[Ffmpeg-devel] lossless video codec comparison

Loren Merritt lorenm
Mon Mar 19 08:11:26 CET 2007


On Sun, 18 Mar 2007, Mike Melanson wrote:
>
> The more interesting part about Lagarith is that it was designed for 
> parallelization and the only version available is pre-optimized for MMX. This 
> makes it difficult to RE a description for the Wiki:

The MMX parts are all identical to functions found in other codecs, so 
that's no problem.
I also don't see anything about the format that's especially "designed for 
parallelization". Any intra-only format is embarrassingly parallel: just 
run multiple codec instances on different frames.

imho the most interesting part is the arithcoder. Unlike 
ffv1/snow/h264/vp*/jpeg2k which use binary arithcoders, lagarith stores a 
whole coefficient in one symbol. End result is apparently that it's only 
a few % slower than vlc.

--Loren Merritt




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