execute ffmpeg in a loop, USE -nostdin

Use the -nostdin flag in the ffmpeg command line

ffmpeg -nostdin -i "$name.wav" -ab 320k -ac 2 "$name.mp3"

See the "-stdin/-nostdin" flags on this page => https://ffmpeg.org/ffmpeg.html

https://stackoverflow.com/questions/21634088/execute-ffmpeg-command-in-a-loop