Element ID not in list): To register a new Element ID in this registry, one needs an Element Name, a Change Controller (IETF or email of registrant), and an optional Reference to a document describing the Element ID. b) Section 27.2: Similar to the question above, should the list in this sentence include "description" and possibly remove "Chapter Codec ID" from the list? Also, please confirm that the Reference is optional. Original: To register a new Chapter Codec ID in this registry, one needs a Chapter Codec ID, a Change Controller (IETF or email of registrant) and an optional Reference to a document describing the Chapter Codec ID. Perhaps (both Chapter Codec ID and description in list): To register a new Chapter Codec ID in this registry, one needs a Chapter Codec ID, description, a Change Controller (IETF or email of registrant), and an optional Reference to a document describing the Chapter Codec ID. Or (Chapter Codec ID not in list): To register a new Chapter Codec ID in this registry, one needs a description, a Change Controller (IETF or email of registrant), and an optional Reference to a document describing the Chapter Codec ID. c) Would it be helpful to include the ranges listed in the registry at https://www.iana.org/assignments/matroska/? Original: One-octet Matroska Element IDs are to be allocated according to the "RFC Required" policy [RFC8126]. Two-octet Matroska Element IDs are to be allocated according to the "Specification Required" policy [RFC8126]. Three-octet and four-octet Matroska Element IDs are to be allocated according to the "First Come First Served" policy [RFC8126]. Perhaps: One-octet Element IDs (range 0x00-0xFF) are to be allocated according to the "RFC Required" policy [RFC8126]. Two-octet Element IDs (range 0x0100-0xFFFF) are to be allocated according to the "Specification Required" policy [RFC8126]. Three-octet and four-octet Element IDs (range 0x00010000-0xFFFFFFFF) are to be allocated according to the "First Come First Served" policy [RFC8126]. d) We have combined the text below into one complete sentence. Should "within a BlockGroup or Chapters" be updated to "BlockGroup or Chapters" (no "within a")? Original: Given the scarcity of the One-octet Element IDs, they should only be created to save space for elements found many times in a file. For example, within a BlockGroup or Chapters. Current: Given the scarcity of one-octet Element IDs, they should only be created to save space for elements found many times in a file (for example, within a BlockGroup or Chapters). Perhaps: Given the scarcity of one-octet Element IDs, they should only be created to save space for elements found many times in a file (for example, BlockGroup or Chapters). e) FYI - We removed "Described in" from the Reference column of the table in Section 27.1 to match the IANA registry at https://www.iana.org/assignments/matroska/. f) The table in Section 27.1 does not contain the "Change Controller" column that appears in the registry at https://www.iana.org/assignments/matroska. Would it be helpful to add a sentence noting that that the change controller for all initial entries in the registry is "IETF"? Current: Table 54 shows the initial contents of the "Matroska Element IDs" registry. Perhaps: Table 54 shows the initial contents of the "Matroska Element IDs" registry. Note that the Change Controller for all entries in Table 54 is "IETF". g) Section 27.2 notes this: Original: The values correspond to the unsigned integer ChapProcessCodecID value described in Section 5.1.7.1.4.15. ... ChapProcessCodecID values of "0" and "1" are RESERVED to the IETF for future use. Values 0 and 1 in the registry are listed as Reserved, with this document as a reference. See https://www.iana.org/assignments/matroska/matroska.xhtml#matroska-chapter-codec-ids. However, Section 5.1.7.1.4.15 notes this about values "0" and "1" for ChapProcessCodecID: Original: definition: Contains the type of the codec used for the processing. A value of 0 means built-in Matroska processing (to be defined), a value of 1 means the DVD command set is used; see Section 20.3 on DVD menus. More codec IDs can be added later. Please review and let us know if any updates are needed. h) Sections 27.3.1-27.3.3: May we update this text to avoid "..." in one of the following ways? Note that this appears three times (in each of the templates in Section 27.3). Original: FFmpeg, VLC, ... Perhaps: FFmpeg, VLC, etc. Or: FFmpeg and VLC i) Sections 27.3.1-27.3.3: We made a few minor edits to the templates in these sections. Please review and let us know any concerns. We will ask IANA to update the templates to match the edited document prior to publication: https://www.iana.org/assignments/media-types/audio/matroska https://www.iana.org/assignments/media-types/video/matroska https://www.iana.org/assignments/media-types/video/matroska-3d --> <!-- [rfced] We see both "color" (American spelling) and "colour" (British spelling) used in the document, with the Colour Element registered with IANA. The document generally uses American spelling (e.g., "optimized" rather than "optimised", etc.). Are any updates needed for consistency? Perhaps update all instances to "color" and request that IANA update the entry in the registry accordingly? Link to registry: https://www.iana.org/assignments/matroska/matroska.xhtml --> <section anchor="matroska-element-ids-registry"><name>Matroska Element IDs Registry</name><t>This document creates<t>IANA has created a newIANAregistry called the"Matroska"Matroska ElementIDs"IDs" registry.</t><t>To<t>The following are needed to register a new Element ID in thisregistry, one needsregistry: an Element ID, a Change Controller (IETF or email ofregistrant)registrant), and an optional Reference to a document describing the Element ID.</t> <t>Element IDs are encoded using the VINT mechanism described inSection 4 of<xreftarget="RFC8794"></xref>target="RFC8794" sectionFormat="of" section="4"></xref> and can be between one and five octets long.Five-octet-longFive-octet Element IDs are possible only if declared in the EBMLheader.</t>Header.</t> <t>Element IDs are described inSection 5 of<xreftarget="RFC8794"></xref>target="RFC8794" sectionFormat="of" section="5"></xref>, witherrata 7189the changes in <xref target="Err7189"/> and7191.</t><xref target="Err7191"/>.</t> <t>One-octet Matroska Element IDs are to be allocated according to the"RFC Required""RFC Required" policy <xref target="RFC8126"></xref>.</t> <t>Two-octet Matroska Element IDs are to be allocated according to the"Specification Required""Specification Required" policy <xref target="RFC8126"></xref>.</t> <t>Three-octet and four-octet Matroska Element IDs are to be allocated according to the"First"First Come FirstServed"Served" policy <xref target="RFC8126"></xref>.</t> <t>The allowed values in theElements IDs"Matroska Element IDs" registry are similar to the ones found in theEBML"EBML ElementIDsIDs" registry defined inSection 17.1 of<xreftarget="RFC8794"></xref>.</t>target="RFC8794" sectionFormat="of" section="17.1"></xref>.</t> <t>EBML Element IDs defined for the EBML Header -- as defined inSection 17.1 of<xreftarget="RFC8794"></xref>target="RFC8794" sectionFormat="of" section="17.1"></xref> -- <bcp14>MUST NOT</bcp14> be used as Matroska Element IDs.</t> <t>Given the scarcity ofthe One-octetone-octet Element IDs, they should only be created to save space for elements found many times in afile. Forfile (for example, within a BlockGroup orChapters.Chapters). TheFour-octetfour-octet Element IDs are mostly for synchronization of large elements. They should only be used for suchhigh levelhigh-level elements. Elements that are not expected to be used often should useThree-octetthree-octet Element IDs.</t> <t>Elements found in <xreftarget="annex-a-historic-deprecated-elements"></xref>target="appendix-a-historic-deprecated-elements"></xref> have an assigned Matroska Element ID for historical reasons. These elements are not in use and <bcp14>SHOULD NOT</bcp14> be reused unless thereisare no other IDs available with the desired size. Such IDs areconsideredmarked as<tt>reclaimed</tt> to"Reclaimed" in theIANA registry"Matroska Element IDs" registry, as they could be used for other things in the future.</t><t>Matroska Element IDs Values found in this document are assigned as<t><xref target="iana-table"></xref> shows the initialvalues as follows:</t> <table><name>IDs and Names for Matroskacontents of the "Matroska ElementIDs assigned by this documentIDs" registry.</t> <table anchor="iana-table"><name>Initial Contents of "Matroska Element IDs" Registry </name> <thead> <tr> <th align="right">Element ID</th> <th align="left">Element Name</th> <th align="left">Reference</th> </tr> </thead> <tbody> <tr> <td align="right">0x80</td> <td align="left">ChapterDisplay</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapterdisplay-element"></xref></td> </tr> <tr> <td align="right">0x83</td> <td align="left">TrackType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracktype-element"></xref></td> </tr> <tr> <td align="right">0x85</td> <td align="left">ChapString</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapstring-element"></xref></td> </tr> <tr> <td align="right">0x86</td> <td align="left">CodecID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="codecid-element"></xref></td> </tr> <tr> <td align="right">0x88</td> <td align="left">FlagDefault</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagdefault-element"></xref></td> </tr> <tr> <td align="right">0x8E</td> <td align="left">Slices</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="slices-element"></xref>)</td> </tr> <tr> <td align="right">0x91</td> <td align="left">ChapterTimeStart</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptertimestart-element"></xref></td> </tr> <tr> <td align="right">0x92</td> <td align="left">ChapterTimeEnd</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptertimeend-element"></xref></td> </tr> <tr> <td align="right">0x96</td> <td align="left">CueRefTime</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuereftime-element"></xref></td> </tr> <tr> <td align="right">0x97</td> <td align="left">CueRefCluster</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="cuerefcluster-element"></xref>)</td> </tr> <tr> <td align="right">0x98</td> <td align="left">ChapterFlagHidden</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapterflaghidden-element"></xref></td> </tr> <tr> <td align="right">0x9A</td> <td align="left">FlagInterlaced</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flaginterlaced-element"></xref></td> </tr> <tr> <td align="right">0x9B</td> <td align="left">BlockDuration</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockduration-element"></xref></td> </tr> <tr> <td align="right">0x9C</td> <td align="left">FlagLacing</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flaglacing-element"></xref></td> </tr> <tr> <td align="right">0x9D</td> <td align="left">FieldOrder</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="fieldorder-element"></xref></td> </tr> <tr> <td align="right">0x9F</td> <td align="left">Channels</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="channels-element"></xref></td> </tr> <tr> <td align="right">0xA0</td> <td align="left">BlockGroup</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockgroup-element"></xref></td> </tr> <tr> <td align="right">0xA1</td> <td align="left">Block</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="block-element"></xref></td> </tr> <tr> <td align="right">0xA2</td> <td align="left">BlockVirtual</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="blockvirtual-element"></xref>)</td> </tr> <tr> <td align="right">0xA3</td> <td align="left">SimpleBlock</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="simpleblock-element"></xref></td> </tr> <tr> <td align="right">0xA4</td> <td align="left">CodecState</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="codecstate-element"></xref></td> </tr> <tr> <td align="right">0xA5</td> <td align="left">BlockAdditional</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockadditional-element"></xref></td> </tr> <tr> <td align="right">0xA6</td> <td align="left">BlockMore</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockmore-element"></xref></td> </tr> <tr> <td align="right">0xA7</td> <td align="left">Position</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="position-element"></xref></td> </tr> <tr> <td align="right">0xAA</td> <td align="left">CodecDecodeAll</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="codecdecodeall-element"></xref>)</td> </tr> <tr> <td align="right">0xAB</td> <td align="left">PrevSize</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="prevsize-element"></xref></td> </tr> <tr> <td align="right">0xAE</td> <td align="left">TrackEntry</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackentry-element"></xref></td> </tr> <tr> <td align="right">0xAF</td> <td align="left">EncryptedBlock</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="encryptedblock-element"></xref>)</td> </tr> <tr> <td align="right">0xB0</td> <td align="left">PixelWidth</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="pixelwidth-element"></xref></td> </tr> <tr> <td align="right">0xB2</td> <td align="left">CueDuration</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cueduration-element"></xref></td> </tr> <tr> <td align="right">0xB3</td> <td align="left">CueTime</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuetime-element"></xref></td> </tr> <tr> <td align="right">0xB5</td> <td align="left">SamplingFrequency</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="samplingfrequency-element"></xref></td> </tr> <tr> <td align="right">0xB6</td> <td align="left">ChapterAtom</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapteratom-element"></xref></td> </tr> <tr> <td align="right">0xB7</td> <td align="left">CueTrackPositions</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuetrackpositions-element"></xref></td> </tr> <tr> <td align="right">0xB9</td> <td align="left">FlagEnabled</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagenabled-element"></xref></td> </tr> <tr> <td align="right">0xBA</td> <td align="left">PixelHeight</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="pixelheight-element"></xref></td> </tr> <tr> <td align="right">0xBB</td> <td align="left">CuePoint</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuepoint-element"></xref></td> </tr> <tr> <td align="right">0xC0</td> <td align="left">TrickTrackUID</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="tricktrackuid-element"></xref>)</td> </tr> <tr> <td align="right">0xC1</td> <td align="left">TrickTrackSegmentUID</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="tricktracksegmentuid-element"></xref>)</td> </tr> <tr> <td align="right">0xC4</td> <td align="left">TrickMasterTrackSegmentUID</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="trickmastertracksegmentuid-element"></xref>)</td> </tr> <tr> <td align="right">0xC6</td> <td align="left">TrickTrackFlag</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="tricktrackflag-element"></xref>)</td> </tr> <tr> <td align="right">0xC7</td> <td align="left">TrickMasterTrackUID</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="trickmastertrackuid-element"></xref>)</td> </tr> <tr> <td align="right">0xC8</td> <td align="left">ReferenceFrame</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="referenceframe-element"></xref>)</td> </tr> <tr> <td align="right">0xC9</td> <td align="left">ReferenceOffset</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="referenceoffset-element"></xref>)</td> </tr> <tr> <td align="right">0xCA</td> <td align="left">ReferenceTimestamp</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="referencetimestamp-element"></xref>)</td> </tr> <tr> <td align="right">0xCB</td> <td align="left">BlockAdditionID</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="blockadditionid-element"></xref>)</td> </tr> <tr> <td align="right">0xCC</td> <td align="left">LaceNumber</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="lacenumber-element"></xref>)</td> </tr> <tr> <td align="right">0xCD</td> <td align="left">FrameNumber</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="framenumber-element"></xref>)</td> </tr> <tr> <td align="right">0xCE</td> <td align="left">Delay</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="delay-element"></xref>)</td> </tr> <tr> <td align="right">0xCF</td> <td align="left">SliceDuration</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="sliceduration-element"></xref>)</td> </tr> <tr> <td align="right">0xD7</td> <td align="left">TrackNumber</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracknumber-element"></xref></td> </tr> <tr> <td align="right">0xDB</td> <td align="left">CueReference</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuereference-element"></xref></td> </tr> <tr> <td align="right">0xE0</td> <td align="left">Video</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="video-element"></xref></td> </tr> <tr> <td align="right">0xE1</td> <td align="left">Audio</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="audio-element"></xref></td> </tr> <tr> <td align="right">0xE2</td> <td align="left">TrackOperation</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackoperation-element"></xref></td> </tr> <tr> <td align="right">0xE3</td> <td align="left">TrackCombinePlanes</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackcombineplanes-element"></xref></td> </tr> <tr> <td align="right">0xE4</td> <td align="left">TrackPlane</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackplane-element"></xref></td> </tr> <tr> <td align="right">0xE5</td> <td align="left">TrackPlaneUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackplaneuid-element"></xref></td> </tr> <tr> <td align="right">0xE6</td> <td align="left">TrackPlaneType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackplanetype-element"></xref></td> </tr> <tr> <td align="right">0xE7</td> <td align="left">Timestamp</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="timestamp-element"></xref></td> </tr> <tr> <td align="right">0xE8</td> <td align="left">TimeSlice</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="timeslice-element"></xref>)</td> </tr> <tr> <td align="right">0xE9</td> <td align="left">TrackJoinBlocks</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackjoinblocks-element"></xref></td> </tr> <tr> <td align="right">0xEA</td> <td align="left">CueCodecState</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuecodecstate-element"></xref></td> </tr> <tr> <td align="right">0xEB</td> <td align="left">CueRefCodecState</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="cuerefcodecstate-element"></xref>)</td> </tr> <tr> <td align="right">0xED</td> <td align="left">TrackJoinUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackjoinuid-element"></xref></td> </tr> <tr> <td align="right">0xEE</td> <td align="left">BlockAddID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockaddid-element"></xref></td> </tr> <tr> <td align="right">0xF0</td> <td align="left">CueRelativePosition</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuerelativeposition-element"></xref></td> </tr> <tr> <td align="right">0xF1</td> <td align="left">CueClusterPosition</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cueclusterposition-element"></xref></td> </tr> <tr> <td align="right">0xF7</td> <td align="left">CueTrack</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cuetrack-element"></xref></td> </tr> <tr> <td align="right">0xFA</td> <td align="left">ReferencePriority</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="referencepriority-element"></xref></td> </tr> <tr> <td align="right">0xFB</td> <td align="left">ReferenceBlock</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="referenceblock-element"></xref></td> </tr> <tr> <td align="right">0xFD</td> <td align="left">ReferenceVirtual</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="referencevirtual-element"></xref>)</td> </tr> <tr> <td align="right">0x41A4</td> <td align="left">BlockAddIDName</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockaddidname-element"></xref></td> </tr> <tr> <td align="right">0x41E4</td> <td align="left">BlockAdditionMapping</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockadditionmapping-element"></xref></td> </tr> <tr> <td align="right">0x41E7</td> <td align="left">BlockAddIDType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockaddidtype-element"></xref></td> </tr> <tr> <td align="right">0x41ED</td> <td align="left">BlockAddIDExtraData</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockaddidextradata-element"></xref></td> </tr> <tr> <td align="right">0x41F0</td> <td align="left">BlockAddIDValue</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockaddidvalue-element"></xref></td> </tr> <tr> <td align="right">0x4254</td> <td align="left">ContentCompAlgo</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentcompalgo-element"></xref></td> </tr> <tr> <td align="right">0x4255</td> <td align="left">ContentCompSettings</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentcompsettings-element"></xref></td> </tr> <tr> <td align="right">0x437C</td> <td align="left">ChapLanguage</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaplanguage-element"></xref></td> </tr> <tr> <td align="right">0x437D</td> <td align="left">ChapLanguageBCP47</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaplanguagebcp47-element"></xref></td> </tr> <tr> <td align="right">0x437E</td> <td align="left">ChapCountry</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapcountry-element"></xref></td> </tr> <tr> <td align="right">0x4444</td> <td align="left">SegmentFamily</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="segmentfamily-element"></xref></td> </tr> <tr> <td align="right">0x4461</td> <td align="left">DateUTC</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="dateutc-element"></xref></td> </tr> <tr> <td align="right">0x447A</td> <td align="left">TagLanguage</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="taglanguage-element"></xref></td> </tr> <tr> <td align="right">0x447B</td> <td align="left">TagLanguageBCP47</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="taglanguagebcp47-element"></xref></td> </tr> <tr> <td align="right">0x4484</td> <td align="left">TagDefault</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagdefault-element"></xref></td> </tr> <tr> <td align="right">0x4485</td> <td align="left">TagBinary</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagbinary-element"></xref></td> </tr> <tr> <td align="right">0x4487</td> <td align="left">TagString</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagstring-element"></xref></td> </tr> <tr> <td align="right">0x4489</td> <td align="left">Duration</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="duration-element"></xref></td> </tr> <tr> <td align="right">0x44B4</td> <td align="left">TagDefaultBogus</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="tagdefaultbogus-element"></xref>)</td> </tr> <tr> <td align="right">0x450D</td> <td align="left">ChapProcessPrivate</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapprocessprivate-element"></xref></td> </tr> <tr> <td align="right">0x45A3</td> <td align="left">TagName</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagname-element"></xref></td> </tr> <tr> <td align="right">0x45B9</td> <td align="left">EditionEntry</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="editionentry-element"></xref></td> </tr> <tr> <td align="right">0x45BC</td> <td align="left">EditionUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="editionuid-element"></xref></td> </tr> <tr> <td align="right">0x45DB</td> <td align="left">EditionFlagDefault</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="editionflagdefault-element"></xref></td> </tr> <tr> <td align="right">0x45DD</td> <td align="left">EditionFlagOrdered</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="editionflagordered-element"></xref></td> </tr> <tr> <td align="right">0x465C</td> <td align="left">FileData</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="filedata-element"></xref></td> </tr> <tr> <td align="right">0x4660</td> <td align="left">FileMediaType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="filemediatype-element"></xref></td> </tr> <tr> <td align="right">0x4661</td> <td align="left">FileUsedStartTime</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="fileusedstarttime-element"></xref>)</td> </tr> <tr> <td align="right">0x4662</td> <td align="left">FileUsedEndTime</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="fileusedendtime-element"></xref>)</td> </tr> <tr> <td align="right">0x466E</td> <td align="left">FileName</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="filename-element"></xref></td> </tr> <tr> <td align="right">0x4675</td> <td align="left">FileReferral</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="filereferral-element"></xref>)</td> </tr> <tr> <td align="right">0x467E</td> <td align="left">FileDescription</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="filedescription-element"></xref></td> </tr> <tr> <td align="right">0x46AE</td> <td align="left">FileUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="fileuid-element"></xref></td> </tr> <tr> <td align="right">0x47E1</td> <td align="left">ContentEncAlgo</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencalgo-element"></xref></td> </tr> <tr> <td align="right">0x47E2</td> <td align="left">ContentEncKeyID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentenckeyid-element"></xref></td> </tr> <tr> <td align="right">0x47E3</td> <td align="left">ContentSignature</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="contentsignature-element"></xref>)</td> </tr> <tr> <td align="right">0x47E4</td> <td align="left">ContentSigKeyID</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="contentsigkeyid-element"></xref>)</td> </tr> <tr> <td align="right">0x47E5</td> <td align="left">ContentSigAlgo</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="contentsigalgo-element"></xref>)</td> </tr> <tr> <td align="right">0x47E6</td> <td align="left">ContentSigHashAlgo</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="contentsighashalgo-element"></xref>)</td> </tr> <tr> <td align="right">0x47E7</td> <td align="left">ContentEncAESSettings</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencaessettings-element"></xref></td> </tr> <tr> <td align="right">0x47E8</td> <td align="left">AESSettingsCipherMode</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="aessettingsciphermode-element"></xref></td> </tr> <tr> <td align="right">0x4D80</td> <td align="left">MuxingApp</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="muxingapp-element"></xref></td> </tr> <tr> <td align="right">0x4DBB</td> <td align="left">Seek</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="seek-element"></xref></td> </tr> <tr> <td align="right">0x5031</td> <td align="left">ContentEncodingOrder</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencodingorder-element"></xref></td> </tr> <tr> <td align="right">0x5032</td> <td align="left">ContentEncodingScope</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencodingscope-element"></xref></td> </tr> <tr> <td align="right">0x5033</td> <td align="left">ContentEncodingType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencodingtype-element"></xref></td> </tr> <tr> <td align="right">0x5034</td> <td align="left">ContentCompression</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentcompression-element"></xref></td> </tr> <tr> <td align="right">0x5035</td> <td align="left">ContentEncryption</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencryption-element"></xref></td> </tr> <tr> <td align="right">0x535F</td> <td align="left">CueRefNumber</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="cuerefnumber-element"></xref>)</td> </tr> <tr> <td align="right">0x536E</td> <td align="left">Name</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="name-element"></xref></td> </tr> <tr> <td align="right">0x5378</td> <td align="left">CueBlockNumber</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cueblocknumber-element"></xref></td> </tr> <tr> <td align="right">0x537F</td> <td align="left">TrackOffset</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="trackoffset-element"></xref>)</td> </tr> <tr> <td align="right">0x53AB</td> <td align="left">SeekID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="seekid-element"></xref></td> </tr> <tr> <td align="right">0x53AC</td> <td align="left">SeekPosition</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="seekposition-element"></xref></td> </tr> <tr> <td align="right">0x53B8</td> <td align="left">StereoMode</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="stereomode-element"></xref></td> </tr> <tr> <td align="right">0x53B9</td> <td align="left">OldStereoMode</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="oldstereomode-element"></xref></td> </tr> <tr> <td align="right">0x53C0</td> <td align="left">AlphaMode</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="alphamode-element"></xref></td> </tr> <tr> <td align="right">0x54AA</td> <td align="left">PixelCropBottom</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="pixelcropbottom-element"></xref></td> </tr> <tr> <td align="right">0x54B0</td> <td align="left">DisplayWidth</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="displaywidth-element"></xref></td> </tr> <tr> <td align="right">0x54B2</td> <td align="left">DisplayUnit</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="displayunit-element"></xref></td> </tr> <tr> <td align="right">0x54B3</td> <td align="left">AspectRatioType</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="aspectratiotype-element"></xref>)</td> </tr> <tr> <td align="right">0x54BA</td> <td align="left">DisplayHeight</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="displayheight-element"></xref></td> </tr> <tr> <td align="right">0x54BB</td> <td align="left">PixelCropTop</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="pixelcroptop-element"></xref></td> </tr> <tr> <td align="right">0x54CC</td> <td align="left">PixelCropLeft</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="pixelcropleft-element"></xref></td> </tr> <tr> <td align="right">0x54DD</td> <td align="left">PixelCropRight</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="pixelcropright-element"></xref></td> </tr> <tr> <td align="right">0x55AA</td> <td align="left">FlagForced</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagforced-element"></xref></td> </tr> <tr> <td align="right">0x55AB</td> <td align="left">FlagHearingImpaired</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flaghearingimpaired-element"></xref></td> </tr> <tr> <td align="right">0x55AC</td> <td align="left">FlagVisualImpaired</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagvisualimpaired-element"></xref></td> </tr> <tr> <td align="right">0x55AD</td> <td align="left">FlagTextDescriptions</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagtextdescriptions-element"></xref></td> </tr> <tr> <td align="right">0x55AE</td> <td align="left">FlagOriginal</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagoriginal-element"></xref></td> </tr> <tr> <td align="right">0x55AF</td> <td align="left">FlagCommentary</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="flagcommentary-element"></xref></td> </tr> <tr> <td align="right">0x55B0</td> <td align="left">Colour</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="colour-element"></xref></td> </tr> <tr> <td align="right">0x55B1</td> <td align="left">MatrixCoefficients</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="matrixcoefficients-element"></xref></td> </tr> <tr> <td align="right">0x55B2</td> <td align="left">BitsPerChannel</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="bitsperchannel-element"></xref></td> </tr> <tr> <td align="right">0x55B3</td> <td align="left">ChromaSubsamplingHorz</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chromasubsamplinghorz-element"></xref></td> </tr> <tr> <td align="right">0x55B4</td> <td align="left">ChromaSubsamplingVert</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chromasubsamplingvert-element"></xref></td> </tr> <tr> <td align="right">0x55B5</td> <td align="left">CbSubsamplingHorz</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cbsubsamplinghorz-element"></xref></td> </tr> <tr> <td align="right">0x55B6</td> <td align="left">CbSubsamplingVert</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cbsubsamplingvert-element"></xref></td> </tr> <tr> <td align="right">0x55B7</td> <td align="left">ChromaSitingHorz</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chromasitinghorz-element"></xref></td> </tr> <tr> <td align="right">0x55B8</td> <td align="left">ChromaSitingVert</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chromasitingvert-element"></xref></td> </tr> <tr> <td align="right">0x55B9</td> <td align="left">Range</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="range-element"></xref></td> </tr> <tr> <td align="right">0x55BA</td> <td align="left">TransferCharacteristics</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="transfercharacteristics-element"></xref></td> </tr> <tr> <td align="right">0x55BB</td> <td align="left">Primaries</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primaries-element"></xref></td> </tr> <tr> <td align="right">0x55BC</td> <td align="left">MaxCLL</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="maxcll-element"></xref></td> </tr> <tr> <td align="right">0x55BD</td> <td align="left">MaxFALL</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="maxfall-element"></xref></td> </tr> <tr> <td align="right">0x55D0</td> <td align="left">MasteringMetadata</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="masteringmetadata-element"></xref></td> </tr> <tr> <td align="right">0x55D1</td> <td align="left">PrimaryRChromaticityX</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primaryrchromaticityx-element"></xref></td> </tr> <tr> <td align="right">0x55D2</td> <td align="left">PrimaryRChromaticityY</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primaryrchromaticityy-element"></xref></td> </tr> <tr> <td align="right">0x55D3</td> <td align="left">PrimaryGChromaticityX</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primarygchromaticityx-element"></xref></td> </tr> <tr> <td align="right">0x55D4</td> <td align="left">PrimaryGChromaticityY</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primarygchromaticityy-element"></xref></td> </tr> <tr> <td align="right">0x55D5</td> <td align="left">PrimaryBChromaticityX</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primarybchromaticityx-element"></xref></td> </tr> <tr> <td align="right">0x55D6</td> <td align="left">PrimaryBChromaticityY</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="primarybchromaticityy-element"></xref></td> </tr> <tr> <td align="right">0x55D7</td> <td align="left">WhitePointChromaticityX</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="whitepointchromaticityx-element"></xref></td> </tr> <tr> <td align="right">0x55D8</td> <td align="left">WhitePointChromaticityY</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="whitepointchromaticityy-element"></xref></td> </tr> <tr> <td align="right">0x55D9</td> <td align="left">LuminanceMax</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="luminancemax-element"></xref></td> </tr> <tr> <td align="right">0x55DA</td> <td align="left">LuminanceMin</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="luminancemin-element"></xref></td> </tr> <tr> <td align="right">0x55EE</td> <td align="left">MaxBlockAdditionID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="maxblockadditionid-element"></xref></td> </tr> <tr> <td align="right">0x5654</td> <td align="left">ChapterStringUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapterstringuid-element"></xref></td> </tr> <tr> <td align="right">0x56AA</td> <td align="left">CodecDelay</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="codecdelay-element"></xref></td> </tr> <tr> <td align="right">0x56BB</td> <td align="left">SeekPreRoll</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="seekpreroll-element"></xref></td> </tr> <tr> <td align="right">0x5741</td> <td align="left">WritingApp</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="writingapp-element"></xref></td> </tr> <tr> <td align="right">0x5854</td> <td align="left">SilentTracks</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="silenttracks-element"></xref>)</td> </tr> <tr> <td align="right">0x58D7</td> <td align="left">SilentTrackNumber</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="silenttracknumber-element"></xref>)</td> </tr> <tr> <td align="right">0x61A7</td> <td align="left">AttachedFile</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="attachedfile-element"></xref></td> </tr> <tr> <td align="right">0x6240</td> <td align="left">ContentEncoding</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencoding-element"></xref></td> </tr> <tr> <td align="right">0x6264</td> <td align="left">BitDepth</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="bitdepth-element"></xref></td> </tr> <tr> <td align="right">0x63A2</td> <td align="left">CodecPrivate</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="codecprivate-element"></xref></td> </tr> <tr> <td align="right">0x63C0</td> <td align="left">Targets</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="targets-element"></xref></td> </tr> <tr> <td align="right">0x63C3</td> <td align="left">ChapterPhysicalEquiv</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapterphysicalequiv-element"></xref></td> </tr> <tr> <td align="right">0x63C4</td> <td align="left">TagChapterUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagchapteruid-element"></xref></td> </tr> <tr> <td align="right">0x63C5</td> <td align="left">TagTrackUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagtrackuid-element"></xref></td> </tr> <tr> <td align="right">0x63C6</td> <td align="left">TagAttachmentUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tagattachmentuid-element"></xref></td> </tr> <tr> <td align="right">0x63C9</td> <td align="left">TagEditionUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tageditionuid-element"></xref></td> </tr> <tr> <td align="right">0x63CA</td> <td align="left">TargetType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="targettype-element"></xref></td> </tr> <tr> <td align="right">0x6624</td> <td align="left">TrackTranslate</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracktranslate-element"></xref></td> </tr> <tr> <td align="right">0x66A5</td> <td align="left">TrackTranslateTrackID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracktranslatetrackid-element"></xref></td> </tr> <tr> <td align="right">0x66BF</td> <td align="left">TrackTranslateCodec</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracktranslatecodec-element"></xref></td> </tr> <tr> <td align="right">0x66FC</td> <td align="left">TrackTranslateEditionUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracktranslateeditionuid-element"></xref></td> </tr> <tr> <td align="right">0x67C8</td> <td align="left">SimpleTag</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="simpletag-element"></xref></td> </tr> <tr> <td align="right">0x68CA</td> <td align="left">TargetTypeValue</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="targettypevalue-element"></xref></td> </tr> <tr> <td align="right">0x6911</td> <td align="left">ChapProcessCommand</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapprocesscommand-element"></xref></td> </tr> <tr> <td align="right">0x6922</td> <td align="left">ChapProcessTime</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapprocesstime-element"></xref></td> </tr> <tr> <td align="right">0x6924</td> <td align="left">ChapterTranslate</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptertranslate-element"></xref></td> </tr> <tr> <td align="right">0x6933</td> <td align="left">ChapProcessData</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapprocessdata-element"></xref></td> </tr> <tr> <td align="right">0x6944</td> <td align="left">ChapProcess</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapprocess-element"></xref></td> </tr> <tr> <td align="right">0x6955</td> <td align="left">ChapProcessCodecID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapprocesscodecid-element"></xref></td> </tr> <tr> <td align="right">0x69A5</td> <td align="left">ChapterTranslateID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptertranslateid-element"></xref></td> </tr> <tr> <td align="right">0x69BF</td> <td align="left">ChapterTranslateCodec</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptertranslatecodec-element"></xref></td> </tr> <tr> <td align="right">0x69FC</td> <td align="left">ChapterTranslateEditionUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptertranslateeditionuid-element"></xref></td> </tr> <tr> <td align="right">0x6D80</td> <td align="left">ContentEncodings</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="contentencodings-element"></xref></td> </tr> <tr> <td align="right">0x6DE7</td> <td align="left">MinCache</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="mincache-element"></xref>)</td> </tr> <tr> <td align="right">0x6DF8</td> <td align="left">MaxCache</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="maxcache-element"></xref>)</td> </tr> <tr> <td align="right">0x6E67</td> <td align="left">ChapterSegmentUUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptersegmentuuid-element"></xref></td> </tr> <tr> <td align="right">0x6EBC</td> <td align="left">ChapterSegmentEditionUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chaptersegmenteditionuid-element"></xref></td> </tr> <tr> <td align="right">0x6FAB</td> <td align="left">TrackOverlay</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="trackoverlay-element"></xref>)</td> </tr> <tr> <td align="right">0x7373</td> <td align="left">Tag</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tag-element"></xref></td> </tr> <tr> <td align="right">0x7384</td> <td align="left">SegmentFilename</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="segmentfilename-element"></xref></td> </tr> <tr> <td align="right">0x73A4</td> <td align="left">SegmentUUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="segmentuuid-element"></xref></td> </tr> <tr> <td align="right">0x73C4</td> <td align="left">ChapterUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapteruid-element"></xref></td> </tr> <tr> <td align="right">0x73C5</td> <td align="left">TrackUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="trackuid-element"></xref></td> </tr> <tr> <td align="right">0x7446</td> <td align="left">AttachmentLink</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="attachmentlink-element"></xref></td> </tr> <tr> <td align="right">0x75A1</td> <td align="left">BlockAdditions</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="blockadditions-element"></xref></td> </tr> <tr> <td align="right">0x75A2</td> <td align="left">DiscardPadding</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="discardpadding-element"></xref></td> </tr> <tr> <td align="right">0x7670</td> <td align="left">Projection</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="projection-element"></xref></td> </tr> <tr> <td align="right">0x7671</td> <td align="left">ProjectionType</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="projectiontype-element"></xref></td> </tr> <tr> <td align="right">0x7672</td> <td align="left">ProjectionPrivate</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="projectionprivate-element"></xref></td> </tr> <tr> <td align="right">0x7673</td> <td align="left">ProjectionPoseYaw</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="projectionposeyaw-element"></xref></td> </tr> <tr> <td align="right">0x7674</td> <td align="left">ProjectionPosePitch</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="projectionposepitch-element"></xref></td> </tr> <tr> <td align="right">0x7675</td> <td align="left">ProjectionPoseRoll</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="projectionposeroll-element"></xref></td> </tr> <tr> <td align="right">0x78B5</td> <td align="left">OutputSamplingFrequency</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="outputsamplingfrequency-element"></xref></td> </tr> <tr> <td align="right">0x7BA9</td> <td align="left">Title</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="title-element"></xref></td> </tr> <tr> <td align="right">0x7D7B</td> <td align="left">ChannelPositions</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="channelpositions-element"></xref>)</td> </tr> <tr> <td align="right">0x22B59C</td> <td align="left">Language</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="language-element"></xref></td> </tr> <tr> <td align="right">0x22B59D</td> <td align="left">LanguageBCP47</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="languagebcp47-element"></xref></td> </tr> <tr> <td align="right">0x23314F</td> <td align="left">TrackTimestampScale</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracktimestampscale-element"></xref></td> </tr> <tr> <td align="right">0x234E7A</td> <td align="left">DefaultDecodedFieldDuration</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="defaultdecodedfieldduration-element"></xref></td> </tr> <tr> <td align="right">0x2383E3</td> <td align="left">FrameRate</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="framerate-element"></xref>)</td> </tr> <tr> <td align="right">0x23E383</td> <td align="left">DefaultDuration</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="defaultduration-element"></xref></td> </tr> <tr> <td align="right">0x258688</td> <td align="left">CodecName</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="codecname-element"></xref></td> </tr> <tr> <td align="right">0x26B240</td> <td align="left">CodecDownloadURL</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="codecdownloadurl-element"></xref>)</td> </tr> <tr> <td align="right">0x2AD7B1</td> <td align="left">TimestampScale</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="timestampscale-element"></xref></td> </tr> <tr> <td align="right">0x2EB524</td> <td align="left">UncompressedFourCC</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="uncompressedfourcc-element"></xref></td> </tr> <tr> <td align="right">0x2FB523</td> <td align="left">GammaValue</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="gammavalue-element"></xref>)</td> </tr> <tr> <td align="right">0x3A9697</td> <td align="left">CodecSettings</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="codecsettings-element"></xref>)</td> </tr> <tr> <td align="right">0x3B4040</td> <td align="left">CodecInfoURL</td> <td align="left">Reclaimed(<xref(RFC 9559, <xref target="codecinfourl-element"></xref>)</td> </tr> <tr> <td align="right">0x3C83AB</td> <td align="left">PrevFilename</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="prevfilename-element"></xref></td> </tr> <tr> <td align="right">0x3CB923</td> <td align="left">PrevUUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="prevuuid-element"></xref></td> </tr> <tr> <td align="right">0x3E83BB</td> <td align="left">NextFilename</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="nextfilename-element"></xref></td> </tr> <tr> <td align="right">0x3EB923</td> <td align="left">NextUUID</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="nextuuid-element"></xref></td> </tr> <tr> <td align="right">0x1043A770</td> <td align="left">Chapters</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="chapters-element"></xref></td> </tr> <tr> <td align="right">0x114D9B74</td> <td align="left">SeekHead</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="seekhead-element"></xref></td> </tr> <tr> <td align="right">0x1254C367</td> <td align="left">Tags</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tags-element"></xref></td> </tr> <tr> <td align="right">0x1549A966</td> <td align="left">Info</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="info-element"></xref></td> </tr> <tr> <td align="right">0x1654AE6B</td> <td align="left">Tracks</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="tracks-element"></xref></td> </tr> <tr> <td align="right">0x18538067</td> <td align="left">Segment</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="segment-element"></xref></td> </tr> <tr> <td align="right">0x1941A469</td> <td align="left">Attachments</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="attachments-element"></xref></td> </tr> <tr> <td align="right">0x1C53BB6B</td> <td align="left">Cues</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cues-element"></xref></td> </tr> <tr> <td align="right">0x1F43B675</td> <td align="left">Cluster</td> <tdalign="left">Described inalign="left">RFC 9559, <xref target="cluster-element"></xref></td> </tr> </tbody> </table></section> <section anchor="chapter-codec-ids-registry"><name>Chapter Codec IDs Registry</name><t>This document creates<t>IANA has created a newIANAregistry called the"Matroska"Matroska Chapter CodecIDs"IDs" registry. The values correspond to the unsigned integer <tt>ChapProcessCodecID</tt> value described in <xref target="chapprocesscodecid-element"></xref>.</t> <t>To register a new Chapter Codec ID in this registry, one needs a Chapter Codec ID, a Change Controller (IETF or email ofregistrant)registrant), and an optional Reference to a document describing the Chapter Codec ID.</t> <t>The Chapter Codec IDs are to be allocated according to the"First"First Come FirstServed"Served" policy <xref target="RFC8126"></xref>.</t><t><tt>ChapProcessCodecID</tt> values<t>Values of"0""0" and"1""1" areRESERVED to the IETFreserved for futureuse.</t>use (with the IETF as the Change Controller).</t> </section> <section anchor="media-types"><name>Media Types</name><t>Matroska<!-- [rfced] Please review the text after the ":" and let us know how to update for clarity. Are the words "files" and "tracks" needed? Original: Matroska files and streams are found in three main forms: audio-video files, audio-only and occasionally with stereoscopic video tracks. Perhaps: Matroska files and streams are found in three main forms: audio-video, audio-only, and (occasionally) stereoscopic video. --> <t>Matroska files and streams are found in three main forms: audio-video files, audio-only, and occasionally with stereoscopic video tracks.</t><t>Historically<t>Historically, Matroska files and streams have used the following media types witha "x-"an "x-" prefix. For bettercompatibilitycompatibility, a system <bcp14>SHOULD</bcp14> be able to handle both formats. Newer systems <bcp14>SHOULD NOT</bcp14> use the historic format and use the format that follows the format in <xref target="RFC6838"></xref>formatinstead.</t><t>Please register<t>IANA has registered three mediatypes,types per the<xref target="RFC6838"></xref>templatesare below:</t>(see <xref target="RFC6838"></xref>) in the following subsections.</t> <section anchor="for-files-containing-video-tracks"><name>Forfiles containing video tracks</name> <dl spacing="compact">Files Containing Video Tracks</name> <dl> <dt>Type name:</dt> <dd>video</dd> <dt>Subtype name:</dt> <dd>matroska</dd> <dt>Required parameters:</dt> <dd>N/A</dd> <dt>Optional parameters:</dt> <dd>N/A</dd> <dt>Encoding considerations:</dt><dd>as<dd>As perthis documentRFCs 9559 andRFC8794</dd>8794</dd> <dt>Security considerations:</dt> <dd>See <xreftarget="security-considerations"></xref>.</dd>target="security-considerations"></xref> of RFC 9559.</dd> <dt>Interoperability considerations:</dt> <dd>Due to the extensibility of Matroska, it is possible to encounter files with unknown but valid EBML Elements. Readers should be ready to handle this case. The fixed byte order, octetboundariesboundaries, and UTF-8 usage allow for broadinteroparability.</dd>interoperability.</dd> <dt>Published specification:</dt><dd>THISRFC</dd><dd>RFC 9559</dd> <dt>Applications that use this media type:</dt> <dd>FFmpeg, VLC, ...</dd> <dt>Fragment identifier considerations:</dt> <dd>N/A</dd></dl> <t>Additional information:</t> <ul> <li><t>Deprecated<dt>Additional information:</dt><dd> <t><br/></t> <dl spacing="compact"> <dt>Deprecated alias names for thistype: video/x-matroska</t> </li> <li><t>Magic number(s): N/A</t> </li> <li><t>File extension(s): mkv</t> </li> <li><t>Macintoshtype:</dt><dd>video/x-matroska</dd> <dt>Magic number(s):</dt><dd>N/A</dd> <dt>File extension(s):</dt><dd>mkv</dd> <dt>Macintosh file typecode(s): N/A</t> </li> </ul> <dl spacing="compact">code(s):</dt><dd>N/A</dd> </dl></dd> <dt>Person & email address to contact for further information:</dt> <dd>IETF CELLAR WGcellar@ietf.org</dd>(cellar@ietf.org)</dd> <dt>Intended usage:</dt> <dd>COMMON</dd> <dt>Restrictions on usage:</dt> <dd>None</dd> <dt>Author:</dt> <dd>IETF CELLAR WG</dd> <dt>Change controller:</dt> <dd>IETF</dd><dt>Provisional registration? (standards tree only):</dt> <dd>No</dd></dl> </section> <section anchor="for-files-containing-audio-tracks-with-no-video-tracks"><name>Forfiles containing audio tracksFiles Containing Audio Tracks withno video tracks</name> <dl spacing="compact">No Video Tracks</name> <dl> <dt>Type name:</dt> <dd>audio</dd> <dt>Subtype name:</dt> <dd>matroska</dd> <dt>Required parameters:</dt> <dd>N/A</dd> <dt>Optional parameters:</dt> <dd>N/A</dd> <dt>Encoding considerations:</dt><dd>as<dd>As perthis documentRFCs 9559 andRFC8794</dd>8794</dd> <dt>Security considerations:</dt> <dd>See <xreftarget="security-considerations"></xref>.</dd>target="security-considerations"></xref> of RFC 9559.</dd> <dt>Interoperability considerations:</dt> <dd>Due to the extensibility of Matroska, it is possible to encounter files with unknown but valid EBML Elements. Readers should be ready to handle this case. The fixed byte order, octetboundariesboundaries, and UTF-8 usage allow for broadinteroparability.</dd>interoperability.</dd> <dt>Published specification:</dt><dd>THISRFC</dd><dd>RFC 9559</dd> <dt>Applications that use this media type:</dt> <dd>FFmpeg, VLC, ...</dd> <dt>Fragment identifier considerations:</dt> <dd>N/A</dd></dl> <t>Additional information:</t> <ul> <li><t>Deprecated<dt>Additional information:</dt><dd> <t><br/></t> <dl spacing="compact"> <dt>Deprecated alias names for thistype: audio/x-matroska</t> </li> <li><t>Magic number(s): N/A</t> </li> <li><t>File extension(s): mka</t> </li> <li><t>Macintoshtype:</dt><dd>audio/x-matroska</dd> <dt>Magic number(s):</dt><dd>N/A</dd> <dt>File extension(s):</dt><dd>mka</dd> <dt>Macintosh file typecode(s): N/A</t> </li> </ul> <dl spacing="compact">code(s):</dt><dd>N/A</dd> </dl> </dd></dl> <dl> <dt>Person & email address to contact for further information:</dt> <dd>IETF CELLAR WGcellar@ietf.org</dd>(cellar@ietf.org)</dd> <dt>Intended usage:</dt> <dd>COMMON</dd> <dt>Restrictions on usage:</dt> <dd>None</dd> <dt>Author:</dt> <dd>IETF CELLAR WG</dd> <dt>Change controller:</dt> <dd>IETF</dd><dt>Provisional registration? (standards tree only):</dt> <dd>No</dd></dl> </section> <section anchor="for-files-containing-a-stereoscopic-video-track"><name>Forfiles containingFiles Containing astereoscopic video track</name> <dl spacing="compact">Stereoscopic Video Track</name> <dl> <dt>Type name:</dt> <dd>video</dd> <dt>Subtype name:</dt> <dd>matroska-3d</dd> <dt>Required parameters:</dt> <dd>N/A</dd> <dt>Optional parameters:</dt> <dd>N/A</dd> <dt>Encoding considerations:</dt><dd>as<dd>As perthis documentRFCs 9559 andRFC8794</dd>8794 </dd> <dt>Security considerations:</dt> <dd>See <xreftarget="security-considerations"></xref>.</dd>target="security-considerations"></xref> of RFC 9559.</dd> <dt>Interoperability considerations:</dt> <dd>Due to the extensibility of Matroska, it is possible to encounter files with unknown but valid EBML Elements. Readers should be ready to handle this case. The fixed byte order, octetboundariesboundaries, and UTF-8 usage allow for broadinteroparability.</dd>interoperability.</dd> <dt>Published specification:</dt><dd>THISRFC</dd><dd>RFC 9559</dd> <dt>Applications that use this media type:</dt> <dd>FFmpeg, VLC, ...</dd> <dt>Fragment identifier considerations:</dt> <dd>N/A</dd></dl> <t>Additional information:</t> <ul> <li><t>Deprecated<dt>Additional information:</dt><dd> <t><br/></t> <dl spacing="compact"> <dt>Deprecated alias names for thistype: video/x-matroska-3d</t> </li> <li><t>Magic number(s): N/A</t> </li> <li><t>File extension(s): mk3d</t> </li> <li><t>Macintoshtype:</dt><dd>video/x-matroska-3d</dd> <dt>Magic number(s):</dt><dd>N/A</dd> <dt>File extension(s):</dt><dd>mk3d</dd> <dt>Macintosh file typecode(s): N/A</t> </li> </ul> <dl spacing="compact">code(s):</dt><dd>N/A</dd> </dl> </dd></dl> <dl> <dt>Person & email address to contact for further information:</dt> <dd>IETF CELLAR WGcellar@ietf.org</dd>(cellar@ietf.org)</dd> <dt>Intended usage:</dt> <dd>COMMON</dd> <dt>Restrictions on usage:</dt> <dd>None</dd> <dt>Author:</dt> <dd>IETF CELLAR WG</dd> <dt>Change controller:</dt> <dd>IETF</dd><dt>Provisional registration? (standards tree only):</dt> <dd>No</dd></dl> </section> </section> </section> </middle> <back> <displayreference target="RFC5646" to="BCP47"/> <displayreference target="I-D.ietf-cellar-codec" to="MatroskaCodec"/> <displayreference target="I-D.ietf-cellar-tags" to="MatroskaTags"/> <!-- [rfced] BCP 47 contains two RFCs: RFC 4647 and RFC 5646. See https://www.rfc-editor.org/info/bcp47. It seems that when "BCP 47" and "[BCP47]" are used, the intent is to refer to RFC 5646. Is this correct? If so, we recommend the following updates. Note that we will not make any changes to element names (e.g., LanguageBCP47 and ChapLanguageBCP47). a) Add the following sentence to the end of Section 12 to clarify that "BCP47" in element names refers specifically to RFC 5646. Perhaps: In this document, "BCP47" in element names refers specifically to [RFC5646], which is part of BCP 47. b) Update these sentences in Section 12 as follows to use RFC 5647 rather than BCP 47 Original: Starting in Matroska version 4, either [ISO639-2] or [BCP47] MAY be used, although BCP 47 is RECOMMENDED. The BCP 47 Language Elements are "LanguageBCP47 Element", "TagLanguageBCP47 Element", and "ChapLanguageBCP47 Element". If a BCP 47 Language Element and an ISO 639-2 Language Element are used within the same Parent Element, then the ISO 639-2 Language Element MUST be ignored and precedence given to the BCP 47 Language Element. Perhaps: Starting in Matroska version 4, the forms defined in either [ISO639-2] or [RFC5646] MAY be used, although the form in [RFC5646] is RECOMMENDED. The Language Elements in the [RFC5646] form are are "LanguageBCP47 Element", "TagLanguageBCP47 Element", and "ChapLanguageBCP47 Element". If both an [ISO639-2] Language Element and an [RFC5646] Language Element are used within the same Parent Element, then the Language Element in the [ISO639-2] form MUST be ignored and precedence given to the Language Element in the [RFC5646] form. c) Update these sentences to use RFC 5647 rather than BCP 47 Original: definition: The language of the track, in the [BCP47] form; see Section 12 on language codes. definition: A language corresponding to the ChapString, in the [BCP47] form; see Section 12 on language codes. definition: The language used in the TagString, in the [BCP47] form; see Section 12 on language codes. Country codes are the [BCP47] two-letter region subtag, without the UK exception. Perhaps: definition: The language of the track, in the form defined in [RFC5646]; see Section 12 on language codes. definition: A language corresponding to the ChapString, in the form defined in [RFC5646]; see Section 12 on language codes. definition: The language used in the TagString, in the form defined in [RFC5646]; see Section 12 on language codes. Country codes are the two-letter region subtag defined in [RFC5646], without the UK exception. --> <!-- [rfced] We see a few instances of "in the Matroska languages form" with a pointer to Section 12, which discusses the [ISO639-2] or [BCP47] forms. Please review and let us know if "in the Matroska languages form" will be clear to readers or if updates are needed. Original: definition: The language of the track, in the Matroska languages form; see Section 12 on language codes. definition: A language corresponding to the string, in the Matroska languages form; see Section 12 on language codes. definition: Specifies the language of the tag specified, in the Matroska languages form; see Section 12 on language codes. --> <!-- [rfced] References a) FYI - For clarity, we added "[RFC8794]" after several instances of "the EBML specification". b) The original link provided for the following reference is a withdrawn standard. We have updated the the date and URL to point to the current version. Please let us know any concerns. Original: [ISO9899] International Organization for Standardization, "Information technology - Programming languages - C", ISO/IEC 9899:2011, 2011, <https://www.iso.org/standard/57853.html>. Current: [ISO9899] International Organization for Standardization, "Information technology - Programming languages - C", ISO/IEC 9899:2018, June 2018, <https://www.iso.org/standard/74528.html>. c) The URL in the following reference entry displays a landing page titled "Welcome to the DVD Forum". We were unable to find a page titled "DVD-Books: Part 3 DVD-Video Book". How may we update this entry so that readers can find the reference? Original: [DVD-Video] DVD Forum, "DVD-Books: Part 3 DVD-Video Book", 1 November 1995, <http://www.dvdforum.org/>. d) We do not see the title "DivX Trick Track Extensions" at the URL provided. Should the title of this reference entry be updated to "DivX Plus MKV extension: Smooth FF/RW" per the URL? Original: [DivXTrickTrack] "DivX Trick Track Extensions", 14 December 2010, <https://web.archive.org/web/20101222001148/ http://labs.divx.com/node/16601>. e) We note that this standard was withdrawn on May 19, 2005. Are any updates needed? Original: [FIPS.46-3] US National Institute of Standards and Technology, "Data Encryption Standard (DES)", FIPS PUB 46, 25 October 1999, <https://csrc.nist.gov/publications/detail/fips/46/3/ archive/1999-10-25>. f) We have updated the reference as follows to reflect 1) the title shown in the URL and 2) the authors listed in the Authors section of the URL. Please let us know any concerns. [LZO] Tarreau, W., Rodgman, R., and M. Oberhumer, "Lempel-Ziv- Oberhumer compression", 30 October 2018, <https://www.kernel.org/doc/Documentation/lzo.txt>. Current: [LZO] Tarreau, W. and R. Rodgman, "LZO stream format as understood by Linux's LZO decompressor", October 2018, <https://www.kernel.org/doc/Documentation/lzo.txt>. g) May we update the URL in this reference entry as follows to point directly to the paper? Original: [Twofish] Schneier, B., Kelsey, J., Whiting, D., Wagner, D., Hall, C., and N. Ferguson, "Twofish: A 128-Bit Block Cipher", 15 June 1998, <https://www.schneier.com/academic/twofish/>. Current: [Twofish] Schneier, B., Kelsey, J., Whiting, D., Wagner, D., Hall, C., and N. Ferguson, "Twofish: A 128-Bit Block Cipher", June 1998, <https://www.schneier.com/academic/archives/1998/06/twofish_a_128-bit_bl.html>. h) The Security Considerations section points to Section 2.1 of [RFC4732], but no corresponding entry in the References section was included. We added [RFC4732] as an informative reference. Please let us know if it should be normative instead. --> <references><name>References</name> <references><name>Normative References</name> <reference anchor="CIE-1931" target="https://en.wikipedia.org/wiki/CIE_1931_color_space"> <front> <title>CIE 1931 color space</title> <author> <organization>Wikipedia</organization> </author> </front> </reference> <reference anchor="ISO639-2" target="https://www.loc.gov/standards/iso639-2/php/code_list.php"> <front> <title>Codes for the Representation of Names of Languages</title> <author> <organization>International Organization for Standardization</organization> </author> <date year="2017" month="December"></date> </front> <seriesInfo name="ISO" value="639-2"></seriesInfo> </reference> <reference anchor="ISO9899" target="https://www.iso.org/standard/74528.html"> <front> <title>Information technology -- Programming languages -- C</title> <author> <organization>International Organization for Standardization</organization> </author> <date month="June" year="2018"></date> </front> <seriesInfo name="ISO/IEC" value="9899:2018"></seriesInfo> </reference> <reference anchor="ITU-H.273" target="https://www.itu.int/rec/T-REC-H.273-202309-P/en"> <front> <title>Coding-independent code points for video signal type identification</title> <author> <organization>ITU-T</organization> </author> <date year="2023" month="September"></date> </front> <seriesInfo name="ITU-T Recommendation" value="H.273"></seriesInfo> </reference> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.5646.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.1950.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4122.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.6838.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8081.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.8794.xml"/> </references> <references><name>Informative References</name> <reference anchor="Err7189" quote-title="false" target="https://www.rfc-editor.org/errata/eid7189"> <front> <title>Erratum ID 7189</title> <author> <organization>RFC Errata</organization> </author> </front> <refcontent>RFC 8794</refcontent> </reference> <reference anchor="Err7191" quote-title="false" target="https://www.rfc-editor.org/errata/eid7191"> <front> <title>Erratum ID 7191</title> <author> <organization>RFC Errata</organization> </author> </front> <refcontent>RFC 8794</refcontent> </reference> <reference anchor="AVIFormat" target="https://docs.microsoft.com/en-us/windows/win32/directshow/avi-riff-file-reference"> <front> <title>AVI RIFF File Reference</title> <author> <organization>Microsoft Corporation</organization> </author> <date year="2023" month="June"></date> </front> </reference> <reference anchor="BZIP2" target="https://sourceware.org/bzip2/"> <front> <title>bzip2</title> <author fullname="Julian Seward" initials="J." surname="Seward"> <organization></organization> </author> <date year="2019" month="July"></date> </front> </reference> <reference anchor="Blowfish" target="https://www.schneier.com/academic/blowfish/"> <front> <title>The Blowfish Encryption Algorithm</title> <author fullname="Bruce Schneier" initials="B." surname="Schneier"> <organization></organization> </author> <date year="1993"></date> </front> </reference> <reference anchor="DVD-Video" target="http://www.dvdforum.org/"> <front> <title>DVD-Books: Part 3 DVD-Video Book</title> <author> <organization>DVD Forum</organization> </author> <date year="1995" month="November"></date> </front> </reference> <reference anchor="DivXTrickTrack" target="https://web.archive.org/web/20101222001148/http://labs.divx.com/node/16601"> <front> <title>DivX Trick Track Extensions</title> <author></author> <date year="2010" month="December"></date> </front> </reference> <reference anchor="DivXWorldFonts" target="https://web.archive.org/web/20110214132246/http://labs.divx.com/node/16602"> <front> <title>World Fonts</title> <author></author> <date year="2010" month="December"></date> </front> </reference> <reference anchor="FIPS197" target="https://csrc.nist.gov/publications/detail/fips/197/final"> <front> <title>Advanced Encryption Standard (AES)</title> <author> <organization>National Institute of Standards and Technology (NIST)</organization> </author> <date year="2001" month="November"></date> </front> <seriesInfo name="FIPS" value="PUB 197"></seriesInfo> <seriesInfo name="DOI" value="10.6028/NIST.FIPS.197"></seriesInfo> </reference> <reference anchor="FIPS46-3" target="https://csrc.nist.gov/publications/detail/fips/46/3/archive/1999-10-25"> <front> <title>Data Encryption Standard (DES)</title> <author> <organization>National Institute of Standards and Technology (NIST)</organization> </author> <date year="1999" month="October"></date> </front> <seriesInfo name="FIPS" value="PUB 46"></seriesInfo> </reference> <reference anchor="FourCC-RGB" target="https://web.archive.org/web/20160609214806/https://www.fourcc.org/rgb.php"> <front> <title>RGB pixel formats</title> <author> <organization>FOURCC</organization> </author> </front> </reference> <reference anchor="FourCC-YUV" target="https://web.archive.org/web/20160609214806/https://www.fourcc.org/yuv.php"> <front> <title>YUV pixel formats</title> <author> <organization>FOURCC</organization> </author> </front> </reference> <reference anchor="JPEG" target="https://www.w3.org/Graphics/JPEG/itu-t81.pdf"> <front> <title>INFORMATION TECHNOLOGY - DIGITAL COMPRESSION AND CODING OF CONTINUOUS-TONE STILL IMAGES - REQUIREMENTS AND GUIDELINES</title> <author> <organization>ITU</organization> </author> <date year="1992" month="September"></date> </front> <seriesInfo name="ITU Recommendation" value="T.81"></seriesInfo> </reference> <reference anchor="LZO" target="https://www.kernel.org/doc/Documentation/lzo.txt"> <front> <title>LZO stream format as understood by Linux's LZO decompressor</title> <author fullname="Willy Tarreau" initials="W." surname="Tarreau"> <organization></organization> </author> <author fullname="Dave Rodgman" initials="R." surname="Rodgman"> <organization></organization> </author> <date year="2018" month="October"></date> </front> </reference> <reference anchor="MCF" target="http://mukoli.free.fr/mcf/"> <front> <title>MCF specification, introduction</title> <author></author> </front> </reference> <reference anchor="MSRGB" target="https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-wmf/4e588f70-bd92-4a6f-b77f-35d0feaf7a57"> <front> <title>Compression Enumeration</title> <author> <organization>Microsoft Corporation</organization> </author> <date month="June" year="2021"/> </front> </reference> <reference anchor="MSYUV16" target="https://learn.microsoft.com/en-us/windows/win32/medfound/10-bit-and-16-bit-yuv-video-formats"> <front> <title>10-bit and 16-bit YUV Video Formats</title> <author> <organization>Microsoft Corporation</organization> </author> <date month="November" year="2022"/> </front> </reference> <reference anchor="MSYUV8" target="https://learn.microsoft.com/en-us/windows/win32/medfound/recommended-8-bit-yuv-formats-for-video-rendering"> <front> <title>Recommended 8-Bit YUV Formats for Video Rendering</title> <author> <organization>Microsoft Corporation</organization> </author> <date month="January" year="2021"/> </front> </reference> <!-- IESG state: I-D Exists as of 3/1 --> <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-cellar-codec.xml"/> <!-- IESG state: I-D Exists as of 3/1 --> <xi:include href="https://datatracker.ietf.org/doc/bibxml3/reference.I-D.ietf-cellar-tags.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.0959.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.2083.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.3533.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.9110.xml"/> <xi:include href="https://bib.ietf.org/public/rfc/bibxml/reference.RFC.4732.xml"/> <reference anchor="SMB-CIFS" target="https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-CIFS/%5bMS-CIFS%5d.pdf"> <front> <title>[MS-CIFS]: Common Internet File System (CIFS) Protocol</title> <author> <organization>Microsoft Corporation</organization> </author> <date year="2020" month="October"/> </front> </reference> <reference anchor="SP800-38A" target="https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38a.pdf"> <front> <title>Recommendation for Block Cipher Modes of Operation: Methods and Techniques</title> <author> <organization>National Institute of Standards and Technology (NIST)</organization> </author> <date year="2001" month="December"></date> </front> <seriesInfo name="DOI" value="10.6028/NIST.SP.800-38A"></seriesInfo> <seriesInfo name="NIST Special Publication" value="800-38A"/> </reference> <reference anchor="SP800-67" target="https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-67r2.pdf"> <front> <title>Recommendation for the Triple Data Encryption Algorithm (TDEA) Block Cipher</title> <author> <organization>National Institute of Standards and Technology (NIST)</organization> </author> <date year="2017" month="November"></date> </front> <seriesInfo name="DOI" value="10.6028/NIST.SP.800-67r2"></seriesInfo> <seriesInfo name="NIST Special Publication" value="800-67"/> </reference> <reference anchor="Twofish" target="https://www.schneier.com/academic/twofish/"> <front> <title>Twofish: A 128-Bit Block Cipher</title> <author fullname="Bruce Schneier" initials="B." surname="Schneier"> <organization></organization> </author> <author fullname="John Kelsey" initials="J." surname="Kelsey"> <organization></organization> </author> <author fullname="Doug Whiting" initials="D." surname="Whiting"> <organization></organization> </author> <author fullname="David Wagner" initials="D." surname="Wagner"> <organization></organization> </author> <author fullname="Chris Hall" initials="C." surname="Hall"> <organization></organization> </author> <author fullname="Niels Ferguson" initials="N." surname="Ferguson"> <organization></organization> </author> <date year="1998" month="June"></date> </front> </reference> <reference anchor="WebM-Enc" target="https://www.webmproject.org/docs/webm-encryption/"> <front> <title>WebM Encryption</title> <author fullname="Frank Galligan"> <organization>Google</organization> </author> <date year="2016" month="September"></date> </front> </reference> <reference anchor="WebVTT" target="https://www.w3.org/TR/2019/CR-webvtt1-20190404/"> <front> <title>WebVTT: The Web Video Text Tracks Format</title> <author fullname="Simon Pieters"> <organization>Opera Software AS</organization> </author> <author fullname="Silvia Pfeiffer" role="editor"> <organization>NICTA</organization> </author> <author fullname="Philip Jaegenstedt"> <organization>Opera Software ASA</organization> </author> <author fullname="Ian Hickson"> <organization>Google</organization> </author> <date year="2019" month="April"></date> </front> <refcontent>W3C Candidate Recommendation</refcontent> </reference> </references> </references> <sectionanchor="annex-a-historic-deprecated-elements"><name>Annex A: Historicanchor="appendix-a-historic-deprecated-elements"><name>Historic Deprecated Elements</name> <t>As Matroska has evolved since20022002, many parts that were considered for use in the format were never used and often incorrectly designed. Many of the elements that werethendefined then are not found in any known files but were part of public specs. DivX also had a few custom elements that were designed for custom features.</t><t>We<t>In this appendix, we listtheseelements that have a known ID that <bcp14>SHOULD NOT</bcp14> be reused to avoid colliding with existing files.TheyThese might be reassigned by IANA in the future if there are no more IDs for a given size. A short description of what each ID was used for is included, but the text is not normative.</t> <section anchor="silenttracks-element"><name>SilentTracks Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>master / 0x5854</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\SilentTracks</tt></dd> <dt>documentation:</dt> <dd>The list of tracks that are not used in that part of the stream. It is useful when using overlay tracksonfor seeking orto decidedeciding what track to use.</dd> </dl> </section> <section anchor="silenttracknumber-element"><name>SilentTrackNumber Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x58D7</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\SilentTracks\SilentTrackNumber</tt></dd> <dt>documentation:</dt> <dd>One of the tracknumbernumbers thatareis not used from now on in the stream. It could change later if not specified as silent in a further Cluster.</dd> </dl> </section> <section anchor="blockvirtual-element"><name>BlockVirtual Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0xA2</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\BlockVirtual</tt></dd> <dt>documentation:</dt> <dd>A Block with no data. It must be stored in the stream at the place the real Block would be in display order.</dd> </dl> </section> <section anchor="referencevirtual-element"><name>ReferenceVirtual Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>integer / 0xFD</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\ReferenceVirtual</tt></dd> <dt>documentation:</dt> <dd>The Segment Position of the data that would otherwise be in position of the virtual block.</dd> </dl> </section> <section anchor="slices-element"><name>Slices Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>master / 0x8E</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices</tt></dd> <dt>documentation:</dt> <dd>Contains slices description.</dd> </dl> </section> <section anchor="timeslice-element"><name>TimeSlice Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>master / 0xE8</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices\TimeSlice</tt></dd> <dt>documentation:</dt> <dd>Contains extra time information about the data contained in the Block. Being able to interpret this Element is not required for playback.</dd> </dl> </section> <section anchor="lacenumber-element"><name>LaceNumber Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xCC</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices\TimeSlice\LaceNumber</tt></dd> <dt>documentation:</dt> <dd>The reverse number of the frame in the lace (0 is the last frame, 1 is the next to last, etc.). Being able to interpret this Element is not required for playback.</dd> </dl> </section> <section anchor="framenumber-element"><name>FrameNumber Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xCD</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices\TimeSlice\FrameNumber</tt></dd> <dt>documentation:</dt> <dd>The number of the frame to generate from this lace with this delay(allow you to generate(allows for the generation of many frames from the same Block/Frame).</dd> </dl> </section> <section anchor="blockadditionid-element"><name>BlockAdditionID Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xCB</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices\TimeSlice\BlockAdditionID</tt></dd> <dt>documentation:</dt> <dd>The ID of the BlockAdditional Element (0 is the main Block).</dd> </dl> </section> <section anchor="delay-element"><name>Delay Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xCE</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices\TimeSlice\Delay</tt></dd> <dt>documentation:</dt> <dd>The delay to apply to the Element, expressed in Track Ticks; see <xref target="timestamp-ticks"></xref>.</dd> </dl> </section> <section anchor="sliceduration-element"><name>SliceDuration Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xCF</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\Slices\TimeSlice\SliceDuration</tt></dd> <dt>documentation:</dt> <dd>The duration to apply to the Element, expressed in Track Ticks; see <xref target="timestamp-ticks"></xref>.</dd> </dl> </section> <section anchor="referenceframe-element"><name>ReferenceFrame Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>master / 0xC8</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\ReferenceFrame</tt></dd> <dt>documentation:</dt> <dd>Contains information about the last reference frame. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="referenceoffset-element"><name>ReferenceOffset Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xC9</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\ReferenceFrame\ReferenceOffset</tt></dd> <dt>documentation:</dt> <dd>The relative offset, in bytes, from the previous BlockGroup element for this Smooth FF/RW video track to the containing BlockGroup element. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="referencetimestamp-element"><name>ReferenceTimestamp Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xCA</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\BlockGroup\ReferenceFrame\ReferenceTimestamp</tt></dd> <dt>documentation:</dt> <dd>The timestamp of the BlockGroup pointed to by ReferenceOffset, expressed in Track Ticks; see <xref target="timestamp-ticks"></xref>. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="encryptedblock-element"><name>EncryptedBlock Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0xAF</dd> <dt>path:</dt> <dd><tt>\Segment\Cluster\EncryptedBlock</tt></dd> <dt>documentation:</dt> <dd>Similar toSimpleBlock, seeSimpleBlock (see <xreftarget="simpleblock-structure"></xref>,target="simpleblock-structure"></xref>), but the data inside the Block are Transformed(encrypt(encrypted and/or signed).</dd> </dl> </section> <section anchor="mincache-element"><name>MinCache Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x6DE7</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\MinCache</tt></dd> <dt>documentation:</dt> <dd>The minimum number of frames a player should be able to cache during playback. If set to 0, the reference pseudo-cache system is not used.</dd> </dl> </section> <section anchor="maxcache-element"><name>MaxCache Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x6DF8</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\MaxCache</tt></dd> <dt>documentation:</dt> <dd>The maximum cache size necessary to store referenced frames in and the current frame. 0 means no cache is needed.</dd> </dl> </section> <section anchor="trackoffset-element"><name>TrackOffset Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>integer / 0x537F</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOffset</tt></dd> <dt>documentation:</dt> <dd>A value to add to the Block's Timestamp, expressed in Matroska Ticks -- i.e., in nanoseconds; see <xref target="timestamp-ticks"></xref>. This can be used to adjust the playback offset of a track.</dd> </dl> </section> <section anchor="codecsettings-element"><name>CodecSettings Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>utf-8 / 0x3A9697</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecSettings</tt></dd> <dt>documentation:</dt> <dd>A string describing the encoding setting used.</dd> </dl> </section> <section anchor="codecinfourl-element"><name>CodecInfoURL Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>string / 0x3B4040</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecInfoURL</tt></dd> <dt>documentation:</dt> <dd>A URL to find information about the codec used.</dd> </dl> </section> <section anchor="codecdownloadurl-element"><name>CodecDownloadURL Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>string / 0x26B240</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecDownloadURL</tt></dd> <dt>documentation:</dt> <!-- [rfced] Please clarify "A URL to download about". Should this text be updated as follows? Original: documentation: A URL to download about the codec used. Perhaps: documentation: A URL to download information about the codec used. --> <dd>A URL to download about the codec used.</dd> </dl> </section> <section anchor="codecdecodeall-element"><name>CodecDecodeAll Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xAA</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\CodecDecodeAll</tt></dd> <dt>documentation:</dt> <dd>Set to 1 if the codec can decode potentially damaged data.</dd> </dl> </section> <section anchor="trackoverlay-element"><name>TrackOverlay Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x6FAB</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrackOverlay</tt></dd> <dt>documentation:</dt> <dd>Specify that this track is an overlay track for the Track specified (in the u-integer).ThatThis means that when this track has a gap on SilentTracks, the overlay track should be used instead. The order of multiple TrackOverlaymatters,matters; the first one is the one that should be used. If the first one is notfoundfound, it should be the second, etc.</dd> </dl> </section> <section anchor="aspectratiotype-element"><name>AspectRatioType Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x54B3</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\AspectRatioType</tt></dd> <dt>documentation:</dt> <dd>Specify the possible modifications to the aspect ratio.</dd> </dl> </section> <section anchor="gammavalue-element"><name>GammaValue Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>float / 0x2FB523</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\GammaValue</tt></dd> <dt>documentation:</dt> <dd>GammaValue.</dd>value.</dd> </dl> </section> <section anchor="framerate-element"><name>FrameRate Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>float / 0x2383E3</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Video\FrameRate</tt></dd> <dt>documentation:</dt> <dd>Number of frames per second. This value isInformationalinformational only. It is intended for constant frame ratestreams,streams and should not be used for a variable frame rate TrackEntry.</dd> </dl> </section> <section anchor="channelpositions-element"><name>ChannelPositions Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0x7D7B</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\Audio\ChannelPositions</tt></dd> <dt>documentation:</dt> <dd>Table of horizontal angles for each successive channel.</dd> </dl> </section> <section anchor="tricktrackuid-element"><name>TrickTrackUID Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xC0</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrickTrackUID</tt></dd> <dt>documentation:</dt> <dd>The TrackUID of the Smooth FF/RW video in the paired EBML structure corresponding to this video track. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="tricktracksegmentuid-element"><name>TrickTrackSegmentUID Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0xC1</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrickTrackSegmentUID</tt></dd> <dt>documentation:</dt> <dd>The SegmentUID of the Segment containing the track identified by TrickTrackUID. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="tricktrackflag-element"><name>TrickTrackFlag Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xC6</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrickTrackFlag</tt></dd> <dt>documentation:</dt> <dd>Set to 1 if this video track is a Smooth FF/RW track. If set to 1, MasterTrackUID and MasterTrackSegUID should bepresentpresent, and BlockGroups for this track must contain ReferenceFrame structures. Otherwise, TrickTrackUID and TrickTrackSegUID must be present if this track has a corresponding Smooth FF/RW track. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="trickmastertrackuid-element"><name>TrickMasterTrackUID Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xC7</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrickMasterTrackUID</tt></dd> <dt>documentation:</dt> <dd>The TrackUID of the video track in the paired EBML structure that corresponds to this Smooth FF/RW track. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="trickmastertracksegmentuid-element"><name>TrickMasterTrackSegmentUID Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0xC4</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\TrickMasterTrackSegmentUID</tt></dd> <dt>documentation:</dt> <dd>The SegmentUID of the Segment containing the track identified by MasterTrackUID. See <xref target="DivXTrickTrack"></xref>.</dd> </dl> </section> <section anchor="contentsignature-element"><name>ContentSignature Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0x47E3</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentSignature</tt></dd> <dt>documentation:</dt> <dd>A cryptographic signature of the contents.</dd> </dl> </section> <section anchor="contentsigkeyid-element"><name>ContentSigKeyID Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0x47E4</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentSigKeyID</tt></dd> <dt>documentation:</dt> <dd>This is the ID of the private key that the data was signed with.</dd> </dl> </section> <section anchor="contentsigalgo-element"><name>ContentSigAlgo Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x47E5</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentSigAlgo</tt></dd> <dt>documentation:</dt> <dd>The algorithm used for the signature.</dd> </dl> </section> <section anchor="contentsighashalgo-element"><name>ContentSigHashAlgo Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x47E6</dd> <dt>path:</dt> <dd><tt>\Segment\Tracks\TrackEntry\ContentEncodings\ContentEncoding\ContentEncryption\ContentSigHashAlgo</tt></dd> <dt>documentation:</dt> <dd>The hash algorithm used for the signature.</dd> </dl> </section> <section anchor="cuerefcluster-element"><name>CueRefCluster Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x97</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueReference\CueRefCluster</tt></dd> <dt>documentation:</dt> <dd>The Segment Position of the Cluster containing the referenced Block.</dd> </dl> </section> <section anchor="cuerefnumber-element"><name>CueRefNumber Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x535F</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueReference\CueRefNumber</tt></dd> <dt>documentation:</dt> <dd>Number of the referenced Block of Track X in the specified Cluster.</dd> </dl> </section> <section anchor="cuerefcodecstate-element"><name>CueRefCodecState Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0xEB</dd> <dt>path:</dt> <dd><tt>\Segment\Cues\CuePoint\CueTrackPositions\CueReference\CueRefCodecState</tt></dd> <dt>documentation:</dt> <dd>The Segment Position of the Codec State corresponding to this referenced Element. 0 means that the data is taken from the initial Track Entry.</dd> </dl> </section> <section anchor="filereferral-element"><name>FileReferral Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>binary / 0x4675</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileReferral</tt></dd> <dt>documentation:</dt> <dd>A binary value that a track/codec can refer to when the attachment is needed.</dd> </dl> </section> <section anchor="fileusedstarttime-element"><name>FileUsedStartTime Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x4661</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileUsedStartTime</tt></dd> <dt>documentation:</dt> <dd>The timestamp at which this optimized font attachment comes into context, expressed in SegmentTicksTicks, whichisare based on TimestampScale. See <xref target="DivXWorldFonts"></xref>.</dd> </dl> </section> <section anchor="fileusedendtime-element"><name>FileUsedEndTime Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x4662</dd> <dt>path:</dt> <dd><tt>\Segment\Attachments\AttachedFile\FileUsedEndTime</tt></dd> <dt>documentation:</dt> <dd>The timestamp at which this optimized font attachment goes out of context, expressed in SegmentTicksTicks, whichisare based on TimestampScale. See <xref target="DivXWorldFonts"></xref>.</dd> </dl> </section> <section anchor="tagdefaultbogus-element"><name>TagDefaultBogus Element</name> <dl spacing="compact"> <dt>type / id:</dt> <dd>uinteger / 0x44B4</dd> <dt>path:</dt> <dd><tt>\Segment\Tags\Tag\+SimpleTag\TagDefaultBogus</tt></dd> <dt>documentation:</dt> <dd>A variant of the TagDefault element with a bogus Element ID; see <xref target="tagdefault-element"></xref>.</dd> </dl> </section> </section></middle> <back> <references><name>Normative References</name> <reference anchor="BCP47" target="https://www.rfc-editor.org/info/rfc5646"> <front> <title>Tags for Identifying Languages</title> <author fullname="A. Phillips" initials="A." surname="Phillips" role="editor"> <organization></organization> </author> <author fullname="M. Davis" initials="M." surname="Davis" role="editor"> <organization></organization> </author> <date year="2009" month="September"></date> </front> <seriesInfo name="BCP" value="47"></seriesInfo> <seriesInfo name="RFC" value="5646"></seriesInfo> <seriesInfo name="DOI" value="10.17487/RFC5646"></seriesInfo> </reference> <reference anchor="CIE-1931" target="https://en.wikipedia.org/wiki/CIE_1931_color_space"> <front> <title>CIE 1931 Standard Colorimetric System</title> <author> <organization>Commission Internationale de l'Eclairage</organization> </author> <date year="1931"></date> </front> </reference> <reference anchor="ISO639-2" target="https://www.loc.gov/standards/iso639-2/php/code_list.php"> <front> <title>Codes for</back> <!-- [rfced] Formatting with <tt> a) Sometimes theRepresentation of Namesword "element" is included in the <tt> tags and sometimes it appears outside the tags. For example, we see both ofLanguages</title> <author> <organization>United States Library Of Congress</organization> </author> <date year="2017" month="December" day="21"></date> </front> <seriesInfo name="ISO" value="639-2:1998"></seriesInfo> </reference> <reference anchor="ISO9899" target="https://www.iso.org/standard/57853.html"> <front> <title>Information technology -- Programming languages -- C</title> <author> <organization>International Organization for Standardization</organization> </author> <date year="2011"></date> </front> <seriesInfo name="ISO/IEC" value="9899:2011"></seriesInfo> </reference> <reference anchor="ITU-H.273" target="https://www.itu.int/rec/T-REC-H.273/en"> <front> <title>Coding-independent code points for video signal type identification</title> <author> <organization>International Telecommunication Union</organization> </author> <date year="2021" month="September" day="24"></date> </front> <seriesInfo name="ITU" value="H.273"></seriesInfo> </reference> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.1950.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2119.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.4122.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.6838.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8081.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8126.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8174.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.8794.xml"/> </references> <references><name>Informative References</name> <reference anchor="AVIFormat" target="https://docs.microsoft.com/en-us/windows/win32/directshow/avi-riff-file-reference"> <front> <title>AVI RIFF File Reference</title> <author> <organization>Microsoft</organization> </author> <date year="2018" month="May" day="31"></date> </front> </reference> <reference anchor="BZIP2" target="https://sourceware.org/bzip2/"> <front> <title>bzip2</title> <author fullname="Julian Seward" initials="J." surname="Seward"> <organization></organization> </author> <date year="1996" month="July" day="18"></date> </front> </reference> <reference anchor="Blowfish" target="https://www.schneier.com/academic/blowfish/"> <front> <title>The Blowfish Encryption Algorithm</title> <author fullname="Bruce Schneier" initials="B." surname="Schneier"> <organization></organization> </author> <date year="1993"></date> </front> </reference> <reference anchor="DVD-Video" target="http://www.dvdforum.org/"> <front> <title>DVD-Books: Part 3 DVD-Video Book</title> <author> <organization>DVD Forum</organization> </author> <date year="1995" month="November" day="1"></date> </front> </reference> <reference anchor="DivXTrickTrack" target="https://web.archive.org/web/20101222001148/http://labs.divx.com/node/16601"> <front> <title>DivX Trickthe following in the xml: <tt>SimpleBlock Element</tt> <tt>SimpleBlock</tt> Element We suggest making such terms consistent. Should "Element" appear in <tt> tagging, or should it appear outside the tags? b) The following terms appear both with and without <tt> in the xml. Please review and let us know if the tagging should be consistent. Attachment Attachments Block BlockAdditions BlockDuration BlockGroup ChapProcessCodecID ChapProcessData ChapProcessPrivate Chapter ChapterAtom Chapters ChapterSegmentEditionUID ChapterSegmentUUID ChapterTranslate ChapterUID Cluster Clusters CodecID Cues DiscardPadding Edition EditionEntry Editions Element FileName Matroska NextUUID PrevUUID SeekHead Segment Segments SegmentUUID SimpleBlock Tag Tags TagString Timestamp TimestampScale TrackExtensions</title> <author></author> <date year="2010" month="December" day="14"></date> </front> </reference> <reference anchor="DivXWorldFonts" target="https://web.archive.org/web/20110214132246/http://labs.divx.com/node/16602"> <front> <title>DivX World Fonts Extensions</title> <author></author> <date year="2010" month="December" day="14"></date> </front> </reference> <reference anchor="FIPS.197" target="https://csrc.nist.gov/publications/detail/fips/197/final"> <front> <title>Advanced Encryption Standard (AES)</title> <author> <organization>US National Institute of StandardsTrackNumber Tracks TrackTranslate --> <!-- [rfced] Terminology a) Please review the following similar terms used in the document. Should these be consistent? Audio/Video container audio andTechnology</organization> </author> <date year="2001" month="November" day="26"></date> </front> <seriesInfo name="FIPS" value="PUB 197"></seriesInfo> <seriesInfo name="DOI" value="10.6028/NIST.FIPS.197"></seriesInfo> </reference> <reference anchor="FIPS.46-3" target="https://csrc.nist.gov/publications/detail/fips/46/3/archive/1999-10-25"> <front> <title>Data Encryption Standard (DES)</title> <author> <organization>US National Institutevisual container audiovisual data container Original: First, it is essential to clarify exactly "What an Audio/Video container is", to avoid any misunderstandings: ... As an audio and visual container format, a Matroska file or stream will potentially encapsulate numerous byte streams created with a variety ofStandardscodecs. ... Matroska is an audiovisual data container format. ... This document defines the Matroska audiovisual data container structure, b) Please review the following andTechnology</organization> </author> <date year="1999" month="October" day="25"></date> </front> <seriesInfo name="FIPS" value="PUB 46"></seriesInfo> </reference> <reference anchor="FourCC-RGB" target="https://web.archive.org/web/20160609214806/https://www.fourcc.org/rgb.php"> <front> <title>RGB Pixel Format FourCCs</title> <author> <organization>Silicon.dk ApS</organization> </author> </front> </reference> <reference anchor="FourCC-YUV" target="https://web.archive.org/web/20160609214806/https://www.fourcc.org/yuv.php"> <front> <title>YUV Pixel Format FourCCs</title> <author> <organization>Silicon.dk ApS</organization> </author> </front> </reference> <reference anchor="JPEG" target="https://www.w3.org/Graphics/JPEG/itu-t81.pdf"> <front> <title>Digital Compressionlet us know if both forms are correct or if updates are needed for consistency. Attachment Element vs. Attachments Element Note: "Attachments Element" is defined in Section 5.1.6. Track Element vs. Tracks Element Note: "Tracks Element" is defined in Section 5.1.4. Cue Element vs. Cues Element Note: "Cues Element" is defined in Section 5.1.5. Chapters Element vs. Chapter Element vs. Chapter element Note: "Chapters Element" is defined in Section 5.1.7, but perhaps "Chapter element" refers to elements like "ChapterAtom" andCoding of Continuous-Tone Still Images</title> <author> <organization>International Telegraph"ChapterTrack"? c) In these sentences, should "Attachment" be updated to "Attachments Element"? When stored, the normal cover SHOULD be the first Attachment in storage order. ... Thus, for maximum compatibility, it's usually better to put the strings in the TrackEntry, ChapterAtom, andTelephone Consultative Committee</organization> </author> <date year="1992" month="September"></date> </front> <seriesInfo name="ITU" value="T.81"></seriesInfo> </reference> <reference anchor="LZO" target="https://www.kernel.org/doc/Documentation/lzo.txt"> <front> <title>Lempel-Ziv-Oberhumer compression</title> <author fullname="Willy Tarreau" initials="W." surname="Tarreau"> <organization></organization> </author> <author fullname="Dave Rodgman" initials="R." surname="Rodgman"> <organization></organization> </author> <author fullname="Markus Oberhumer" initials="M." surname="Oberhumer"> <organization></organization> </author> <date year="2018" month="October" day="30"></date> </front> </reference> <reference anchor="MCF" target="http://mukoli.free.fr/mcf/"> <front> <title>Media Container Format</title> <author></author> <date year="2002" month="July" day="17"></date> </front> </reference> <reference anchor="MSRGB" target="https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-wmf/4e588f70-bd92-4a6f-b77f-35d0feaf7a57"> <front> <title>WMF Compression Enumeration</title> <author> <organization>Microsoft</organization> </author> </front> </reference> <reference anchor="MSYUV16" target="https://learn.microsoft.com/en-us/windows/win32/medfound/10-bit-and-16-bit-yuv-video-formats"> <front> <title>10-bitAttachment and16-bit YUV Video Formats</title> <author> <organization>Microsoft</organization> </author> </front> </reference> <reference anchor="MSYUV8" target="https://learn.microsoft.com/en-us/windows/win32/medfound/recommended-8-bit-yuv-formats-for-video-rendering"> <front> <title>Recommended 8-Bit YUV Formatskeep the tags matching these values if tags are also used. d) Please review the use of lowercase "attachment" in the document. Should any instances be updated to "Attachments Element"? e) We note inconsistencies in the terms listed below. We chose the form on the right. Please let us know any objections. Matroska reader vs. Matroska Reader Matroska writer vs. Matroska Writer Matroska player vs. Matroska Player f) We see the following forms used in the document. We believe that the capitalized form indicates the element (even when not followed by the word "Element"), while the lowercase is forVideo Rendering</title> <author> <organization>Microsoft</organization> </author> </front> </reference> <reference anchor="MatroskaCodec" target=""> <front> <title>Media Container Codec Specifications</title> <author fullname="Steve Lhomme" initials="S." surname="Lhomme"></author> <author fullname="Moritz Bunkus" initials="M." surname="Bunkus"></author> <author fullname="Dave Rice" initials="D." surname="Rice"></author> <date year="2021" month="April" day="12"></date> </front> <seriesInfo name="Internet-Draft" value="draft-ietf-cellar-codec-10"></seriesInfo> </reference> <reference anchor="MatroskaTags" target=""> <front> <title>Matroska Media Containergeneral use. Please review that this usage is consistent. TagSpecifications</title> <author fullname="Steve Lhomme" initials="S." surname="Lhomme"></author> <author fullname="Moritz Bunkus" initials="M." surname="Bunkus"></author> <author fullname="Dave Rice" initials="D." surname="Rice"></author> <date year="2021" month="April" day="12"></date> </front> <seriesInfo name="Internet-Draft" value="draft-ietf-cellar-tags-10"></seriesInfo> </reference> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.0959.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.2083.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.3533.xml"/> <xi:include href="https://xml2rfc.ietf.org/public/rfc/bibxml/reference.RFC.9110.xml"/> <reference anchor="SMB-CIFS" target="https://winprotocoldoc.blob.core.windows.net/productionwindowsarchives/MS-CIFS/%5bMS-CIFS%5d.pdf"> <front> <title>Common Internet File System (CIFS) Protocol</title> <author> <organization>Microsoft Corporation</organization> </author> <date year="2020" month="October" day="1"></date> </front> </reference> <reference anchor="SP.800-38A" target="https://csrc.nist.gov/publications/detail/fips/197/final"> <front> <title>Recommendationvs. tag Tags vs. tags Example general use: When tags from the previous layout Examples of capped form not followed by "Element": ...has its UID listed in the Tags. The Tags contain all extra information g) We note that the following terms are used inconsistently throughout the document. Please review and let us know if any updates are needed for consistency. segment vs. Segment alpha vs. Alpha Note: In context of "Alpha data" and "alpha channel data". AnaGlyph vs. anaglyph EBML header vs. EBML Header block element vs. BlockCipher ModesElement block header vs. Block header vs. Block Header Note: We will make capitalization ofOperation: Methods"header" in "SimpleBlock header" consistent with the decision here. block vs. Block Note: In general text, e.g., "of the virtual block" andTechniques</title> <author> <organization>US National Institute"contained in the Block". chapter codec vs. Chapter Codec chapter edition(s) vs. Chapter Edition(s) child element vs. Child Element codec ID vs. Codec ID Note: We will not change "CodecID" used in element names. codec state vs. Codec State filename vs. file name Note: We are asking about instances aside from "FileName Element". fourcc vs. FourCC Note: "fourcc" is only used in the context ofStandards"fourcc field". linked Segment vs. Linked Segment track name vs. Track Name Track vs. track Note: In general text, e.g., "For separate tracks" andTechnology</organization> </author> <date year="2001" month="December" day="01"></date> </front> <seriesInfo name="DOI" value="10.6028/NIST.SP.800-38A"></seriesInfo> </reference> <reference anchor="SP.800-67" target="https://csrc.nist.gov/publications/detail/sp/800-67/rev-2/final"> <front> <title>Recommendation"end of a Track") trackUID vs. TrackUID segment vs. Segment cluster vs. Cluster Stereo-3D vs. stereo 3D edition vs. Edition Control Track vs. control track --> <!-- [rfced] Capitalization of "element" a) We note that capitalization of "element" is inconsistent when following the name of elements. Please review and let us know if any updates are needed for consistency. Some examples: Capitalized: Root Element Top-Level Element Empty Element Segment Element Info Element SeekHead Element Chapters Element Cluster Element Lowercase: DiscardPadding element NextFilename element TagDefault element TrackEntry\Name element AttachmentLink element Mixed capitalization: CRC-32 element vs. CRC-32 Element ReferenceBlock element vs. ReferenceBlock Element Chapter element vs. Chapter Element ChapterTimeEnd element vs. ChapterTimeEnd Element ChapterSegmentUUID element vs. ChapterSegmentUUID Element ChapterAtom element vs. ChapterAtom Element b) Should "element" (lowercase) vs. "Element" (uppercase) be used in general text? Some examples: When both values exist in theTriplefile, the value found in Tags takes precedence over the value found in original location of the element. In that case these elements are informational only. These Elements allow edges of the frame that are not intended for display, An Element which is not stored within a Segment Element, such as the Elements of the EBML Header, do not have a Segment Position. The Segment Position of an Element refers to the position of the first octet of the Element ID of that Element, measured in octets, from the beginning of the Element DataEncryption Algorithm (TDEA) Block Cipher</title> <author> <organization>US National Institutesection ofStandardsthe containing Segment Element. --> <!-- [rfced] Abbreviations a) FYI - We have added expansions for abbreviations upon first use per Section 3.6 of RFC 7322 ("RFC Style Guide"). Please review each expansion in the document carefully to ensure correctness. b) How may we expanded "VANC" here? We do not see this in published RFCs. Original: These Elements allow edges of the frame that are not intended for display, such as the sprockets of a full-frame film scan or the VANC area of a digitized analog videotape... c) Should "SBR" be expanded as "Spectral Band Replication"? Original: Real output sampling frequency in Hz (used for SBR techniques). Perhaps: Real output sampling frequency in Hz that is used for Spectral Band Replication (SBR) techniques. --> <!-- [rfced] Please review the "Inclusive Language" portion of the online Style Guide <https://www.rfc-editor.org/styleguide/part2/#inclusive_language> andTechnology</organization> </author> <date year="2017" month="November" day="01"></date> </front> <seriesInfo name="DOI" value="10.6028/10.6028/NIST.SP.800-67r2"></seriesInfo> </reference> <reference anchor="Twofish" target="https://www.schneier.com/academic/twofish/"> <front> <title>Twofish: A 128-Bit Block Cipher</title> <author fullname="Bruce Schneier" initials="B." surname="Schneier"> <organization></organization> </author> <author fullname="John Kelsey" initials="J." surname="Kelsey"> <organization></organization> </author> <author fullname="Doug Whiting" initials="D." surname="Whiting"> <organization></organization> </author> <author fullname="David Wagner" initials="D." surname="Wagner"> <organization></organization> </author> <author fullname="Chris Hall" initials="C." surname="Hall"> <organization></organization> </author> <author fullname="Niels Ferguson" initials="N." surname="Ferguson"> <organization></organization> </author> <date year="1998" month="June" day="15"></date> </front> </reference> <reference anchor="WebM-Enc" target="https://www.webmproject.org/docs/webm-encryption/"> <front> <title>WebM Encryption</title> <author fullname="Frank Galligan"> <organization>Google</organization> </author> <date year="2016" month="September" day="19"></date> </front> </reference> <reference anchor="WebVTT" target="https://www.w3.org/TR/webvtt1/#webvtt-cue-identifier"> <front> <title>WebVTT Cue Identifier</title> <author fullname="Simon Pieters"> <organization>Opera Software AS</organization> </author> <author fullname="Silvia Pfeiffer" role="editor"> <organization>NICTA</organization> </author> <author fullname="Philip Jaegenstedt"> <organization>Opera Software ASA</organization> </author> <author fullname="Ian Hickson"> <organization>Google</organization> </author> <date year="2019" month="April" day="4"></date> </front> </reference> </references> </back>let us know if any changes are needed. For example, please consider whether the following should be updated: black white master --> </rfc>