--- a/ttml-ww-profiles/ttml-ww-profiles.html Wed Jun 10 22:05:07 2015 -0700
+++ b/ttml-ww-profiles/ttml-ww-profiles.html Wed Jun 10 22:15:46 2015 -0700
@@ -698,18 +698,20 @@
<section id="related-video-object" typeof="bibo:Chapter" resource="#related-video-object" property="bibo:hasPart">
<h3 id="h-related-video-object" resource="#h-related-video-object"><span property="xhv:role" resource="xhv:heading"><span class="secno">6.5 </span>Related Video Object</span></h3>
- <p>A <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> <em class="rfc2119" title="MAY">MAY</em> be associated with a related video object, which <em class="rfc2119" title="SHALL">SHALL</em> consist of a sequence of image frames, each
+ <p>A <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> <em class="rfc2119" title="MAY">MAY</em> be associated with a <dfn id="dfn-related-video-object">related video object</dfn>, which <em class="rfc2119" title="SHALL">SHALL</em> consist of a sequence of image frames, each
a rectangular array of pixels, and <em class="rfc2119" title="SHALL">SHALL</em> be considered the <a href="#dfn-related-media-object" class="internalDFN">Related Media Object</a>.</p>
+
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note4"><span>Note</span></div><p class="">While this specification contains specific provisions when a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> is associated with a <a href="#dfn-related-video-object" class="internalDFN">related video object</a>, it does not prevent the use of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> with other kinds of <a href="#dfn-related-media-object" class="internalDFN">Related Media Object</a>, e.g. an audio object.</p></div>
</section>
<section id="synchronization" typeof="bibo:Chapter" resource="#synchronization" property="bibo:hasPart">
<h3 id="h-synchronization" resource="#h-synchronization"><span property="xhv:role" resource="xhv:heading"><span class="secno">6.6 </span>Synchronization</span></h3>
<p>Each <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a> of the <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> 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
- <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> 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
+ removed on a specific frame of the <a href="#dfn-related-video-object" class="internalDFN">related video object</a>.</p>
+
+ <p>When mapping a media time expression M to a frame F of a <a href="#dfn-related-video-object" class="internalDFN">related video object</a>, e.g. for the purpose of rendering a
+ <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> onto the <a href="#dfn-related-video-object" class="internalDFN">related video object</a>, 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
presentation time that is the closest to, but not less, than M.</p>
<aside class="example"><div class="example-title"><span>Example 1</span></div>
@@ -717,8 +719,8 @@
object with a frame rate of 1000 / 1001 × 30 ≈ 29.97.
</aside>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note4"><span>Note</span></div><p class="">In typical scenario, the same video program (the related video object) will be used for <a href="#dfn-document-instance" class="internalDFN">Document Instance</a>
- authoring, delivery and user playback. The mapping from media time expression to related video object above allows the author
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note5"><span>Note</span></div><p class="">In typical scenario, the same video program (the <a href="#dfn-related-video-object" class="internalDFN">related video object</a>) will be used for <a href="#dfn-document-instance" class="internalDFN">Document Instance</a>
+ authoring, delivery and user playback. The mapping from media time expression to <a href="#dfn-related-video-object" class="internalDFN">related video object</a> above allows the author
to precisely associate subtitle video content with video frames, e.g. around scene transitions. In circumstances where the
video program is downsampled during delivery, the application can specify that, at playback, the relative video object be
considered the delivered video program upsampled to is original rate, thereby allowing subtitle content to be rendered at the
@@ -732,7 +734,7 @@
<section id="ttp-aspectRatio" typeof="bibo:Chapter" resource="#ttp-aspectRatio" property="bibo:hasPart">
<h4 id="h-ttp-aspectratio" resource="#h-ttp-aspectratio"><span property="xhv:role" resource="xhv:heading"><span class="secno">6.7.1 </span>ittp:aspectRatio</span></h4>
- <p>The <code>ittp:aspectRatio</code> attributes allows authorial control of the mapping of the root container of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> to the related video object frame.</p>
+ <p>The <code>ittp:aspectRatio</code> attributes allows authorial control of the mapping of the root container of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> to the <a href="#dfn-related-video-object" class="internalDFN">related video object</a> frame.</p>
<p>If present, the <code>ittp:aspectRatio</code> attribute <em class="rfc2119" title="SHALL">SHALL</em> conform to the following syntax:</p>
@@ -754,28 +756,28 @@
</tbody>
</table>
- <p>The root container of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> <em class="rfc2119" title="SHALL">SHALL</em> be mapped to the related video object frame according to the
+ <p>The root container of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> <em class="rfc2119" title="SHALL">SHALL</em> be mapped to the <a href="#dfn-related-video-object" class="internalDFN">related video object</a> frame according to the
following:</p>
<ol>
<li>
<p>If <code>ittp:aspectRatio</code> is present, the root container <em class="rfc2119" title="SHALL">SHALL</em> be mapped to a rectangular area within the
- related video object such that:</p>
+ <a href="#dfn-related-video-object" class="internalDFN">related video object</a> such that:</p>
<ol style="list-style-type: lower-roman;">
<li>the ratio of the width to the height of the rectangular area is equal to <code>ittp:aspectRatio</code>,</li>
- <li>the center of the rectangular area is collocated with the center of the related video object frame,</li>
-
- <li>the rectangular area (including its boundary) is entirely within the related video object frame (including its
+ <li>the center of the rectangular area is collocated with the center of the <a href="#dfn-related-video-object" class="internalDFN">related video object</a> frame,</li>
+
+ <li>the rectangular area (including its boundary) is entirely within the <a href="#dfn-related-video-object" class="internalDFN">related video object</a> frame (including its
boundary), and</li>
- <li>the rectangular area has a height or width equal to that of the related video object frame.</li>
+ <li>the rectangular area has a height or width equal to that of the <a href="#dfn-related-video-object" class="internalDFN">related video object</a> frame.</li>
</ol>
</li>
<li>
- <p>Otherwise, the root container of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> <em class="rfc2119" title="SHALL">SHALL</em> be mapped to the related video object frame in its
+ <p>Otherwise, the root container of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> <em class="rfc2119" title="SHALL">SHALL</em> be mapped to the <a href="#dfn-related-video-object" class="internalDFN">related video object</a> frame in its
entirety.</p>
</li>
</ol>
@@ -856,7 +858,7 @@
...
</tt></pre></div>
- <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note5"><span>Note</span></div><div class="">
+ <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note6"><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>
@@ -968,17 +970,17 @@
...</pre></div>
- <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note6"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], the background of a region can be visible even if the computed value of <code>tts:visibility</code> equals
+ <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note7"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], the background of a region can be visible even if the computed value of <code>tts:visibility</code> equals
"hidden" for all active content within. The background of a region for which <code>itts:forcedDisplay</code> equals "true" can therefore remain visible even if <code>itts:forcedDisplay</code> equals "false" for all active
content elements within the region and <code>displayForcedOnlyMode</code> equals "true". Authors can avoid this situation, for instance, by ensuring that content
elements and the regions that they are flowed into always have the same value of <code>itts:forcedDisplay</code>.</p></div>
- <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note7"><span>Note</span></div><p class="">Although <code>itts:forcedDisplay</code>, like all the TTML style attributes, has no defined semantics on a
+ <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note8"><span>Note</span></div><p class="">Although <code>itts:forcedDisplay</code>, like all the TTML style attributes, has no defined semantics on a
<code>br</code> content element, <code>itts:forcedDisplay</code> will apply to a <code>br</code> content element if it is
either defined on an ancestor content element of the <code>br</code> content element or it is applied to a region element
corresponding to a region that the <code>br</code> content element is being flowed into.</p></div>
- <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note8"><span>Note</span></div><p class="">It is expected that the functionality of <code>itts:forcedDisplay</code> will be mapped to a conditional
+ <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note9"><span>Note</span></div><p class="">It is expected that the functionality of <code>itts:forcedDisplay</code> will be mapped to a conditional
style construct in a future revision of this specification.</p></div>
</section>
@@ -1022,7 +1024,7 @@
</div>
...</pre></div>
- <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note9"><span>Note</span></div><p class="">In contrast to the common use of <code>alt</code> attributes in [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>], the <code>ittm:altText</code>
+ <div class="note"><div class="note-title" aria-level="5" role="heading" id="h-note10"><span>Note</span></div><p class="">In contrast to the common use of <code>alt</code> attributes in [<cite><a class="bibref" href="#bib-HTML5">HTML5</a></cite>], the <code>ittm:altText</code>
attribute content is not intended to be displayed in place of the element if the element is not loaded. The
<code>ittm:altText</code> attribute content can however be read and used by assistive technologies.</p></div>
</section>
@@ -1523,7 +1525,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note10"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], a <code>#time-offset-with-frames</code> expression is translated to a media time
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note11"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], a <code>#time-offset-with-frames</code> expression is translated to a media time
M according to M = 3600 · hours + 60 · minutes + seconds + (frames ÷ (<code>ttp:frameRateMultiplier</code> ·
<code>ttp:frameRate</code>)).</p></div>
</section>
@@ -1555,7 +1557,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note11"><span>Note</span></div><p class="">As specified in <a href="#common-features" class="sec-ref"><span class="secno">6.10</span> <span class="sec-title">Features</span></a>, the presence of the <code>ttp:profile</code> attribute is
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note12"><span>Note</span></div><p class="">As specified in <a href="#common-features" class="sec-ref"><span class="secno">6.10</span> <span class="sec-title">Features</span></a>, the presence of the <code>ttp:profile</code> attribute is
not required by this profile. The profile designator specified above is intended to be generally used to signal conformance
of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> to the profile. The details of such signaling depends on the application, and can, for instance, use
metadata structures out-of-band of the <a href="#dfn-document-instance" class="internalDFN">Document Instance</a>.</p></div>
@@ -1574,7 +1576,7 @@
<p>When processing glyphs that match the combinations of computed font family and code point listed in <a href="#reference-fonts" class="sec-ref"><span class="secno">A.</span> <span class="sec-title">Reference Fonts</span></a>, e.g. during layout, a <a href="#dfn-presentation-processor" class="internalDFN">presentation processor</a> or <a href="#dfn-transformation-processor" class="internalDFN">transformation processor</a> <em class="rfc2119" title="SHALL">SHALL</em> use glyph metrics equal to the metrics of the specified reference font, unless the glyph is not defined by the reference font.</p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note12"><span>Note</span></div><p class="">Implementations can use fonts other than those specified in <a href="#reference-fonts" class="sec-ref"><span class="secno">A.</span> <span class="sec-title">Reference Fonts</span></a>. Two fonts with equal metrics can have a different appearance, but flow identically.</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note13"><span>Note</span></div><p class="">Implementations can use fonts other than those specified in <a href="#reference-fonts" class="sec-ref"><span class="secno">A.</span> <span class="sec-title">Reference Fonts</span></a>. Two fonts with equal metrics can have a different appearance, but flow identically.</p></div>
</section>
@@ -1894,7 +1896,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note13"><span>Note</span></div><p class="">In contrast to this specification, [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>] specifies that the attributes <code>ebutts:linePadding</code> and <code>ebutts:multiRowAlign</code> are allowed only on the <code>style</code> element.</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note14"><span>Note</span></div><p class="">In contrast to this specification, [<cite><a class="bibref" href="#bib-EBU-TT-D">EBU-TT-D</a></cite>] specifies that the attributes <code>ebutts:linePadding</code> and <code>ebutts:multiRowAlign</code> are allowed only on the <code>style</code> element.</p></div>
</section>
</section>
@@ -1923,7 +1925,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note14"><span>Note</span></div><p class="">As specified in <a href="#common-features" class="sec-ref"><span class="secno">6.10</span> <span class="sec-title">Features</span></a>, the presence of the <code>ttp:profile</code> attribute is
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note15"><span>Note</span></div><p class="">As specified in <a href="#common-features" class="sec-ref"><span class="secno">6.10</span> <span class="sec-title">Features</span></a>, the presence of the <code>ttp:profile</code> attribute is
not required by this profile. The profile designator specified above is intended to be generally used to signal conformance
of a <a href="#dfn-document-instance" class="internalDFN">Document Instance</a> to the profile. The details of such signaling depends on the application, and can, for instance, use
metadata structures out-of-band of the <a href="#dfn-document-instance" class="internalDFN">Document Instance</a>.</p></div>
@@ -1967,7 +1969,7 @@
<p></p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note15"><span>Note</span></div><p class="">In [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], <code>tts:extent</code> and <code>tts:origin</code> do not apply to <code>div</code> elements. In order to individually position multiple <code>div</code> elements, each <code>div</code> can be associated with a distinct <code>region</code> with the desired <code>tts:extent</code> and <code>tts:origin</code>.</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note16"><span>Note</span></div><p class="">In [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], <code>tts:extent</code> and <code>tts:origin</code> do not apply to <code>div</code> elements. In order to individually position multiple <code>div</code> elements, each <code>div</code> can be associated with a distinct <code>region</code> with the desired <code>tts:extent</code> and <code>tts:origin</code>.</p></div>
</section>
<section id="features-1" typeof="bibo:Chapter" resource="#features-1" property="bibo:hasPart">
@@ -2166,7 +2168,7 @@
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>
+ authored independently of <a href="#dfn-related-video-object" class="internalDFN">related video object</a> 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
@@ -2229,9 +2231,9 @@
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-note16"><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
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note17"><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
- video frame boundaries of the related video object.</p></div>
+ video frame boundaries of the <a href="#dfn-related-video-object" class="internalDFN">related video object</a>.</p></div>
<p>It <em class="rfc2119" title="SHALL">SHALL</em> be an error for the Presentation Compositor to fail to complete painting pixels for E<sub>n</sub> before the
presentation time of E<sub>n</sub>.</p>
@@ -2262,11 +2264,11 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note17"><span>Note</span></div><p class="">BDraw effectively sets a limit on fillings regions - for example, assuming that the root container is
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note18"><span>Note</span></div><p class="">BDraw effectively sets a limit on fillings regions - for example, assuming that the root container is
ultimately rendered at 1920×1080 resolution, a BDraw of 12 s<sup>-1</sup> would correspond to a fill rate of
1920×1080×12/s=23.7×2<sup>20</sup>pixels s<sup>-1</sup>.</p></div>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note18"><span>Note</span></div><p class="">IPD effectively sets a limit on the complexity of any given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>.</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note19"><span>Note</span></div><p class="">IPD effectively sets a limit on the complexity of any given <a href="#dfn-intermediate-synchronic-document" class="internalDFN">intermediate synchronic document</a>.</p></div>
</section>
<section id="paint-regions" typeof="bibo:Chapter" resource="#paint-regions" property="bibo:hasPart">
@@ -2279,7 +2281,7 @@
<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-note19"><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
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note20"><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
@@ -2538,7 +2540,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note20"><span>Note</span></div><p class="">NRGA(G<sub>i</sub>) does not take into account glyph decorations (e.g. underline), glyph effects (e.g.
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h-note21"><span>Note</span></div><p class="">NRGA(G<sub>i</sub>) does not take into account glyph decorations (e.g. underline), glyph effects (e.g.
outline) or actual glyph aspect ratio. An implementation can determine an actual buffer size needs based on worst-case
glyph size complexity.</p></div>
@@ -2614,7 +2616,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="3" role="heading" id="h-note21"><span>Note</span></div><p class="">proportionalSansSerif is not used in practice for Hebrew and Arabic captions and subtitles.</p></div>
+ <div class="note"><div class="note-title" aria-level="3" role="heading" id="h-note22"><span>Note</span></div><p class="">proportionalSansSerif is not used in practice for Hebrew and Arabic captions and subtitles.</p></div>
</section>
--- a/ttml-ww-profiles/ttml-ww-profiles.source.html Wed Jun 10 22:05:07 2015 -0700
+++ b/ttml-ww-profiles/ttml-ww-profiles.source.html Wed Jun 10 22:15:46 2015 -0700
@@ -369,18 +369,20 @@
<section>
<h3>Related Video Object</h3>
- <p>A <a>Document Instance</a> MAY be associated with a related video object, which SHALL consist of a sequence of image frames, each
+ <p>A <a>Document Instance</a> MAY be associated with a <dfn>related video object</dfn>, which SHALL consist of a sequence of image frames, each
a rectangular array of pixels, and SHALL be considered the <a>Related Media Object</a>.</p>
+
+ <p class="note">While this specification contains specific provisions when a <a>Document Instance</a> is associated with a <a>related video object</a>, it does not prevent the use of a <a>Document Instance</a> with other kinds of <a>Related Media Object</a>, e.g. an audio object.</p>
</section>
<section>
<h3>Synchronization</h3>
<p>Each <a>intermediate synchronic document</a> of the <a>Document Instance</a> 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
- <a>Document Instance</a> onto the related video object, the <a>presentation processor</a> SHALL map M to the frame F with the
+ removed on a specific frame of the <a>related video object</a>.</p>
+
+ <p>When mapping a media time expression M to a frame F of a <a>related video object</a>, e.g. for the purpose of rendering a
+ <a>Document Instance</a> onto the <a>related video object</a>, the <a>presentation processor</a> SHALL map M to the frame F with the
presentation time that is the closest to, but not less, than M.</p>
<aside class="example">
@@ -388,8 +390,8 @@
object with a frame rate of 1000 / 1001 × 30 ≈ 29.97.
</aside>
- <p class="note">In typical scenario, the same video program (the related video object) will be used for <a>Document Instance</a>
- authoring, delivery and user playback. The mapping from media time expression to related video object above allows the author
+ <p class="note">In typical scenario, the same video program (the <a>related video object</a>) will be used for <a>Document Instance</a>
+ authoring, delivery and user playback. The mapping from media time expression to <a>related video object</a> above allows the author
to precisely associate subtitle video content with video frames, e.g. around scene transitions. In circumstances where the
video program is downsampled during delivery, the application can specify that, at playback, the relative video object be
considered the delivered video program upsampled to is original rate, thereby allowing subtitle content to be rendered at the
@@ -403,7 +405,7 @@
<section id='ttp-aspectRatio'>
<h4>ittp:aspectRatio</h4>
- <p>The <code>ittp:aspectRatio</code> attributes allows authorial control of the mapping of the root container of a <a>Document Instance</a> to the related video object frame.</p>
+ <p>The <code>ittp:aspectRatio</code> attributes allows authorial control of the mapping of the root container of a <a>Document Instance</a> to the <a>related video object</a> frame.</p>
<p>If present, the <code>ittp:aspectRatio</code> attribute SHALL conform to the following syntax:</p>
@@ -426,28 +428,28 @@
</tbody>
</table>
- <p>The root container of a <a>Document Instance</a> SHALL be mapped to the related video object frame according to the
+ <p>The root container of a <a>Document Instance</a> SHALL be mapped to the <a>related video object</a> frame according to the
following:</p>
<ol>
<li>
<p>If <code>ittp:aspectRatio</code> is present, the root container SHALL be mapped to a rectangular area within the
- related video object such that:</p>
+ <a>related video object</a> such that:</p>
<ol style="list-style-type: lower-roman;">
<li>the ratio of the width to the height of the rectangular area is equal to <code>ittp:aspectRatio</code>,</li>
- <li>the center of the rectangular area is collocated with the center of the related video object frame,</li>
-
- <li>the rectangular area (including its boundary) is entirely within the related video object frame (including its
+ <li>the center of the rectangular area is collocated with the center of the <a>related video object</a> frame,</li>
+
+ <li>the rectangular area (including its boundary) is entirely within the <a>related video object</a> frame (including its
boundary), and</li>
- <li>the rectangular area has a height or width equal to that of the related video object frame.</li>
+ <li>the rectangular area has a height or width equal to that of the <a>related video object</a> frame.</li>
</ol>
</li>
<li>
- <p>Otherwise, the root container of a <a>Document Instance</a> SHALL be mapped to the related video object frame in its
+ <p>Otherwise, the root container of a <a>Document Instance</a> SHALL be mapped to the <a>related video object</a> frame in its
entirety.</p>
</li>
</ol>
@@ -1849,7 +1851,7 @@
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>
+ authored independently of <a>related video object</a> 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
@@ -1916,7 +1918,7 @@
<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
- video frame boundaries of the related video object.</p>
+ video frame boundaries of the <a>related video object</a>.</p>
<p>It SHALL be an error for the Presentation Compositor to fail to complete painting pixels for E<sub>n</sub> before the
presentation time of E<sub>n</sub>.</p>