--- a/ttml-ww-profiles/ttml-ww-profiles.html Wed Jul 16 20:33:21 2014 -0700
+++ b/ttml-ww-profiles/ttml-ww-profiles.html Wed Jul 16 21:09:07 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="2014-07-17T10:31:07.000Z" id="w3c-first-public-working-draft-17-july-2014"><abbr title="World Wide Web Consortium">W3C</abbr> First Public Working Draft <time class="dt-published" datetime="2014-07-17">17 July 2014</time></h2>
+ <h2 property="dcterms:issued" datatype="xsd:dateTime" content="2014-07-17T11:06:25.000Z" id="w3c-first-public-working-draft-17-july-2014"><abbr title="World Wide Web Consortium">W3C</abbr> First Public Working Draft <time class="dt-published" datetime="2014-07-17">17 July 2014</time></h2>
<dl>
<dt>This version:</dt>
@@ -567,16 +567,18 @@
<p>A media time expression M <em class="rfc2119" title="SHALL">SHALL</em> correspond to the frame of the related video object 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>
A media time expression of 00:00:05.1 corresponds to frame ceiling(5.1 × ( 1000 / 1001 × 30) = 153 of a related video
object with a frame rate of 1000 / 1001 × 30 ≈ 29.97.
</aside>
+
+ <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_2"><span>Note</span></div><p class="">In typical scenario, the same video program (the related video object) will be used for subtitle document authoring, delivery and user playback. The mapping from media time expression to related video object 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 same temporal locations it was authored.</p></div>
<p>If <code>ttp:frameRate</code> is specified, then the product of <code>ttp:frameRate</code> and
<code>ttp:frameRateMultiplier</code> <em class="rfc2119" title="SHALL">SHALL</em> be the frame rate of the related video object.</p>
- <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_2"><span>Note</span></div><p class="">A document can be made independent of the frame rate of the related video object by never using the
+ <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_3"><span>Note</span></div><p class="">A document can be made independent of the frame rate of the related video object by never using the
<em>frames</em> term in a time expression: as specified in <a href="#common-features" class="sec-ref"><span class="secno">4.8</span> <span class="sec-title">Features</span></a>, <code>ttp:frameRate</code> is
required only if the document includes one or more time expressions that uses the <em>frames</em> term.</p></div>
</section>
@@ -619,7 +621,7 @@
<p><code>ittp:aspectRatio</code> <em class="rfc2119" title="SHALL NOT">SHALL NOT</em> be present if <code>tts:extent</code> is present.<br></p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_3"><span>Note</span></div><p class="">As specified in Section <a href="#common-features" class="sec-ref"><span class="secno">4.8</span> <span class="sec-title">Features</span></a>, <code>tts:extent</code> is present if the
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_4"><span>Note</span></div><p class="">As specified in Section <a href="#common-features" class="sec-ref"><span class="secno">4.8</span> <span class="sec-title">Features</span></a>, <code>tts:extent</code> is present if the
<code>px</code> length measure is used anywhere within the document.</p></div>
<p>Integer pixel positions on the related video object frame computed from real percentage length values <em class="rfc2119" title="SHALL">SHALL</em> use half-up
@@ -668,7 +670,7 @@
<p>A <code>ittp:progressivelyDecodable</code> attribute is considered to be significant only when specified on the
<code>tt</code> element.</p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_4"><span>Note</span></div><p class="">The placement and use of <code>div</code>, <code>region</code> and <code>span</code> that contain time
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_5"><span>Note</span></div><p class="">The placement and use of <code>div</code>, <code>region</code> and <code>span</code> that contain time
attributes, and the use of <code>set</code> are constrained when <code>ittp:progressivelyDecodable="true"</code>
.</p></div>
</section>
@@ -727,14 +729,14 @@
<p>If the value of <code>displayForcedOnlyMode</code> is "true", a content element with a <code>itts:forcedDisplay</code> computed value of "false" shall be assumed to have a <code>tts:visibility</code> computed value equal to "hidden", even if <code>tts:visibility</code> is otherwise set to "true".</p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_5"><span>Note</span></div><p class="">A region will remain visible even if all content elements have a computed <code>tts:visibility</code> value of "hidden" unless <code>tts:showBackground</code> is set to "whenActive" (the initial value of <code>tts:showBackground</code> is "always".)</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_6"><span>Note</span></div><p class="">A region will remain visible even if all content elements have a computed <code>tts:visibility</code> value of "hidden" unless <code>tts:showBackground</code> is set to "whenActive" (the initial value of <code>tts:showBackground</code> is "always".)</p></div>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_6"><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="4" role="heading" id="h_note_7"><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="4" role="heading" id="h_note_7"><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>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_8"><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>
<section id="ttm-altText" typeof="bibo:Chapter" resource="#ttm-altText" rel="bibo:Chapter">
@@ -765,7 +767,7 @@
<p><a href="#image-profile-constraints" class="sec-ref"><span class="secno">6.</span> <span class="sec-title">Image Profile Constraints</span></a> specifies the use of the <code>ittm:altText</code> element with images.</p>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_8"><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.
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_9"><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>
@@ -795,7 +797,7 @@
</li>
</ol>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_9"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], the initial value of <code>tts:opacity</code> is "1.0", the initial
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_10"><span>Note</span></div><p class="">As specified in [<cite><a class="bibref" href="#bib-TTML1">TTML1</a></cite>], the initial value of <code>tts:opacity</code> is "1.0", the initial
value of <code>tts:showBackground</code> is "always", and the initial value of <code>tts:display</code> is
"auto"</p></div>
</section>
@@ -1261,7 +1263,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_10"><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="3" role="heading" id="h_note_11"><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>
@@ -1928,7 +1930,7 @@
P<sub>n-1</sub> at the presentation time of intermediate synchronic document 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_11"><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_note_12"><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>
@@ -1961,11 +1963,11 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_12"><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_note_13"><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_note_13"><span>Note</span></div><p class="">IPD effectively sets a limit on the complexity of any given intermediate synchronic document.</p></div>
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_14"><span>Note</span></div><p class="">IPD effectively sets a limit on the complexity of any given intermediate synchronic document.</p></div>
</section>
<section id="paint-regions" typeof="bibo:Chapter" resource="#paint-regions" rel="bibo:Chapter">
@@ -1977,7 +1979,7 @@
<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_note_14"><span>Note</span></div><p class="">To ensure consistency of the Presentation Buffer, a new intermediate synchronic document requires clearing
+ <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_15"><span>Note</span></div><p class="">To ensure consistency of the Presentation Buffer, a new intermediate synchronic document 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
@@ -2228,7 +2230,7 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="4" role="heading" id="h_note_15"><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_note_16"><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>
@@ -2309,10 +2311,10 @@
</tbody>
</table>
- <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_16"><span>Note</span></div><p class="">Implementations can use use fonts other than those specified above. Two fonts with equal metrics can have a
+ <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_17"><span>Note</span></div><p class="">Implementations can use use fonts other than those specified above. Two fonts with equal metrics can have a
different appearance, but flow identically.</p></div>
- <div class="note"><div class="note-title" aria-level="3" role="heading" id="h_note_17"><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_note_18"><span>Note</span></div><p class="">proportionalSansSerif is not used in practice for Hebrew and Arabic captions and subtitles.</p></div>
</section>
</section>
--- a/ttml-ww-profiles/ttml-ww-profiles.source.html Wed Jul 16 20:33:21 2014 -0700
+++ b/ttml-ww-profiles/ttml-ww-profiles.source.html Wed Jul 16 21:09:07 2014 -0700
@@ -271,11 +271,13 @@
<p>A media time expression M SHALL correspond to the frame of the related video object with the presentation time that is the
closest to, but not less, than M.</p>
-
+
<aside class="example">
A media time expression of 00:00:05.1 corresponds to frame ceiling(5.1 × ( 1000 / 1001 × 30) = 153 of a related video
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 subtitle document authoring, delivery and user playback. The mapping from media time expression to related video object 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 same temporal locations it was authored.</p>
<p>If <code>ttp:frameRate</code> is specified, then the product of <code>ttp:frameRate</code> and
<code>ttp:frameRateMultiplier</code> SHALL be the frame rate of the related video object.</p>