[FFmpeg-devel] dealing with tables in DV codec

Måns Rullgård mans
Thu Sep 11 04:39:21 CEST 2008

"Roman V. Shaposhnik" <rvs at sun.com> writes:

> On Thu, 2008-09-11 at 02:02 +0200, Stefan de Konink wrote:
>> > It's a binary codec for DV that MPlayer can use.  It performs up to 50%
>> > better than FFmpeg on some samples.  Not on all samples though, for a
>> > few FFmpeg is slightly faster, but most of the time qdv wins by a
>> > considerable and sometimes even huge margin.  Just try all DV samples
>> > from the MPlayer collection.
>> Could it be they have implemented partial 'caching' of motionless
>> blocks? 
> Huh? 
>> By looking at the difference between two frames? Or is such case
>> also handled in ffmpeg?
> That goes way over my head. DV is an intra-frame codec, so what
> exactly do you mean by "'caching' of motionless blocks"?

I'm guessing here, but maybe it could, at least in some cases, be
faster to compare a coded block with the corresponding coded block
from the previous frame, and if they are the same, simply copy the
pixels instead of decoding the block again.

M?ns Rullg?rd
mans at mansr.com

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