[FFmpeg-devel] dealing with tables in DV codec

[Måns Rullgård]

"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