- From: CVS User spfeiffe <cvsmail@w3.org>
- Date: Sat, 07 Jun 2014 08:07:00 +0000
- To: public-html-commits@w3.org
Update of /sources/public/html5/html-sourcing-inband-tracks
In directory roscoe:/tmp/cvs-serv30175
Modified Files:
Overview.html
Log Message:
Sync HTML sourcing inband tracks spec with Git commit b8eae0e9123e65f5000bb37ca4ddbe801752397a
--- /sources/public/html5/html-sourcing-inband-tracks/Overview.html 2014/06/06 06:09:53 1.3
+++ /sources/public/html5/html-sourcing-inband-tracks/Overview.html 2014/06/07 08:07:00 1.4
@@ -176,13 +176,13 @@
</style><link rel="stylesheet" href="https://www.w3.org/StyleSheets/TR/w3c-unofficial"><!--[if lt IE 9]><script src='https://www.w3.org/2008/site/js/html5shiv.js'></script><![endif]--></head>
- <body style="" class="h-entry" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
+ <body class="h-entry" role="document" id="respecDocument"><div class="head" role="contentinfo" id="respecHeader">
<p>
</p>
<h1 class="title p-name" id="title" property="dcterms:title">Sourcing In-band Media Resource Tracks from Media Containers into HTML</h1>
- <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-06-05T20:07:51.000Z" id="unofficial-draft-06-june-2014">Unofficial Draft <time class="dt-published" datetime="2014-06-06">06 June 2014</time></h2>
+ <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-06-06T22:03:42.000Z" id="unofficial-draft-07-june-2014">Unofficial Draft <time class="dt-published" datetime="2014-06-07">07 June 2014</time></h2>
<dl>
@@ -240,7 +240,7 @@
</p>
-</section><section id="toc"><h2 class="introductory" aria-level="1" role="heading" id="h2_toc">Table of Contents</h2><ul class="toc" role="directory" id="respecContents"><li class="tocline"><a href="#introduction" class="tocxref"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a href="#mpegdash" class="tocxref"><span class="secno">2. </span>MPEG DASH</a></li><li class="tocline"><a href="#mpeg2ts" class="tocxref"><span class="secno">3. </span>MPEG-2 Transport Streams</a></li><li class="tocline"><a href="#mpeg4" class="tocxref"><span class="secno">4. </span>MPEG-4 ISOBMFF</a></li><li class="tocline"><a href="#webm" class="tocxref"><span class="secno">5. </span>WebM</a></li><li class="tocline"><a href="#ogg" class="tocxref"><span class="secno">6. </span>Ogg</a></li><li class="tocline"><a href="#acknowledgements" class="tocxref"><span class="secno">A. </span>Acknowledgements</a></li></ul></section>
+</section><section id="toc"><h2 class="introductory" aria-level="1" role="heading" id="h2_toc">Table of Contents</h2><ul class="toc" role="directory" id="respecContents"><li class="tocline"><a href="#introduction" class="tocxref"><span class="secno">1. </span>Introduction</a></li><li class="tocline"><a href="#mpegdash" class="tocxref"><span class="secno">2. </span>MPEG DASH</a></li><li class="tocline"><a href="#mpeg2ts" class="tocxref"><span class="secno">3. </span>MPEG-2 Transport Streams</a></li><li class="tocline"><a href="#mpeg4" class="tocxref"><span class="secno">4. </span>MPEG-4 ISOBMFF</a></li><li class="tocline"><a href="#webm" class="tocxref"><span class="secno">5. </span>WebM</a></li><li class="tocline"><a href="#ogg" class="tocxref"><span class="secno">6. </span>Ogg</a></li><li class="tocline"><a href="#acknowledgements" class="tocxref"><span class="secno">A. </span>Acknowledgements</a></li><li class="tocline"><a href="#references" class="tocxref"><span class="secno">B. </span>References</a><ulclass="toc"><li class="tocline"><a href="#informative-references" class="tocxref"><span class="secno">B.1 </span>Informative references</a></li></ul></li></ul></section>
@@ -406,8 +406,12 @@
<p>
A user agent recognises and supports data from a MPEG-2 TS resource as being equivalent to a HTML track based on the value of the 'stream_id' field of an elementary stream as given in a Transport or Program Stream header and which maps to a "stream type":
</p><ul>
- <li>text track: the elementary stream with PID 0x02 or the stream type value is "0x02", "0x05" or between "0x80" and "0xFF"</li>
- <li>video track: the stream type value is "0x01", "0x02", "0x10", "0x1B", or between "0x1E" and "0x23"</li>
+ <li>text track:
+ <ul>
+ <li>The elementary stream with PID 0x02 or the stream type value is "0x02", "0x05" or between "0x80" and "0xFF". </li>
+ <li>The CEA 708 caption service [<cite><a class="bibref" href="#bib-CEA708">CEA708</a></cite>] in the 'Picture User Data' of a video stream, as identified by a 'Caption Service Descriptor' [<cite><a class="bibref" href="#bib-ATSC65">ATSC65</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a video stream with stream type 0x02.</li>
+ </ul>
+ </li><li>video track: the stream type value is "0x01", "0x02", "0x10", "0x1B", or between "0x1E" and "0x23"</li>
<li>audio track: the stream type value is "0x03", "0x04", "0x0F", "0x11", or "0x1C"</li>
</ul>
<p></p>
@@ -423,14 +427,17 @@
<tbody><tr>
<th>id</th>
<td>
- Decimal representation of the elementary stream's identifier ('elementary_PID' field) in the PMT. In the case of CEA708 closed captions this will be the identifier of the video elementary stream containing captions in the Picture User Data.
+ Decimal representation of the elementary stream's identifier ('elementary_PID' field) in the PMT.
+ <p>
+ In the case of CEA 708 closed captions, decimal representation of the 'caption_service_number' in the 'Caption Service Descriptor' in the PMT.
+ </p>
</td>
</tr>
<tr>
<th>kind</th>
<td>
<ul>
- <li>"captions": if a "Caption Service Descriptor section" is present in a video elementary stream of stream type "0x02" and its 'cc_type' is 1 (True)</li><!-- see http://www.etherguidesystems.com/help/sdos/atsc/semantics/descriptors/CaptionService.aspx -->
+ <li>"captions": for a <a href="#captionservice">caption service</a></li>
<li>"subtitles": if the stream type value is "0x82"</li>
<li>"metadata": otherwise</li>
</ul>
@@ -444,8 +451,12 @@
</tr>
<tr>
<th>language</th>
- <td>
- Content of the 'ISO_639_language_descriptor' field.
+ <td>@kind is
+ <ul>
+ <li>'captions': Content of the 'language' field for the caption service in the 'Caption Service Descriptor'.</li>
+ <li>'subtitles': Content of the 'ISO_639_language_descriptor' in the elementary stream descriptor array in the PMT.</li>
+ <li>'metadata': The empty string.</li>
+ </ul>
</td>
</tr>
</tbody></table>
@@ -550,15 +561,89 @@
<p>
</p><li>Captions cues
<p>
- MPEG-2 captions are in the CEA 708 format [<cite><a class="bibref" href="#bib-CEA708">CEA708</a></cite>] so cues on an MPEG-2 captions text track require an as yet to be specified CEA708Cue format to expose them, unless browsers want to map the CEA708 features into a WebVTTCue [<cite><a class="bibref" href="#bib-VTT708">VTT708</a></cite>].
+ Cues on an MPEG-2 captions text track are created as DataCue objects [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>]. MPEG-2 captions data is in the CEA 708 format [<cite><a class="bibref" href="#bib-CEA708">CEA708</a></cite>]. Each 'service block' in an digital TV closed caption (DTVCC) transport channel creates a DataCue object with TexTrackCue attributes sourced as follows:
</p>
+ <table>
+ <thead>
+ <tr><th>Attribute</th>
+ <th>How to source its value</th>
+ </tr></thead>
+ <tbody><tr>
+ <th>id</th>
+ <td>
+ Decimal representation of the 'service_number' in the 'service_block'.
+ </td>
+ </tr>
+ <tr>
+ <th>startTime</th>
+ <td>
+ The time, in the HTML media resource timeline, that corresponds to the presentation time stamp for the video frame that contained the first 'Caption Channel Data Byte' of the 'service_block'.
+ </td>
+ </tr>
+ <tr>
+ <th>endTime</th>
+ <td>
+ The sum of the startTime and 4 seconds.
+ <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_4"><span>Note</span></div><p class="">
+ CEA 708 captions do not have an explicit end time - a rendering device derives the end time for a caption based on subsequent caption data. Setting endTime equal to startTime might be more appropriate but this would require better support for zero-length cues, as proposed in <a href="https://www.w3.org/Bugs/Public/show_bug.cgi?id=25693">HTML Bug 25693</a>.
+ </p></div>
+ </td>
+ </tr>
+ <tr>
+ <th>pauseOnExit</th>
+ <td>
+ 'false'
+ </td>
+ </tr>
+ <tr>
+ <th>data</th>
+ <td>
+ The 'service_block'.
+ </td>
+ </tr>
+ </tbody></table>
+
</li>
<p></p>
<p>
</p><li> Subtitles cues
<p>
- MPEG-2 subtitles are in the SCTE 27 format [<cite><a class="bibref" href="#bib-SCTE27">SCTE27</a></cite>] so cues on an MPEG-2 subtitle text track require an as yet to be specified SCTE27Cue format to expose them, unless browsers want to map the SCTE 27 features into a WebVTTCue. This mapping process has not been defined.
+ Cues on an MPEG-2 subtitles text track are created as DataCue objects [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>]. MPEG-2 subtitle data is in the SCTE 27 format [<cite><a class="bibref" href="#bib-SCTE27">SCTE27</a></cite>]. Each 'section' in an elementary stream identified as a subtitles text track creates a DataCue object with TexTrackCue attributes sourced as follows:
</p>
+ <table>
+ <thead>
+ <tr><th>Attribute</th>
+ <th>How to source its value</th>
+ </tr></thead>
+ <tbody><tr>
+ <th>id</th>
+ <td>
+ Decimal representation of the 'table_id' in the first 8 bits of the 'section' data.
+ </td>
+ </tr>
+ <tr>
+ <th>startTime</th>
+ <td>
+ The time, in the HTML media resource timeline, that corresponds to the 'display_in_PTS' field in the section data.
+ </td>
+ </tr>
+ <tr>
+ <th>endTime</th>
+ <td>
+ The sum of the startTime and the 'display_duration' field in the section data expressed in seconds.
+ </td>
+ </tr>
+ <tr>
+ <th>pauseOnExit</th>
+ <td>'false'</td>
+ </tr>
+ <tr>
+ <th>data</th>
+ <td>
+ The 'section_length' number of bytes immediately following the 'section_length' field in the 'section'.
+ </td>
+ </tr>
+ </tbody></table>
</li>
<p></p>
</ol>
@@ -749,7 +834,7 @@
<p>
Tracks of kind "chapters" are found in the "Chapters" section of the WebM file Segment, which are all at the beginning of the WebM file, such that chapters can be used for navigation. The details of this mapping have not been specified yet and simply point to the more powerful Matroska chapter specification [<cite><a class="bibref" href="#bib-Matroska">Matroska</a></cite>]. Presumably, the 'id' attribute could be found in 'EditionUID', 'label' is empty, and 'language' can come from the first ChapterAtom's 'ChapLanguage' value.
</p>
- <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_4"><span>Note</span></div><p class="">The Matroska container format, which is the basis for WebM, has specifications for other text tracks, in particular SRT, SSA/ASS, and VOBSUB. The described attribute mappings can be applied to these, too, except that the 'kind' field will always be "subtitles". The information of their 'CodecPrivate' field is exposed in the 'inBandMetadataTrackDispatchType' attribute.
+ <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_5"><span>Note</span></div><p class="">The Matroska container format, which is the basis for WebM, has specifications for other text tracks, in particular SRT, SSA/ASS, and VOBSUB. The described attribute mappings can be applied to these, too, except that the 'kind' field will always be "subtitles". The information of their 'CodecPrivate' field is exposed in the 'inBandMetadataTrackDispatchType' attribute.
</p></div>
</li>
@@ -845,7 +930,7 @@
</td>
</tr>
</tbody></table>
- <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_5"><span>Note</span></div><p class="">Other Matroska container format's text tracks can also be mapped to TextTrackCue objects. These will be created as DataCue objects [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>] with 'id', 'startTime', 'endTime', and 'pauseOnExit' attributes filled identically to the VTTCue objects, and the 'data' attribute containing the Block's data.
+ <div class="note"><div class="note-title" aria-level="2" role="heading" id="h_note_6"><span>Note</span></div><p class="">Other Matroska container format's text tracks can also be mapped to TextTrackCue objects. These will be created as DataCue objects [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>] with 'id', 'startTime', 'endTime', and 'pauseOnExit' attributes filled identically to the VTTCue objects, and the 'data' attribute containing the Block's data.
</p></div>
</li>
</ol>
@@ -983,4 +1068,18 @@
</section>
-</body></html>
\ No newline at end of file
+<section id="references" class="appendix" typeof="bibo:Chapter" resource="#references" rel="bibo:Chapter"><!--OddPage--><h2 aria-level="1" role="heading" id="h2_references"><span class="secno">B. </span>References</h2><section id="informative-references" typeof="bibo:Chapter" resource="#informative-references" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_informative-references"><span class="secno">B.1 </span>Informative references</h3><dl class="bibliography" about=""><dt id="bib-ATSC65">[ATSC65]</dt><dd rel="dcterms:references"><em style="color: #f00">Reference not found.</em>
+</dd><dt id="bib-CEA708">[CEA708]</dt><dd rel="dcterms:references"><a href="http://www.ce.org/Standards/Standard-Listings/R4-3-Television-Data-Systems-Subcommittee/CEA-708-D.aspx"><cite>Digital Television (DTV) Closed Captioning CEA-708-B</cite></a>. URL: <a href="http://www.ce.org/Standards/Standard-Listings/R4-3-Television-Data-Systems-Subcommittee/CEA-708-D.aspx">http://www.ce.org/Standards/Standard-Listings/R4-3-Television-Data-Systems-Subcommittee/CEA-708-D.aspx</a>
+</dd><dt id="bib-HTML">[HTML]</dt><dd rel="dcterms:references">Ian Hickson. <a href="http://www.whatwg.org/specs/web-apps/current-work/"><cite>HTML</cite></a>. Living Standard. URL: <a href="http://www.whatwg.org/specs/web-apps/current-work/">http://www.whatwg.org/specs/web-apps/current-work/</a>
+</dd><dt id="bib-HTML5">[HTML5]</dt><dd rel="dcterms:references">Robin Berjon; Steve Faulkner; Travis Leithead; Erika Doyle Navara; Edward O'Connor; Silvia Pfeiffer. <a href="http://www.w3.org/TR/html5/"><cite>HTML5</cite></a>. 29 April 2014. W3C Candidate Recommendation. URL: <a href="http://www.w3.org/TR/html5/">http://www.w3.org/TR/html5/</a>
+</dd><dt id="bib-ISOBMFF">[ISOBMFF]</dt><dd rel="dcterms:references"><a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c061988_ISO_IEC_14496-12_2012.zip"><cite>Information technology -- Coding of audio-visual objects -- Part 12: ISO base media file format</cite></a> ISO/IEC 14496-12:2012. URL: <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c061988_ISO_IEC_14496-12_2012.zip">http://standards.iso.org/ittf/PubliclyAvailableStandards/c061988_ISO_IEC_14496-12_2012.zip</a>
+</dd><dt id="bib-MPEG2TS">[MPEG2TS]</dt><dd rel="dcterms:references"><a href="http://www.itu.int/rec/T-REC-H.222.0-201206-I"><cite>Information technology -- Generic coding of moving pictures and associated audio information: Systems ITU-T Rec. H.222.0 / ISO/IEC 13818-1:2013</cite></a>. URL: <a href="http://www.itu.int/rec/T-REC-H.222.0-201206-I">http://www.itu.int/rec/T-REC-H.222.0-201206-I</a>
+</dd><dt id="bib-MPEGDASH">[MPEGDASH]</dt><dd rel="dcterms:references"><a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c057623_ISO_IEC_23009-1_2012.zip"><cite>Information technology -- Dynamic adaptive streaming over HTTP (DASH) -- Part 1: Media presentation description and segment formats</cite></a> ISO/IEC 23009-1:2012. URL: <a href="http://standards.iso.org/ittf/PubliclyAvailableStandards/c057623_ISO_IEC_23009-1_2012.zip">http://standards.iso.org/ittf/PubliclyAvailableStandards/c057623_ISO_IEC_23009-1_2012.zip</a>
+</dd><dt id="bib-Matroska">[Matroska]</dt><dd rel="dcterms:references"><a href="http://matroska.org/technical/specs/index.html"><cite>Matroska Specifications</cite></a>. 9 January 2014. URL: <a href="http://matroska.org/technical/specs/index.html">http://matroska.org/technical/specs/index.html</a>
+</dd><dt id="bib-OGG">[OGG]</dt><dd rel="dcterms:references">S. Pfeiffer. <a href="http://www.ietf.org/rfc/rfc3533.txt"><cite>The Ogg Encapsulation Format Version 0 (RFC 3533)</cite></a>. May 2003. RFC. URL: <a href="http://www.ietf.org/rfc/rfc3533.txt">http://www.ietf.org/rfc/rfc3533.txt</a>
+</dd><dt id="bib-OGGSKELETON">[OGGSKELETON]</dt><dd rel="dcterms:references"><a href="http://wiki.xiph.org/SkeletonHeaders"><cite>Ogg Skeleton 4 Message Headers</cite></a>. 17 March 2014. URL: <a href="http://wiki.xiph.org/SkeletonHeaders">http://wiki.xiph.org/SkeletonHeaders</a>
+</dd><dt id="bib-SCTE27">[SCTE27]</dt><dd rel="dcterms:references"><a href="http://www.scte.org/documents/pdf/Standards/ANSI_SCTE_27_2011.pdf"><cite>Subtitling Methods For Broadcast Cable</cite></a>. URL: <a href="http://www.scte.org/documents/pdf/Standards/ANSI_SCTE_27_2011.pdf">http://www.scte.org/documents/pdf/Standards/ANSI_SCTE_27_2011.pdf</a>
+</dd><dt id="bib-WEBVTT">[WEBVTT]</dt><dd rel="dcterms:references">Silvia Pfeiffer; Philip Jägenstedt; Ian Hickson. <a href="http://dev.w3.org/html5/webvtt/"><cite>WebVTT: The Web Video Text Tracks Format</cite></a>. 16 May 2014. W3C Editor's Draft. URL: <a href="http://dev.w3.org/html5/webvtt/">http://dev.w3.org/html5/webvtt/</a>
+</dd><dt id="bib-WEBVTT-WEBM">[WEBVTT-WEBM]</dt><dd rel="dcterms:references">Matthew Heaney; Frank Galligan. <a href="http://wiki.webmproject.org/webm-metadata/temporal-metadata/webvtt-in-webm"><cite>Embedding WebVTT in WebM</cite></a>. 1 February 2012. URL: <a href="http://wiki.webmproject.org/webm-metadata/temporal-metadata/webvtt-in-webm">http://wiki.webmproject.org/webm-metadata/temporal-metadata/webvtt-in-webm</a>
+</dd><dt id="bib-WebM">[WebM]</dt><dd rel="dcterms:references"><a href="http://www.webmproject.org/code/specs/container/"><cite>WebM Container Guidelines</cite></a>. 28 April 2014. URL: <a href="http://www.webmproject.org/code/specs/container/">http://www.webmproject.org/code/specs/container/</a>
+</dd></dl></section></section></body></html>
\ No newline at end of file
Received on Saturday, 7 June 2014 08:07:05 UTC