Von meinem iPhone gesendet
Anfang der weitergeleiteten E‑Mail: > Von: Daniel Oberhoff <danieloberh...@gmail.com> > Datum: 25. November 2014 09:59:39 MEZ > An: Timothy Gu <timothyg...@gmail.com> > Betreff: Re: [FFmpeg-devel] pipeline multithreading > > > Von meinem iPhone gesendet > >> Am 24.11.2014 um 16:54 schrieb Timothy Gu <timothyg...@gmail.com>: >> >> On Mon, Nov 24, 2014 at 3:35 AM, Daniel Oberhoff >> <danieloberh...@gmail.com> wrote: >>> Hi, >>> >>> From what I gather the filter graph is utilizing modern multicores by >>> “striping” where filters support it, i.e. an image is divided in stripes >>> and the filter gets called in separate threads for separate stripes. >> >> In FFmpeg we call it slice threading. >> >>> I was wondering if there is or will be pipeline multuthreading, i.e. >>> with a setup such as >>> >>> inout -> filter1 -> filter2 -> output >>> >>> some threads processing frame n in the output (i.e. encoding), >>> other threads procesing frame n+1 in filter2, others processing frame >>> n+2 in filter1, and yet others processing frame n+3 decoding. This >>> way non-parallel filters can be sped up, and diminishing returns for >>> too much striping can be avoided. With modern cpus scaling easily >>> up to 24 hardware threads I see this as neccessary to fully utilize the >>> hardware. >> >> We call it "frame threading." There are some decoders that already support >> it. >> >>> >>> Is this already done? Or are there plans? If it is not done, how much >>> more work is it? Could I help (not promising much, but I may find time, >>> especially as this limits us…). >> >> If the filter is independent of past and future frames then it is >> pretty easy (just like the "intra-only" decoders). For other ones I am >> not so sure. Clément knows more about it. > > Most are, no? Otherwise they would need buffers, but frame multithreading > would still be possible, the pipeline just gets deeper > >> >> Timothy _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
