> > In my experience, x264 is very fast and you may not be able to beat it at > low quality. That said, there are a lot of possibilities for why it may be > slow. Look at: > https://devblogs.nvidia.com/nvidia-ffmpeg-transcoding-guide/ which will > give you some tips for minimizing PCIe transfers to keep it fast. > Cheers.
Thanks! I read through the nvidia docs. It seems that I need to pass in the "hwaccel: cuvid" option in order to keep the raw frame in GPU memory. Do you have any idea how to do this in Libav (C)? I tried following this Stackoverflow post, <https://stackoverflow.com/questions/5985273/using-ffmpeg-hwaccel-from-c?fbclid=IwAR0bI8NuMoc29Kw_tCwGQVogXAsG4liAqYSw6hftOZ2n8H5jn-JIV6RVdko> but av_hwaccel_next() kept returning NULL for a pixel format of AV_PIX_FMT_YUV420P and a codec of "h264_nvenc." I also see that av_hwaccel_next is deprecated. Do you have any suggestions? Thanks! Philippe On Fri, Jan 17, 2020 at 12:07 AM Jodon Karlik <[email protected]> wrote: > > > On Thu, Jan 16, 2020 at 5:28 PM Philippe Noël < > [email protected]> wrote: > >> Hi, >> >> I was using libx264 to encode a video file using libav from a C file and >> switched to nvenc_h264 and now the encode is very slow. It appears >> nvenc_h264 does not have a "ultrafast" setting. >> >> With nvenc_h264 I am using preset "llhq" and tune "zerolatency". Am I >> using the wrong settings? >> >> Cheers, >> >> Philippe >> _______________________________________________ >> Libav-user mailing list >> [email protected] >> https://ffmpeg.org/mailman/listinfo/libav-user >> >> To unsubscribe, visit link above, or email >> [email protected] with subject "unsubscribe". > > > In my experience, x264 is very fast and you may not be able to beat it at > low quality. That said, there are a lot of possibilities for why it may be > slow. Look at: > https://devblogs.nvidia.com/nvidia-ffmpeg-transcoding-guide/ which will > give you some tips for minimizing PCIe transfers to keep it fast. > > Cheers. > _______________________________________________ > Libav-user mailing list > [email protected] > https://ffmpeg.org/mailman/listinfo/libav-user > > To unsubscribe, visit link above, or email > [email protected] with subject "unsubscribe".
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