New comment by travankor on void-packages repository https://github.com/void-linux/void-packages/pull/13379#issuecomment-516396593 Comment: ffmpeg is also used for muxing (yt-dl's default behaviour) and grabbing audio downloads. By default, youtube-dl tries to dl the best format possible (as per the man page). The non-muxing option for best format is actually a fallback mode when ffmpeg is not present. ffmpeg is more efficient for hls streams than the python implementation.