W3C home > Mailing lists > Public > public-media-fragment@w3.org > April 2009

Should we consider the user?

From: Jack Jansen <Jack.Jansen@cwi.nl>
Date: Wed, 1 Apr 2009 10:59:11 +0200
Message-Id: <D119DAC5-12EC-47ED-860D-B9FD8B808E4F@cwi.nl>
To: Media Fragment <public-media-fragment@w3.org>
Another angle on the issues I found this week: maybe part of the  
problem is that the only entities we've considered so far are (1) the  
client-side software, (2) the server and (3) a caching server.

If we also specify what the user can expect things may get easier. For  
example, if the user does

     wget http://www.example.com/movie.ogg#t=1,2&xywy=9,9,101,101

there are a number of questions:
1. Does this return the exact 1s-2s time fragment? This is probably  
impossible, the next best thing is the smallest interval that contains  
this interval, i.e. from the last frame before or at 1s to the first  
frame at or after 2s.
2. Alternatively, we could say the user gets a "reasonable" interval  
around 1s-2s, so implementations can cut at I frames. This would  
forestall transcoding. But: now we need to define "reasonable".
3. What about audio/video sync? If the user gets synced a/v we need to  
do recoding.
4. What about timestamps in the media? Are these the originals?
5. What about spatial crops? Same questions as for (1) and (2)
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  
Received on Wednesday, 1 April 2009 08:59:56 UTC

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