[Bug 18576] Confused requirements on updating implicit duration

https://www.w3.org/Bugs/Public/show_bug.cgi?id=18576

--- Comment #1 from Aaron Colwell <acolwell@chromium.org> 2012-08-17 23:15:00 UTC ---
(In reply to comment #0)
> http://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html#source-buffer-duration-updates
> 
> In this section (which should be non-normative) it says that "Any time a media
> segment that goes beyond the current value of the duration attribute is
> appended to a SourceBuffer, the duration attribute will get updated to end
> timestamp of the media segment."
> 
> (Note also that this should be scoped to only implicit duration, but the
> section nesting doesn't make it so.)

I don't quite understand what you are saying here. The explicit vs implicit
difference is only how the duration is set. The intent is not to maintain 2
different values. All four sections under 2.12 are intended to change the same
underlying duration value. 

Are you saying the duration set via append() is just another form of implicitly
setting the duration and therefore should be part of 2.12.2?

> 
> http://dvcs.w3.org/hg/html-media/raw-file/tip/media-source/media-source.html#dom-append
> 
> This section says "Update the duration attribute to reflect the end of the
> appended data. (ie Highest end timestamp reported by
> HTMLMediaElement.buffered)"
> 
> This looks like it's assuming that segments are always appended in order.
> Should be rephrased to set duration to the maximum of the current duration and
> the end timestamp of the appended segment.

That was not the intent. Maybe this is a little clearer

"Update the duration attribute to the maximum of the current duration and the
highest end timestamp reported by HTMLMediaElement.buffered."

I just realized the spec doesn't define how SourceBuffer.buffered maps to
HTMLMediaElement.buffered so I filed
https://www.w3.org/Bugs/Public/show_bug.cgi?id=18615 . If that proposal is
accepted, the new text above is slightly different then what you proposed. If
that definition of HTMLMediaElement.buffered was used then duration would only
change when the playable region changed not when a segment was appended to a
single SourceBuffer.

-- 
Configure bugmail: https://www.w3.org/Bugs/Public/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the QA contact for the bug.

Received on Friday, 17 August 2012 23:15:02 UTC