(more exactly the computer energy consumption) Le 4 sept. 2013 à 16:24, Lucas Soltic <[email protected]> a écrit :
> Hi Kirill, > > Do you know by how much it is slower? Because I'm not only interested in > speed, but also in CPU consumption. > > Le 4 sept. 2013 à 16:21, Kirill Gavrilov <[email protected]> a écrit : > >> Hi, >> >> On Wed, Sep 4, 2013 at 5:33 PM, Attila Sukosd <[email protected]> >> wrote: >> I've looked at OS X's VDA acceleration, but it seems as though you need to >> do some extra work in the application to support the different hwaccels, but >> I haven't found any nice examples on how to do it. >> Most accelerated decoders decode picture into API-specific surface in GPU >> memory, which can be drawn using OpenGL (VDPAU) or Direct3D (DXVA2) without >> extra copying it back to CPU memory. >> For this reason you need to do a lot of extra work to configure FFmpeg using >> specific hardware decoder (or detect when it can not be used), render result >> on the screen using more complicated scenarios. >> Because this stuff is really overcomplicated, painful and contradicts to >> implemented decoding+rendering pipeline - I haven't tried it in my >> application yet. >> >> VDA is somewhat simpler than most others because the original Apple API >> doesn't provide the way to render result directly and you should copy frame >> back to CPU memory anyway. >> Technically you should just try to open another decoder and use it instead >> of auto-detected one in avcodec_open2 (with extra checks and + probably >> overridden get_format2 if you like planar YUV420P): >> AVCodec* aCodecVda = avcodec_find_decoder_by_name ("h264_vda"); >> avcodec_open2 (theCodecCtx, aCodecVda, NULL); >> >> I have tried this decoder on my old Macbook and it is significantly slower >> than software decoder. >> There is also patch in mail list which introduces similar decoder (automatic >> GPU->CPU memory copying) with DXVA2 acceleration. >> ----------------------------------------------- >> Kirill Gavrilov, >> Software designer. >> _______________________________________________ >> Libav-user mailing list >> [email protected] >> http://ffmpeg.org/mailman/listinfo/libav-user > > _______________________________________________ > Libav-user mailing list > [email protected] > http://ffmpeg.org/mailman/listinfo/libav-user
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