How to conver/compress VP9 video/Webm 12bit video to Webm 10bit video with ffmpeg?

Question

I have tried to convert/compress webm 12 bit video to webm 10 bit, but I have not found right one command recipe. Best what I have become was:

ffmpeg -i video.webm -c:v libvpx-vp9 -s 3840x2160 -b:a 2500000M -keyint_min 60 -g 60 -tile-columns 4 -frame-parallel 1 -an -f webm -dash 1 test_video_3840x2160.webm

Can someone help me?

Answer 1

You need to set the -pix_fmt of the output file, since you want it different from what's in the input file. Add -pix_fmt yuv420p10le somewhere after the -i inputfile and before the outputfile, e.g.:

ffmpeg -i video.webm -c:v libvpx-vp9 -s 3840x2160 -b:a 2500000M -keyint_min 60 -g 60 -tile-columns 4 -frame-parallel 1 -an -f webm -dash 1 -pix_fmt yuv420p10le test_video_3840x2160.webm

If that fails, please provide the output of the FFmpeg command and we can take it from there.