remove audio from video with ffmpeg
https://superuser.com/questions/268985/remove-audio-from-video-file-with-ffmpeg
ffmpeg -i example.mkv -c copy -an example-nosound.mkv
remove audio from video with ffmpeg
https://superuser.com/questions/268985/remove-audio-from-video-file-with-ffmpeg
ffmpeg -i example.mkv -c copy -an example-nosound.mkv