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Re: Description of the 2-ways and the 4-ways handshake

From: Jack Jansen <Jack.Jansen@cwi.nl>
Date: Fri, 3 Apr 2009 10:12:10 +0200
Cc: Media Fragment <public-media-fragment@w3.org>, Eric Carlson <eric.carlson@apple.com>
Message-Id: <02DFDA90-6515-4C87-8F0B-2DDC1DFCD45A@cwi.nl>
To: David Singer <singer@apple.com>
More questions:

On 3 apr 2009, at 01:37, David Singer wrote:

[...]

> samples are stored in chunks;  the chunk offset table gives the  
> starting sample number, the number of samples, and the absolute file  
> byte-offset of the first byte of that sample, for each chunk.  find  
> the chunk the sample we want is in, and its byte offset.

This table seems to be unbounded in size, or not? What would be the  
size for, say, a 1-hour video?
>
> (typically, for data loading, we stop here and just add that chunk  
> start point to the data we need, find the chunk starts for the other  
> tracks, and if they are close together, load a whole bunch-o-bytes  
> from the earliest offset, such that we get all of them)
>
> there is also a table which gives (compacted again) the size of each  
> sample;  for the sample preceding the one we want, but in the same  
> chunk, add their sizes to the chunk offset.  this gives the absolute  
> byte offset of the access unit want.

Again, this table seems to be unbounded. Or did I misunderstand, and  
is this information stored in the chunk (as opposed to in the moov)?

--
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
Received on Friday, 3 April 2009 08:12:53 GMT

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