[Libav-user] Decoding HD videos on iPad devices
Dear FFMpeg team, We are creating player for iPad and using FFMPeg with libavcodec to decode video frames. FFMpeg helped to process a lot of formats and really reduced the development time. Unfortunately with HD videos we experience a poor performance and the video playback is breaking up. According to profile stats the decode time is taking longer then the playback Profile shows ~100% CPU usage on the call to avcodec_decode_video2 function. In the same time the GPU is almost not used. We wonder whether it is possible to perform decoding on iPad GPU to speed up decoding process (by compiling it with special flags, or with some patches) or run it parallel on dual core (iPad2) / quad-core (new iPad) or are there any other methods to speed up decoding process? Thanks in advance. Regards, Gohar ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Decoding HD videos on iPad devices
Gohar Hovhannisyan writes: > We wonder whether it is possible to perform decoding on > iPad GPU to speed up decoding process (by compiling > it with special flags, or with some patches) Only if you implement it. > or run it parallel on dual core (iPad2) / quad-core (new iPad) > or are there any other methods to speed up decoding process? You can set the number of threads that decoding should use. Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Decoding HD videos on iPad devices
Hi Carl, thank you for your answer. I've set the number of threads to 10, but every time my app crashes on avcodec_decode_video2. Could you please assist me what I'm doing wrong? Thanks, Gohar On 12/19/12 2:59 PM, Carl Eugen Hoyos wrote: Gohar Hovhannisyan writes: We wonder whether it is possible to perform decoding on iPad GPU to speed up decoding process (by compiling it with special flags, or with some patches) Only if you implement it. or run it parallel on dual core (iPad2) / quad-core (new iPad) or are there any other methods to speed up decoding process? You can set the number of threads that decoding should use. Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Decoding HD videos on iPad devices
Carl Eugen Hoyos writes: > > We wonder whether it is possible to perform decoding on > > iPad GPU to speed up decoding process (by compiling > > it with special flags, or with some patches) > > Only if you implement it. Reconsidering this, it is possible that -vcodec h264_vda is what you are searching for (I don't know for sure). Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
Re: [Libav-user] Decoding HD videos on iPad devices
Gohar Hovhannisyan writes: > I've set the number of threads to 10, but every time my app > crashes on avcodec_decode_video2. (Backtrace etc. missing, see https://ffmpeg.org/bugreports.html ) Is the crash reproducible with ffmpeg (the application)? Please do not top-post here, Carl Eugen ___ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
