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
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