[FFmpeg-devel] [RFC] cpu specific implementation of libavutil functions

Nigel Pearson nigel
Mon Sep 10 02:35:39 CEST 2007

> 2. do we even have a working altivec detection routine?

1) MythTV uses the one in libavcodec/ppc/dsputil_altivec.c
which seems to work correctly on Darwin.

2) We use something like this:
% cat libmythtv/yuv2rgb.cpp
static void altivec_yuv420_2vuy (...
yuv2vuy_fun get_yuv2vuy_conv(void)
     if (has_altivec())
         return altivec_yuv420_2vuy;

#ifdef MMX
     return mmx_yuv420_2vuy;

     return non_vec_yuv420_2vuy; /* Fallback to C */

3) I think having _just_ compile-time detection
would be a big step backwards for packagers.

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