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<body class="h-entry" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
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</p>
<h1 class="title p-name" id="title" property="dcterms:title">MPEG-2 TS Byte Stream Format</h1>
<h2 id="w3c-editor-s-draft-20-july-2016"><abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft <time property="dcterms:issued" class="dt-published" datetime="2016-07-20">20 July 2016</time></h2>
<dl>
<dt>This version:</dt>
<dd><a class="u-url" href="https://w3c.github.io/media-source/mp2t-byte-stream-format.html">https://w3c.github.io/media-source/mp2t-byte-stream-format.html</a></dd>
<dt>Latest published version:</dt>
<dd><a href="http://www.w3.org/TR/media-source/">http://www.w3.org/TR/media-source/</a></dd>
<dt>Latest editor's draft:</dt>
<dd><a href="https://w3c.github.io/media-source/mp2t-byte-stream-format.html">https://w3c.github.io/media-source/mp2t-byte-stream-format.html</a></dd>
<dt>Editors:</dt>
<dd class="p-author h-card vcard" property="bibo:editor" resource="_:editor0"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Matthew Wolenetz</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.google.com/">Google Inc.</a></span>
<span property="rdf:rest" resource="_:editor1"></span>
</dd>
<dd class="p-author h-card vcard" resource="_:editor1"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Jerry Smith</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.microsoft.com/">Microsoft Corporation</a></span>
<span property="rdf:rest" resource="_:editor2"></span>
</dd>
<dd class="p-author h-card vcard" resource="_:editor2"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Mark Watson</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.netflix.com/">Netflix Inc.</a></span>
<span property="rdf:rest" resource="_:editor3"></span>
</dd>
<dd class="p-author h-card vcard" resource="_:editor3"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Aaron Colwell (until April 2015)</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.google.com/">Google Inc.</a></span>
<span property="rdf:rest" resource="_:editor4"></span>
</dd>
<dd class="p-author h-card vcard" resource="_:editor4"><span property="rdf:first" typeof="foaf:Person"><span property="foaf:name" class="p-name fn">Adrian Bateman (until April 2015)</span>, <a property="foaf:workplaceHomepage" class="p-org org h-org h-card" href="http://www.microsoft.com/">Microsoft Corporation</a></span>
<span property="rdf:rest" resource="rdf:nil"></span>
</dd>
<dt>Repository:</dt>
<dd>
<a href="https://github.com/w3c/media-source/">
We are on GitHub
</a>
</dd>
<dd>
<a href="https://github.com/w3c/media-source/issues">
File a bug
</a>
</dd>
<dd>
<a href="https://github.com/w3c/media-source/commits/gh-pages/mp2t-byte-stream-format-respec.html">
Commit history
</a>
</dd>
<dt>Mailing list:</dt>
<dd>
<a href="https://lists.w3.org/Archives/Public/public-html-media/">
</a>
</dd>
</dl>
<p class="copyright">
<a href="http://www.w3.org/Consortium/Legal/ipr-notice#Copyright">Copyright</a> ©
2016
<a href="http://www.w3.org/"><abbr title="World Wide Web Consortium">W3C</abbr></a><sup>®</sup>
(<a href="http://www.csail.mit.edu/"><abbr title="Massachusetts Institute of Technology">MIT</abbr></a>,
<a href="http://www.ercim.eu/"><abbr title="European Research Consortium for Informatics and Mathematics">ERCIM</abbr></a>,
<a href="http://www.keio.ac.jp/">Keio</a>, <a href="http://ev.buaa.edu.cn/">Beihang</a>).
<abbr title="World Wide Web Consortium">W3C</abbr> <a href="http://www.w3.org/Consortium/Legal/ipr-notice#Legal_Disclaimer">liability</a>,
<a href="http://www.w3.org/Consortium/Legal/ipr-notice#W3C_Trademarks">trademark</a> and
<a rel="license" href="http://www.w3.org/Consortium/Legal/copyright-documents">document use</a>
rules apply.
</p>
<hr title="Separator for header">
</div>
<section id="abstract" class="introductory" property="dc:abstract"><h2 id="h-abstract" resource="#h-abstract"><span property="xhv:role" resource="xhv:heading">Abstract</span></h2><p>
This specification defines a <a href="http://www.w3.org/TR/media-source/">Media Source Extensions</a> byte stream format specification based on MPEG-2 Transport Streams.
</p></section><section id="sotd" class="introductory"><h2 id="h-sotd" resource="#h-sotd"><span property="xhv:role" resource="xhv:heading">Status of This Document</span></h2>
<p>
<em>This section describes the status of this document at the time of its publication. Other documents may supersede this document. A list of current <abbr title="World Wide Web Consortium">W3C</abbr> publications and the latest revision of this technical report can be found in the <a href="http://www.w3.org/TR/"><abbr title="World Wide Web Consortium">W3C</abbr> technical reports index</a> at http://www.w3.org/TR/.</em>
</p>
<p>The working group maintains <a href="https://github.com/w3c/media-source/issues">a list of all bug reports that the editors have not yet tried to address</a>; there may also be open bugs in the <a href="http://w3.org/brief/Mjcw">previous bug tracker</a>.</p>
<p>Implementors should be aware that this specification is not stable. <strong>Implementors who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways.</strong> Vendors interested in implementing this specification before it eventually reaches the Candidate Recommendation stage should join the mailing list mentioned below and take part in the discussions.</p>
<p>
This document was published by the <a href="http://www.w3.org/html/wg/">HTML Media Extensions Working Group</a> as an Editor's Draft.
If you wish to make comments regarding this document, please send them to
<a href="mailto:[email protected]">[email protected]</a>
(<a href="mailto:[email protected]?subject=subscribe">subscribe</a>,
<a href="http://lists.w3.org/Archives/Public/public-html-media/">archives</a>).
All comments are welcome.
</p>
<p>
Publication as an Editor's Draft does not imply endorsement by the <abbr title="World Wide Web Consortium">W3C</abbr>
Membership. This is a draft document and may be updated, replaced or obsoleted by other
documents at any time. It is inappropriate to cite this document as other than work in
progress.
</p>
<p>
This document was produced by
a group
operating under the
<a id="sotd_patent" property="w3p:patentRules" href="http://www.w3.org/Consortium/Patent-Policy-20040205/">5 February 2004 <abbr title="World Wide Web Consortium">W3C</abbr> Patent
Policy</a>.
<abbr title="World Wide Web Consortium">W3C</abbr> maintains a <a href="http://www.w3.org/2004/01/pp-impl/40318/status" rel="disclosure">public list of any patent
disclosures</a>
made in connection with the deliverables of
the group; that page also includes
instructions for disclosing a patent. An individual who has actual knowledge of a patent
which the individual believes contains
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential">Essential
Claim(s)</a> must disclose the information in accordance with
<a href="http://www.w3.org/Consortium/Patent-Policy-20040205/#sec-Disclosure">section
6 of the <abbr title="World Wide Web Consortium">W3C</abbr> Patent Policy</a>.
</p>
<p>This document is governed by the <a id="w3c_process_revision" href="http://www.w3.org/2015/Process-20150901/">1 September 2015 <abbr title="World Wide Web Consortium">W3C</abbr> Process Document</a>.
</p>
</section><section id="toc"><h2 class="introductory" id="h-toc" resource="#h-toc"><span property="xhv:role" resource="xhv:heading">Table of Contents</span></h2><ul class="toc" role="directory"><li class="tocline"><a href="#introduction" class="tocxref"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a href="#mime-parameters" class="tocxref"><span class="secno">2. </span>MIME-type info</a></li><li class="tocline"><a href="#mpeg2ts-general" class="tocxref"><span class="secno">3. </span>General Transport Stream Requirements</a></li><li class="tocline"><a href="#mpeg2ts-init-segments" class="tocxref"><span class="secno">4. </span>Initialization Segments</a></li><li class="tocline"><a href="#mpeg2ts-media-segments" class="tocxref"><span class="secno">5. </span>Media Segments</a></li><li class="tocline"><a href="#mpeg2ts-random-access-points" class="tocxref"><span class="secno">6. </span>Random Access Points</a></li><li class="tocline"><a href="#mpeg2ts-discontinuities" class="tocxref"><span class="secno">7. </span>Timestamp Rollover & Discontinuities</a></li><li class="tocline"><a href="#conformance" class="tocxref"><span class="secno">8. </span>Conformance</a></li><li class="tocline"><a href="#acknowledgements" class="tocxref"><span class="secno">9. </span>Acknowledgments</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">A. </span>References</a><ul class="toc"><li class="tocline"><a href="#normative-references" class="tocxref"><span class="secno">A.1 </span>Normative references</a></li><li class="tocline"><a href="#informative-references" class="tocxref"><span class="secno">A.2 </span>Informative references</a></li></ul></li></ul></section>
<section id="introduction" typeof="bibo:Chapter" resource="#introduction" property="bibo:hasPart">
<!--OddPage--><h2 id="h-introduction" resource="#h-introduction"><span property="xhv:role" resource="xhv:heading"><span class="secno">1. </span>Introduction</span></h2>
<p>This specification defines segment formats for implementations that choose to support MPEG-2 Transport Streams
(MPEG-2 TS) specified in <a href="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=44169">ISO/IEC 13818-1</a>.</p> It defines the MIME-type parameters used to signal codecs, and provides
the necessary format specific definitions for <a href="index.html#init-segment">initialization segments</a>, <a href="index.html#media-segment">media segments</a>, and <a href="index.html#random-access-point">random access points</a> required by
the <a href="index.html#byte-stream-formats">byte stream formats section</a> of the Media Source Extensions spec. This document also defines extra behaviors and state that only apply to this
byte stream format.<p></p>
</section>
<section id="mime-parameters" typeof="bibo:Chapter" resource="#mime-parameters" property="bibo:hasPart">
<!--OddPage--><h2 id="h-mime-parameters" resource="#h-mime-parameters"><span property="xhv:role" resource="xhv:heading"><span class="secno">2. </span>MIME-type info</span></h2>
<p>The MIME-type/subtype pair of "video/MP2T", as specified in <a href="http://tools.ietf.org/html/rfc3551">RFC 3551</a>, <em class="rfc2119" title="MUST">MUST</em> be used for byte streams that conform
to this specification.</p>
<p>This following parameters can be used in the MIME-type passed to <code><a href="index.html#widl-MediaSource-isTypeSupported-boolean-DOMString-type">isTypeSupported()</a></code> or <code><a href="index.html#widl-MediaSource-addSourceBuffer-SourceBuffer-DOMString-type">addSourceBuffer()</a></code>.</p>
<dl>
<dt>codecs</dt>
<dd>
A comma separated list of codec IDs used to specify what codecs will be used in the byte stream. Implementations <em class="rfc2119" title="SHOULD">SHOULD</em> accept IDs in the form specified by
<a href="http://tools.ietf.org/html/rfc6381">RFC 6381</a>.
<div class="note"><div class="note-title" aria-level="3" role="heading" id="h-note1"><span>Note</span></div><div class="">Implementations <em class="rfc2119" title="MAY">MAY</em> only implement a subset of the codecs and profiles mentioned in the RFC.</div></div>
</dd>
</dl>
</section>
<section id="mpeg2ts-general" typeof="bibo:Chapter" resource="#mpeg2ts-general" property="bibo:hasPart">
<!--OddPage--><h2 id="h-mpeg2ts-general" resource="#h-mpeg2ts-general"><span property="xhv:role" resource="xhv:heading"><span class="secno">3. </span>General Transport Stream Requirements</span></h2>
<p>MPEG-2 TS media and initialization segments <em class="rfc2119" title="MUST">MUST</em> conform to the MPEG-2 TS Adaptive Profile (ISO/IEC 13818-1:2012 Amd. 2).</p>
<p>The user agent <em class="rfc2119" title="MUST">MUST</em> run the <a href="index.html#sourcebuffer-append-error">append error algorithm</a> with the <var>decode error</var> parameter set to true if any of the following conditions are met:</p>
<ol>
<li>Segments do not contain complete MPEG-2 TS packets.</li>
<li>Segments do not contain complete PES packets and sections.</li>
<li>Segments contain more than one program.</li>
<li>At least one MPEG-2 TS packet has a non-zero transport_error_indicator.</li>
</ol>
</section>
<section id="mpeg2ts-init-segments" typeof="bibo:Chapter" resource="#mpeg2ts-init-segments" property="bibo:hasPart">
<!--OddPage--><h2 id="h-mpeg2ts-init-segments" resource="#h-mpeg2ts-init-segments"><span property="xhv:role" resource="xhv:heading"><span class="secno">4. </span>Initialization Segments</span></h2>
<p>An MPEG-2 TS initialization segment consists of a single PAT and a single PMT.</p>
<p>The user agent <em class="rfc2119" title="MUST">MUST</em> run the <a href="index.html#sourcebuffer-append-error">append error algorithm</a> with the <var>decode error</var> parameter set to true if any of the following conditions are met:</p>
<ol>
<li>A PAT is not present in the <a href="index.html#init-segment">initialization segment</a></li>
<li>A PMT is not present in the <a href="index.html#init-segment">initialization segment</a></li>
</ol>
<p>The user agent <em class="rfc2119" title="MUST">MUST</em> accept and ignore other SI, such as CAT, that are invariant for all subsequent media segments.</p>
<p>The user agent <em class="rfc2119" title="MUST">MUST</em> source attribute values for id, kind, label and language for <code><a href="https://www.w3.org/TR/html51/semantics-embedded-content.html#audiotrack-audiotrack">AudioTrack</a></code>, <code><a href="https://www.w3.org/TR/html51/semantics-embedded-content.html#videotrack-videotrack">VideoTrack</a></code> and
<code><a href="https://www.w3.org/TR/html51/semantics-embedded-content.html#texttrack-texttrack">TextTrack</a></code> objects as described for MPEG-2 Transport Streams in the in-band tracks spec [<cite><a class="bibref" href="#bib-INBANDTRACKS">INBANDTRACKS</a></cite>].</p>
</section>
<section id="mpeg2ts-media-segments" typeof="bibo:Chapter" resource="#mpeg2ts-media-segments" property="bibo:hasPart">
<!--OddPage--><h2 id="h-mpeg2ts-media-segments" resource="#h-mpeg2ts-media-segments"><span property="xhv:role" resource="xhv:heading"><span class="secno">5. </span>Media Segments</span></h2>
<p>The user agent <em class="rfc2119" title="MUST">MUST</em> run the <a href="index.html#sourcebuffer-append-error">append error algorithm</a> with the <var>decode error</var> parameter set to true if any of the following conditions are met:</p>
<ol>
<li>A media segment relies on initialization information in another media segment.</li>
<li>At least one PES packet does not have a PTS timestamp.</li>
<li>PCR is not present in the Segment prior to the first byte of a TS packet payload containing media data.</li>
</ol>
The user agent will accept and ignore PSI that is identical to the information in the last initialization segment which may appear repeatedly throughout the segment.
</section>
<section id="mpeg2ts-random-access-points" typeof="bibo:Chapter" resource="#mpeg2ts-random-access-points" property="bibo:hasPart">
<!--OddPage--><h2 id="h-mpeg2ts-random-access-points" resource="#h-mpeg2ts-random-access-points"><span property="xhv:role" resource="xhv:heading"><span class="secno">6. </span>Random Access Points</span></h2>
<p>A random access point as defined in this specification corresponds to Elementary Stream Random Access Point as defined in
<a href="http://www.iso.org/iso/home/store/catalogue_tc/catalogue_detail.htm?csnumber=44169">ISO/IEC 13818-1</a>.</p>
</section>
<section id="mpeg2ts-discontinuities" typeof="bibo:Chapter" resource="#mpeg2ts-discontinuities" property="bibo:hasPart">
<!--OddPage--><h2 id="h-mpeg2ts-discontinuities" resource="#h-mpeg2ts-discontinuities"><span property="xhv:role" resource="xhv:heading"><span class="secno">7. </span>Timestamp Rollover & Discontinuities</span></h2>
<p>Timestamp rollovers and discontinuities <em class="rfc2119" title="MUST">MUST</em> be handled by the UA. The UA's MPEG-2 TS implementation <em class="rfc2119" title="MUST">MUST</em> maintain an internal offset
variable, <dfn id="mpeg2ts-timestampOffset" data-dfn-type="dfn">MPEG2TS_timestampOffset</dfn>, to keep track of the offset that needs to be applied to timestamps
that have rolled over or are part of a discontinuity. <var>MPEG2TS_timestampOffset</var> is initially set to 0 when the <code><a href="index.html#idl-def-SourceBuffer" class="idlType">SourceBuffer</a></code> is
created. This offset <em class="rfc2119" title="MUST">MUST</em> be applied to the timestamps as part of the conversion process from MPEG-2 TS packets
into <a href="index.html#coded-frame">coded frames</a> for the <a href="index.html#sourcebuffer-coded-frame-processing">coded frame processing algorithm</a>. This results in the coded frame timestamps
for a packet being computed by the following equations:</p>
<pre> Coded Frame Presentation Timestamp = (MPEG-2 TS presentation timestamp) + <var>MPEG2TS_timestampOffset</var>
Coded Frame Decode Timestamp = (MPEG-2 TS decode timestamp) + <var>MPEG2TS_timestampOffset</var></pre>
<p><var><a href="#mpeg2ts-timestampOffset">MPEG2TS_timestampOffset</a></var> is updated in the following ways:</p>
<ul>
<li>Each time a timestamp rollover is detected, 2^33 <em class="rfc2119" title="MUST">MUST</em> be added to <var><a href="#mpeg2ts-timestampOffset">MPEG2TS_timestampOffset</a></var>.</li>
<li>When a discontinuity is detected, <var><a href="#mpeg2ts-timestampOffset">MPEG2TS_timestampOffset</a></var> <em class="rfc2119" title="MUST">MUST</em> be adjusted to make the timestamps after the discontinuity appear
to come immediately after the timestamps before the discontinuity.</li>
<li>When <code><a href="index.html#widl-SourceBuffer-abort-void">abort()</a></code> is called, <var><a href="#mpeg2ts-timestampOffset">MPEG2TS_timestampOffset</a></var> <em class="rfc2119" title="MUST">MUST</em> be set to 0.</li>
<li>When <code><a href="index.html#widl-SourceBuffer-timestampOffset">timestampOffset</a></code> is successfully set, <var><a href="#mpeg2ts-timestampOffset">MPEG2TS_timestampOffset</a></var> <em class="rfc2119" title="MUST">MUST</em> be set to 0.</li>
</ul>
</section>
<section id="conformance" typeof="bibo:Chapter" resource="#conformance" property="bibo:hasPart"><!--OddPage--><h2 id="h-conformance" resource="#h-conformance"><span property="xhv:role" resource="xhv:heading"><span class="secno">8. </span>Conformance</span></h2>
<p>
As well as sections marked as non-normative, all authoring guidelines, diagrams, examples,
and notes in this specification are non-normative. Everything else in this specification is
normative.
</p>
<p id="respecRFC2119">The key words <em class="rfc2119" title="MAY">MAY</em>, <em class="rfc2119" title="MUST">MUST</em>, and <em class="rfc2119" title="SHOULD">SHOULD</em> are
to be interpreted as described in [<cite><a class="bibref" href="#bib-RFC2119">RFC2119</a></cite>].
</p>
</section>
<section id="acknowledgements" typeof="bibo:Chapter" resource="#acknowledgements" property="bibo:hasPart">
<!--OddPage--><h2 id="h-acknowledgements" resource="#h-acknowledgements"><span property="xhv:role" resource="xhv:heading"><span class="secno">9. </span>Acknowledgments</span></h2>
The editors would like to thank Alex Giladi, Bob Lund, David Singer, Duncan Rowden, Glenn Adams, Mark Vickers, and Michael Thornburgh for their contributions to this specification.
</section>
<section id="references" class="appendix" typeof="bibo:Chapter" resource="#references" property="bibo:hasPart"><!--OddPage--><h2 id="h-references" resource="#h-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A. </span>References</span></h2><section id="normative-references" typeof="bibo:Chapter" resource="#normative-references" property="bibo:hasPart"><h3 id="h-normative-references" resource="#h-normative-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A.1 </span>Normative references</span></h3><dl class="bibliography" resource=""><dt id="bib-RFC2119">[RFC2119]</dt><dd>S. Bradner. <a href="https://tools.ietf.org/html/rfc2119" property="dc:requires"><cite>Key words for use in RFCs to Indicate Requirement Levels</cite></a>. March 1997. Best Current Practice. URL: <a href="https://tools.ietf.org/html/rfc2119" property="dc:requires">https://tools.ietf.org/html/rfc2119</a>
</dd></dl></section><section id="informative-references" typeof="bibo:Chapter" resource="#informative-references" property="bibo:hasPart"><h3 id="h-informative-references" resource="#h-informative-references"><span property="xhv:role" resource="xhv:heading"><span class="secno">A.2 </span>Informative references</span></h3><dl class="bibliography" resource=""><dt id="bib-INBANDTRACKS">[INBANDTRACKS]</dt><dd>Bob Lund; Silvia Pfeiffer. <a href="http://dev.w3.org/html5/html-sourcing-inband-tracks/" property="dc:references"><cite>Sourcing In-band Media Resource Tracks from Media Containers into HTML</cite></a>. URL: <a href="http://dev.w3.org/html5/html-sourcing-inband-tracks/" property="dc:references">http://dev.w3.org/html5/html-sourcing-inband-tracks/</a>
</dd></dl></section></section></body></html>