[html5] r2494 - [gow] (2) Clarify that playbackRate, and allow it to be 0.0.

whatwg at whatwg.org whatwg at whatwg.org
Mon Dec 1 02:43:56 PST 2008


Author: ianh
Date: 2008-12-01 02:43:56 -0800 (Mon, 01 Dec 2008)
New Revision: 2494

Modified:
   index
   source
Log:
[gow] (2) Clarify that playbackRate, and allow it to be 0.0.

Modified: index
===================================================================
--- index	2008-12-01 10:15:15 UTC (rev 2493)
+++ index	2008-12-01 10:43:56 UTC (rev 2494)
@@ -18035,23 +18035,29 @@
   </ol><p>The <dfn id=dom-media-defaultplaybackrate title=dom-media-defaultPlaybackRate><code>defaultPlaybackRate</code></dfn>
   attribute gives the desired speed at which the <a href=#media-resource>media
   resource</a> is to play, as a multiple of its intrinsic
-  speed. The attribute is mutable, but on setting, if the new value is
-  0.0, a <code><a href=#not_supported_err>NOT_SUPPORTED_ERR</a></code> exception must be raised
-  instead of the value being changed. It must initially have the value
-  1.0.</p>
+  speed. The attribute is mutable: on getting it must return the last
+  value it was set to, or 1.0 if it hasn't yet been set; on setting
+  the attribute must be set to the new value.</p>
 
   <p>The <dfn id=dom-media-playbackrate title=dom-media-playbackRate><code>playbackRate</code></dfn>
   attribute gives the speed at which the <a href=#media-resource>media resource</a>
   plays, as a multiple of its intrinsic speed. If it is not equal to
   the <code title=dom-media-defaultPlaybackRate><a href=#dom-media-defaultplaybackrate>defaultPlaybackRate</a></code>,
   then the implication is that the user is using a feature such as
-  fast forward or slow motion playback. The attribute is mutable, but
-  on setting, if the new value is 0.0, a
-  <code><a href=#not_supported_err>NOT_SUPPORTED_ERR</a></code> exception must be raised instead of
-  the value being changed. Otherwise, the playback must change speed
-  (if the element is <a href=#potentially-playing>potentially playing</a>). It must initially
-  have the value 1.0.</p>
+  fast forward or slow motion playback. The attribute is mutable: on
+  getting it must return the last value it was set to, or 1.0 if it
+  hasn't yet been set; on setting the attribute must be set to the new
+  value, and the playback must change speed (if the element is
+  <a href=#potentially-playing>potentially playing</a>).</p>
 
+  <p>The "play" function in a user agent's interface must set the
+  <code title=dom-media-playbackRate><a href=#dom-media-playbackrate>playbackRate</a></code> attribute
+  to the value of the <code title=dom-media-defaultPlaybackRate><a href=#dom-media-defaultplaybackrate>defaultPlaybackRate</a></code>
+  attribute before invoking the <code title=dom-media-play><a href=#dom-media-play>play()</a></code> method's steps. Features such
+  as fast-forward or rewind must be implemented by only changing the
+  <code title=dom-media-playbackRate><a href=#dom-media-playbackrate>playbackRate</a></code>
+  attribute.</p>
+
   <p id=rateUpdate>When the <code title=dom-media-defaultPlaybackRate><a href=#dom-media-defaultplaybackrate>defaultPlaybackRate</a></code> or
   <code title=dom-media-playbackRate><a href=#dom-media-playbackrate>playbackRate</a></code> attributes
   change value (either by being set by script or by being changed
@@ -18150,6 +18156,11 @@
   user agent may apply pitch adjustments to the audio as necessary to
   render it faithfully.</p>
 
+  <p>The <code title=dom-media-playbackRate><a href=#dom-media-playbackrate>playbackRate</a></code> can
+  be 0.0, in which case the <a href=#current-playback-position>current playback position</a>
+  doesn't move, despite playback not being paused (<code title=dom-media-paused><a href=#dom-media-paused>paused</a></code> doesn't become true, and the
+  <code title=event-pause><a href=#event-pause>pause</a></code> event doesn't fire).</p>
+
   <p><a href=#media-element title="media element">Media elements</a> that are
   <a href=#potentially-playing>potentially playing</a> while not <span>in a
   <code>Document</code></span><!-- XXX xref --> must not play any
@@ -18157,9 +18168,9 @@
   stop playing just because all references to them have been removed;
   only once a media element to which no references exist has reached a
   point where no further audio remains to be played for that element
-  (e.g. because the element is paused or because the end of the clip
-  has been reached) may the element be <span>garbage
-  collected</span><!-- XXX xref -->.</p>
+  (e.g. because the element is paused, or because the end of the clip
+  has been reached, or because its <code title=dom-media-playbackRate><a href=#dom-media-playbackrate>playbackRate</a></code> is 0.0) may the
+  element be <span>garbage collected</span><!-- XXX xref -->.</p>
 
   <hr><p>When the <a href=#current-playback-position>current playback position</a> of a <a href=#media-element>media
   element</a> changes (e.g. due to playback or seeking), the user

Modified: source
===================================================================
--- source	2008-12-01 10:15:15 UTC (rev 2493)
+++ source	2008-12-01 10:43:56 UTC (rev 2494)
@@ -19522,10 +19522,9 @@
   title="dom-media-defaultPlaybackRate"><code>defaultPlaybackRate</code></dfn>
   attribute gives the desired speed at which the <span>media
   resource</span> is to play, as a multiple of its intrinsic
-  speed. The attribute is mutable, but on setting, if the new value is
-  0.0, a <code>NOT_SUPPORTED_ERR</code> exception must be raised
-  instead of the value being changed. It must initially have the value
-  1.0.</p>
+  speed. The attribute is mutable: on getting it must return the last
+  value it was set to, or 1.0 if it hasn't yet been set; on setting
+  the attribute must be set to the new value.</p>
 
   <p>The <dfn
   title="dom-media-playbackRate"><code>playbackRate</code></dfn>
@@ -19534,13 +19533,22 @@
   the <code
   title="dom-media-defaultPlaybackRate">defaultPlaybackRate</code>,
   then the implication is that the user is using a feature such as
-  fast forward or slow motion playback. The attribute is mutable, but
-  on setting, if the new value is 0.0, a
-  <code>NOT_SUPPORTED_ERR</code> exception must be raised instead of
-  the value being changed. Otherwise, the playback must change speed
-  (if the element is <span>potentially playing</span>). It must initially
-  have the value 1.0.</p>
+  fast forward or slow motion playback. The attribute is mutable: on
+  getting it must return the last value it was set to, or 1.0 if it
+  hasn't yet been set; on setting the attribute must be set to the new
+  value, and the playback must change speed (if the element is
+  <span>potentially playing</span>).</p>
 
+  <p>The "play" function in a user agent's interface must set the
+  <code title="dom-media-playbackRate">playbackRate</code> attribute
+  to the value of the <code
+  title="dom-media-defaultPlaybackRate">defaultPlaybackRate</code>
+  attribute before invoking the <code
+  title="dom-media-play">play()</code> method's steps. Features such
+  as fast-forward or rewind must be implemented by only changing the
+  <code title="dom-media-playbackRate">playbackRate</code>
+  attribute.</p>
+
   <p id="rateUpdate">When the <code
   title="dom-media-defaultPlaybackRate">defaultPlaybackRate</code> or
   <code title="dom-media-playbackRate">playbackRate</code> attributes
@@ -19668,6 +19676,12 @@
   user agent may apply pitch adjustments to the audio as necessary to
   render it faithfully.</p>
 
+  <p>The <code title="dom-media-playbackRate">playbackRate</code> can
+  be 0.0, in which case the <span>current playback position</span>
+  doesn't move, despite playback not being paused (<code
+  title="dom-media-paused">paused</code> doesn't become true, and the
+  <code title="event-pause">pause</code> event doesn't fire).</p>
+
   <p><span title="media element">Media elements</span> that are
   <span>potentially playing</span> while not <span>in a
   <code>Document</code></span><!-- XXX xref --> must not play any
@@ -19675,9 +19689,10 @@
   stop playing just because all references to them have been removed;
   only once a media element to which no references exist has reached a
   point where no further audio remains to be played for that element
-  (e.g. because the element is paused or because the end of the clip
-  has been reached) may the element be <span>garbage
-  collected</span><!-- XXX xref -->.</p>
+  (e.g. because the element is paused, or because the end of the clip
+  has been reached, or because its <code
+  title="dom-media-playbackRate">playbackRate</code> is 0.0) may the
+  element be <span>garbage collected</span><!-- XXX xref -->.</p>
 
   <hr>
 




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