[Ffmpeg-devel] Parallel mpeg4/h264 decoding in same process

[François Revol]

> 
> I have noticed that when trying to do parallel decoding with MPEG4 
> decoder
> (meaning simultaneous avcodec_decode_video calls, serialized by a 
> global
> mutex), video decoding corrupts the image.
> Note that I am not talking about using the same codec context of 
> course.
> I mean different streams using different AVCodecContext*.

As in
http://clapcrest.free.fr/revol/beos/
shot_FFDecoders_bad_multithreading.png
?

btw you don't need a mutex on avcodec_decode...(), it should only be 
needed around find/alloc_foo.

I've been told here several times that was fixed... *g*

> My question is:
> 
> 1) Has anyone succeeded in decoding simultaneous streams in the same
> process?

Not better than on that screenshot :)

> 2) If I move the static variables that I suspect to be shared among 
> the
> decoding operations, is there a chance to patch it into repository?

Yes please.
Note some static variables are const tables though, those shouldn't 
need to be moved.

Fran?ois.