[FFmpeg-devel] WMV2 decoding performance

Diego Biurrun diego
Sun Nov 11 12:55:29 CET 2007


On Sat, Nov 10, 2007 at 04:44:38PM -0700, Loren Merritt wrote:
> On Sat, 10 Nov 2007, Diego Biurrun wrote:
> 
> > I notice that our WMV2 decoder is vastly faster for most of the samples
> > I try it on, for example all the stuff from
> >
> > http://samples.mplayerhq.hu/V-codecs/WMV8/
> >
> > except for the following sample:
> >
> > http://samples.mplayerhq.hu/V-codecs/WMV8/vandread_ep13_op_wm8_ver.wmv
> >
> > Any clues what could be the reason?  Benjamin suspects a non-optimized
> > IDCT.  The only difference I notice right off is that the above sample
> > is much higher resolution that the others.
> 
> It's fast for me.
> [...]
 
Loren said on IRC that his numbers are from an old snapshot without
XIntra8 support that was using the optimized IDCT.  If I test with
'-lavdopts idct=3' (simplemmx) I also get a considerable speedup and the
native decoder becomes much faster than the binary.

Diego




More information about the ffmpeg-devel mailing list