reencode

#!/bin/bash
# A trivial MP3 Reencoder
# Copyright (C) 2005 Eskild Hustvedt
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
TARGETDIR=""
NOREMOVE="0"
IFEXIST_KEEP="0"
VERSION="0.1"
DEFAULT_BITRATE="128"
BITRATE=""
echo ""
echo "ZD MP3 Reencode version $VERSION"
# Help screen
DisplayHelp () {
	echo "Reencodes mp3 files."
	echo ""
	echo "-t, --targetdir		Put converted files into target directory rather than"
	echo "			overwriting the old one."
	echo "-n, --noremove		Save files with a .mp3new prefix instead of overwriting"
	echo "			the old one."
	echo "			(if a file with a .mp3new prefix already exists, it"
	echo "			 will be overwritten!)"
	echo "-e, --noremoveexist	Don't convert if target file already exists"
	echo "			(requires --targetdir)"
	echo "-b, --bitrate		Reencode to the supplied bitrate (default: $DEFAULT_BITRATE)"
	echo "-h, --help		Display this help screen"
}
# The function that calls lame to do the actual encoding
DoEncode ()
{
	# A function that gets ID3 tags from files
	GetInfo ()
	{
		# The function that actually does the id3 extracting.
		GetInfo_real () {
			shift 1
			case $1 in
				TIT2|TALB|TCON|TPE1 ) shift 3;;
				TRCK ) shift 5;;
				TYER ) shift 2;;
				* ) shift 2 ;;
			esac
			echo "$@"|sed -e s,"'","",g|sed -e s,'\\','',g
		}
		local info="`echo "$id3info"|grep -i $1`"
		echo "`GetInfo_real $info`"
	}
	# Get the id3 infomration and convert
	if type id3info &>/dev/null && type sed &>/dev/null; then
		id3info="`id3info $1`"
		TITLE="`GetInfo TIT2`"
		ARTIST="`GetInfo TPE1`"
		ALBUM="`GetInfo TALB`"
		YEAR="`GetInfo TYER`"
		GENRE="`GetInfo TCON|sed -e s,'(','',g |sed -e s,')','',g`"
		TRACK="`GetInfo TRCK`"
		lame -b $BITRATE --ignore-tag-errors --ty "$YEAR" --tt "$TITLE" --ta "$ARTIST" --tl "$ALBUM" --tg "$GENRE" --tn "$TRACK" "$1"
		ret="$?"
	else
		# Don't have id3info :( - just tell lame to convert
		lame -b $BITRATE "$1"
		ret="$?"
	fi
	if [ -e "$1.mp3" ]; then
		mv -f "$1.mp3" "$1"
	fi
	# If lame returned nonzero allow the user 2 seconds to ctrl+c me
	if [ "$ret" != "0" ]; then
		echo -ne "\rlame returned nonzero ($ret) waiting 2 seconds before continuing!";
		sleep 1s
		echo -ne "\rlame returned nonzero ($ret) waiting 1 second before continuing! ";
		sleep 1s
		echo -e "\rlame returned nonzero ($ret)!                                        "
	fi
}
# Test for some required/recommended components
if ! type lame &>/dev/null; then
	echo "I need \"lame\" to work! Please install it, then re-run me."
	exit 1
fi
if ! type id3info &>/dev/null; then
	echo "I need \"id3info\" to be able to extract ID3 tags. Without this installed ID3 tags might be lost."
fi
if ! type sed &>/dev/null; then
	echo "I need \"sed\" to be able to parse ID3 tags. Without this installed ID3 tags might be lost."
fi
# Parse commandline options
if [ "$#" == "0" ]; then DisplayHelp;exit 0;fi
while [ "$#" -gt "0" ]; do
	case $1 in
		-t | --targetdir ) TARGETDIR="$2";echo "Target directory is $TARGETDIR";shift 2;;
		-n | --noremove ) NOREMOVE="1";shift 1;;
		-e | --noremoveexist ) IFEXIST_KEEP="1";shift 1;;
		-h | --help ) DisplayHelp; exit 0;;
		-v | --version ) exit 0;;
		-b | --bitrate ) if [ "$2" == "" ]; then echo "--bitrate requires an additional option: The bitrate to use"
		echo "It can be either 32, 40, 48, 56, 64, 80, 96, 112, 128, 160,  192,  224,  256, 320"
		echo "Default is $DEFAULT_BITRATE";
	else BITRATE="$2";shift 2;fi;;
		# Stop processing here
		* ) break;;
	esac
done
# Check for components
if ! type lame &>/dev/null; then
	echo "I need \"lame\" to work! Please install it, then re-run me."
	exit 1
fi
if [ "$BITRATE" == "" ]; then BITRATE="$DEFAULT_BITRATE";fi
echo "Files to convert: $#"
# Do the convertion
for a in "$@"; do
	echo ""
	BASENAME="`basename $a`"
	TMPFILE="/tmp/$BASENAME.`whoami`.mp3new"
	if [ ! -e $a ]; then
		echo "$a: no such file."
	elif [ "$TARGETDIR" != "" ]; then
		if [ "$IFEXIST_KEEP" ] && [ -e $TARGETDIR/$BASENAME ]; then
			echo "$TARGETDIR/$BASENAME existed! Skipping."
		elif [ "$NOREMOVE" == "1" ] && [ -e "$TARGETDIR/$BASENAME" ]; then
			DoEncode "$a" "$TARGETDIR/$BASENAME.mp3new"
			echo "";echo "Wrote file: $TARGETDIR/$BASENAME.mp3new"
		else
			DoEncode "$a" "$TARGETDIR/$BASENAME"
			echo "";echo "Wrote file: $TARGETDIR/$BASENAME"
		fi
	elif [ "$NOREMOVE" == "1" ]; then
		DoEncode "$a" "$TMPFILE"
		if [ -e $TMPFILE ]; then
			mv -f "$TMPFILE" "$a.mp3new"
			echo "";echo "Wrote file: $a.mp3new"
		fi
	else
		DoEncode "$a" "$TMPFILE"
		if [ -e $TMPFILE ]; then
			mv -f $TMPFILE $a
			echo "";echo "Wrote file: $a"
		fi
	fi
done