[Ffmpeg-devel] [PATCH] *_h264_chroma_mc8 mmx optimizaitons

Corey Hickey bugfood-ml
Mon May 23 10:05:07 CEST 2005

Zoltan Hidvegi wrote:
> I've been playing with x264, and it's pretty cool, but it takes too
> much time to decode.  So I've run the profiler, and saw lots of time
> (11% of the total time) spent in *_h264_chroma_mc8.  They are not the
> best for mmx, but I rewrote them in MMX, and I was able to speed it up
> a bit, I guess they are about 30-40% faster on my 533MHz Pentimum
> III-M laptop (800MHz CPU speedsteped to 533MHz), reducing the overall
> time to decode by 3-4%.
> I've tested it with mplayer -vo md5sum on a 1024x576 x264 video I've
> created.
> Zoli

Nice! I tested it on my Athlon64 with the highest-res h.264 file I have:

$ mplayer bbc_1080p.mov -nosound -vo null -benchmark

Without your patch:
BENCHMARKs: VC:  94.892s VO:   0.005s A:   0.000s Sys:   0.712s =   95.608s
BENCHMARK%: VC: 99.2505% VO:  0.0048% A:  0.0000% Sys:  0.7448% = 100.0000%

With your patch:
BENCHMARKs: VC:  85.855s VO:   0.005s A:   0.000s Sys:   0.352s =   86.211s
BENCHMARK%: VC: 99.5862% VO:  0.0053% A:  0.0000% Sys:  0.4086% = 100.0000%

Decoding with the patch reduces the time by about 9.5% and -vo md5sum
outputs are the same.


More information about the ffmpeg-devel mailing list