- From: CVS User spfeiffe <cvsmail@w3.org>
- Date: Sat, 08 Nov 2014 07:59:44 +0000
- To: public-html-commits@w3.org
Update of /sources/public/html5/html-sourcing-inband-tracks
In directory roscoe:/tmp/cvs-serv28483
Modified Files:
Overview.html
Log Message:
Sync HTML sourcing inband tracks spec with Git commit 7bba338d934acdd785646ec7089dc935566e7ae8
--- /sources/public/html5/html-sourcing-inband-tracks/Overview.html 2014/10/15 12:06:44 1.8
+++ /sources/public/html5/html-sourcing-inband-tracks/Overview.html 2014/11/08 07:59:43 1.9
@@ -205,7 +205,7 @@
</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="2014-10-15T01:03:04.000Z" id="unofficial-draft-15-october-2014">Unofficial Draft <time class="dt-published" datetime="2014-10-15">15 October 2014</time></h2>
+ <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-11-07T20:58:50.000Z" id="unofficial-draft-08-november-2014">Unofficial Draft <time class="dt-published" datetime="2014-11-08">08 November 2014</time></h2>
<dl>
@@ -270,38 +270,44 @@
<section id="introduction">
<!--OddPage--><h2 role="heading" id="h2_introduction"><span class="secno">1. </span>Introduction</h2>
<p>
- The specification maintains mappings from in-band audio, video and other data tracks of media resources to HTML VideoTrack, AudioTrack, and TextTrack objects and their attribute values.
+ The specification maintains mappings from in-band audio, video and other data tracks of media resources to HTML <code>VideoTrack</code>, <code>AudioTrack</code>, and <code>TextTrack</code> objects and their attribute values.
</p>
<p>
A generic rule to follow is that a track as exposed in HTML only ever represents a single semantic concept. When mapping from a media resource, sometimes an in-band track does not relate 1-to-1 to a HTML text, audio or video track.
</p>
- <div class="note"><div class="note-title" aria-level="1" role="heading" id="h_note_1"><span>Note</span></div><p class="">For example, a HTML TextTrack object is either a subtitle track or a caption track, never both. However, in-band text tracks may encapsulate caption and subtitle cues of the same language as a single in-band track. Since a caption track is essentially a subtitle track with additional cues of transcripts of audio-only information, such an encapsulation in a single in-band track can save space. In HTML, these tracks should be exposed as two TextTrack objects, since they represent different semantic concepts. The cues appear in their relevant tracks - subtitle cues would be present in both. This allows users to choose between the two tracks and activate the desired one in the same manner that they do when the two tracks are provided through two track elements.
+ <div class="note"><div class="note-title" aria-level="1" role="heading" id="h_note_1"><span>Note</span></div><p class="">For example, a HTML <code>TextTrack</code> object is either a subtitle track or a caption track, never both. However, in-band text tracks may encapsulate caption and subtitle cues of the same language as a single in-band track. Since a caption track is essentially a subtitle track with additional cues of transcripts of audio-only information, such an encapsulation in a single in-band track can save space. In HTML, these tracks should be exposed as two <code>TextTrack</code> objects, since they represent different semantic concepts. The cues appear in their relevant tracks - subtitle cues would be present in both. This allows users to choose between the two tracks and activate the desired one in the same manner that they do when the two tracks are provided through two track elements.
</p></div>
<div class="note"><div class="note-title" aria-level="1" role="heading" id="h_note_2"><span>Note</span></div><p class="">
A similar logic applies to in-band text tracks that have subtitle cues of different languages mixed together in one track. They, too, should be exposed in a track of their own language each.
</p></div>
<div class="note"><div class="note-title" aria-level="1" role="heading" id="h_note_3"><span>Note</span></div><p class="">
- A further example is when a UA decides to implement rendering for a caption track but without exposing the caption track through the TextTrack API. To the Web developer and the Web page user, such a video appears as though it has burnt-in captions. Therefore, the UA could expose two video tracks on the HTMLMediaElement - one with captions and a kind="captions" and one without captions with a kind="main". In this way, the user and the Web developer still get the choice of whether to see the video with or without captions.
+ A further example is when a UA decides to implement rendering for a caption track but without exposing the caption track through the <code>TextTrack</code> API. To the Web developer and the Web page user, such a video appears as though it has burnt-in captions. Therefore, the UA could expose two video tracks on the HTMLMediaElement - one with captions and a <code>kind</code> attribute set to <code>captions</code> and one without captions with a <code>kind</code> attribute set to <code>main</code>. In this way, the user and the Web developer still get the choice of whether to see the video with or without captions.
</p></div>
<p>
- Another generic rule to follow for in-band data tracks is that in order to map them to TextTrack objects, the contents of the track need to be mapped to media-time aligned cues that relate to a non-zero interval of time.
+ Another generic rule to follow for in-band data tracks is that in order to map them to <code>TextTrack</code> objects, the contents of the track need to be mapped to media-time aligned cues that relate to a non-zero interval of time.
</p>
<p>
For every MIME-type/subtype of an existing media container format, this specification defines the following information:
</p>
<ol>
- <li>Track order.</li>
- <li>How to identify the type of tracks.</li>
- <li>Setting track attributes 'id', 'kind', 'language' and 'label' for sourced Text Tracks.</li>
- <li>Setting track attributes 'id', 'kind', 'language' and 'label' for sourced Audio and Video tracks.</li>
+ <li>Track order.
+ <p>Tracks sourced according to this specification are referenced by HTML <code>TrackList</code> objects (<code>audioTracks</code>, <code>videoTracks</code> or <code>textTracks</code>). The [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>]/[<cite><a class="bibref" href="#bib-HTML">HTML</a></cite>] specification mandates that the tracks in those objects be consistently ordered. This requirement insures that the order of tracks is not changed when a track is added or removed, e.g. that <code>videoTracks[3]</code> points to the same object if the tracks with indices 0, 1, 2 and 3 were not removed. This also insures a deterministic result when calls to <code>getTrackById</code> are made with media resources, possibly invalid, that declares two tracks with the same id. This specification defines a consistent ordering of tracks between the media resource and <code>TrackList</code> objects when the media resource is consumed by the user agent.</p>
+ <p>Note that in some media workflows, the order of tracks in a media resource may be subject to changes (e.g. tracks may be added or removed) between authoring and publication. Applications associated with a media resource should not rely on an order of tracks being the same between when the media resource was authored and when it is consumed by the user agent.</p>
+ <p>All media resource formats used in this specification support identifying tracks using a unique identifier. This specification defines how those unique identifiers are mapped onto the <code>id</code> attribute of HTML Track objects. Application authors are encouraged to use the <code>id</code> attribute to identify tracks, rather than the index in a <code>TrackList</code> object.</p>
+ </li>
+ <li>How to identify the type of tracks - one of audio, video or text.</li>
+ <li>Setting the attributes <code>id</code>, <code>kind</code>, <code>language</code> and <code>label</code> for sourced <code>TextTrack</code> objects.</li>
+ <li>Setting the attributes <code>id</code>, <code>kind</code>, <code>language</code> and <code>label</code> for sourced <code>AudioTrack</code> and <code>VideoTrack</code> objects.</li>
<li>Mapping Text Track content into text track cues.</li>
</ol>
</section>
<section id="mpegdash" typeof="bibo:Chapter" resource="#mpegdash" rel="bibo:Chapter">
<!--OddPage--><h2 role="heading" id="h2_mpegdash"><span class="secno">2. </span>MPEG DASH</h2>
- <b>MIME type/subtype: application/dash+xml</b>
-
+ <b>MIME type/subtype: <code>application/dash+xml</code></b>
+ <p>
+ [<cite><a class="bibref" href="#bib-MPEGDASH">MPEGDASH</a></cite>] defines formats for a media manifest, called MPD (Media Presentation Description), which references media containers, called media segments. [<cite><a class="bibref" href="#bib-MPEGDASH">MPEGDASH</a></cite>] also defines some media segments formats based on [<cite><a class="bibref" href="#bib-MPEG2TS">MPEG2TS</a></cite>] or [<cite><a class="bibref" href="#bib-ISOBMFF">ISOBMFF</a></cite>]. Processing of media manifests and segments to expose tracks to Web applications can be done by the user agent. Alternatively, a web application can process the manifests and segments to expose tracks. When the user agent processes MPD and media segments directly, it exposes tracks for <code>AdaptationSet</code> and <code>ContentComponent</code> elements, as defined in this document. When the Web application processes the MPD and media segments, it passes media segments to the user agent according to the MediaSource Extension [<cite><a class="bibref href="#bib-MSE">MSE</a></cite>] specification. In this case, the tracks are exposed by the user agent according to [<cite><a class="bibref" href="#bib-MSE">MSE</a></cite>]. The Web application may set default track attributes from MPD data, using the <code>trackDefaults</code> object, that will be used by the user agent to set attributes not set from initialization segment data.
+ </p>
<ol>
<li><p>Track Order</p>
<p>
@@ -311,12 +317,12 @@
<li><p>Determining the type of track</p>
<p>
- A user agent recognises and supports data from a MPEG DASH media resource as being equivalent to a HTML track based on the AdaptationSet or ContentComponent mimeType:
+ A user agent recognises and supports data from a MPEG DASH media resource as being equivalent to a HTML track based on the <code>AdaptationSet</code> or <code>ContentComponent</code> <code>mimeType</code>:
</p>
<ul>
- <li>text track: the mimeType is of main type "application" or "text"</li>
- <li>video track: the mimeType is of main type "video"</li>
- <li>audio track: the mimeType is of main type "audio"</li>
+ <li>text track: the <code>mimeType</code> is of main type "<code>application</code>" or "<code>text</code>"</li>
+ <li>video track: the <code>mimeType</code> is of main type "<code>video</code>"</li>
+ <li>audio track: the <code>mimeType</code> is of main type "<code>audio</code>"</li>
</ul>
</li>
@@ -330,38 +336,44 @@
<th>How to source its value</th>
</tr></thead>
<tbody><tr>
- <th>id</th>
+ <th><code>id</code></th>
<td>
- Content of the 'id' attribute in the AdaptationSet or ContentComponent element. Empty string if 'id' attribute is not present.
+ Content of the <code>id</code> attribute in the <code>AdaptationSet</code> or <code>ContentComponent</code> element. Empty string if <code>id</code> attribute is not present.
</td>
</tr>
<tr>
- <th>kind</th>
+ <th><code>kind</code></th>
<td>
- <p>Given URN="urn:mpeg:dash:role:2011":</p>
+ <p>Given URN="<code>urn:mpeg:dash:role:2011</code>":</p>
<ul>
- <li>"captions": if the role descriptor's value is "caption"</li>
- <li>"subtitles": if the role descriptor's value is "subtitle"</li>
- <li>"metadata": otherwise</li>
+ <li>"<code>captions</code>": if the <code>Role</code> descriptor's value is "<code>caption</code>"</li>
+ <li>"<code>subtitles</code>": if the <code>Role</code> descriptor's value is "<code>subtitle</code>"</li>
+ <li>"<code>metadata</code>": otherwise</li>
</ul>
</td>
</tr>
<tr>
- <th>label</th>
+ <th><code>label</code></th>
<td>
The empty string.
</td>
</tr>
<tr>
- <th>language</th>
+ <th><code>language</code></th>
+ <td>
+ Content of the <code>lang</code> attribute in the <code>AdaptationSet</code> or <code>ContentComponent</code> element.
+ </td>
+ </tr>
+ <tr>
+ <th><code>inBandMetadataTrackDispatchType</code></th>
<td>
- Content of the 'lang' attribute in the AdaptationSet or ContentComponent element.
+ If <code>kind</code> is "<code>metadata</code>", the concatenation of the <code>AdaptationSet</code> element and all child <code>Role</code> descriptors. The empty string otherwise.
</td>
</tr>
<tr>
- <th>inBandMetadataTrackDispatchType</th>
+ <th><code>mode</code></th>
<td>
- If @kind is "metadata" the concatenation of the AdaptationSet element and all child Role descriptors. The empty string otherwise.
+ "<code>disabled</code>"
</td>
</tr>
</tbody></table>
@@ -377,39 +389,39 @@
<th>How to source its value</th>
</tr></thead>
<tbody><tr>
- <th>id</th>
+ <th><code>id</code></th>
<td>
- Content of the 'id' attribute in the AdaptationSet or ContentComponent element. Empty string if 'id' attribute is not present.
+ Content of the <code>id</code> attribute in the <code>AdaptationSet</code> or <code>ContentComponent</code> element. Empty string if the <code>id</code> attribute is not present.
</td>
</tr>
<tr>
- <th>kind</th>
+ <th><code>kind</code></th>
<td>
- <p>Given a role scheme of "urn:mpeg:dash:role:2011", determine the 'kind' attribute from the value of the role descriptors in the AdaptationSet element.</p>
+ <p>Given a <code>Role</code> scheme of "<code>urn:mpeg:dash:role:2011</code>", determine the <code>kind</code> attribute from the value of the <code>Role</code> descriptors in the <code>AdaptationSet</code> element.</p>
<ul>
- <li>"alternative": if the role is "alternate" but not also "main" or "commentary", or "dub"</li>
- <li>"captions": if the role is "caption" and also "main"</li>
- <li>"descriptions": if the role is "description" and also "supplementary"</li>
- <li>"main": if the role is "main" but not also "caption", "subtitle", or "dub"</li>
- <li>"main-desc": if the role is "main" and also "description"</li>
- <li>"sign": not used</li>
- <li>"subtitles": if the role is "subtitle" and also "main"</li>
- <li>"translation": if the role is "dub" and also "main"</li>
- <li>"commentary": if the role is "commentary" but not also "main"</li>
+ <li>"<code>alternative</code>": if the role is "<code>alternate</code>" but not also "<code>main</code>" or "<code>commentary</code>", or "<code>dub</code>"</li>
+ <li>"<code>captions</code>": if the role is "<code>caption</code>" and also "<code>main</code>"</li>
+ <li>"<code>descriptions</code>": if the role is "<code>description</code>" and also "<code>supplementary</code>"</li>
+ <li>"<code>main</code>": if the role is "<code>main</code>" but not also "<code>caption</code>", "<code>subtitle</code>", or "<code>dub</code>"</li>
+ <li>"<code>main-desc</code>": if the role is "<code>main</code>" and also "<code>description</code>"</li>
+ <li>"<code>sign</code>": not used</li>
+ <li>"<code>subtitles</code>": if the role is "<code>subtitle</code>" and also "<code>main</code>"</li>
+ <li>"<code>translation</code>": if the role is "<code>dub</code>" and also "<code>main</code>"</li>
+ <li>"<code>commentary</code>": if the role is "<code>commentary</code>" but not also "<code>main</code>"</li>
<li>"": otherwise</li>
</ul>
</td>
</tr>
<tr>
- <th>label</th>
+ <th><code>label</code></th>
<td>
The empty string.
</td>
</tr>
<tr>
- <th>language</th>
+ <th><code>language</code></th>
<td>
- Content of the 'lang' attribute in the AdaptationSet or ContentComponent element.
+ Content of the <code>lang</code> attribute in the <code>AdaptationSet</code> or <code>ContentComponent</code> element.
</td>
</tr>
</tbody></table>
@@ -417,13 +429,13 @@
<li><p>Mapping Text Track content into text track cues</p>
<p>
- TextTrackCues may be sourced from DASH media content in the WebVTT, TTML, MPEG-2 TS or ISOBMFF format.
+ <code>TextTrackCue</code> objects may be sourced from DASH media content in the WebVTT, TTML, MPEG-2 TS or ISOBMFF format.
</p>
<p>
- Media content with the MIME type "text/vtt" is in the WebVTT format and should be exposed as a VTTCue as defined in [<cite><a class="bibref" href="#bib-WEBVTT">WEBVTT</a></cite>].
+ Media content with the MIME type "<code>text/vtt</code>" is in the WebVTT format and should be exposed as a <code>VTTCue</code> object as defined in [<cite><a class="bibref" href="#bib-WEBVTT">WEBVTT</a></cite>].
</p>
<p>
- Media content with the MIME type "application/ttml+xml" is in the TTML format and should be exposed as an as yet to be defined TTMLCue. Alternatively, browsers can also map the TTML features to WebVTTCue objects. Finally, browsers that cannot render TTML [<cite><a class="bibref" href="#bib-ttaf1-dfxp">ttaf1-dfxp</a></cite>] format data should expose them as DataCue objects [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>]. In this case, the TTML file must be parsed in its entirety and then converted into a sequence of TTML Intermediate Synchronic Documents (ISDs). Each ISD creates a DataCue object with attributes sourced as follows:
+ Media content with the MIME type "<code>application/ttml+xml</code>" is in the TTML format and should be exposed as an as yet to be defined <code>TTMLCue</code> object. Alternatively, browsers can also map the TTML features to <code>VTTCue</code> objects [<cite><a class="bibref" href="#bib-WEBVTT">WEBVTT</a></cite>]. Finally, browsers that cannot render TTML [<cite><a class="bibref" href="#bib-ttaf1-dfxp">ttaf1-dfxp</a></cite>] format data should expose them as <code>DataCue</code> objects [<cite><a class="bibref" href="#bib-HTML51">HTML51</a></cite>]. In this case, the TTML file must be parsed in its entirety and then converted into a sequence of TTML Intermediate Synchronic Documents (ISDs). Each ISD creates a <code>DataCue</code> object with attributes sourced as follows:
</p><p>
</p><table>
<thead>
@@ -431,37 +443,37 @@
<th>How to source its value</th>
</tr></thead>
<tbody><tr>
- <th>id</th>
- <td>Decimal representation of the ‘id’ attribute of the ‘head’ element in the XML document. Null if there is no ‘id’ attribute.</td>
+ <th><code>id</code></th>
+ <td>Decimal representation of the <code>id</code> attribute of the <code>head</code> element in the XML document. Null if there is no <code>id</code> attribute.</td>
</tr>
<tr>
- <th>startTime</th>
+ <th><code>startTime</code></th>
<td>
Value of the beginning media time of the active temporal interval of the ISD.
</td>
</tr>
<tr>
- <th>endTime</th>
+ <th><code>endTime</code></th>
<td>
Value of the ending media time of the active temporal interval of the ISD.
</td>
</tr>
<tr>
- <th>pauseOnExit</th>
- <td>"false"</td>
+ <th><code>pauseOnExit</code></th>
+ <td>"<code>false</code>"</td>
</tr>
<tr>
- <th>data</th>
- <td>The (UTF-16 encoded) ArrayBuffer composing the ISD resource.</td>
+ <th><code>data</code></th>
+ <td>The (UTF-16 encoded) <code>ArrayBuffer</code> composing the ISD resource.</td>
</tr>
</tbody></table>
<p></p>
<p></p>
<p>
- Media content with the MIME type "application/mp4" or "video/mp4" is in the ISOBMFF format and should be exposed following the same rules as for <a href="#ISOBMFF-TT">ISOBMFF text track</a>.
+ Media content with the MIME type "<code>application/mp4</code>" or "<code>video/mp4</code>" is in the [<cite><a class="bibref" href="#bib-ISOBMFF">ISOBMFF</a></cite>] format and should be exposed following the same rules as for <a href="#ISOBMFF-TT">ISOBMFF text track</a>.
</p>
<p>
- Media content with the MIME type "video/mp2t" is in the MPEG-2 TS format and should be exposed following the same rules as for <a href="#MPEG2TS-TT">MPEG-2 TS text track</a>.
+ Media content with the MIME type "<code>video/mp2t</code>" is in the MPEG-2 TS format and should be exposed following the same rules as for <a href="#MPEG2TS-TT">MPEG-2 TS text track</a>.
</p>
</li>
</ol>
@@ -470,43 +482,43 @@
<section id="mpeg2ts" typeof="bibo:Chapter" resource="#mpeg2ts" rel="bibo:Chapter">
<!--OddPage--><h2 role="heading" id="h2_mpeg2ts"><span class="secno">3. </span>MPEG-2 Transport Streams</h2>
- <b>MIME type/subtype: audio/mp2t , video/mp2t</b>
+ <b>MIME type/subtype: <code>audio/mp2t</code>, <code>video/mp2t</code></b>
<ol>
<li><p>Track Order</p>
<p>
- Tracks are called "elementary streams" in a MPEG-2 Transport Stream (TS) [<cite><a class="bibref" href="#bib-MPEG2TS">MPEG2TS</a></cite>]. The order in which elementary streams are listed in the "Program Map Table" (PMT) of a MPEG-2 TS is maintained when sourcing multiple MPEG-2 tracks into HTML.
+ Tracks are called "elementary streams" in a MPEG-2 Transport Stream (TS) [<cite><a class="bibref" href="#bib-MPEG2TS">MPEG2TS</a></cite>]. The order in which elementary streams are listed in the "Program Map Table" (PMT) of a MPEG-2 TS is maintained when sourcing multiple MPEG-2 tracks into HTML. Additions or deletions of elementary streams in the PMT should invoke <code>addtrack</code> or <code>removetrack</code> events in the user agent.
</p>
<div class="note"><div class="note-title" aria-level="1" role="heading" id="h_note_4"><span>Note</span></div><p class="">The order of elementary streams in the PMT may change between when the media resource was created and when it is received by the user agent. Scripts should not infer any information from the ordering, or rely on any particular ordering being present.</p></div>
</li>
<li><p>Determining the type of track</p>
<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":
+ A user agent recognizes and supports data in an MPEG-2 TS elementary stream identified by the <code>elementary_PID</code> field in the Program Map Table as being equivalent to an HTML track based on the value of the <code>stream_type</code> field associated with that <code>elementary_PID</code>:
</p>
<ul>
<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 elementary stream with PID 0x02 or the <code>stream_type</code> value is "0x02", "0x05" or between "0x80" and "0xFF". </li>
<li><dfn id="captionservice">The CEA 708 caption service</dfn> [<cite><a class="bibref" href="#bib-CEA708">CEA708</a></cite>], as identified by:
<ul>
- <li>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 or 0x1B.</li>
- <li>For 'stream_type' 0x02, the presence of caption data in the 'user_data()' field [<cite><a class="bibref" href="#bib-ATSC52">ATSC52</a></cite>].</li>
- <li>For stream type 0x1B, the presence of caption data in the ‘ATSC1_data()’ field [<cite><a class="bibref" href="#bib-SCTE128-1">SCTE128-1</a></cite>].</li>
+ <li>A <code>caption_service_descriptor</code> [<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 or 0x1B.</li>
+ <li>For <code>stream_type</code> 0x02, the presence of caption data in the <code>user_data()</code> field [<cite><a class="bibref" href="#bib-ATSC52">ATSC52</a></cite>].</li>
+ <li>For <code>stream_type</code> 0x1B, the presence of caption data in the <code>ATSC1_data()</code> field [<cite><a class="bibref" href="#bib-SCTE128-1">SCTE128-1</a></cite>].</li>
</ul>
</li>
- <li>a DVB subtitle component [<cite><a class="bibref" href="#bib-DVB-SUB">DVB-SUB</a></cite>] as identified by a 'subtitling_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>]in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
- <li>an ITU-R System B Teletext component [<cite><a class="bibref" href="#bib-DVB-TXT">DVB-TXT</a></cite>] as identified by an 'teletext_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
- <li>a VBI data component [<cite><a class="bibref" href="#bib-DVB-VBI">DVB-VBI</a></cite>] as identified by a 'VBI_data_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] or a 'VBI_teletext_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
+ <li>a DVB subtitle component [<cite><a class="bibref" href="#bib-DVB-SUB">DVB-SUB</a></cite>] as identified by a <code>subtitling_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
+ <li>an ITU-R System B Teletext component [<cite><a class="bibref" href="#bib-DVB-TXT">DVB-TXT</a></cite>] as identified by an <code>teletext_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
+ <li>a VBI data component [<cite><a class="bibref" href="#bib-DVB-VBI">DVB-VBI</a></cite>] as identified by a <code>VBI_data_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] or a <code>VBI_teletext_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
</ul>
- </li><li>video track: the stream type value is "0x01", "0x02", "0x10", "0x1B", between "0x1E" and "0x24" or "0xEA".</li>
+ </li><li>video track: the <code>stream_type</code> value is "0x01", "0x02", "0x10", "0x1B", between "0x1E" and "0x24" or "0xEA".</li>
<li>audio track:
<ul>
- <li>the stream type value is "0x03", "0x04", "0x0F", "0x11", "0x1C", "0x81" or "0x87".</li>
- <li>an AC-3 audio component as identified by an 'AC-3_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
- <li>an Enhanced AC-3 audio component as identified by an 'enhanced_ac-3_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>]in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
- <li>a DTS® audio component as identified by a 'DTS_audio_stream_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
- <li>a DTS-HD® audio component as identified by a 'DTS-HD_audio_stream_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a 'stream_type' of "0x06"</li>
+ <li>the <code>stream_type</code> value is "0x03", "0x04", "0x0F", "0x11", "0x1C", "0x81" or "0x87".</li>
+ <li>an AC-3 audio component as identified by an <code>AC-3_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
+ <li>an Enhanced AC-3 audio component as identified by an <code>enhanced_ac-3_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>]in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
+ <li>a DTS® audio component as identified by a <code>DTS_audio_stream_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
+ <li>a DTS-HD® audio component as identified by a <code>DTS-HD_audio_stream_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the 'Elementary Stream Descriptors' in the PMT entry for a stream with a <code>stream_type</code> of "0x06"</li>
</ul>
</li></ul>
</li>
@@ -518,22 +530,22 @@
<th>How to source its value</th>
</tr></thead>
<tbody><tr>
- <th>id</th>
+ <th><code>id</code></th>
<td>
- Decimal representation of the elementary stream's identifier ('elementary_PID' field) in the PMT.
+ Decimal representation of the elementary stream's identifier (<code>elementary_PID</code> 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.
+ In the case of CEA 708 closed captions, decimal representation of the <code>caption_service_number</code> in the 'Caption Service Descriptor' in the PMT.
</p>
<p>
If program 0 (zero) is present in the transport stream, a string of the format "OOOO.TTTT.SSSS.CC" consisting of the following, lower-case hexadecimal encoded fields:
</p><ul>
- <li>OOOO is the four character representation of the 16-bit 'original_network_id' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>].</li>
- <li>TTTT is the four character representation of the 16-bit 'transport_stream_id' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>].</li>
- <li>SSSS is the four character representation of the 16-bit 'service_id' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>].</li>
+ <li>OOOO is the four character representation of the 16-bit <code>original_network_id</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>].</li>
+ <li>TTTT is the four character representation of the 16-bit <code>transport_stream_id</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>].</li>
+ <li>SSSS is the four character representation of the 16-bit <code>service_id</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>].</li>
<li>CC is:
<ul>
- <li>If a 'stream_identifier_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] is present in the PMT, a two character representation of the 8-bit 'component_tag' value.</li>
- <li>Otherwise, a four character representation of the elementary stream's identifier (13-bit 'elementary_PID' field) in the PMT.</li>
+ <li>If a <code>stream_identifier_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] is present in the PMT, a two character representation of the 8-bit <code>component_tag</code> value.</li>
+ <li>Otherwise, a four character representation of the elementary stream's identifier (13-bit <code>elementary_PID</code> field) in the PMT.</li>
</ul>
</li>
</ul>
@@ -541,69 +553,77 @@
</td>
</tr>
<tr>
- <th>kind</th>
+ <th><code>kind</code></th>
<td>
<ul>
- <li>"captions":
+ <li>"<code>captions</code>":
<ul>
<li>For a <a href="#captionservice">CEA708 caption service.</a></li>
- <li>for a DVB subtitle component [<cite><a class="bibref" href="#bib-DVB-SUB">DVB-SUB</a></cite>] as identified by a 'subtitling_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the PMT with a 'subtitling_type' in the range "0x20" to "0x25".</li>
- <li>an ITU-R System B Teletext component [<cite><a class="bibref" href="#bib-DVB-TXT">DVB-TXT</a></cite>] as identified by an 'teletext_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a 'teletext_type' value of "0x05" in the PMT</li>
- <li>a VBI data component [<cite><a class="bibref" href="#bib-DVB-VBI">DVB-VBI</a></cite>] as identified by a 'VBI_teletext_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a 'teletext_type' value of "0x05" in the PMT.</li>
+ <li>for a DVB subtitle component [<cite><a class="bibref" href="#bib-DVB-SUB">DVB-SUB</a></cite>] as identified by a <code>subtitling_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the PMT with a <code>subtitling_type</code> in the range "0x20" to "0x25".</li>
+ <li>an ITU-R System B Teletext component [<cite><a class="bibref" href="#bib-DVB-TXT">DVB-TXT</a></cite>] as identified by an <code>teletext_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a <code>teletext_type</code> value of "0x05" in the PMT</li>
+ <li>a VBI data component [<cite><a class="bibref" href="#bib-DVB-VBI">DVB-VBI</a></cite>] as identified by a <code>VBI_teletext_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a <code>teletext_type</code> value of "0x05" in the PMT.</li>
</ul>
- </li><li>"subtitles":
+ </li><li>"<code>subtitles</code>":
<ul>
<li>If the stream type value is "0x82".</li>
- <li>for a DVB subtitle component [<cite><a class="bibref" href="#bib-DVB-SUB">DVB-SUB</a></cite>] as identified by a 'subtitling_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the PMT with a 'subtitling_type' in the range "0x10" to "0x15".</li>
- <li>an ITU-R System B Teletext component [<cite><a class="bibref" href="#bib-DVB-TXT">DVB-TXT</a></cite>] as identified by an 'teletext_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a 'teletext_type' value of "0x02" in the PMT</li>
- <li>a VBI data component [<cite><a class="bibref" href="#bib-DVB-VBI">DVB-VBI</a></cite>] as identified by a 'VBI_teletext_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a 'teletext_type' value of "0x02" in the PMT.</li>
+ <li>for a DVB subtitle component [<cite><a class="bibref" href="#bib-DVB-SUB">DVB-SUB</a></cite>] as identified by a <code>subtitling_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] in the PMT with a <code>subtitling_type</code> in the range "0x10" to "0x15".</li>
+ <li>an ITU-R System B Teletext component [<cite><a class="bibref" href="#bib-DVB-TXT">DVB-TXT</a></cite>] as identified by an <code>teletext_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a <code>teletext_type</code> value of "0x02" in the PMT</li>
+ <li>a VBI data component [<cite><a class="bibref" href="#bib-DVB-VBI">DVB-VBI</a></cite>] as identified by a <code>VBI_teletext_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] with a <code>teletext_type</code> value of "0x02" in the PMT.</li>
</ul>
- </li><li>"metadata": otherwise</li>
+ </li><li>"<code>metadata</code>": otherwise</li>
</ul>
</td>
</tr>
<tr>
- <th>label</th>
+ <th><code>label</code></th>
<td>
<ul>
- <li>If a 'component_name_descriptor' [<cite><a class="bibref" href="#bib-ATSC65">ATSC65</a></cite>] is found immediately after the 'ES_info_length' field in the Program Map Table [<cite><a class="bibref" href="#bib-MPEG2TS">MPEG2TS</a></cite>], the DOMString representation of the 'component_name_string' in that 'component_name_descriptor'.</li>
- <li>If a 'component_descriptor' [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] for the component is present in the SDT or EIT, the DOMString representation of the content of the text field in that 'component_descriptor'</li>The empty string otherwise.
- </ul></td>
+ <li>If a <code>component_name_descriptor</code> [<cite><a class="bibref" href="#bib-ATSC65">ATSC65</a></cite>] is found immediately after the <code>ES_info_length</code> field in the Program Map Table [<cite><a class="bibref" href="#bib-MPEG2TS">MPEG2TS</a></cite>], the <code>DOMString</code> representation of the <code>component_name_string</code> in that <code>component_name_descriptor</code>.</li>
+ <li>If a <code>component_descriptor</code> [<cite><a class="bibref" href="#bib-DVB-SI">DVB-SI</a></cite>] for the component is present in the SDT or EIT, the <code>DOMString</code> representation of the content of the text field in that <code>component_descriptor</code></li>
+ <li>The empty string otherwise.</li>
+ </ul>
+ </td>
[1013 lines skipped]
Received on Saturday, 8 November 2014 07:59:58 UTC