Hi Peter, On Mon, 8 Mar 2021 at 19:18, Peter White <[email protected]> wrote: > Try: > > ffmpeg -i input_file -sws_flags show_info ... output_file '-sws_flags print_info' gives: [swscaler @ 0x4752f00] bicubic scaler, from gbrp10le to yuv444p16le using MMXEXT
> Do you really have to use RGB on the Decklink? Seems pointless to me, if > it has to be converted anyway. Why not simply keep it in YUV-mode? Basically because the SDI signal I feed to the Decklink card is received from a RGB-10 bit monitor feed. I've been thinking about inserting a hardware RGB->YUV converter in between, but unfortunately the ffmpeg decklink input device doesn't support yuv444p10. Therefore, doing so will introduce an unnecessary chroma subsampling step which I'm trying to avoid. > Maybe it is because of the massive amount of data that needs to be > shifted around. Not sure, but 4K is four times as much data as 1080p. Yes, converting RGB 10bit ->YUV in 1920x1080 creates about 40% load on the 4GHz Ryzen processor thread at 25fps. So I guess 4K would need 4x40%=160%(impossible) load on that one thread, or a multi-thread solution for libswscale's rgb2yuv conversion? _______________________________________________ ffmpeg-user mailing list [email protected] https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email [email protected] with subject "unsubscribe".
