On Sun, Aug 24, 2008 at 02:10:20AM -0400, Brad wrote:
> The following diff for FFmpeg corrects the architecture detection.
> This results in the AltiVec support now being enabled. I have now
> also added support for the sysctl method of detecting the pressence
> of AltiVec. In addition since the architecture detection support
> has been fixed for OpenBSD that means this also needs checking
> on SuperH systems (landisk), ARM systems (armish/zaurus) and MIPS
> systems (sgi).
This seems to reduce ffplay cpu usage by 25% on a G4 (even more
when converting video files with ffmpeg). I didn't notice any
improvement on arm, however.
And there's a big caveat: ffplay with altivec enabled fails on some
video files either by exiting immediately or by showing lots of
artefacts (there seems to be a tendency to "green out" the video,
i.e. you get green blurring patterns).
The later problem is easy to reproduce; just convert any video file
with mplayer's mencode with -oac mp3lame -ovc lavc amd play the
resulting file on a G4 with ffplay.
Ciao,
Kili
