[FFmpeg-devel] [PATCH 5/5] libavcodec/ffv1: Support storing LSB raw

Michael Niedermayer michael at niedermayer.cc
Thu Oct 17 00:25:45 EEST 2024


On Wed, Oct 16, 2024 at 10:53:37PM +0200, Michael Niedermayer wrote:
> Hi Jerome
> 
> On Wed, Oct 16, 2024 at 10:29:18PM +0200, Jerome Martinez wrote:
> > Le 16/10/2024 à 21:51, Michael Niedermayer a écrit :
> > > did you try qtable 1 ? strangely it performed better for the file i used compression wise
> > 
> > Updated with latest code (in practice, no change in previous values):
> > 0,037x    0,471    No patch
> > 0,051x    0,491    bitfield
> > 0,046x    0,489    rangecoder
> > 0,046x    0,486    rangecoder qtable=1
> > 
> > qtable=1 helps but still not enough for being interesting compared to the
> > bitfield version.
> > 
> > > also i cleaned the code up a bit and reposted, some of the code was
> > > not exactly optimized
> > > 
> > > here the old "bitfield"
> > > real	0m5.545s
> > > real	0m5.655s
> > > real	0m5.643s
> > > 
> > > vs. just now posted:
> > > real	0m5.407s
> > > real	0m5.393s
> > > real	0m5.404s
> > 
> > Even more interesting to keep the bitfield version rather than the range
> > coder!
> 
> what are you testing?
> the new code is faster than the old code.
> There is something not right here, the range coder based implementation
> i posted now is 5% faster then the range coder based one i posted earlier today
> thats overall speed meassured with "time ./ffmpeg"
> if you see no difference there is something fishy
> 
> i simply tested this:
> ./ffmpeg -i rawsamples/16/01.dpx -threads 1  -c:v ffv1 -context 1 -coder 1 -strict -2 -level 4 -rawlsb 4   -y /tmp/speedtest4.nut

compiler was this:  gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.2)

thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Freedom in capitalist society always remains about the same as it was in
ancient Greek republics: Freedom for slave owners. -- Vladimir Lenin
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20241016/b8441d8b/attachment.sig>


More information about the ffmpeg-devel mailing list