#!/bin/bash

mp3_dir=MP3

for i in *.mp3; do
	j=${i%mp3}
	j=${j}wav
#		echo "$i @@@ $j"
	if test ! -e "$j" && test ! -e "$mp3_dir/$j"; then
		 ffmpeg -i "$i" -ab 128 -ar 44100 "$j"
	fi
done