hixie: Yet more polishing of the media timeline phraseology. (whatwg r7048)

hixie: Yet more polishing of the media timeline phraseology. (whatwg
r7048)

http://dev.w3.org/cvsweb/html5/spec/Overview.html?r1=1.5618&r2=1.5619&f=h
http://html5.org/tools/web-apps-tracker?from=7047&to=7048

===================================================================
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 18:56:25 UTC