[Ffmpeg-devel] dsputil arm patch

Siarhei Siamashka siarhei.siamashka
Wed Apr 25 08:50:16 CEST 2007

On Tuesday 24 April 2007 23:26, Tim Chick wrote:

> > I have tested this patch and it really improves performance, some
> > tests with 'mplayer -vo md5sum' did not reveal any problems as well. I
> > just wonder why some of these dsp functions were commented out while
> > marked as ok? I earlier thought that they could probably cause
> > performance regression on XScale (original author of that code
> > developed it for Sharp Zaurus PDA which is XScale powered). If there
> > are any XScale users subscribed to this mailing list, maybe they could
> > run some benchmarks?
> I have a zaurus with xscale and iwmmxt (pxa270). I am willing to benchmark,
> if you let me know exactly what you want me to test. Can I get the same
> video as you used from somewhere?
> I will not be using gcc 4 - so that could clear up another difference.

Tao's patch does not directly affect you (as you can use iwmmx optimized
code), but owners of older xscale chips such as pxa255 which don't have 
iwmmx support.

Anyway if you can build ffmpeg with and without this patch and iwmmx
optimizations disabled, please run benchmarks for any mpeg4 file, that 
would be interesting to see.

It is better to use the files which are easily available to anyone for
benchmarking, so I would prefer some movie clip from:

More information about the ffmpeg-devel mailing list