W3C home > Mailing lists > Public > public-media-fragment@w3.org > January 2010

Re: Temporal fragments of media with time stamps

From: David Singer <singer@apple.com>
Date: Mon, 18 Jan 2010 10:38:16 +0900
Cc: Davy Van Deursen <davy.vandeursen@ugent.be>, "'Bailer, Werner'" <werner.bailer@joanneum.at>, public-media-fragment@w3.org, 'Richard Wright-ARCHIVES' <richard.wright@bbc.co.uk>
Message-Id: <8CA1DB90-DDF4-42B4-9E5E-75DFBD76AD6E@apple.com>
To: Jack Jansen <Jack.Jansen@cwi.nl>

On Jan 18, 2010, at 8:06 , Jack Jansen wrote:

> 
> On 16 jan 2010, at 10:25, Davy Van Deursen wrote:
>> 
>> Temporal fragments should indeed take into account embedded time stamps.

'may', I think, surely.  It depends on whether the fragment time is expressed in NPT, or (say) SMPTE time-codes.  NPT starts at 0;  to resolve a fragment here, you're fine without inspecting the media.

SMPTE time-codes, OTOH, need to be found.  They might not even be continuous in the media.

>> Note that this is already stated in the specification [1].
>> 
>> Best regards,
>> 
>> Davy
>> 
>> [1] http://www.w3.org/TR/media-frags/#processing-overview-interpretation  
> 
> 
> Thanks for finding this one!
> 
> But: this means that we have to look through the protocol description with this in mind. 
> 
> If I have a video http://www.example.com/example.mp4, which has 10 seconds worth of video, with timestamps 01:00:00:00 through 01:00:10:00, and a UA sends a request
> with 
> 	Range: t:smpte=01:00:05:00-01:00:06:00
> what does it get back in the Content-Range header?
> I would assume the timestamps are as expected, but what is the duration returned? 
> --
> Jack Jansen, <Jack.Jansen@cwi.nl>, http://www.cwi.nl/~jack
> If I can't dance I don't want to be part of your revolution -- Emma Goldman
> 
> 
> 
> 

David Singer
Multimedia and Software Standards, Apple Inc.
Received on Monday, 18 January 2010 01:38:50 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Wednesday, 21 September 2011 12:13:35 GMT