[FFmpeg-devel] [PATCH] Fix XvMC

Michael Niedermayer michaelni
Sun Oct 11 13:48:52 CEST 2009


On Sat, Oct 10, 2009 at 05:17:59PM +0200, Gwenole Beauchesne wrote:
> Hi,
>
> This patch fixes a crash with XvMC... According to online bug reports, this 
> affects all platforms (AMD, Intel, NVIDIA). XVMCCreateBlocks() may not 
> allocate 16-byte aligned blocks so an SSE optimized clear_blocks() could 
> crash on platforms not supporting MSSE. Besides, since the XvMC decode 
> context initialization is a mixture of FFmpeg and player parts, we can't 
> expect players to fix that. By chance, this generally is a driver 
> limitation anyway. So a fix in FFmpeg is the better approach IMHO.
>
> Another solution is to set xvmc_acceleration to 1, this doesn't make a real 
> difference though my platform is recent enough.

iam not xvmc maintainer but i consider it a driver bug if the driver does not
align arrays as is needed on the architecture
final decission is ivans but i am against disabling optimizations, rather
print an error pointing the user to his drivers being buggy and maybe
suggest him to try a different acceleration architecture that has less
buggy drivers or if one prefers to argue it the other way around, a less
buggy API specification.


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Old school: Use the lowest level language in which you can solve the problem
            conveniently.
New school: Use the highest level language in which the latest supercomputer
            can solve the problem without the user falling asleep waiting.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20091011/356a33fb/attachment.pgp>



More information about the ffmpeg-devel mailing list