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

Darren Horrocks killallthehumans
Fri Mar 4 23:15:57 CET 2011

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:

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

could anyone else test this patch and submit it to trunk if its usable?


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