[ttml2, ttml1-errata] clarify interpretation of closest supported value for border (ttml2), extent, padding
authorGlenn Adams <glenn@skynav.com>
Wed, 16 Jul 2014 22:16:53 -0600
changeset 656 52998d4ca12c
parent 650 0332a03866a6
child 657 dcb87524a568
[ttml2, ttml1-errata] clarify interpretation of closest supported value for border (ttml2), extent, padding
ttml1/spec/ttml1-errata.html
ttml2/spec/ttml2.xml
--- a/ttml1/spec/ttml1-errata.html	Wed Jul 16 20:03:22 2014 -0600
+++ b/ttml1/spec/ttml1-errata.html	Wed Jul 16 22:16:53 2014 -0600
@@ -58,8 +58,12 @@
     <ul>
       <li><a href="#errata-5.2-1">Correction in TTML1 Section 5.2 Profiles</a>
           (published 2014-01-30)</li>
-      <li><a href="#errata-10.2.3-1">Correction in TTML1 Section 10.2.3 Duration (dur) Attribute</a>
-          (published 2014-04-24)</li>
+      <li><a href="#errata-8.2.7-1">Correction in TTML1 Section 8.2.7 tts:extent attribute</a>
+          (published 2014-07-16)</li>
+      <li><a href="#errata-8.2.16-1">Correction in TTML1 Section 8.2.16 tts:padding attribute</a>
+          (published 2014-07-16)</li>
+      <li><a href="#errata-10.2.3-1">Correction in TTML1 Section 10.2.3 Duration (dur) attribute</a>
+          (published 2014-07-16)</li>
       <li><a href="#errata-C-1">Correction in TTML1 Appendix C - Media Type
           Registration</a> (published 2014-01-30)</li>
       <li><a href="#errata-M-1">Correction in TTML1 Appendix M - Concrete
@@ -72,16 +76,40 @@
     <p class="description"><span class="title-description">Description</span>:</p>
     Minor typographical error, in the third paragraph under Table 2.
     <p class="description"><em><strong><span class="title-correction">Resolution</span></strong></em>:</p>
-    <p>change "... and must not <span class="diff-del">be </span>appear ..."</p>
+    <p>Change "... and must not <span class="diff-del">be </span>appear ..."</p>
     <p>to read "... and must not appear ...".</p>
     <hr />
+    <p id="errata-8.2.7-1">Correction
+        in <a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/#style-attribute-extent">TTML1 Section 8.2.7 - tts:extent attribute</a> (published 2014-07-16) </p>
+    <p class="description"><span class="title-description">Description</span>:</p>
+    Provide rationale for use of greater value when interpreting closest supported value..
+    <p class="description"><em><strong><span class="title-correction">Resolution</span></strong></em>:</p>
+    <p>Add a 2nd paragraph to <strong>Note</strong> as follows:</p>
+    <p><span class="diff-add">This rule for resolving <em>closest supported value</em> for the <code>tts:extent</code> attribute makes use of the nearest larger rather than nearest smaller supported distance.
+    The rationale for this difference in treatment is that use of a larger extent ensures that the affected content will be contained in the region area without
+    causing region overflow, while use of a smaller extent makes region overflow more likely.</span></p>
+    <hr />
+    <p id="errata-8.2.16-1">Correction
+        in <a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/#style-attribute-padding">TTML1 Section 8.2.16 - tts:padding attribute</a> (published 2014-07-16) </p>
+    <p class="description"><span class="title-description">Description</span>:</p>
+    Interpret closest supported value as least (not greatest) padding on a per-edge basis in order to prevent content area overflow.
+    <p class="description"><em><strong><span class="title-correction">Resolution</span></strong></em>:</p>
+    <p>Change text of <strong>Note</strong> from:</p>
+    <p>"In this context, the phrase <em>closest supported value</em> means the value for which the Euclidean distance between the computed padding and the
+    supported padding is minimized. If there are multiple closest supported values equally distant from the computed value, then the value most
+    distant from 0, i.e., the greatest padding, is used."</p>
+    <p>to read:</p>
+    <p>"In this context, the phrase <em>closest supported value</em> means the value for which the <span class="diff-add">one-dimensional </span>Euclidean distance between the computed padding and the
+    supported padding is minimized<span class="diff-add"> on a per-edge basis</span>. If there are multiple closest supported values equally distant from the computed value<span class="diff-add"> for a given edge</span>, then the value <span class="diff-chg">least</span>
+    distant from 0, i.e., the <span class="diff-chg">least</span> padding, is used."</p>
+    <hr />
     <p id="errata-10.2.3-1">Correction
-        in <a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/#timing-attribute-dur">TTML1 Section 10.2.3 - dur attribute</a> (published 2014-04-24) </p>
+        in <a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/#timing-attribute-dur">TTML1 Section 10.2.3 - dur attribute</a> (published 2014-07-16) </p>
     <p class="description"><span class="title-description">Description</span>:</p>
     Add clarification about use of zero duration.
     <p class="description"><em><strong><span class="title-correction">Resolution</span></strong></em>:</p>
     <p>Add the following sentence to the last paragraph (that cites [SMIL 2.1] § 10.4.1):</p>
-    <p><span class="diff-add">In a willful violation of <a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/#smil21">[SMIL 2.1]</a>, § 10.4.1,
+    <p><span class="diff-add">In a deliberate divergence from <a href="http://www.w3.org/TR/2013/REC-ttml1-20130924/#smil21">[SMIL 2.1]</a>, § 10.4.1,
     the value of the <code>dur</code> attribute is permitted to be zero (0).</span></p>
     <hr />
     <p id="errata-C-1">Correction
@@ -242,7 +270,7 @@
     <p class="description"><span class="title-description">Description</span>:</p>
     Add standard XML named character entities unintentionally omitted from note.
     <p class="description"><em><strong><span class="title-correction">Resolution</span></strong></em>:</p>
-    <p>change &quot;... only the following named character entities are defined:
+    <p>Change &quot;... only the following named character entities are defined:
     <code>&amp;amp;</code>,
     <code>&amp;lt;</code>,
     and <code>&amp;gt;</code>.&quot;
--- a/ttml2/spec/ttml2.xml	Wed Jul 16 20:03:22 2014 -0600
+++ b/ttml2/spec/ttml2.xml	Wed Jul 16 22:16:53 2014 -0600
@@ -5169,9 +5169,9 @@
 <p>If a computed value of the border width associated with this attribute is not supported,
 then a <loc href="#terms-presentation-processor">presentation processor</loc> must use the closest supported value.</p>
 <note role="elaboration">
-<p>In this context, the phrase <emph>closest supported value</emph> means the value for which the Euclidean distance between
-the computed border width and the supported border width is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value most distant from 0, i.e., the greatest border width, is used.</p>
+<p>In this context, the phrase <emph>closest supported value</emph> means the value for which the one-dimensional Euclidean distance between
+the computed border width and the supported border width is minimized on a per-edge basis. If there are multiple closest supported values equally distant from
+the computed value for a given edge, then the value least distant from 0, i.e., the least border width, is used.</p>
 </note>
 <p>If no border style is specified in the value of the <att>tts:border</att> property,
 then the border style must be interpreted as if a style of
@@ -5720,8 +5720,8 @@
 <p>In this context, the phrase <emph>closest supported value</emph> means the value for which the Euclidean distance between
 the computed extent and the supported extent is minimized. If there are multiple closest supported values equally distant from
 the computed value, then the value most distant from [0,0], i.e., of greatest extent, is used.</p>
-<p>Unlike other style attributes, the rule for resolving <emph>closest supported value</emph> for the <att>tts:extent</att> attribute
-makes use of the nearest larger rather than nearest smaller supported distance. The rationale for this difference in treatment is
+<p>This rule for resolving <emph>closest supported value</emph> makes use of the nearest larger rather than nearest smaller supported distance.
+The rationale for this difference in treatment is
 that use of a larger extent ensures that the affected content will be contained in the region area without causing region overflow,
 while use of a smaller extent makes region overflow more likely.</p>
 </note>
@@ -6731,9 +6731,9 @@
 <p>If a computed value of the property associated with this attribute is not supported,
 then a <loc href="#terms-presentation-processor">presentation processor</loc> must use the closest supported value.</p>
 <note role="elaboration">
-<p>In this context, the phrase <emph>closest supported value</emph> means the value for which the Euclidean distance between
-the computed padding and the supported padding is minimized. If there are multiple closest supported values equally distant from
-the computed value, then the value most distant from 0, i.e., the greatest padding, is used.</p>
+<p>In this context, the phrase <emph>closest supported value</emph> means the value for which the one-dimensional Euclidean distance between
+the computed padding and the supported padding is minimized on a per-edge basis. If there are multiple closest supported values equally distant from
+the computed value for a given edge, then the value least distant from 0, i.e., the least padding, is used.</p>
 </note>
 <p>The <att>tts:padding</att> style is illustrated by the following example.</p>
 <ednote>