something else

`video -> mp3`

ffmpeg -i input.wav -vn -ar 44100 -ac 2 -b:a 320k output.mp3

ffmpeg -fflags +genpts -i x.webm -r 24 x.mp4

generate with same filename

all.sh

for f in *.mp4; do ffmpeg -i "$f" -vn -ar 44100 -ac 2 -b:a 320k "$f".mp3; done