- From: Ian Hickson via cvs-syncmail <cvsmail@w3.org>
- Date: Wed, 04 Apr 2012 18:56:12 +0000
- To: public-html-commits@w3.org
Update of /sources/public/html5/spec In directory hutz:/tmp/cvs-serv5129 Modified Files: Overview.html Log Message: Yet more polishing of the media timeline phraseology. (whatwg r7048) Index: Overview.html =================================================================== RCS file: /sources/public/html5/spec/Overview.html,v retrieving revision 1.5618 retrieving revision 1.5619 diff -u -d -r1.5618 -r1.5619 --- Overview.html 3 Apr 2012 17:07:46 -0000 1.5618 +++ Overview.html 4 Apr 2012 18:56:07 -0000 1.5619 @@ -27878,14 +27878,15 @@ <p><dfn id="defineTimeline" title="establish the media timeline">Establishing the media timeline</dfn>: If the <a href="#media-resource">media resource</a> somehow specifies an explicit timeline whose origin - is not negative, then the <a href="#media-timeline">media timeline</a> should be that - timeline. (Whether the <a href="#media-resource">media resource</a> can specify a - timeline or not depends on the <a href="#media-resource" title="media resource">media - resource's</a> format.) If the <a href="#media-resource">media resource</a> - specifies an explicit start time <em>and date</em>, then that time - and date should be considered the zero point in the <a href="#media-timeline">media - timeline</a>; the <a href="#timeline-offset">timeline offset</a> will be the time - and date, exposed using the <code title="dom-media-startDate"><a href="#dom-media-startdate">startDate</a></code> attribute.</p> + is not negative (i.e. gives each frame a specific time offset and + gives the first frame a zero or positive offset), then the + <a href="#media-timeline">media timeline</a> should be that timeline. (Whether the + <a href="#media-resource">media resource</a> can specify a timeline or not depends on + the <a href="#media-resource" title="media resource">media resource's</a> format.) If + the <a href="#media-resource">media resource</a> specifies an explicit start time + <em>and date</em>, then that time and date should be considered the + zero point in the <a href="#media-timeline">media timeline</a>; the <a href="#timeline-offset">timeline + offset</a> will be the time and date, exposed using the <code title="dom-media-startDate"><a href="#dom-media-startdate">startDate</a></code> attribute.</p> <p>If the <a href="#media-resource">media resource</a> has a discontinuous timeline, the user agent must extend the timeline used at the start of the @@ -27906,26 +27907,28 @@ have an explicit timeline, the zero time on the <a href="#media-timeline">media timeline</a> should correspond to the first frame of the <a href="#media-resource">media resource</a>. In the even rarer case of a <a href="#media-resource">media - resource</a> with no explicit timings ofd any kind, the user - agent must determine the time for each frame.</p> + resource</a> with no explicit timings of any kind, not even frame + durations, the user agent must itself determine the time for each + frame in a user-agent-defined manner.</p> <p class="note">An example of a file format with no explicit - timeline but with explicit timings is the Animated GIF format. An - example of a file format with no explicit timings at all is the - JPEG-push format (<code title="">multipart/x-mixed-replace</code> - with JPEG frames, often used as the format for MJPEG streams).</p> + timeline but with explicit frame durations is the Animated GIF + format. An example of a file format with no explicit timings at all + is the JPEG-push format (<code title="">multipart/x-mixed-replace</code> with JPEG frames, often + used as the format for MJPEG streams).</p> - <p>If, even in the absence of timing information, the user agent - will be able to seek to an earlier point than the first frame - originally provided by the server, then the zero time should - correspond to the earliest seekable time of the <a href="#media-resource">media - resource</a>; otherwise, it should correspond to the first frame - received from the server (the point in the <a href="#media-resource">media + <p>If, in the case of a resource with no timing information, the + user agent will nonetheless be able to seek to an earlier point than + the first frame originally provided by the server, then the zero + time should correspond to the earliest seekable time of the + <a href="#media-resource">media resource</a>; otherwise, it should correspond to the + first frame received from the server (the point in the <a href="#media-resource">media resource</a> at which the user agent began receiving the stream).</p> - <p class="note">At the time of writing, no format without an - explicit <a href="#media-timeline">media timeline</a> supported seeking.</p> + <p class="note">At the time of writing, there is no known format + that lacks explicit frame time offsets yet still supports seeking to + a frame before the first frame sent by the server.</p> <div class="example">
Received on Wednesday, 4 April 2012 18:56:14 UTC