[html5] r3012 - [gow] (2) Fix a variety of issues with how media playback works when playbackRat [...]

whatwg at whatwg.org whatwg at whatwg.org
Tue Apr 28 15:38:21 PDT 2009


Author: ianh
Date: 2009-04-28 15:38:20 -0700 (Tue, 28 Apr 2009)
New Revision: 3012

Modified:
   index
   source
Log:
[gow] (2) Fix a variety of issues with how media playback works when playbackRate is backwards.

Modified: index
===================================================================
--- index	2009-04-28 22:11:44 UTC (rev 3011)
+++ index	2009-04-28 22:38:20 UTC (rev 3012)
@@ -20918,30 +20918,36 @@
    <dt><dfn id=dom-media-have_current_data title=dom-media-HAVE_CURRENT_DATA><code>HAVE_CURRENT_DATA</code></dfn> (numeric value 2)</dt>
 
    <dd>Data for the immediate <a href=#current-playback-position>current playback position</a>
-   is available, but not enough data is available that the user agent
-   could successfully advance the <a href=#current-playback-position>current playback
-   position</a> at all without immediately reverting to the <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> state. For
-   example, in video this corresponds to the user agent having data
-   from the current frame, but not the next frame.</dd>
+   is available, but either not enough data is available that the user
+   agent could successfully advance the <a href=#current-playback-position>current playback
+   position</a> in the <a href=#direction-of-playback>direction of playback</a> at all
+   without immediately reverting to the <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> state, or
+   there is no more data to obtain in the <a href=#direction-of-playback>direction of
+   playback</a>. For example, in video this corresponds to the user
+   agent having data from the current frame, but not the next frame;
+   and to when <a href=#ended-playback title="ended playback">playback has
+   ended</a>.</dd>
 
    <dt><dfn id=dom-media-have_future_data title=dom-media-HAVE_FUTURE_DATA><code>HAVE_FUTURE_DATA</code></dfn> (numeric value 3)</dt>
 
    <dd>Data for the immediate <a href=#current-playback-position>current playback position</a>
    is available, as well as enough data for the user agent to advance
-   the <a href=#current-playback-position>current playback position</a> at least a little
-   without immediately reverting to the <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> state. For
-   example, In video this corresponds to the user agent having data
-   for at least the current frame and the next frame.</dd>
+   the <a href=#current-playback-position>current playback position</a> in the <a href=#direction-of-playback>direction
+   of playback</a> at least a little without immediately reverting
+   to the <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code>
+   state. For example, in video this corresponds to the user agent
+   having data for at least the current frame and the next frame. The
+   user agent cannot be in this state if <a href=#ended-playback title="ended
+   playback">playback has ended</a>, as the <a href=#current-playback-position>current playback
+   position</a> can never advanced in this case.</dd>
 
    <dt><dfn id=dom-media-have_enough_data title=dom-media-HAVE_ENOUGH_DATA><code>HAVE_ENOUGH_DATA</code></dfn> (numeric value 4)</dt>
 
-   <dd>Data for the immediate <a href=#current-playback-position>current playback position</a>
-   is available, as well as enough data for the user agent to advance
-   the <a href=#current-playback-position>current playback position</a> at least a little
-   without immediately reverting to the <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> state, and,
-   in addition, the user agent estimates that data is being fetched at
-   a rate where the <a href=#current-playback-position>current playback position</a>, if it were
-   to advance at the rate given by the <code title=dom-media-defaultPlaybackRate><a href=#dom-media-defaultplaybackrate>defaultPlaybackRate</a></code>
+   <dd>All the conditions described for the <code title=dom-media-HAVE_FUTURE_DATA><a href=#dom-media-have_future_data>HAVE_FUTURE_DATA</a></code> state
+   are met, and, in addition, the user agent estimates that data is
+   being fetched at a rate where the <a href=#current-playback-position>current playback
+   position</a>, if it were to advance at the rate given by the
+   <code title=dom-media-defaultPlaybackRate><a href=#dom-media-defaultplaybackrate>defaultPlaybackRate</a></code>
    attribute, would not overtake the available data before playback
    reaches the end of the <a href=#media-resource>media resource</a>.</dd>
 
@@ -21241,14 +21247,18 @@
 
   <p>A <a href=#media-element>media element</a> is said to have <dfn id=ended-playback>ended
   playback</dfn> when the element's <code title=dom-media-readyState><a href=#dom-media-readystate>readyState</a></code> attribute is <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> or greater, and
-  the <a href=#current-playback-position>current playback position</a> is the end of the
-  <a href=#media-resource>media resource</a>, and the <a href=#media-element>media element</a> does
+  either the <a href=#current-playback-position>current playback position</a> is the end of the
+  <a href=#media-resource>media resource</a> and the <a href=#direction-of-playback>direction of
+  playback</a> is forwards and the <a href=#media-element>media element</a> does
   not have a <code title=attr-media-loop><a href=#attr-media-loop>loop</a></code> attribute
-  specified.</p>
+  specified, or the <a href=#current-playback-position>current playback position</a> is the
+  <var><a href=#earliest-possible-position>earliest possible position</a></var> and the <a href=#direction-of-playback>direction of
+  playback</a> is backwards.</p>
 
   <p>The <dfn id=dom-media-ended title=dom-media-ended><code>ended</code></dfn>
   attribute must return true if the <a href=#media-element>media element</a> has
-  <a href=#ended-playback>ended playback</a>, and false otherwise.</p>
+  <a href=#ended-playback>ended playback</a> and the <a href=#direction-of-playback>direction of
+  playback</a> is forwards, and false otherwise.</p>
 
   <p>A <a href=#media-element>media element</a> is said to have <dfn id=stopped-due-to-errors>stopped due to
   errors</dfn> when the element's <code title=dom-media-readyState><a href=#dom-media-readystate>readyState</a></code> attribute is <code title=dom-media-HAVE_METADATA><a href=#dom-media-have_metadata>HAVE_METADATA</a></code> or greater, and
@@ -21288,8 +21298,9 @@
   the element.</p>
 
   <p>When the <a href=#current-playback-position>current playback position</a> reaches the end
-  of the <a href=#media-resource>media resource</a>, then the user agent must follow
-  these steps:</p>
+  of the <a href=#media-resource>media resource</a> when the <a href=#direction-of-playback>direction of
+  playback</a> is forwards, then the user agent must follow these
+  steps:</p>
 
   <ol><li><p>If the <a href=#media-element>media element</a> has a <code title=attr-media-loop><a href=#attr-media-loop>loop</a></code> attribute specified, then <a href=#dom-media-seek title=dom-media-seek>seek</a> to the <var><a href=#earliest-possible-position>earliest possible
    position</a></var> of the <a href=#media-resource>media resource</a> and abort these
@@ -21310,6 +21321,16 @@
    a simple event</a> called <code title=event-ended><a href=#event-ended>ended</a></code>
    at the element.</li>
 
+  </ol><p>When the <a href=#current-playback-position>current playback position</a> reaches the
+  <var><a href=#earliest-possible-position>earliest possible position</a></var> of the <a href=#media-resource>media
+  resource</a> when the <a href=#direction-of-playback>direction of playback</a> is
+  backwards, then the user agent must follow these steps:</p>
+
+  <ol><li><p>Stop playback.</li>
+
+   <li><p>The user agent must <a href=#queue-a-task>queue a task</a> to <a href=#fire-a-simple-event>fire
+   a simple event</a> called <code title=event-timeupdate><a href=#event-timeupdate>timeupdate</a></code> at the element.</li>
+
   </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
@@ -21328,6 +21349,10 @@
   value, and the playback must change speed (if the element is
   <a href=#potentially-playing>potentially playing</a>).</p>
 
+  <p>If the <code title=dom-media-playbackRate><a href=#dom-media-playbackrate>playbackRate</a></code>
+  is positive or zero, then the <dfn id=direction-of-playback>direction of playback</dfn> is
+  forwards. Otherwise, it is backwards.</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>

Modified: source
===================================================================
--- source	2009-04-28 22:11:44 UTC (rev 3011)
+++ source	2009-04-28 22:38:20 UTC (rev 3012)
@@ -22672,33 +22672,38 @@
    <dt><dfn title="dom-media-HAVE_CURRENT_DATA"><code>HAVE_CURRENT_DATA</code></dfn> (numeric value 2)</dt>
 
    <dd>Data for the immediate <span>current playback position</span>
-   is available, but not enough data is available that the user agent
-   could successfully advance the <span>current playback
-   position</span> at all without immediately reverting to the <code
-   title="dom-media-HAVE_METADATA">HAVE_METADATA</code> state. For
-   example, in video this corresponds to the user agent having data
-   from the current frame, but not the next frame.</dd>
+   is available, but either not enough data is available that the user
+   agent could successfully advance the <span>current playback
+   position</span> in the <span>direction of playback</span> at all
+   without immediately reverting to the <code
+   title="dom-media-HAVE_METADATA">HAVE_METADATA</code> state, or
+   there is no more data to obtain in the <span>direction of
+   playback</span>. For example, in video this corresponds to the user
+   agent having data from the current frame, but not the next frame;
+   and to when <span title="ended playback">playback has
+   ended</span>.</dd>
 
    <dt><dfn title="dom-media-HAVE_FUTURE_DATA"><code>HAVE_FUTURE_DATA</code></dfn> (numeric value 3)</dt>
 
    <dd>Data for the immediate <span>current playback position</span>
    is available, as well as enough data for the user agent to advance
-   the <span>current playback position</span> at least a little
-   without immediately reverting to the <code
-   title="dom-media-HAVE_METADATA">HAVE_METADATA</code> state. For
-   example, In video this corresponds to the user agent having data
-   for at least the current frame and the next frame.</dd>
+   the <span>current playback position</span> in the <span>direction
+   of playback</span> at least a little without immediately reverting
+   to the <code title="dom-media-HAVE_METADATA">HAVE_METADATA</code>
+   state. For example, in video this corresponds to the user agent
+   having data for at least the current frame and the next frame. The
+   user agent cannot be in this state if <span title="ended
+   playback">playback has ended</span>, as the <span>current playback
+   position</span> can never advanced in this case.</dd>
 
    <dt><dfn title="dom-media-HAVE_ENOUGH_DATA"><code>HAVE_ENOUGH_DATA</code></dfn> (numeric value 4)</dt>
 
-   <dd>Data for the immediate <span>current playback position</span>
-   is available, as well as enough data for the user agent to advance
-   the <span>current playback position</span> at least a little
-   without immediately reverting to the <code
-   title="dom-media-HAVE_METADATA">HAVE_METADATA</code> state, and,
-   in addition, the user agent estimates that data is being fetched at
-   a rate where the <span>current playback position</span>, if it were
-   to advance at the rate given by the <code
+   <dd>All the conditions described for the <code
+   title="dom-media-HAVE_FUTURE_DATA">HAVE_FUTURE_DATA</code> state
+   are met, and, in addition, the user agent estimates that data is
+   being fetched at a rate where the <span>current playback
+   position</span>, if it were to advance at the rate given by the
+   <code
    title="dom-media-defaultPlaybackRate">defaultPlaybackRate</code>
    attribute, would not overtake the available data before playback
    reaches the end of the <span>media resource</span>.</dd>
@@ -23063,14 +23068,18 @@
   playback</dfn> when the element's <code
   title="dom-media-readyState">readyState</code> attribute is <code
   title="dom-media-HAVE_METADATA">HAVE_METADATA</code> or greater, and
-  the <span>current playback position</span> is the end of the
-  <span>media resource</span>, and the <span>media element</span> does
+  either the <span>current playback position</span> is the end of the
+  <span>media resource</span> and the <span>direction of
+  playback</span> is forwards and the <span>media element</span> does
   not have a <code title="attr-media-loop">loop</code> attribute
-  specified.</p>
+  specified, or the <span>current playback position</span> is the
+  <var>earliest possible position</var> and the <span>direction of
+  playback</span> is backwards.</p>
 
   <p>The <dfn title="dom-media-ended"><code>ended</code></dfn>
   attribute must return true if the <span>media element</span> has
-  <span>ended playback</span>, and false otherwise.</p>
+  <span>ended playback</span> and the <span>direction of
+  playback</span> is forwards, and false otherwise.</p>
 
   <p>A <span>media element</span> is said to have <dfn>stopped due to
   errors</dfn> when the element's <code
@@ -23117,8 +23126,9 @@
   the element.</p>
 
   <p>When the <span>current playback position</span> reaches the end
-  of the <span>media resource</span>, then the user agent must follow
-  these steps:</p>
+  of the <span>media resource</span> when the <span>direction of
+  playback</span> is forwards, then the user agent must follow these
+  steps:</p>
 
   <ol>
 
@@ -23147,6 +23157,21 @@
 
   </ol>
 
+  <p>When the <span>current playback position</span> reaches the
+  <var>earliest possible position</var> of the <span>media
+  resource</span> when the <span>direction of playback</span> is
+  backwards, then the user agent must follow these steps:</p>
+
+  <ol>
+
+   <li><p>Stop playback.</p></li>
+
+   <li><p>The user agent must <span>queue a task</span> to <span>fire
+   a simple event</span> called <code
+   title="event-timeupdate">timeupdate</code> at the element.</p></li>
+
+  </ol>
+
   <p>The <dfn
   title="dom-media-defaultPlaybackRate"><code>defaultPlaybackRate</code></dfn>
   attribute gives the desired speed at which the <span>media
@@ -23168,6 +23193,10 @@
   value, and the playback must change speed (if the element is
   <span>potentially playing</span>).</p>
 
+  <p>If the <code title="dom-media-playbackRate">playbackRate</code>
+  is positive or zero, then the <dfn>direction of playback</dfn> is
+  forwards. Otherwise, it is backwards.</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




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