Merge pull request #556 from w3c/issue-0330-deprecate-pixels-sans-extent

Deprecate pixels without specified extent (#330).
w3c · Jan 29, 2018 · 36b42d8 · 36b42d8
2 parents c129dc3 + b0eaf74
commit 36b42d8
Showing 1 changed file with 12 additions and 3 deletions.
diff --git a/spec/ttml2.xml b/spec/ttml2.xml
@@ -5257,7 +5257,7 @@ and <code>10:00:01:00</code>.
 </div3>
 <div3 id="parameter-attribute-pixelAspectRatio">
 <head>ttp:pixelAspectRatio</head>
-<p>The <att>ttp:pixelAspectRatio</att> attribute is used to specify the <loc href="#terms-pixel-aspect-ratio">pixel aspect ratio</loc> of the <loc href="#terms-root-container-region">root container region</loc> as elaborated in <specref ref="root-container-region-semantics"/>.</p>
+<p>The <att>ttp:pixelAspectRatio</att> attribute is used to specify the <loc href="#terms-pixel-aspect-ratio">pixel aspect ratio</loc> of the <loc href="#terms-root-container-region">root container region</loc> as elaborated in <specref ref="root-container-region-semantics"/></p>
 <p>If specified, the value of this attribute must adhere to the following syntax:</p>
 <table id="parameter-attribute-pixelAspectRatio-syntax" role="syntax">
 <caption>Syntax Representation &ndash; ttp:pixelAspectRatio</caption>
@@ -5279,6 +5279,11 @@ numerator | denominator
 the <loc href="#terms-root-container-region">root container region</loc> is determined by <specref ref="root-container-region-semantics"/>.</p>
 <p>A <att>ttp:pixelAspectRatio</att> attribute is considered to be significant only
 when specified on the <el>tt</el> element.</p>
+<p>The <att>ttp:pixelAspectRatio</att> attribute should not be specified
+unless a <loc href="#style-attribute-extent"><att>tts:extent</att></loc> attribute consisting
+of two <loc href="#style-value-length">&lt;length&gt;</loc> specifications using <code>px</code> (pixel) units is also
+specified on the <loc href="#document-structure-vocabulary-tt"><el>tt</el></loc> element,
+<phrase role="deprecated">without which the use of a <att>ttp:pixelAspectRatio</att> attribute is deprecated</phrase>.</p>
 </div3>
 <div3 id="parameter-attribute-subFrameRate">
 <head>ttp:subFrameRate</head>
@@ -14844,7 +14849,12 @@ units
 if <code>px</code> (pixels) units were specified.</p>
 <p>The unit of measure <code>px</code> (pixel) corresponds to a logical pixel of
 the <loc href="#terms-document-coordinate-space">document coordinate space</loc>,
-as defined by <specref ref="root-container-region-semantics-coordinate-space"/>.</p>
+as defined by <specref ref="root-container-region-semantics-coordinate-space"/>; however,
+the <code>px</code> (pixel) unit should not be used in a <loc href="#style-value-length">&lt;length&gt;</loc> expression
+unless a <loc href="#style-attribute-extent"><att>tts:extent</att></loc> attribute consisting
+of two <loc href="#style-value-length">&lt;length&gt;</loc> specifications using <code>px</code> (pixel) units is
+specified on the <loc href="#document-structure-vocabulary-tt"><el>tt</el></loc> element,
+<phrase role="deprecated">without which the use of the <code>px</code> (pixel) unit of measure is deprecated</phrase></p>
 <p>When specified relative to a font whose size is expressed as a single length
 measure or as two length measures of equal length, the unit of measure <code>em</code> is considered to be
 identical to that defined by <bibref ref="xsl11"/>, &sect; 5.9.13;
@@ -17677,7 +17687,6 @@ in the preceding syntax definition.</p>
 minutes, seconds, and frames less than 10. Minutes are constrained to
 [0&hellip;59], while seconds (including any fractional part) are constrained to the closed
 interval [0,60], where the value 60 applies only to leap seconds.
-
 Except when <loc href="#parameter-attribute-timeBase"><att>ttp:timeBase</att></loc> is <code>clock</code>
 and <loc href="#parameter-attribute-clockMode"><att>ttp:clockMode</att></loc> is <code>local</code> or <code>utc</code>,
 use of the <phrase role="deprecated">special value of 60 seconds to denote a leap second is deprecated</phrase>.