[Ffmpeg-devel] Threading in libavcodec
Mon Jan 23 14:17:00 CET 2006
> wait, you can always implement anything with 2 threads what can be done
> with 1 binary identically, the question is how fast it is
Here are figures that can be found here :
> Fourth, some random speed results (defaults, vhq4, NO bframes. X2
> 4200+ CPU).
> 1 thread : 1:48
> 2 threads : 1:05
> 3 threads : 1:06
> 4 threads : 1:08
> 16 threads: 1:11
So, as I said, it scales pretty well.
>i cant find any multithreaded code in cvs
>am i blind? IIRC there was some patch for multithreaded motion estimation
>on the xvid-dev list, is that what you are talking about?
I don't know where / how Radek posted his patches, and I'm not reading
>and last, keep in mind that the way lavc splits the image during
>multithreaded encoding has the advantage that it could also be decoded with
Indeed, but you don't necessarily control who and with what it will be
decoded. And if we reverse the problem, if you have only a decoder, you
don't necessarily have control over how the encoding is done. So
multithreaded decoding on a slice basis isn't imho that useful, because
it needs control over both encoding and decoding. I'll admit however
that on low end computers - or with high definition AVC content - it
might be the only way to ensure realtime decoding.
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