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

Michael Niedermayer michaelni
Wed Jun 1 01:48:45 CEST 2005


On Wednesday 01 June 2005 00:45, Dario Souza wrote:
> 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*.
> After looking at the code, I could see that (although AVCodecContext holds
> the priv member with the codec specific context that *should* in thesis
> store the codec state), some static variables are being used and that may
> hold state during the decode process.

where are these? 


> 1) Has anyone succeeded in decoding simultaneous streams in the same
> process?


> 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?

certainly if the patch is clean, there should be no non constant static 
variables in libavcodec


More information about the ffmpeg-devel mailing list