Bash Knowledge
How to convert many video files (webm, mp4, mkv) to audio files (mp3)
for i in *.webm; do ffmpeg -i "$i" "${i%.*}.mp3"; done
Loop over files in a directory
for i in (FILES); do (COMMAND); done
for i in *.webm; do ffmpeg -i "$i" "${i%.*}.mp3"; done
for i in (FILES); do (COMMAND); done