spec/Overview.html 1.1579 2407 Specify how frequently the timeupdate ev

Specify how frequently the timeupdate event should fire. (whatwg r2407)

When a media element is potentially playing and its Document is an active document, its current playback position must increase monotonically at playbackRate units of media time per unit time of wall clock time.
http://people.w3.org/mike/diffs/html5/spec/Overview.1.1579.html#media-playback

http://people.w3.org/mike/diffs/html5/spec/Overview.diff.html
http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.1578&r2=1.1579&f=h
http://html5.org/tools/web-apps-tracker?from=2406&to=2407

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RCS file: /sources/public/html5/spec/Overview.html,v
retrieving revision 1.1578
retrieving revision 1.1579
diff -u -d -r1.1578 -r1.1579
--- Overview.html 17 Nov 2008 01:06:30 -0000 1.1578
+++ Overview.html 17 Nov 2008 01:11:59 -0000 1.1579
@@ -14869,12 +14869,20 @@
    steps.</li>
 
    <li><p>If the time was reached through the usual monotonic increase
-   of the current playback position during normal playback, the user
-   agent must then <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. (In the
+   of the current playback position during normal playback, and if the
+   user agent has not fired a <code title=event-timeupdate><a href=#event-timeupdate>timeupdate</a></code> event at the element in
+   the past 15 to 250ms, the user agent must then <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. (In the
    other cases, such as explicit seeks, relevant events get fired as
    part of the overall process of changing the current playback
-   position.)</li>
+   position.)</p>
+
+   <p class=note>The event thus is not to be fired faster than about
+   66Hz or slower than 4Hz. User agents are encouraged to vary the
+   frequency of the event based on the system load and the average
+   cost of processing the event each time, so that the UI updates are
+   not any more frequent than the user agent can comfortably handle
+   while decoding the video.</li>
 
    <li><p>If the time was reached through the usual monotonic increase
    of the current playback position during normal playback, and there

Received on Monday, 17 November 2008 01:15:51 UTC