[FFmpeg-devel] MMX version for put_no_rnd_h264_chroma_mc8_c

Kostya kostya.shishkov
Fri Jul 6 03:46:23 CEST 2007

On Thu, Jul 05, 2007 at 11:43:12PM +0200, Christophe GISQUET wrote:
> Hello,
> from the opreport log concerning Robotica_720.wmv as seen in the
> previous thread, it was noticeable that put_no_rnd_h264_chroma_mc8_c was
> taking around 10%. I observed the same phenomenon on another "WMV HD"
> sample (Amazing Caves 720p).
> However, the few AVC samples from mphq I tested didn't seem to use it,
> so it probably of lesser importance for this codec.

It is only used in WMV3/VC-1 and based on H.264 function.
> So here is a patch to provide a MMX implementation of it. I also had a
> MMX2 implementation (using pshufw where useful), but the performance
> difference of the functions (~2%, measured with START/STOP_TIMER) wasn't
> worth increasing object size.
> I'm fine with the license (LGPL 2.1 or any version) of h264dsp_mmx.c
> where most of the code is located.

It could be made from put_rnd_h264_chroma_mc8_* by simply changing one
instruction or constant but I was busy with other things to do it myself.
Thanks for your work.
> Best regards,
> -- 
> Christophe GISQUET

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