[FFmpeg-devel] SOC Qualifiction tasks

Uoti Urpala uoti.urpala
Fri Mar 14 19:54:19 CET 2008

On Fri, 2008-03-14 at 18:56 +0100, Andreas ?man wrote:
> * Asynchronous decoding (I.e. decoding frames even when the caller
>    is not currently in 'avcodec_decode_video()').
>    Of course this must be fully hidden from the caller POV.

You can't hide it from the caller. Normally the caller gives the frame
data and expects full results before the call returns. With that API
there is nothing to decode when the caller is not currently in
avcodec_decode_video(). For asynchronous decoding you need a different
API that allows the caller to queue frames in advance.

> * Add/Benchmark low level synchronization primitives.
>    I'm thinking of using SFENCE, MWAIT and MONITOR on x86 for
>    synchronization. In particular I think it would be useful when
>    waiting for a particular MB to be completed in a reference (not
>    yet fully decoded) frame. Ought to be much faster than pthread_
>    -stuff.

Do you really need to make the synchronization so finegrained that
custom synchronization primitives would help? If you're calling pthread
routines so often that their overhead is significant you'll probably
waste a lot of CPU on synchronization using any custom routines too.

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