--- a/ttml-ww-profiles/ttml-ww-profiles.html Wed Sep 24 15:31:11 2014 -0700
+++ b/ttml-ww-profiles/ttml-ww-profiles.html Thu Sep 25 09:23:00 2014 -0700
@@ -217,7 +217,7 @@
</p>
<h1 class="title p-name" id="title" property="dcterms:title">TTML Text and Image Profiles for Internet Media Subtitles and Captions 1.0</h1>
- <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-09-25T05:30:30.000Z" id="w3c-editor-s-draft-24-september-2014"><abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft <time class="dt-published" datetime="2014-09-24">24 September 2014</time></h2>
+ <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-09-25T23:20:13.000Z" id="w3c-editor-s-draft-25-september-2014"><abbr title="World Wide Web Consortium">W3C</abbr> Editor's Draft <time class="dt-published" datetime="2014-09-25">25 September 2014</time></h2>
<dl>
<dt>This version:</dt>
@@ -277,6 +277,9 @@
consistent rendering and conversion to other subtitling and captioning formats. The text profile is a superset of
[<cite><a class="bibref" href="#bib-SDPUS">SDPUS</a></cite>].</p>
+ <p>The document defines extensions to [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], as well as incorporates extensions specified in [<cite><a class="bibref" href="#bib-ST2052-1">ST2052-1</a></cite>] and
+ [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>].</p>
+
<p>Both profiles are based on [<cite><a class="bibref" href="#bib-SUBM">SUBM</a></cite>].</p>
</section><section id="sotd" class="introductory" typeof="bibo:Chapter" resource="#sotd" rel="bibo:Chapter"><h2 aria-level="1" role="heading" id="h2_sotd">Status of This Document</h2>
@@ -357,8 +360,10 @@
intended for subtitle and caption delivery worldwide, including dialog language translation, content description, captions for
deaf and hard of hearing, etc.</p>
- <p>The text-only profile is a strict superset of [<cite><a class="bibref" href="#bib-SDPUS">SDPUS</a></cite>] and the image-only profile uses extensions specified in
- [<cite><a class="bibref" href="#bib-ST2052-1">ST2052-1</a></cite>].</p>
+ <p>The text-only profile is a strict superset of [<cite><a class="bibref" href="#bib-SDPUS">SDPUS</a></cite>].</p>
+
+ <p>The document defines extensions to [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], as well as incorporates extensions specified in [<cite><a class="bibref" href="#bib-ST2052-1">ST2052-1</a></cite>] and
+ [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>].</p>
</section>
<section id="terms" typeof="bibo:Chapter" resource="#terms" rel="bibo:Chapter">
@@ -367,10 +372,10 @@
<p><dfn id="dfn-presentation-processor">Presentation processor</dfn>. See Section 2.2 at [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>].</p>
<p><dfn id="dfn-transformation-processor">Transformation processor</dfn>. See Section 2.2 at [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>].</p>
-
- <p><dfn id="dfn-intermediate-synchronic-document">Intermediate synchronic document</dfn>. See Section 9.3.2 at [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>].</p>
-
- <p><dfn id="dfn-related-media-object">Related Media Object</dfn>. See Section 2.2 at [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>].</p>
+
+ <p><dfn id="dfn-intermediate-synchronic-document">Intermediate synchronic document</dfn>. See Section 9.3.2 at [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>].</p>
+
+ <p><dfn id="dfn-related-media-object">Related Media Object</dfn>. See Section 2.2 at [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>].</p>
</section>
<section id="conformance" typeof="bibo:Chapter" resource="#conformance" rel="bibo:Chapter"><!--OddPage--><h2 aria-level="1" role="heading" id="h2_conformance"><span class="secno">3. </span>Conformance</h2>
@@ -425,9 +430,10 @@
<p>A subtitle document <em class="rfc2119" title="SHALL NOT">SHALL NOT</em> conform to the <a href="#dfn-text-profile" class="internalDFN">Text Profile</a> and <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> simultaneously.</p>
<p>In applications that require subtitle/caption content in image form to be simultaneously available in text form, two
- distinct subtitle documents, one conforming to the <a href="#dfn-text-profile" class="internalDFN">Text Profile</a> and the other conforming to the <a href="#dfn-image-profile" class="internalDFN">Image Profile</a>, <em class="rfc2119" title="SHOULD">SHOULD</em> be
- offered. In addition, the <a href="#dfn-text-profile" class="internalDFN">Text Profile</a> subtitle document <em class="rfc2119" title="SHOULD">SHOULD</em> be associated with the <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> subtitle document such
- that, when image content is encountered, assistive technologies have access to its corresponding text form.</p>
+ distinct subtitle documents, one conforming to the <a href="#dfn-text-profile" class="internalDFN">Text Profile</a> and the other conforming to the <a href="#dfn-image-profile" class="internalDFN">Image Profile</a>,
+ <em class="rfc2119" title="SHOULD">SHOULD</em> be offered. In addition, the <a href="#dfn-text-profile" class="internalDFN">Text Profile</a> subtitle document <em class="rfc2119" title="SHOULD">SHOULD</em> be associated with the <a href="#dfn-image-profile" class="internalDFN">Image Profile</a>
+ subtitle document such that, when image content is encountered, assistive technologies have access to its corresponding text
+ form.</p>
<div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_2"><span>Note</span></div><p class="">The <code>ittm:altText</code> element specified <a href="#ttm-altText" class="sec-ref"><span class="secno">5.7.4</span> <span class="sec-title">ittm:altText</span></a> also allows text equivalent
string to be associated with an image, e.g. to support indexation of the content and also facilitate quality checking of the
@@ -535,17 +541,17 @@
<td>[<cite><a class="bibref" href="#bib-ST2052-1">ST2052-1</a></cite>]</td>
</tr>
+
<tr>
-
<td>EBU-TT Styling</td>
<td>ebutts</td>
<td>urn:ebu:tt:style</td>
- <td>[<cite><a class="bibref" href="#bib-EBUTTD">EBUTTD</a></cite>]</td>
+ <td>[<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>]</td>
</tr>
-
+
<tr>
<td>IMSC 1.0 Styling</td>
@@ -611,14 +617,15 @@
<p>The namespace prefix values defined above are for convenience and document instances may use any prefix value that
conforms to [<cite><a class="bibref" href="#bib-xml-names">xml-names</a></cite>].</p>
</section>
-
- <section id="overflow">
+
+ <section id="overflow">
<h3 aria-level="2" role="heading" id="h3_overflow"><span class="secno">5.4 </span>Overflow</h3>
- <p>Subtitle documents should be authored assuming strict clipping of content that falls out of region areas, regardless of the computed value of <code>tts:overflow</code> for the region.</p>
-
- <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_3"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], <code>tts:overflow</code> has no effect on the extent of the region, and hence the total normalized drawing area S(En) at <a href="#paint-regions" class="sec-ref"><span class="secno">8.1.3</span> <span class="sec-title">Paint Regions</span></a>.</p></div>
-
+ <p>Subtitle documents should be authored assuming strict clipping of content that falls out of region areas, regardless of
+ the computed value of <code>tts:overflow</code> for the region.</p>
+
+ <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_3"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], <code>tts:overflow</code> has no effect on the extent of the region, and hence
+ the total normalized drawing area S(En) at <a href="#paint-regions" class="sec-ref"><span class="secno">8.1.3</span> <span class="sec-title">Paint Regions</span></a>.</p></div>
</section>
<section id="related-video-object">
@@ -631,8 +638,8 @@
<section id="synchronization">
<h3 aria-level="2" role="heading" id="h3_synchronization"><span class="secno">5.6 </span>Synchronization</h3>
- <p>Each <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> of the subtitle document is intended to be displayed on a specific frame and removed
- on a specific frame of the related video object.</p>
+ <p>Each <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> of the subtitle document is intended to be displayed on a specific frame and
+ removed on a specific frame of the related video object.</p>
<p>When mapping a media time expression M to a frame F of a related video object, e.g. for the purpose of rendering a
subtitle document onto the related video object, the <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> <em class="rfc2119" title="SHALL">SHALL</em> map M to the frame F with the
@@ -728,17 +735,19 @@
<section id="ttp-progressivelyDecodable" typeof="bibo:Chapter" resource="#ttp-progressivelyDecodable" rel="bibo:Chapter">
<h4 aria-level="3" role="heading" id="h4_ttp-progressivelyDecodable"><span class="secno">5.7.2 </span>ittp:progressivelyDecodable</h4>
- <p>A <a href="#dfn-progressively-decodable-subtitle-document" class="internalDFN">progressively decodable subtitle document</a> is structured to facilitate presentation before the document is received in
- its entirety, and can be identified using <code>ittp:progressivelyDecodable</code> attribute.</p>
+ <p>A <a href="#dfn-progressively-decodable-subtitle-document" class="internalDFN">progressively decodable subtitle document</a> is structured to facilitate presentation before the document is
+ received in its entirety, and can be identified using <code>ittp:progressivelyDecodable</code> attribute.</p>
<p>A <dfn id="dfn-progressively-decodable-subtitle-document">progressively decodable subtitle document</dfn> is a subtitle document that conforms to the following:</p>
<ol>
<li>no attribute or element of the TTML timing vocabulary is present within the <code>head</code> element;</li>
- <li>given two <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a> <em>A</em> and <em>B</em> of the subtitle document, with start times
- <em>TA</em> and <em>TB</em>, respectively, <em>TA</em> is not greater than <em>TB</em> if <em>A</em> includes a
- <code>p</code> element that occurs earlier in the document than any <code>p</code> element that <em>B</em> includes;</li>
+ <li>given two <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a> <em>A</em> and <em>B</em>
+ of the subtitle document, with start times <em>TA</em> and <em>TB</em>, respectively, <em>TA</em> is not greater than
+ <em>TB</em> if <em>A</em> includes a <code>p</code> element that occurs earlier in the document than any <code>p</code>
+ element that <em>B</em> includes;
+ </li>
<li>no attribute of the TTML timing vocabulary is present on a descendant element of <code>p</code>; and</li>
@@ -774,32 +783,31 @@
<p>A subtitle document for which the computed value of <code>ittp:progressivelyDecodable</code> is "false" is neither
asserted to be a <a href="#dfn-progressively-decodable-subtitle-document" class="internalDFN">progressively decodable subtitle document</a> nor asserted not to be a progressively decodable subtitle
document.</p>
-
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_7"><span>Note</span></div><div class="">
-
- <p>[<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>] specifies explicitly referencing of elements identified using <code>xml:id</code> in the
- following circumstances:</p>
-
- <ul>
- <li>an element in <code>body</code> referencing <code>region</code> elements. In this case, Requirement 4 above is always
- satisfied.</li>
-
- <li>an element in <code>body</code> referencing <code>style</code> elements. In this case, Requirement 4 above is always
- satisfied.</li>
-
- <li>a <code>region</code> element referencing <code>style</code> elements. In this case, Requirement 4 above is always
- satisfied.</li>
-
- <li>a <code>style</code> element referencing other <code>style</code> elements. In this case, Requirement 4 provides an
- optimization of <code>style</code> element ordering within the <code>head</code> element.</li>
-
- <li>a <code>ttm:actor</code> element referencing a <code>ttm:agent</code> element. In this case, Requirement 4 provides
- optimization of metadata elements ordering within the document.</li>
-
- <li>a content element referencing <code>ttm:agent</code> elements using the <code>ttm:agent</code> attribute. In this
- case, Requirement 4 provides optimization of metadata elements ordering within the document.</li>
- </ul>
- </div></div>
+
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_7"><span>Note</span></div><div class="">
+ <p>[<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>] specifies explicitly referencing of elements identified using <code>xml:id</code> in the following
+ circumstances:</p>
+
+ <ul>
+ <li>an element in <code>body</code> referencing <code>region</code> elements. In this case, Requirement 4 above is
+ always satisfied.</li>
+
+ <li>an element in <code>body</code> referencing <code>style</code> elements. In this case, Requirement 4 above is
+ always satisfied.</li>
+
+ <li>a <code>region</code> element referencing <code>style</code> elements. In this case, Requirement 4 above is always
+ satisfied.</li>
+
+ <li>a <code>style</code> element referencing other <code>style</code> elements. In this case, Requirement 4 provides an
+ optimization of <code>style</code> element ordering within the <code>head</code> element.</li>
+
+ <li>a <code>ttm:actor</code> element referencing a <code>ttm:agent</code> element. In this case, Requirement 4 provides
+ optimization of metadata elements ordering within the document.</li>
+
+ <li>a content element referencing <code>ttm:agent</code> elements using the <code>ttm:agent</code> attribute. In this
+ case, Requirement 4 provides optimization of metadata elements ordering within the document.</li>
+ </ul>
+ </div></div>
</section>
<section id="tts-forcedDisplay" typeof="bibo:Chapter" resource="#tts-forcedDisplay" rel="bibo:Chapter">
@@ -890,8 +898,8 @@
<h4 aria-level="3" role="heading" id="h4_ttm-altText"><span class="secno">5.7.4 </span>ittm:altText</h4>
<p><code>ittm:altText</code> allows an author to provide a text string equivalent for an element, typically an image. This
- text equivalent <em class="rfc2119" title="MAY">MAY</em> be used to support indexing of the content and also facilitate quality checking of the document
- during authoring.</p>
+ text equivalent <em class="rfc2119" title="MAY">MAY</em> be used to support indexing of the content and also facilitate quality checking of the document during
+ authoring.</p>
<p>The <code>ittm:altText</code> element <em class="rfc2119" title="SHALL">SHALL</em> conform to the following syntax:</p>
@@ -949,22 +957,24 @@
region (including its boundary) and the sets of coordinates belonging to the root container (including its boundary) is the
set of coordinates belonging to the region (including its boundary).</p>
- <p>No two <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> in a given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> <em class="rfc2119" title="SHALL">SHALL</em> overlap, i.e. the intersection of the sets of
- coordinates within each region (including its boundary) is empty.</p>
+ <p>No two <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> in a given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> <em class="rfc2119" title="SHALL">SHALL</em>
+ overlap, i.e. the intersection of the sets of coordinates within each region (including its boundary) is empty.</p>
</section>
<section id="maximum-number">
<h4 aria-level="3" role="heading" id="h4_maximum-number"><span class="secno">5.8.3 </span>Maximum number</h4>
- <p>The number of <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> in a given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> <em class="rfc2119" title="SHALL NOT">SHALL NOT</em> be greater than 4.</p>
+ <p>The number of <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> in a given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> <em class="rfc2119" title="SHALL
+ NOT">SHALL
+ NOT</em> be greater than 4.</p>
</section>
</section>
<section id="hypothetical-render-model-1">
<h3 aria-level="2" role="heading" id="h3_hypothetical-render-model-1"><span class="secno">5.9 </span>Hypothetical Render Model</h3>
- <p>Any sequence of consecutive <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a> <em class="rfc2119" title="SHALL">SHALL</em> be reproducible without error by the Hypothetical
- Render Model specified in Section <a href="#hypothetical-render-model" class="sec-ref"><span class="secno">8.</span> <span class="sec-title">Hypothetical Render Model</span></a>.</p>
+ <p>Any sequence of consecutive <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a> <em class="rfc2119" title="SHALL">SHALL</em> be
+ reproducible without error by the Hypothetical Render Model specified in Section <a href="#hypothetical-render-model" class="sec-ref"><span class="secno">8.</span> <span class="sec-title">Hypothetical Render Model</span></a>.</p>
</section>
<section id="common-features" typeof="bibo:Chapter" resource="#common-features" rel="bibo:Chapter">
@@ -1751,8 +1761,8 @@
<td><em class="rfc2119" title="SHALL NOT">SHALL NOT</em> be used.</td>
</tr>
-
- <tr>
+
+ <tr>
<td colspan="4"><em>Relative to the IMSC 1.0 Extension namespace</em></td>
</tr>
@@ -1767,7 +1777,6 @@
<td><em class="rfc2119" title="MAY">MAY</em> be used.</td>
</tr>
-
</tbody>
</table>
</section>
@@ -1809,8 +1818,8 @@
<section id="definition">
<h4 aria-level="3" role="heading" id="h4_definition"><span class="secno">7.2.1 </span>Definition</h4>
- <p>A <dfn id="dfn-presented-image">presented image</dfn> is a <code>div</code> element with a <code>smpte:backgroundImage</code> attribute that does not extend
- beyond a <a href="#dfn-presented-region" class="internalDFN">presented region</a>.</p>
+ <p>A <dfn id="dfn-presented-image">presented image</dfn> is a <code>div</code> element with a <code>smpte:backgroundImage</code> attribute that does
+ not extend beyond a <a href="#dfn-presented-region" class="internalDFN">presented region</a>.</p>
</section>
<section id="number-per-region">
@@ -2026,23 +2035,23 @@
</span></figcaption>
</figure>
- <p>The model operates on successive <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a> obtained from an input subtitle document, and uses a
- simple double buffering model: while an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> is being painted into Presentation
- Buffer P<sub>n</sub> (the "front buffer" of the model), the previous <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n-1</sub> is
- available for display in Presentation Buffer P<sub>n-1</sub> (the "back buffer" of the model).</p>
-
- <p>The model specifies an (hypothetical) time required for completely painting an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> as a
- proxy for complexity. Painting includes drawing region backgrounds, rendering and copying glyphs, and decoding and copying
- images. Complexity is then limited by requiring that painting of <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> completes
- before the end of <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n-1</sub>.</p>
+ <p>The model operates on successive <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a>
+ obtained from an input subtitle document, and uses a simple double buffering model: while an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic
+ document</a> E<sub>n</sub> is being painted into Presentation Buffer P<sub>n</sub> (the "front buffer" of the model), the
+ previous <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n-1</sub> is available for display in Presentation Buffer
+ P<sub>n-1</sub> (the "back buffer" of the model).</p>
+
+ <p>The model specifies an (hypothetical) time required for completely painting an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>
+ as a proxy for complexity. Painting includes drawing region backgrounds, rendering and copying glyphs, and decoding and
+ copying images. Complexity is then limited by requiring that painting of <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>
+ E<sub>n</sub> completes before the end of <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n-1</sub>.</p>
<p>Whenever applicable, constraints are specified relative to root container dimensions, allowing subtitle sequences to be
authored independently of related video object resolution.</p>
- <p>To enables scenarios where the same glyphs are used in multiple successive <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a>, e.g. to
- convey a CEA-608/708-style roll-up (see [<cite><a class="bibref" href="#bib-CEA-608">CEA-608</a></cite>] and [<cite><a class="bibref" href="#bib-CEA-708">CEA-708</a></cite>]), the Glyph Buffers G<sub>n</sub> and G<sub>n-1</sub>
- store rendered glyphs across <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a>, allowing glyphs to be copied into the Presentation Buffer
- instead of rendered, a more costly operation.</p>
+ <p>To enables scenarios where the same glyphs are used in multiple successive <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a>, e.g. to convey a CEA-608/708-style roll-up (see
+ [<cite><a class="bibref" href="#bib-CEA-608">CEA-608</a></cite>] and [<cite><a class="bibref" href="#bib-CEA-708">CEA-708</a></cite>]), the Glyph Buffers G<sub>n</sub> and G<sub>n-1</sub> store rendered glyphs across <a title="intermediate synchronic document" href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic documents</a>, allowing glyphs to be copied into the
+ Presentation Buffer instead of rendered, a more costly operation.</p>
<p>Similarly, Decoded Image Buffers D<sub>n</sub> and D<sub>n-1</sub> store decoded images across intermediate synchronic
documents, allowing images to be copied into the Presentation Buffer instead of decoded.</p>
@@ -2055,8 +2064,9 @@
document E<sub>n</sub> using the following steps in order:</p>
<ol>
- <li>clear the pixels, except for the first <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>0</sub> for the which the pixels of
- P<sub>0</sub> <em class="rfc2119" title="SHALL">SHALL</em> be assumed to have been cleared;</li>
+ <li>clear the pixels, except for the first <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>0</sub> for the which the pixels
+ of P<sub>0</sub> <em class="rfc2119" title="SHALL">SHALL</em> be assumed to have been cleared;
+ </li>
<li>paint, according to stacking order, all background pixels for each region;</li>
@@ -2073,8 +2083,8 @@
<li>at the presentation time of E<sub>n-1</sub>, if n > 0</li>
</ul>
- <p>The duration DUR(E<sub>n</sub>) for painting an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> in the Presentation
- Buffer P<sub>n</sub> <em class="rfc2119" title="SHALL">SHALL</em> be:</p>
+ <p>The duration DUR(E<sub>n</sub>) for painting an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> in the
+ Presentation Buffer P<sub>n</sub> <em class="rfc2119" title="SHALL">SHALL</em> be:</p>
<p>DUR(E<sub>n</sub>) = S(E<sub>n</sub>) / BDraw + DUR<sub>T</sub>(E<sub>n</sub>) + DUR<sub>I</sub>(E<sub>n</sub>)</p>
@@ -2097,8 +2107,8 @@
</ul>
<p>The contents of the Presentation Buffer P<sub>n</sub> <em class="rfc2119" title="SHALL">SHALL</em> be transferred instantaneously to Presentation Buffer
- P<sub>n-1</sub> at the presentation time of <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>, making the latter available for
- display.</p>
+ P<sub>n-1</sub> at the presentation time of <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>, making the latter
+ available for display.</p>
<div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_15"><span>Note</span></div><p class="">It is possible for the contents of Presentation Buffer P<sub>n-1</sub> to never be displayed. This can
happen if Presentation Buffer P<sub>n</sub> is copied twice to Presentation Buffer P<sub>n-1</sub> between two consecutive
@@ -2143,21 +2153,23 @@
<section id="paint-regions" typeof="bibo:Chapter" resource="#paint-regions" rel="bibo:Chapter">
<h4 aria-level="3" role="heading" id="h4_paint-regions"><span class="secno">8.1.3 </span>Paint Regions</h4>
- <p>The total normalized drawing area S(E<sub>n</sub>) for <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> <em class="rfc2119" title="SHALL">SHALL</em> be</p>
+ <p>The total normalized drawing area S(E<sub>n</sub>) for <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> <em class="rfc2119" title="SHALL">SHALL</em>
+ be</p>
<p>S(E<sub>n</sub>) = CLEAR(E<sub>n</sub>) + PAINT(E<sub>n</sub> )</p>
<p>where CLEAR(E<sub>0</sub>) = 0 and CLEAR(E<sub>n | n > 0</sub>) = 1, i.e. the root container in its entirety.</p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_18"><span>Note</span></div><p class="">To ensure consistency of the Presentation Buffer, a new <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> requires clearing
- of the root container.</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_18"><span>Note</span></div><p class="">To ensure consistency of the Presentation Buffer, a new <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> requires
+ clearing of the root container.</p></div>
<p>PAINT(E<sub>n</sub>) <em class="rfc2119" title="SHALL">SHALL</em> be the normalized area to be painted for all regions that are used in intermediate synchronic
document E<sub>n</sub> according to</p>
<p>PAINT(E<sub>n</sub>) = ∑<sub>R<sub>i</sub>∈R<sub>p</sub></sub> SIZE(R<sub>i</sub>) ∙ NBG(R<sub>i</sub>)</p>
- <p>where R_p <em class="rfc2119" title="SHALL">SHALL</em> be the set of <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>.</p>
+ <p>where R_p <em class="rfc2119" title="SHALL">SHALL</em> be the set of <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic
+ document</a> E<sub>n</sub>.</p>
<p>NSIZE(R<sub>i</sub>) <em class="rfc2119" title="SHALL">SHALL</em> be given by:</p>
@@ -2170,20 +2182,22 @@
</aside>
<p>NBG(R<sub>i</sub>) <em class="rfc2119" title="SHALL">SHALL</em> be the total number of <code>tts:backgroundColor</code> attributes associated with the given
- region R<sub>i</sub> in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>. A <code>tts:backgroundColor</code> attribute is associated
- with a region when it is explicitly specified (either as an attribute in the element, or by reference to a declared style)
- in the following circumstances:</p>
+ region R<sub>i</sub> in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>. A <code>tts:backgroundColor</code> attribute is
+ associated with a region when it is explicitly specified (either as an attribute in the element, or by reference to a
+ declared style) in the following circumstances:</p>
<ul>
<li>It is specified on the <code>region</code> layout element that defines the region.</li>
<li>It is specified on a <code>div</code>, <code>p</code>, <code>span</code> or <code>br</code> content element that is
- to be flowed into the region for presentation in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> (see [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>] for more details on
- when a content element is followed into a region).</li>
+ to be flowed into the region for presentation in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> (see [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>] for more
+ details on when a content element is followed into a region).
+ </li>
<li>It is specified on a <code>set</code> animation element that is to be applied to content elements that are to be
- flowed into the region for presentation in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> (see [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>] for more details on when
- a <code>set</code> animation element is applied to content elements).</li>
+ flowed into the region for presentation in the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> (see [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>] for more details
+ on when a <code>set</code> animation element is applied to content elements).
+ </li>
</ul>
<p>Even if a specified <code>tts:backgroundColor</code> is the same as specified on the nearest ancestor content element or
@@ -2203,9 +2217,10 @@
<li>if an identical image is present in Decoded Image Buffer D<sub>n</sub>, copy the image from Decoded Image Buffer
D<sub>n</sub> to the Presentation Buffer P<sub>n</sub> using the Image Copier; or</li>
- <li>if an identical image is present in Decoded Image Buffer D<sub>n-1</sub>, i.e. an identical image was present in
- <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n-1</sub>, copy using the Image Copier the glyph from Decoded Image Buffer
- D<sub>n-1</sub> to both the Decoded Image Buffer D<sub>n</sub> and the Presentation Buffer P<sub>n</sub>; or</li>
+ <li>if an identical image is present in Decoded Image Buffer D<sub>n-1</sub>, i.e. an identical image was present in <a href="#dfn-intermediate-synchronic-document" class="internalDFN">
+ intermediate synchronic document</a> E<sub>n-1</sub>, copy using the Image Copier the glyph from Decoded Image Buffer
+ D<sub>n-1</sub> to both the Decoded Image Buffer D<sub>n</sub> and the Presentation Buffer P<sub>n</sub>; or
+ </li>
<li>Otherwise, decode the image using the Image Decoder the image into the Presentation Buffer P<sub>n</sub> and Decoded
Image Buffer D<sub>n</sub>.</li>
@@ -2213,8 +2228,8 @@
<p>Two images <em class="rfc2119" title="SHALL">SHALL</em> be identical if and only if they reference the same encoded image source.</p>
- <p>The duration DUR<sub>I</sub>(E<sub>n</sub>) for painting images of an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub> in
- the Presentation Buffer <em class="rfc2119" title="SHALL">SHALL</em> be as follows:</p>
+ <p>The duration DUR<sub>I</sub>(E<sub>n</sub>) for painting images of an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>
+ E<sub>n</sub> in the Presentation Buffer <em class="rfc2119" title="SHALL">SHALL</em> be as follows:</p>
<p>DUR<sub>I</sub>(E<sub>n</sub>) = ∑<sub>I<sub>i</sub> ∈ I<sub>c</sub></sub> NRGA(I<sub>i</sub>) / ICpy +
∑<sub>I<sub>j</sub> ∈ I<sub>d</sub></sub> NSIZ(I<sub>j</sub>) / IDec</p>
@@ -2222,9 +2237,11 @@
<p>where</p>
<ul>
- <li>I<sub>c</sub> is the set of images copied when painting <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub></li>
-
- <li>I<sub>d</sub> is the set of images decoded when painting <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub></li>
+ <li>I<sub>c</sub> is the set of images copied when painting <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>
+ </li>
+
+ <li>I<sub>d</sub> is the set of images decoded when painting <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>
+ </li>
<li>IDec is the image decoding rate</li>
@@ -2283,7 +2300,8 @@
<section id="paint-text" typeof="bibo:Chapter" resource="#paint-text" rel="bibo:Chapter">
<h4 aria-level="3" role="heading" id="h4_paint-text"><span class="secno">8.1.5 </span>Paint Text</h4>
- <p>For each glyph displayed in <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>, the Presentation Compositor <em class="rfc2119" title="SHALL">SHALL</em>:</p>
+ <p>For each glyph displayed in <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>, the Presentation Compositor
+ <em class="rfc2119" title="SHALL">SHALL</em>:</p>
<ul>
<li>if an identical glyph is present in Glyph Buffer G<sub>n</sub>, copy the glyph from Glyph Buffer G<sub>n</sub> to the
@@ -2323,8 +2341,8 @@
</span></figcaption>
</figure>
- <p>The duration DUR<sub>T</sub>(E<sub>n</sub>) for painting the text of an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>
- in the Presentation Buffer is as follows:</p>
+ <p>The duration DUR<sub>T</sub>(E<sub>n</sub>) for painting the text of an <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>
+ E<sub>n</sub> in the Presentation Buffer is as follows:</p>
<p>DUR<sub>T</sub>(E<sub>n</sub>) = ∑<sub>G<sub>i</sub> ∈ G<sub>r</sub></sub> NRGA(G<sub>i</sub>) / Ren(G<sub>i</sub>)
+ ∑<sub>G<sub>j</sub> ∈ G<sub>c</sub></sub> NRGA(G<sub>j</sub>) / GCpy</p>
@@ -2333,18 +2351,22 @@
<ul>
<li>G<sub>r</sub> is the set of glyphs rendered into the Presentation Buffer P<sub>n</sub> using the Glyph Renderer in
- <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>.</li>
+ <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>.
+ </li>
<li>G<sub>c</sub> is the set of glyphs copied to the Presentation Buffer P<sub>n</sub> using the Glyph Copier in
- <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>.</li>
+ <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>.
+ </li>
<li>Ren(G<sub>i</sub>) is the text rendering performance factor glyph G<sub>i</sub></li>
<li>GCpy is the normalized glyph copy performance factor</li>
</ul>
- <p>G<sub>r</sub> and G<sub>c</sub> <em class="rfc2119" title="SHALL">SHALL</em> include only glyphs in <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> and <em class="rfc2119" title="SHALL NOT">SHALL NOT</em> include a [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] Code
- Point if it does not result in a change to presentation, e.g. the Code Point is ignored.</p>
+ <p>G<sub>r</sub> and G<sub>c</sub> <em class="rfc2119" title="SHALL">SHALL</em> include only glyphs in <a title="presented region" href="#dfn-presented-region" class="internalDFN">presented regions</a> and <em class="rfc2119" title="SHALL
+ NOT">SHALL
+ NOT</em> include a [<cite><a class="bibref" href="#bib-UNICODE">UNICODE</a></cite>] Code Point if it does not result in a change to presentation, e.g. the Code Point is
+ ignored.</p>
<p>The Normalized Rendered Glyph Area NRGA(G<sub>i</sub>) of a glyph G<sub>i</sub> <em class="rfc2119" title="SHALL">SHALL</em> be equal to:</p>
@@ -2405,17 +2427,17 @@
<aside class="example"><div class="example-title"><span>Example 3</span></div>
Setting a Glyph Buffer Normalized Size effectively sets a limit on the total number of distinct glyphs present in any
- given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>. For example, assuming a maximum Normalized Glyph Buffer Size of 1
- and the default tts:fontSize of 1c are used, the glyph's height as percentage of root container height is 1/15 , and the
- maximum number of distinct glyphs that can be buffered is 1÷(1÷15)^2=225 glyphs. In this example, an implementation
+ given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> E<sub>n</sub>. For example, assuming a maximum Normalized Glyph Buffer Size
+ of 1 and the default tts:fontSize of 1c are used, the glyph's height as percentage of root container height is 1/15 , and
+ the maximum number of distinct glyphs that can be buffered is 1÷(1÷15)^2=225 glyphs. In this example, an implementation
rendering at 1920x1080 would need to allocate a glyph buffer no smaller than (1920÷32)×(1080÷15)×225=~1 Mpixels.
</aside>
<aside class="example"><div class="example-title"><span>Example 4</span></div>
GCpy effectively sets a limit on animating glyphs. For example, assuming that the root container is ultimately rendered
at 1920×1080 resolution and no regions need to have background color painted (so only a CLEAR(E<sub>n</sub>) operation
- is required for the normalized drawing area for the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>), a GCpy and BDraw of 12 s-1 would
- mean that a group of 160 glyphs with a tts:fontSize equal to 5% of the root container height could be moved at most
+ is required for the normalized drawing area for the <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>), a GCpy and BDraw of 12 s-1
+ would mean that a group of 160 glyphs with a tts:fontSize equal to 5% of the root container height could be moved at most
approximately 12 s<sup>-1</sup> ÷ (1 + ( 160 × 0.05<sup>2</sup> )) = 8.6 times per second.
</aside>
@@ -2861,21 +2883,22 @@
<p>Guideline 1.1 of [<cite><a class="bibref" href="#bib-WCAG20">WCAG20</a></cite>] recommends that an implementation provide text alternatives for all non-text content. In the
context of this specification, this text alternative is intended primarily to support users of the subtitles who cannot see
- images. Since the images of an <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> subtitle document usually represent subtitle or caption text, the guidelines for
- authoring text equivalent strings given at <span class="sec-no">Images of text</span> of [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>] are appropriate.</p>
-
- <p>Thus, for each subtitle in an <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> subtitle document, a text equivalent content in a <a href="#dfn-text-profile" class="internalDFN">Text Profile</a> subtitle document
- <em class="rfc2119" title="SHOULD">SHOULD</em> be written so that it conveys all essential content and fulfills the same function as the corresponding subtitle image.
- In the context of subtitling and captioning, this content will be (as a minimum) the verbatim equivalent of the image without
- précis or summarization. However, the author <em class="rfc2119" title="MAY">MAY</em> include extra information to the text equivalent string in cases where
- styling is applied to the text image with a deliberate connotation, as a <em>functional</em> replacement for the applied
- style.</p>
+ images. Since the images of an <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> subtitle document usually represent subtitle or caption text, the
+ guidelines for authoring text equivalent strings given at <span class="sec-no">Images of text</span> of [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>] are
+ appropriate.</p>
+
+ <p>Thus, for each subtitle in an <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> subtitle document, a text equivalent content in a <a href="#dfn-text-profile" class="internalDFN">Text Profile</a>
+ subtitle document <em class="rfc2119" title="SHOULD">SHOULD</em> be written so that it conveys all essential content and fulfills the same function as the
+ corresponding subtitle image. In the context of subtitling and captioning, this content will be (as a minimum) the verbatim
+ equivalent of the image without précis or summarization. However, the author <em class="rfc2119" title="MAY">MAY</em> include extra information to the text
+ equivalent string in cases where styling is applied to the text image with a deliberate connotation, as a <em>functional</em>
+ replacement for the applied style.</p>
<p>For instance, in subtitling and captioning, italics can be used to indicate an off screen speaker context (for example a
voice from a radio). An author can choose to include this functional information in the text equivalent; for example, by
- including the word "Radio: " before the image equivalent text. It should also be noted that images in an <a href="#dfn-image-profile" class="internalDFN">Image Profile</a> subtitle
- document that are intended for use as <em>captions</em>, i.e. intended for a hard of hearing audience, might already include
- this functional information in the rendered text.</p>
+ including the word "Radio: " before the image equivalent text. It should also be noted that images in an <a href="#dfn-image-profile" class="internalDFN">Image Profile</a>
+ subtitle document that are intended for use as <em>captions</em>, i.e. intended for a hard of hearing audience, might already
+ include this functional information in the rendered text.</p>
<p>Guideline 1.1 of [<cite><a class="bibref" href="#bib-WCAG20">WCAG20</a></cite>] also recommends that accessible text alternatives must be "programmatically determinable." This
means that the text must be able to be read and used by the assistive technologies (and the accessibility features in browsers)
@@ -2933,31 +2956,31 @@
<p>A <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> supports the <code>#altText</code> feature if it implements presentation semantic support
for values of the <a href="#ttm-altText"><code>ittm:altText</code></a> element.</p>
</section>
-
- <section class="appendix" id="linepadding">
+
+ <section class="appendix" id="linepadding">
<h3 aria-level="2" role="heading" id="h3_linepadding"><span class="secno">D.6 </span>#linePadding</h3>
<p>A <a href="#dfn-transformation-processor" class="internalDFN">transformation processor</a> supports the <code>#linePadding</code> feature if it recognizes and is capable of
- transforming values of the <code>ebutts:linePadding</code> attribute specified in [<cite><a class="bibref" href="#bib-EBUTTD">EBUTTD</a></cite>].</p>
-
- <p>A <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> supports the <code>#linePadding</code> feature if it implements presentation semantic support
- for values of the <code>ebutts:linePadding</code> attribute specified in [<cite><a class="bibref" href="#bib-EBUTTD">EBUTTD</a></cite>].</p>
+ transforming values of the <code>ebutts:linePadding</code> attribute specified in [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>].</p>
+
+ <p>A <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> supports the <code>#linePadding</code> feature if it implements presentation semantic
+ support for values of the <code>ebutts:linePadding</code> attribute specified in [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>].</p>
</section>
-
- <section class="appendix" id="multirowalign">
+
+ <section class="appendix" id="multirowalign">
<h3 aria-level="2" role="heading" id="h3_multirowalign"><span class="secno">D.7 </span>#multiRowAlign</h3>
<p>A <a href="#dfn-transformation-processor" class="internalDFN">transformation processor</a> supports the <code>#multiRowAlign</code> feature if it recognizes and is capable of
- transforming values of the <code>ebutts:multiRowAlign</code> attribute specified in [<cite><a class="bibref" href="#bib-EBUTTD">EBUTTD</a></cite>].</p>
-
- <p>A <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> supports the <code>#multiRowAlign</code> feature if it implements presentation semantic support
- for values of the <code>ebutts:multiRowAlign</code> attribute specified in [<cite><a class="bibref" href="#bib-EBUTTD">EBUTTD</a></cite>].</p>
+ transforming values of the <code>ebutts:multiRowAlign</code> attribute specified in [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>].</p>
+
+ <p>A <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> supports the <code>#multiRowAlign</code> feature if it implements presentation semantic
+ support for values of the <code>ebutts:multiRowAlign</code> attribute specified in [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>].</p>
</section>
</section>
<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">E. </span>References</h2><section id="normative-references" typeof="bibo:Chapter" resource="#normative-references" rel="bibo:Chapter"><h3 aria-level="2" role="heading" id="h3_normative-references"><span class="secno">E.1 </span>Normative references</h3><dl class="bibliography" about=""><dt id="bib-CLDR">[CLDR]</dt><dd rel="dcterms:requires">Unicode Consortium. <a href="http://cldr.unicode.org">The Common Locale Data Repository Project</a>
-</dd><dt id="bib-EBUTTD">[EBUTTD]</dt><dd rel="dcterms:requires">European Broadcasting Union (EBU). <a href="https://tech.ebu.ch/docs/tech/tech3380.pdf">Tech 3380, EBU-TT-D Subtitling Distribution Format Version 1.0</a>
+</dd><dt id="bib-EBU-TT-D">[EBU-TT-D]</dt><dd rel="dcterms:requires">European Broadcasting Union (EBU). <a href="https://tech.ebu.ch/docs/tech/tech3380.pdf">Tech 3380, EBU-TT-D Subtitling Distribution Format Version 1.0</a>
</dd><dt id="bib-MHP">[MHP]</dt><dd rel="dcterms:requires">ETSI TS 101 812 V1.3.1, Digital Video Broadcasting (DVB); Multimedia Home
</dd><dt id="bib-RFC2119">[RFC2119]</dt><dd rel="dcterms:requires">S. Bradner. <a href="http://www.ietf.org/rfc/rfc2119.txt"><cite>Key words for use in RFCs to Indicate Requirement Levels</cite></a>. March 1997. Best Current Practice. URL: <a href="http://www.ietf.org/rfc/rfc2119.txt">http://www.ietf.org/rfc/rfc2119.txt</a>
</dd><dt id="bib-ST2052-1">[ST2052-1]</dt><dd rel="dcterms:requires">SMPTE ST 2052-1, Timed Text Format (SMPTE-TT)
--- a/ttml-ww-profiles/ttml-ww-profiles.source.html Wed Sep 24 15:31:11 2014 -0700
+++ b/ttml-ww-profiles/ttml-ww-profiles.source.html Thu Sep 25 09:23:00 2014 -0700
@@ -10,7 +10,7 @@
<script class='remove'>
var respecConfig = {
specStatus: "ED"
- , processVersion: 2014
+ , processVersion: 2014
, shortName: "ttml-imsc1"
, editors: [{ name: "Pierre Lemieux", mailto: "pal@sandflow.com" }]
, wg: "Timed Text Working Group"
@@ -26,7 +26,7 @@
"CEA-708": "<a href='http://www.ce.org/Standards/Standard-Listings/R4-3-Television-Data-Systems-Subcommittee/CEA-708-D.aspx'>Digital Television (DTV) Closed Captioning</a>, ANSI/CEA Standard.",
"MHP" : "ETSI TS 101 812 V1.3.1, Digital Video Broadcasting (DVB); Multimedia Home",
"ST2052-1": "SMPTE ST 2052-1, Timed Text Format (SMPTE-TT)",
- "EBUTTD": "European Broadcasting Union (EBU). <a href='https://tech.ebu.ch/docs/tech/tech3380.pdf'>Tech 3380, EBU-TT-D Subtitling Distribution Format Version 1.0</a>",
+ "EBU-TT-D": "European Broadcasting Union (EBU). <a href='https://tech.ebu.ch/docs/tech/tech3380.pdf'>Tech 3380, EBU-TT-D Subtitling Distribution Format Version 1.0</a>",
"SDPUS": "World Wide Web Consortium (W3C). <a href='http://www.w3.org/TR/ttml10-sdp-us/'>TTML Simple Delivery Profile for Closed Captions (US)</a> (W3C Working Group Note, 05 February 2013)",
"CLDR": "Unicode Consortium. <a href='http://cldr.unicode.org'>The Common Locale Data Repository Project</a>",
@@ -57,6 +57,9 @@
consistent rendering and conversion to other subtitling and captioning formats. The text profile is a superset of
[[SDPUS]].</p>
+ <p>The document defines extensions to [[!TTML1]], as well as incorporates extensions specified in [[!ST2052-1]] and
+ [[!EBU-TT-D]].</p>
+
<p>Both profiles are based on [[SUBM]].</p>
</section>
@@ -69,8 +72,10 @@
intended for subtitle and caption delivery worldwide, including dialog language translation, content description, captions for
deaf and hard of hearing, etc.</p>
- <p>The text-only profile is a strict superset of [[SDPUS]] and the image-only profile uses extensions specified in
- [[!ST2052-1]].</p>
+ <p>The text-only profile is a strict superset of [[SDPUS]].</p>
+
+ <p>The document defines extensions to [[!TTML1]], as well as incorporates extensions specified in [[!ST2052-1]] and
+ [[!EBU-TT-D]].</p>
</section>
<section id='terms'>
@@ -79,10 +84,10 @@
<p><dfn>Presentation processor</dfn>. See Section 2.2 at [[!TTML1]].</p>
<p><dfn>Transformation processor</dfn>. See Section 2.2 at [[!TTML1]].</p>
-
- <p><dfn>Intermediate synchronic document</dfn>. See Section 9.3.2 at [[!TTML1]].</p>
-
- <p><dfn>Related Media Object</dfn>. See Section 2.2 at [[!TTML1]].</p>
+
+ <p><dfn>Intermediate synchronic document</dfn>. See Section 9.3.2 at [[!TTML1]].</p>
+
+ <p><dfn>Related Media Object</dfn>. See Section 2.2 at [[!TTML1]].</p>
</section>
<section id="conformance">
@@ -127,9 +132,10 @@
<p>A subtitle document SHALL NOT conform to the <a>Text Profile</a> and <a>Image Profile</a> simultaneously.</p>
<p>In applications that require subtitle/caption content in image form to be simultaneously available in text form, two
- distinct subtitle documents, one conforming to the <a>Text Profile</a> and the other conforming to the <a>Image Profile</a>, SHOULD be
- offered. In addition, the <a>Text Profile</a> subtitle document SHOULD be associated with the <a>Image Profile</a> subtitle document such
- that, when image content is encountered, assistive technologies have access to its corresponding text form.</p>
+ distinct subtitle documents, one conforming to the <a>Text Profile</a> and the other conforming to the <a>Image Profile</a>,
+ SHOULD be offered. In addition, the <a>Text Profile</a> subtitle document SHOULD be associated with the <a>Image Profile</a>
+ subtitle document such that, when image content is encountered, assistive technologies have access to its corresponding text
+ form.</p>
<p class='note'>The <code>ittm:altText</code> element specified <a href='#ttm-altText'></a> also allows text equivalent
string to be associated with an image, e.g. to support indexation of the content and also facilitate quality checking of the
@@ -142,7 +148,8 @@
<section>
<h3>Text Profile</h3>
- <p>The <dfn>Text Profile</dfn> consists of Sections <a href="#common-constraints"></a> and <a href="#text-profile-constraints"></a>.</p>
+ <p>The <dfn>Text Profile</dfn> consists of Sections <a href="#common-constraints"></a> and <a href=
+ "#text-profile-constraints"></a>.</p>
</section>
<section>
@@ -238,17 +245,17 @@
<td>[[!ST2052-1]]</td>
</tr>
+
<tr>
-
<td>EBU-TT Styling</td>
<td>ebutts</td>
<td>urn:ebu:tt:style</td>
- <td>[[!EBUTTD]]</td>
+ <td>[[!EBU-TT-D]]</td>
</tr>
-
+
<tr>
<td>IMSC 1.0 Styling</td>
@@ -314,14 +321,15 @@
<p>The namespace prefix values defined above are for convenience and document instances may use any prefix value that
conforms to [[!xml-names]].</p>
</section>
-
- <section>
+
+ <section>
<h3>Overflow</h3>
- <p>Subtitle documents should be authored assuming strict clipping of content that falls out of region areas, regardless of the computed value of <code>tts:overflow</code> for the region.</p>
-
- <p class="note">As specified in [[!TTML1]], <code>tts:overflow</code> has no effect on the extent of the region, and hence the total normalized drawing area S(En) at <a href='#paint-regions'></a>.</p>
-
+ <p>Subtitle documents should be authored assuming strict clipping of content that falls out of region areas, regardless of
+ the computed value of <code>tts:overflow</code> for the region.</p>
+
+ <p class="note">As specified in [[!TTML1]], <code>tts:overflow</code> has no effect on the extent of the region, and hence
+ the total normalized drawing area S(En) at <a href='#paint-regions'></a>.</p>
</section>
<section>
@@ -334,8 +342,8 @@
<section>
<h3>Synchronization</h3>
- <p>Each <a>intermediate synchronic document</a> of the subtitle document is intended to be displayed on a specific frame and removed
- on a specific frame of the related video object.</p>
+ <p>Each <a>intermediate synchronic document</a> of the subtitle document is intended to be displayed on a specific frame and
+ removed on a specific frame of the related video object.</p>
<p>When mapping a media time expression M to a frame F of a related video object, e.g. for the purpose of rendering a
subtitle document onto the related video object, the <a>presentation processor</a> SHALL map M to the frame F with the
@@ -432,17 +440,19 @@
<section id='ttp-progressivelyDecodable'>
<h4>ittp:progressivelyDecodable</h4>
- <p>A <a>progressively decodable subtitle document</a> is structured to facilitate presentation before the document is received in
- its entirety, and can be identified using <code>ittp:progressivelyDecodable</code> attribute.</p>
+ <p>A <a>progressively decodable subtitle document</a> is structured to facilitate presentation before the document is
+ received in its entirety, and can be identified using <code>ittp:progressivelyDecodable</code> attribute.</p>
<p>A <dfn>progressively decodable subtitle document</dfn> is a subtitle document that conforms to the following:</p>
<ol>
<li>no attribute or element of the TTML timing vocabulary is present within the <code>head</code> element;</li>
- <li>given two <a title="intermediate synchronic document">intermediate synchronic documents</a> <em>A</em> and <em>B</em> of the subtitle document, with start times
- <em>TA</em> and <em>TB</em>, respectively, <em>TA</em> is not greater than <em>TB</em> if <em>A</em> includes a
- <code>p</code> element that occurs earlier in the document than any <code>p</code> element that <em>B</em> includes;</li>
+ <li>given two <a title="intermediate synchronic document">intermediate synchronic documents</a> <em>A</em> and <em>B</em>
+ of the subtitle document, with start times <em>TA</em> and <em>TB</em>, respectively, <em>TA</em> is not greater than
+ <em>TB</em> if <em>A</em> includes a <code>p</code> element that occurs earlier in the document than any <code>p</code>
+ element that <em>B</em> includes;
+ </li>
<li>no attribute of the TTML timing vocabulary is present on a descendant element of <code>p</code>; and</li>
@@ -479,32 +489,31 @@
<p>A subtitle document for which the computed value of <code>ittp:progressivelyDecodable</code> is "false" is neither
asserted to be a <a>progressively decodable subtitle document</a> nor asserted not to be a progressively decodable subtitle
document.</p>
-
- <div class='note'>
-
- <p>[[!TTML1]] specifies explicitly referencing of elements identified using <code>xml:id</code> in the
- following circumstances:</p>
-
- <ul>
- <li>an element in <code>body</code> referencing <code>region</code> elements. In this case, Requirement 4 above is always
- satisfied.</li>
-
- <li>an element in <code>body</code> referencing <code>style</code> elements. In this case, Requirement 4 above is always
- satisfied.</li>
-
- <li>a <code>region</code> element referencing <code>style</code> elements. In this case, Requirement 4 above is always
- satisfied.</li>
-
- <li>a <code>style</code> element referencing other <code>style</code> elements. In this case, Requirement 4 provides an
- optimization of <code>style</code> element ordering within the <code>head</code> element.</li>
-
- <li>a <code>ttm:actor</code> element referencing a <code>ttm:agent</code> element. In this case, Requirement 4 provides
- optimization of metadata elements ordering within the document.</li>
-
- <li>a content element referencing <code>ttm:agent</code> elements using the <code>ttm:agent</code> attribute. In this
- case, Requirement 4 provides optimization of metadata elements ordering within the document.</li>
- </ul>
- </div>
+
+ <div class='note'>
+ <p>[[!TTML1]] specifies explicitly referencing of elements identified using <code>xml:id</code> in the following
+ circumstances:</p>
+
+ <ul>
+ <li>an element in <code>body</code> referencing <code>region</code> elements. In this case, Requirement 4 above is
+ always satisfied.</li>
+
+ <li>an element in <code>body</code> referencing <code>style</code> elements. In this case, Requirement 4 above is
+ always satisfied.</li>
+
+ <li>a <code>region</code> element referencing <code>style</code> elements. In this case, Requirement 4 above is always
+ satisfied.</li>
+
+ <li>a <code>style</code> element referencing other <code>style</code> elements. In this case, Requirement 4 provides an
+ optimization of <code>style</code> element ordering within the <code>head</code> element.</li>
+
+ <li>a <code>ttm:actor</code> element referencing a <code>ttm:agent</code> element. In this case, Requirement 4 provides
+ optimization of metadata elements ordering within the document.</li>
+
+ <li>a content element referencing <code>ttm:agent</code> elements using the <code>ttm:agent</code> attribute. In this
+ case, Requirement 4 provides optimization of metadata elements ordering within the document.</li>
+ </ul>
+ </div>
</section>
<section id='tts-forcedDisplay'>
@@ -595,8 +604,8 @@
<h4>ittm:altText</h4>
<p><code>ittm:altText</code> allows an author to provide a text string equivalent for an element, typically an image. This
- text equivalent MAY be used to support indexing of the content and also facilitate quality checking of the document
- during authoring.</p>
+ text equivalent MAY be used to support indexing of the content and also facilitate quality checking of the document during
+ authoring.</p>
<p>The <code>ittm:altText</code> element SHALL conform to the following syntax:</p>
@@ -655,22 +664,24 @@
region (including its boundary) and the sets of coordinates belonging to the root container (including its boundary) is the
set of coordinates belonging to the region (including its boundary).</p>
- <p>No two <a title="presented region">presented regions</a> in a given <a>intermediate synchronic document</a> SHALL overlap, i.e. the intersection of the sets of
- coordinates within each region (including its boundary) is empty.</p>
+ <p>No two <a title="presented region">presented regions</a> in a given <a>intermediate synchronic document</a> SHALL
+ overlap, i.e. the intersection of the sets of coordinates within each region (including its boundary) is empty.</p>
</section>
<section>
<h4>Maximum number</h4>
- <p>The number of <a title="presented region">presented regions</a> in a given <a>intermediate synchronic document</a> SHALL NOT be greater than 4.</p>
+ <p>The number of <a title="presented region">presented regions</a> in a given <a>intermediate synchronic document</a> SHALL
+ NOT be greater than 4.</p>
</section>
</section>
<section>
<h3>Hypothetical Render Model</h3>
- <p>Any sequence of consecutive <a title="intermediate synchronic document">intermediate synchronic documents</a> SHALL be reproducible without error by the Hypothetical
- Render Model specified in Section <a href="#hypothetical-render-model"></a>.</p>
+ <p>Any sequence of consecutive <a title="intermediate synchronic document">intermediate synchronic documents</a> SHALL be
+ reproducible without error by the Hypothetical Render Model specified in Section <a href=
+ "#hypothetical-render-model"></a>.</p>
</section>
<section id='common-features'>
@@ -1458,8 +1469,8 @@
<td>SHALL NOT be used.</td>
</tr>
-
- <tr>
+
+ <tr>
<td colspan="4"><em>Relative to the IMSC 1.0 Extension namespace</em></td>
</tr>
@@ -1474,7 +1485,6 @@
<td>MAY be used.</td>
</tr>
-
</tbody>
</table>
</section>
@@ -1516,8 +1526,8 @@
<section>
<h4>Definition</h4>
- <p>A <dfn>presented image</dfn> is a <code>div</code> element with a <code>smpte:backgroundImage</code> attribute that does not extend
- beyond a <a>presented region</a>.</p>
+ <p>A <dfn>presented image</dfn> is a <code>div</code> element with a <code>smpte:backgroundImage</code> attribute that does
+ not extend beyond a <a>presented region</a>.</p>
</section>
<section>
@@ -1731,23 +1741,25 @@
</figcaption>
</figure>
- <p>The model operates on successive <a title="intermediate synchronic document">intermediate synchronic documents</a> obtained from an input subtitle document, and uses a
- simple double buffering model: while an <a>intermediate synchronic document</a> E<sub>n</sub> is being painted into Presentation
- Buffer P<sub>n</sub> (the "front buffer" of the model), the previous <a>intermediate synchronic document</a> E<sub>n-1</sub> is
- available for display in Presentation Buffer P<sub>n-1</sub> (the "back buffer" of the model).</p>
-
- <p>The model specifies an (hypothetical) time required for completely painting an <a>intermediate synchronic document</a> as a
- proxy for complexity. Painting includes drawing region backgrounds, rendering and copying glyphs, and decoding and copying
- images. Complexity is then limited by requiring that painting of <a>intermediate synchronic document</a> E<sub>n</sub> completes
- before the end of <a>intermediate synchronic document</a> E<sub>n-1</sub>.</p>
+ <p>The model operates on successive <a title="intermediate synchronic document">intermediate synchronic documents</a>
+ obtained from an input subtitle document, and uses a simple double buffering model: while an <a>intermediate synchronic
+ document</a> E<sub>n</sub> is being painted into Presentation Buffer P<sub>n</sub> (the "front buffer" of the model), the
+ previous <a>intermediate synchronic document</a> E<sub>n-1</sub> is available for display in Presentation Buffer
+ P<sub>n-1</sub> (the "back buffer" of the model).</p>
+
+ <p>The model specifies an (hypothetical) time required for completely painting an <a>intermediate synchronic document</a>
+ as a proxy for complexity. Painting includes drawing region backgrounds, rendering and copying glyphs, and decoding and
+ copying images. Complexity is then limited by requiring that painting of <a>intermediate synchronic document</a>
+ E<sub>n</sub> completes before the end of <a>intermediate synchronic document</a> E<sub>n-1</sub>.</p>
<p>Whenever applicable, constraints are specified relative to root container dimensions, allowing subtitle sequences to be
authored independently of related video object resolution.</p>
- <p>To enables scenarios where the same glyphs are used in multiple successive <a title="intermediate synchronic document">intermediate synchronic documents</a>, e.g. to
- convey a CEA-608/708-style roll-up (see [[CEA-608]] and [[CEA-708]]), the Glyph Buffers G<sub>n</sub> and G<sub>n-1</sub>
- store rendered glyphs across <a title="intermediate synchronic document">intermediate synchronic documents</a>, allowing glyphs to be copied into the Presentation Buffer
- instead of rendered, a more costly operation.</p>
+ <p>To enables scenarios where the same glyphs are used in multiple successive <a title=
+ "intermediate synchronic document">intermediate synchronic documents</a>, e.g. to convey a CEA-608/708-style roll-up (see
+ [[CEA-608]] and [[CEA-708]]), the Glyph Buffers G<sub>n</sub> and G<sub>n-1</sub> store rendered glyphs across <a title=
+ "intermediate synchronic document">intermediate synchronic documents</a>, allowing glyphs to be copied into the
+ Presentation Buffer instead of rendered, a more costly operation.</p>
<p>Similarly, Decoded Image Buffers D<sub>n</sub> and D<sub>n-1</sub> store decoded images across intermediate synchronic
documents, allowing images to be copied into the Presentation Buffer instead of decoded.</p>
@@ -1760,8 +1772,9 @@
document E<sub>n</sub> using the following steps in order:</p>
<ol>
- <li>clear the pixels, except for the first <a>intermediate synchronic document</a> E<sub>0</sub> for the which the pixels of
- P<sub>0</sub> SHALL be assumed to have been cleared;</li>
+ <li>clear the pixels, except for the first <a>intermediate synchronic document</a> E<sub>0</sub> for the which the pixels
+ of P<sub>0</sub> SHALL be assumed to have been cleared;
+ </li>
<li>paint, according to stacking order, all background pixels for each region;</li>
@@ -1778,8 +1791,8 @@
<li>at the presentation time of E<sub>n-1</sub>, if n > 0</li>
</ul>
- <p>The duration DUR(E<sub>n</sub>) for painting an <a>intermediate synchronic document</a> E<sub>n</sub> in the Presentation
- Buffer P<sub>n</sub> SHALL be:</p>
+ <p>The duration DUR(E<sub>n</sub>) for painting an <a>intermediate synchronic document</a> E<sub>n</sub> in the
+ Presentation Buffer P<sub>n</sub> SHALL be:</p>
<p>DUR(E<sub>n</sub>) = S(E<sub>n</sub>) / BDraw + DUR<sub>T</sub>(E<sub>n</sub>) + DUR<sub>I</sub>(E<sub>n</sub>)</p>
@@ -1802,8 +1815,8 @@
</ul>
<p>The contents of the Presentation Buffer P<sub>n</sub> SHALL be transferred instantaneously to Presentation Buffer
- P<sub>n-1</sub> at the presentation time of <a>intermediate synchronic document</a> E<sub>n</sub>, making the latter available for
- display.</p>
+ P<sub>n-1</sub> at the presentation time of <a>intermediate synchronic document</a> E<sub>n</sub>, making the latter
+ available for display.</p>
<p class='note'>It is possible for the contents of Presentation Buffer P<sub>n-1</sub> to never be displayed. This can
happen if Presentation Buffer P<sub>n</sub> is copied twice to Presentation Buffer P<sub>n-1</sub> between two consecutive
@@ -1848,21 +1861,23 @@
<section id='paint-regions'>
<h4>Paint Regions</h4>
- <p>The total normalized drawing area S(E<sub>n</sub>) for <a>intermediate synchronic document</a> E<sub>n</sub> SHALL be</p>
+ <p>The total normalized drawing area S(E<sub>n</sub>) for <a>intermediate synchronic document</a> E<sub>n</sub> SHALL
+ be</p>
<p>S(E<sub>n</sub>) = CLEAR(E<sub>n</sub>) + PAINT(E<sub>n</sub> )</p>
<p>where CLEAR(E<sub>0</sub>) = 0 and CLEAR(E<sub>n | n > 0</sub>) = 1, i.e. the root container in its entirety.</p>
- <p class='note'>To ensure consistency of the Presentation Buffer, a new <a>intermediate synchronic document</a> requires clearing
- of the root container.</p>
+ <p class='note'>To ensure consistency of the Presentation Buffer, a new <a>intermediate synchronic document</a> requires
+ clearing of the root container.</p>
<p>PAINT(E<sub>n</sub>) SHALL be the normalized area to be painted for all regions that are used in intermediate synchronic
document E<sub>n</sub> according to</p>
<p>PAINT(E<sub>n</sub>) = ∑<sub>R<sub>i</sub>∈R<sub>p</sub></sub> SIZE(R<sub>i</sub>) ∙ NBG(R<sub>i</sub>)</p>
- <p>where R_p SHALL be the set of <a title="presented region">presented regions</a> in the <a>intermediate synchronic document</a> E<sub>n</sub>.</p>
+ <p>where R_p SHALL be the set of <a title="presented region">presented regions</a> in the <a>intermediate synchronic
+ document</a> E<sub>n</sub>.</p>
<p>NSIZE(R<sub>i</sub>) SHALL be given by:</p>
@@ -1875,20 +1890,22 @@
</aside>
<p>NBG(R<sub>i</sub>) SHALL be the total number of <code>tts:backgroundColor</code> attributes associated with the given
- region R<sub>i</sub> in the <a>intermediate synchronic document</a>. A <code>tts:backgroundColor</code> attribute is associated
- with a region when it is explicitly specified (either as an attribute in the element, or by reference to a declared style)
- in the following circumstances:</p>
+ region R<sub>i</sub> in the <a>intermediate synchronic document</a>. A <code>tts:backgroundColor</code> attribute is
+ associated with a region when it is explicitly specified (either as an attribute in the element, or by reference to a
+ declared style) in the following circumstances:</p>
<ul>
<li>It is specified on the <code>region</code> layout element that defines the region.</li>
<li>It is specified on a <code>div</code>, <code>p</code>, <code>span</code> or <code>br</code> content element that is
- to be flowed into the region for presentation in the <a>intermediate synchronic document</a> (see [[!TTML1]] for more details on
- when a content element is followed into a region).</li>
+ to be flowed into the region for presentation in the <a>intermediate synchronic document</a> (see [[!TTML1]] for more
+ details on when a content element is followed into a region).
+ </li>
<li>It is specified on a <code>set</code> animation element that is to be applied to content elements that are to be
- flowed into the region for presentation in the <a>intermediate synchronic document</a> (see [[!TTML1]] for more details on when
- a <code>set</code> animation element is applied to content elements).</li>
+ flowed into the region for presentation in the <a>intermediate synchronic document</a> (see [[!TTML1]] for more details
+ on when a <code>set</code> animation element is applied to content elements).
+ </li>
</ul>
<p>Even if a specified <code>tts:backgroundColor</code> is the same as specified on the nearest ancestor content element or
@@ -1908,9 +1925,10 @@
<li>if an identical image is present in Decoded Image Buffer D<sub>n</sub>, copy the image from Decoded Image Buffer
D<sub>n</sub> to the Presentation Buffer P<sub>n</sub> using the Image Copier; or</li>
- <li>if an identical image is present in Decoded Image Buffer D<sub>n-1</sub>, i.e. an identical image was present in
- <a>intermediate synchronic document</a> E<sub>n-1</sub>, copy using the Image Copier the glyph from Decoded Image Buffer
- D<sub>n-1</sub> to both the Decoded Image Buffer D<sub>n</sub> and the Presentation Buffer P<sub>n</sub>; or</li>
+ <li>if an identical image is present in Decoded Image Buffer D<sub>n-1</sub>, i.e. an identical image was present in <a>
+ intermediate synchronic document</a> E<sub>n-1</sub>, copy using the Image Copier the glyph from Decoded Image Buffer
+ D<sub>n-1</sub> to both the Decoded Image Buffer D<sub>n</sub> and the Presentation Buffer P<sub>n</sub>; or
+ </li>
<li>Otherwise, decode the image using the Image Decoder the image into the Presentation Buffer P<sub>n</sub> and Decoded
Image Buffer D<sub>n</sub>.</li>
@@ -1918,8 +1936,8 @@
<p>Two images SHALL be identical if and only if they reference the same encoded image source.</p>
- <p>The duration DUR<sub>I</sub>(E<sub>n</sub>) for painting images of an <a>intermediate synchronic document</a> E<sub>n</sub> in
- the Presentation Buffer SHALL be as follows:</p>
+ <p>The duration DUR<sub>I</sub>(E<sub>n</sub>) for painting images of an <a>intermediate synchronic document</a>
+ E<sub>n</sub> in the Presentation Buffer SHALL be as follows:</p>
<p>DUR<sub>I</sub>(E<sub>n</sub>) = ∑<sub>I<sub>i</sub> ∈ I<sub>c</sub></sub> NRGA(I<sub>i</sub>) / ICpy +
∑<sub>I<sub>j</sub> ∈ I<sub>d</sub></sub> NSIZ(I<sub>j</sub>) / IDec</p>
@@ -1927,9 +1945,11 @@
<p>where</p>
<ul>
- <li>I<sub>c</sub> is the set of images copied when painting <a>intermediate synchronic document</a> E<sub>n</sub></li>
-
- <li>I<sub>d</sub> is the set of images decoded when painting <a>intermediate synchronic document</a> E<sub>n</sub></li>
+ <li>I<sub>c</sub> is the set of images copied when painting <a>intermediate synchronic document</a> E<sub>n</sub>
+ </li>
+
+ <li>I<sub>d</sub> is the set of images decoded when painting <a>intermediate synchronic document</a> E<sub>n</sub>
+ </li>
<li>IDec is the image decoding rate</li>
@@ -1988,7 +2008,8 @@
<section id='paint-text'>
<h4>Paint Text</h4>
- <p>For each glyph displayed in <a>intermediate synchronic document</a> E<sub>n</sub>, the Presentation Compositor SHALL:</p>
+ <p>For each glyph displayed in <a>intermediate synchronic document</a> E<sub>n</sub>, the Presentation Compositor
+ SHALL:</p>
<ul>
<li>if an identical glyph is present in Glyph Buffer G<sub>n</sub>, copy the glyph from Glyph Buffer G<sub>n</sub> to the
@@ -2029,8 +2050,8 @@
</figcaption>
</figure>
- <p>The duration DUR<sub>T</sub>(E<sub>n</sub>) for painting the text of an <a>intermediate synchronic document</a> E<sub>n</sub>
- in the Presentation Buffer is as follows:</p>
+ <p>The duration DUR<sub>T</sub>(E<sub>n</sub>) for painting the text of an <a>intermediate synchronic document</a>
+ E<sub>n</sub> in the Presentation Buffer is as follows:</p>
<p>DUR<sub>T</sub>(E<sub>n</sub>) = ∑<sub>G<sub>i</sub> ∈ G<sub>r</sub></sub> NRGA(G<sub>i</sub>) / Ren(G<sub>i</sub>)
+ ∑<sub>G<sub>j</sub> ∈ G<sub>c</sub></sub> NRGA(G<sub>j</sub>) / GCpy</p>
@@ -2039,18 +2060,21 @@
<ul>
<li>G<sub>r</sub> is the set of glyphs rendered into the Presentation Buffer P<sub>n</sub> using the Glyph Renderer in
- <a>intermediate synchronic document</a> E<sub>n</sub>.</li>
+ <a>intermediate synchronic document</a> E<sub>n</sub>.
+ </li>
<li>G<sub>c</sub> is the set of glyphs copied to the Presentation Buffer P<sub>n</sub> using the Glyph Copier in
- <a>intermediate synchronic document</a> E<sub>n</sub>.</li>
+ <a>intermediate synchronic document</a> E<sub>n</sub>.
+ </li>
<li>Ren(G<sub>i</sub>) is the text rendering performance factor glyph G<sub>i</sub></li>
<li>GCpy is the normalized glyph copy performance factor</li>
</ul>
- <p>G<sub>r</sub> and G<sub>c</sub> SHALL include only glyphs in <a title="presented region">presented regions</a> and SHALL NOT include a [[!UNICODE]] Code
- Point if it does not result in a change to presentation, e.g. the Code Point is ignored.</p>
+ <p>G<sub>r</sub> and G<sub>c</sub> SHALL include only glyphs in <a title="presented region">presented regions</a> and SHALL
+ NOT include a [[!UNICODE]] Code Point if it does not result in a change to presentation, e.g. the Code Point is
+ ignored.</p>
<p>The Normalized Rendered Glyph Area NRGA(G<sub>i</sub>) of a glyph G<sub>i</sub> SHALL be equal to:</p>
@@ -2111,17 +2135,17 @@
<aside class='example'>
Setting a Glyph Buffer Normalized Size effectively sets a limit on the total number of distinct glyphs present in any
- given <a>intermediate synchronic document</a> E<sub>n</sub>. For example, assuming a maximum Normalized Glyph Buffer Size of 1
- and the default tts:fontSize of 1c are used, the glyph's height as percentage of root container height is 1/15 , and the
- maximum number of distinct glyphs that can be buffered is 1÷(1÷15)^2=225 glyphs. In this example, an implementation
+ given <a>intermediate synchronic document</a> E<sub>n</sub>. For example, assuming a maximum Normalized Glyph Buffer Size
+ of 1 and the default tts:fontSize of 1c are used, the glyph's height as percentage of root container height is 1/15 , and
+ the maximum number of distinct glyphs that can be buffered is 1÷(1÷15)^2=225 glyphs. In this example, an implementation
rendering at 1920x1080 would need to allocate a glyph buffer no smaller than (1920÷32)×(1080÷15)×225=~1 Mpixels.
</aside>
<aside class='example'>
GCpy effectively sets a limit on animating glyphs. For example, assuming that the root container is ultimately rendered
at 1920×1080 resolution and no regions need to have background color painted (so only a CLEAR(E<sub>n</sub>) operation
- is required for the normalized drawing area for the <a>intermediate synchronic document</a>), a GCpy and BDraw of 12 s-1 would
- mean that a group of 160 glyphs with a tts:fontSize equal to 5% of the root container height could be moved at most
+ is required for the normalized drawing area for the <a>intermediate synchronic document</a>), a GCpy and BDraw of 12 s-1
+ would mean that a group of 160 glyphs with a tts:fontSize equal to 5% of the root container height could be moved at most
approximately 12 s<sup>-1</sup> ÷ (1 + ( 160 × 0.05<sup>2</sup> )) = 8.6 times per second.
</aside>
@@ -2568,21 +2592,22 @@
<p>Guideline 1.1 of [[!WCAG20]] recommends that an implementation provide text alternatives for all non-text content. In the
context of this specification, this text alternative is intended primarily to support users of the subtitles who cannot see
- images. Since the images of an <a>Image Profile</a> subtitle document usually represent subtitle or caption text, the guidelines for
- authoring text equivalent strings given at <span class='sec-no'>Images of text</span> of [[HTML5]] are appropriate.</p>
-
- <p>Thus, for each subtitle in an <a>Image Profile</a> subtitle document, a text equivalent content in a <a>Text Profile</a> subtitle document
- SHOULD be written so that it conveys all essential content and fulfills the same function as the corresponding subtitle image.
- In the context of subtitling and captioning, this content will be (as a minimum) the verbatim equivalent of the image without
- précis or summarization. However, the author MAY include extra information to the text equivalent string in cases where
- styling is applied to the text image with a deliberate connotation, as a <em>functional</em> replacement for the applied
- style.</p>
+ images. Since the images of an <a>Image Profile</a> subtitle document usually represent subtitle or caption text, the
+ guidelines for authoring text equivalent strings given at <span class='sec-no'>Images of text</span> of [[HTML5]] are
+ appropriate.</p>
+
+ <p>Thus, for each subtitle in an <a>Image Profile</a> subtitle document, a text equivalent content in a <a>Text Profile</a>
+ subtitle document SHOULD be written so that it conveys all essential content and fulfills the same function as the
+ corresponding subtitle image. In the context of subtitling and captioning, this content will be (as a minimum) the verbatim
+ equivalent of the image without précis or summarization. However, the author MAY include extra information to the text
+ equivalent string in cases where styling is applied to the text image with a deliberate connotation, as a <em>functional</em>
+ replacement for the applied style.</p>
<p>For instance, in subtitling and captioning, italics can be used to indicate an off screen speaker context (for example a
voice from a radio). An author can choose to include this functional information in the text equivalent; for example, by
- including the word "Radio: " before the image equivalent text. It should also be noted that images in an <a>Image Profile</a> subtitle
- document that are intended for use as <em>captions</em>, i.e. intended for a hard of hearing audience, might already include
- this functional information in the rendered text.</p>
+ including the word "Radio: " before the image equivalent text. It should also be noted that images in an <a>Image Profile</a>
+ subtitle document that are intended for use as <em>captions</em>, i.e. intended for a hard of hearing audience, might already
+ include this functional information in the rendered text.</p>
<p>Guideline 1.1 of [[!WCAG20]] also recommends that accessible text alternatives must be "programmatically determinable." This
means that the text must be able to be read and used by the assistive technologies (and the accessibility features in browsers)
@@ -2640,25 +2665,25 @@
<p>A <a>presentation processor</a> supports the <code>#altText</code> feature if it implements presentation semantic support
for values of the <a href="#ttm-altText"><code>ittm:altText</code></a> element.</p>
</section>
-
- <section class='appendix'>
+
+ <section class='appendix'>
<h3>#linePadding</h3>
<p>A <a>transformation processor</a> supports the <code>#linePadding</code> feature if it recognizes and is capable of
- transforming values of the <code>ebutts:linePadding</code> attribute specified in [[!EBUTTD]].</p>
-
- <p>A <a>presentation processor</a> supports the <code>#linePadding</code> feature if it implements presentation semantic support
- for values of the <code>ebutts:linePadding</code> attribute specified in [[!EBUTTD]].</p>
+ transforming values of the <code>ebutts:linePadding</code> attribute specified in [[!EBU-TT-D]].</p>
+
+ <p>A <a>presentation processor</a> supports the <code>#linePadding</code> feature if it implements presentation semantic
+ support for values of the <code>ebutts:linePadding</code> attribute specified in [[!EBU-TT-D]].</p>
</section>
-
- <section class='appendix'>
+
+ <section class='appendix'>
<h3>#multiRowAlign</h3>
<p>A <a>transformation processor</a> supports the <code>#multiRowAlign</code> feature if it recognizes and is capable of
- transforming values of the <code>ebutts:multiRowAlign</code> attribute specified in [[!EBUTTD]].</p>
-
- <p>A <a>presentation processor</a> supports the <code>#multiRowAlign</code> feature if it implements presentation semantic support
- for values of the <code>ebutts:multiRowAlign</code> attribute specified in [[!EBUTTD]].</p>
+ transforming values of the <code>ebutts:multiRowAlign</code> attribute specified in [[!EBU-TT-D]].</p>
+
+ <p>A <a>presentation processor</a> supports the <code>#multiRowAlign</code> feature if it implements presentation semantic
+ support for values of the <code>ebutts:multiRowAlign</code> attribute specified in [[!EBU-TT-D]].</p>
</section>
</section>
</body>