On Mon, 8 Mar 2021 at 17:49, Anders Degerberg <and...@europasound.se> wrote:
> Hi, > > I've come across a problem I really can't figure out when trying to stream > realtime a RGB 10-bit Decklink input, as YUV444 10-bit HEVC in 25fps. > In a 1920x1080 resolution on the Decklink input, it all works very well, > using hevc_nvenc codec on a Nvidia GPU. Auto_scaler kicks in converting the > correctly identified 'gbrp10le' input format to 'yuv44416le' for > hevc_nvenc. > But doing the same in 4K resolution causes input buffer overruns, only > capable of about 20 fps. When watching CPU usage, there's only real load on > one of the 32 threads, and that load is maxing out at 99%. CPU frequency is > close to 4GHz on the AMD CPU. > If I then switch the Decklink input to YUV instead, 4K works fine, so the > hevc encoding on the gpu or streaming protocol is not the bottleneck. > This makes me think the problem lies with the auto_scaler RGB->YUV not > keeping up with 4096x2160 pixels. This RGB->YUV conversion is done in > libswscale I understand. I've tried to use -filter_threads and -threads to > increase thread usage of the swscale, but it still seems to use only one > thread. > > Any suggestions how I can do this 4K RGB 10-bit->YUV444 10-bit colorspace > conversion in ffmpeg in realtime? > > I've tried to hwupload to the gpu to be able to use scale_npp, but > auto_scaler kicks in before I have the chance to send the RGB data to the > -vf filters. > > I've also tried to build with a patch for multi-thread swscale found here: > > https://patchwork.ffmpeg.org/project/ffmpeg/patch/c1125bd979e9ae41908dc4913cbfacbb67a31...@irsmsx103.ger.corp.intel.com/ > But this patch doesn't seem to make a difference for the rgb2yuv colorspace > conversions, it's probably only affective for image up/downscaling? > > Kind regards > Anders > > Hello there, What is your exact ffmpeg command, and output? _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
