Batch AAC to MP3 convert

AACtoMP3.sh

export PATH=/usr/local/bin:$PATH
# for use within Automator, the path to usr/local/bin has to be added
# so that faad and lame can be used

# last argument is the output path - add a trailing slash
outputpath=${@:$#}"/"

# start numbering depending on the # of files already in that directory
count=$(ls -1 $outputpath | wc -l)

# all arguments but last are the files to be converted
for file in "${@:1:$#-1}"; do
	let count++
	# get the original file name without its path
	filebase=${file##*/}
	# get the original file extension
	fileext=${filebase##*.}
	# remove the suffix (.m4a or whatever)
	newprefix=${filebase%.*}
	# make a new file name
	newfilename=$(printf "%03d" $count)" "$newprefix".mp3"
	# for some reason, trying to concatenate $newprefix within printf
	# produces strange results
	
	# debugging output
	echo $filebase

	# check the original format, trusting the extension (for now)
	case $fileext in
	"mp3")
		echo "mp3 file, just copy"
		cp "$file" "$outputpath$newfilename"
		;;
	"m4a")
		echo "aac file, let's convert"
		
		# do the actual conversion
		# faad converts original file into wav, outputs to stdout
		# lame encodes piped stdin into mp3, stores in new file
		faad -q -o - "$file" | lame - "$outputpath$newfilename"
		;;
	*)
		echo "unknown format :("
	esac
done

This is meant to be used as part of an Automator workflow, see http://notes.timtom.ch/Coding/USBplaylist