[FFmpeg-devel] Format for fast extraction (was: [PATCH] Dynamic plugins loading)

Nicolas George nicolas.george
Mon Nov 1 21:37:36 CET 2010

Le primidi 11 brumaire, an CCXIX, Michael Niedermayer a ?crit?:
> > (On the other hand, if anyone knows a supported format that allows efficient
> > extraction of two 1-hour shows from a 3-hours recording with commercials, I
> > would like to hear about it.)
> where is the problem with existing formats? mpeg4/h264/mp3/aac in nut?

They require a lot of disc-to-disc copy. With the example I chose, the
original file will be about 6?giga-octets and requires two copies of
2?giga-octets each.

The format I have designed splits the video into fragments of about 1?minute
each, which makes them about 30 or 40 mega-octets, plus a global index.
Extracting a segments uses mostly hardlinks, only the index and the
fragments at the cut points are rebuilt. The whole thing is done in less
than one second. As a bonus, it works even if the disk space is tight.


  Nicolas George

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