[FFmpeg-devel] runtime-cpu-detect bug in swscale

Reinhard Tartler siretart
Sat Mar 5 08:21:42 CET 2011

On Fri, Mar 04, 2011 at 23:15:57 (CET), Darren Horrocks wrote:

> swscale doesnt ever actually do any runtime detection at all when
> runtime cpu detection is enabled, it simply passes whatever is passed
> to -sws_flags, which could be nothing at all making swscale default to
> the C implementation.
> i have uploaded a patched libswscale.dll (win32 build), the patch its
> self, and a pre-patched swscale.c file:
> http://www.bizzeh.com/ffmpeg/free/swstest/
> the patch has been tested, an unpatched swscale gained roughly 79fps
> during an encode with no flags and around 190fps with mmx2 set in the
> sws_flags. the patched swscale dll gained 190fps without any flags set
> at all since it detected the capabilities of the processor before
> choosing.
> could anyone else test this patch and submit it to trunk if its usable?

please post the patch as unified diff to this mailing list so that it is
automatically picked up at http://patches.ffmpeg.org

Reinhard Tartler, KeyID 945348A4

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