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Range request and transcoding.

From: Yves Lafon <ylafon@w3.org>
Date: Tue, 30 Jun 2009 10:26:34 -0400 (EDT)
To: www-tag@w3.org
cc: public-media-fragment@w3.org
Message-ID: <alpine.DEB.1.10.0906300958500.14524@wnl.j3.bet>
All,
The Media Fragment WG is working on... defining how to identify and server 
media fragments, the primary use case is of course video, but it is not 
limited to it [1]. There is a aso a clear relation to the TAG WD "Usage 
Patterns For Client-Side URI parameters" [2], as hash parameters are used 
to generate range requests to send back to the clients only the desired 
sub-part of the resource representation.

There are different axis defined, the most obvious and easy to handle is 
the time axis for video and audio, as in most cases the sub-part 
extraction can be done in the compressed domain.

The geometrical axis (like asking for a clipped version of a picture or a 
video) is the origin of this email, as the WG did not reach a conclusion 
on "Is it legal to do transcoding when serving a fragment".

ie: the World Map is defined by http://www.example.com/earthmap.jpg and is 
a 10000x10000 picture.
Small country M is defined by the following URI:
http://www.example.com/earthmap.jpg#xywh=pixel:5160,5120,32,24

Suppose that we have a way to construct a ranged request out of that, 
serving only that 32x34 jpg file requires transcoding, while being served 
as a partial response.

Input needed :)
Thanks,

[1] http://www.w3.org/TR/2009/WD-media-frags-reqs-20090430/
[2] http://www.w3.org/TR/2009/WD-hash-in-uri-20090415/

-- 
Baroula que barouleras, au tiéu toujou t'entourneras.

         ~~Yves
Received on Tuesday, 30 June 2009 14:26:45 GMT

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