This script will convert all m4a files in a directory to mp3 format. For each mp4 file, the faad program converts it into wav format, then lame converts it to mp3 (a temporary wav file will be created, with the same name as the mp4 but with an added .wav extension). The original files will be left intact.
Usage: m4a2mp3 [directory_containing_m4a_files]
#!/bin/bash
#
# Convert m4a to mp3
if [ -n "$1" ]; then
for i in $1/*.m4a
do
faad -o "$i.wav" "$i"
dest=`echo "$i.wav"|sed -e 's/m4a.wav$/mp3/'`
lame -h -b 192 "$i.wav" "$dest"
rm "$i.wav"
done
else
echo "Usage: m4a2mp3 [directory_containing_m4a_files]"
fi
References
Original script modified from that by mwiertz posted on the Gentoo forums: converting m4a files under linux (gentoo).
faad usage taken from this useful list of conversion commands: Konverzija između različitih audio formata.
