[FFmpeg-devel] [PATCH] Fix ffmpeg crash on G3 based computers introduced with revision 10637

[Reimar Döffinger]

Hello,
On Sat, Feb 09, 2008 at 12:11:01PM +0000, Patrice Bensoussan wrote:
> It seems that ffmpeg is trying to use altivec on PowerPC G3 although it's 
> not available. This was introduced with revision 10637. Here is a patch to 
> fix the issue.
>
> Patrice
>

> Index: libavcodec/mpegvideo.c
> ===================================================================
> --- libavcodec/mpegvideo.c	(revision 11880)
> +++ libavcodec/mpegvideo.c	(working copy)
> @@ -61,6 +61,10 @@
>  extern void XVMC_decode_mb(MpegEncContext *s);
>  #endif
>  
> +#ifdef HAVE_ALTIVEC
> +extern int has_altivec(void);
> +#endif

That #ifdef is pointless.

> @@ -152,7 +156,8 @@
>  #elif defined(ARCH_ARMV4L)
>      MPV_common_init_armv4l(s);
>  #elif defined(HAVE_ALTIVEC)
> -    MPV_common_init_altivec(s);
> +    if ( has_altivec() )
> +        MPV_common_init_altivec(s);

And IMO this check belongs into the MPV_common_init_altivec, if for no
other reason than that there are different levels of altivec support and
it's easier to add checks with finer granularity in that function than
here.

Greetings,
Reimar D?ffinger