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Re: Squid experts

From: Olivier Aubert <olivier.aubert@liris.cnrs.fr>
Date: Fri, 07 Nov 2008 10:53:13 +0100
To: public-media-fragment@w3.org
Message-Id: <1226051593.5611.26.camel@pennylane>

Hello all

> I think we are theorizing a lot and are not actually looking at
> concrete codecs. We should start getting our hands dirty. ;-) By which
> I mean: start classifying the different codecs according to the
> criteria that you have listed above and find out for which we are
> actually able to do fragments and what types of fragments.
It is not only a matter of codec, but also a problem of container
format. Ogg was conceived to be streamed, and each Ogg page contains the
time offset of the contained data. MPEG TS/PS is also conceived to be
streamed. But AVI causes more trouble, because its index (the definition
of the location of data, i.e. basically the source of time to byte
mapping) is located at the end of the file.

IMO, the simplest approach wrt. caches is not to try to put too much
intelligence in them, and consider that they simply store chunks of
data. Players on the client side are perfectly able to do byte-based
HTTP Range requests, just like they would do a lseek() when accessing a
local movie file. The http access module of VLC optimizes this, for
instance.

Cheers,
Olivier
Received on Friday, 7 November 2008 10:31:34 GMT

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