- From: David Singer <singer@apple.com>
- Date: Wed, 13 Apr 2011 12:30:48 -0700
- To: Philip Jägenstedt <philipj@opera.com>
- Cc: Media Fragment <public-media-fragment@w3.org>
On Apr 13, 2011, at 3:03 , Philip Jägenstedt wrote: > From todays teleconf. > > The question comes up in some test cases in <http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases.html>. > > It it my experience that media not starting at time 0 is extremely rare, I've really only seen it in poorly remuxed MPEG-2 transport streams and similar. I would say that *if* a user agent supports media that doesn't start at 0, then we should clamp the request start to the start time when necessary. I don't think that we should make the start/end relative to the media start position, as that would be inconsistent. > > Discuss. > I think it's a definition of the 't' in the media fragment that its origin (the first available media) is at 0. The media can have any kind of bizarre timelines associated with it, if it likes. So, if you say "start at SMPTE time-code 10:0:0.0" that might, indeed, be the beginning, or it might not. But if you say "start at the relative time into this media resource of 0" that's perfectly clear no matter what other timelines might exist. Which is long-winded way of saying I agree, essentially, but by definition, not by experience. David Singer Multimedia and Software Standards, Apple Inc.
Received on Wednesday, 13 April 2011 19:31:17 UTC