FFMPEG mp3 normalization

ffmpg_mp3_normalization.sh

#!/bin/bash
find . -type f -not -name ".*" -print0 | while read -d $'\0' file; do
	echo $file
	level=$(ffmpeg -y -nostdin -i $file -af "volumedetect" -vn -sn -dn -f null /dev/null 2>&1 | grep max_volume | sed -n 's/.*max_volume: \([^ ]*\) .*/\1/p')
	gain=$(bc -l <<< "-($level)")
	echo "${gain}dB"
	ffmpeg -y -nostdin -loglevel panic -i $file -af "volume=${gain}dB" temp.mp3
	rm $file
	mv temp.mp3 $file
done