http://what.cd/forums.php?action=viewthread&threadid=17085&post=10#post581310

music-converter.pl

#!/usr/bin/perl -w
use strict;
use warnings;
use File::Basename;
use Getopt::Long;

#########################################################
# Flac to Mp3 Perl Converter - Terminal Edition
# Created by: Somnorific
# Based on: Scripts by Falkano and Nick Sklaventitis
# Date: June 26, 2008
# Edited by: mlapaglia
# Format Selection & m3u Output by: Gravey
# Date: June 1, 2009
#
# Requires: perl, zenity, flac, lame, and rsync
# Tested on: Ubuntu (Hardy x86 and Intrepid x64)
#########################################################
# Configuration
# 1 = true, 0 = false
#########################################################
# Do you always want to move additional files (.jpg, .log, etc)? (disables the prompt)
my $move_other = 1;
#
# If you want a different default folder, enter it in quotes. ("/home/mlapaglia/Desktop/")
my $defaultOutput_folder = "";
#
# Do you want to use FLAC tags for naming the output files? (will fail is tags aren't present)
my $fileName_choice = 1;
#
# Do you want to create an m3u file?  (requires FLAC tags)
my $make_m3u = 1;
#
# Do you want track numbers (in the filenames and tags) to be 01, 02, 03, 04 instead of 1, 2, 3, 4?
my $numberName_choice = 1;
#
# Do you want to generate a .torrent file? (requires mktorrent 0.9.9)
# Place passkey in quotes, and the output directory for the .torrent file in quotes ("/home/mlapaglia/Desktop/")
my $torrent_passkey = "";
my $torrent_output_directory = "";
#
# List of default encoding options, add to this list if you want more
my %lameOptions = (
	"320" => ["-b 320 --ignore-tag-errors", ''],
	"V0"  => ["-V 0 --vbr-new --ignore-tag-errors", ''],
	"V2"  => ["-V 2 --vbr-new --ignore-tag-errors", '']
);
#########################################################
#End of configuration
#########################################################
my $use_320 = 0;
my $use_v0 = 0;
my $use_v2 = 0;

# Retrieve command line arguments
GetOptions('320' => \$use_320, 'v0' => \$use_v0, 'v2' => \$use_v2);

# Check if specific formats were selected
if ($use_320 || $use_v0 || $use_v2) {
	
	# clear default encoder settings
	%lameOptions = ();
	
	# add specified settings to array
	if ($use_320) {
		$lameOptions{320} = ["-b 320 --ignore-tag-errors", ''];
	}
	if ($use_v0) {
		$lameOptions{V0} = ["-V 0 --vbr-new --ignore-tag-errors", ''];
	}
	if ($use_v2) {
		$lameOptions{V2} = ["-V 2 --vbr-new --ignore-tag-errors", ''];
	}
}

my $numArgs = $#ARGV;
my $flac_dir = '';
if ($numArgs == -1) {
	print "Need FLAC file parameter\n";
	exit 0;
}
foreach $numArgs ($#ARGV) {
	$flac_dir = $ARGV[$numArgs];
}
# get rid of trailing slash if present
$flac_dir =~ s/\/$//;
# create folders, either using default output folder, or user chosen
foreach my $lame_option (keys %lameOptions) {
	my $mp3_dir = '';
	my $flac_dir_proper = $flac_dir;
	# Try and remove ([{FLAC}]) and ([{what.cd}]) variations
	$flac_dir_proper =~ s/[\||\(|\[|\{| \|| \(| \[| \{]+[what.cd|FLAC]+[\}|\]|\)]//gi;
	if ($defaultOutput_folder eq '') {
		$mp3_dir = $flac_dir_proper . " ($lame_option)";
	} else {
		$mp3_dir = $defaultOutput_folder . fileparse($flac_dir_proper) . " ($lame_option)";
	}
	`mkdir "$mp3_dir"`;
	$lameOptions{ $lame_option }[1] = $mp3_dir;
}

# Gather all of the flac files
print "$flac_dir\n";
opendir(DIR, $flac_dir);
my @files = grep(/\.flac$/,readdir(DIR));
closedir(DIR);

my $output_name = "";
# Loop through each of the encodings chosen
for my $lame_option ( keys %lameOptions ) {
	print "\nEncoding with $lame_option started...\n";

	# Pull out the directories and flags from the array
	my @mp3_arry = @{$lameOptions{$lame_option}};
	my $mp3_dir = $mp3_arry[1];
	my $lame_flags = $mp3_arry[0];

	# Loop through each of the FLAC files
	foreach my $file (@files) {
		# Grab the tag info from the FLAC, if configured
		my %flac_tags = ('TITLE','','ALBUM','','ARTIST','','TRACKNUMBER','','GENRE','','COMMENT','','DATE','');
		for my $tag ( keys %flac_tags ) {
			$flac_tags{ $tag } = `metaflac --show-tag=$tag "$flac_dir/$file" | awk -F = '{ printf(\$2) }'`;
			# Remove :'s and ?'s
			$flac_tags{ $tag } =~ s/[:,?,\/]/-/g;
		}
	
		# Add a '0' to the track number if needed, if configured
		if ($numberName_choice && $flac_tags{'TRACKNUMBER'} && $flac_tags{'TRACKNUMBER'} < 10 && substr($flac_tags{'TRACKNUMBER'}, 0, 1) != 0) {
			$flac_tags{'TRACKNUMBER'} = "0$flac_tags{'TRACKNUMBER'}";
		}

		# Create the destination mp3 filename using the FLAC tags, if configured
		# exit if the FLAC tags are not populated
		my $mp3_filename = '';
		if ($fileName_choice && $flac_tags{'TRACKNUMBER'} && $flac_tags{'TITLE'}) {
			$mp3_filename = `basename "$flac_tags{'TRACKNUMBER'} - $flac_tags{'TITLE'}" .flac`;
		} else {
			print "\n****FLAC TAG ERROR: NO TAGS DETECTED****";
			print "\nEither the files are incomplete or they are missing tags";
			print "\nTag the FLAC music correctly then re-attempt transcoding\n";
			exit 0;
		}
		chomp($mp3_filename);
		$mp3_filename = $mp3_dir."/".$mp3_filename.".mp3";
		# Build the conversion script and do the actual conversion
		my $flac_command = "flac -dc \"$flac_dir/$file\" | lame $lame_flags " .
			"--tt \"" . $flac_tags{'TITLE'} . "\" " .
			"--tl \"" . $flac_tags{'ALBUM'} . "\" " .
			"--ta \"" . $flac_tags{'ARTIST'} . "\" " .
			"--tn \"" . $flac_tags{'TRACKNUMBER'} . "\" " .
			"--tg \"" . $flac_tags{'GENRE'} . "\" " .
			"--ty \"" . $flac_tags{'DATE'} . "\" " .
			"--add-id3v2 - \"$mp3_filename\" 2>&1";
		`$flac_command`;
		$output_name = "$flac_tags{'ARTIST'} - $flac_tags{'ALBUM'}";
	}

	# Create m3u file, if configured
	if ($make_m3u) {
		print "\nCreating m3u file...\n";
		my $playlist = "$mp3_dir/$output_name.m3u";
		open(FILE,'>',$playlist);
		opendir(DIR,"$mp3_dir");
		my @files = grep(/\.mp3$/,readdir(DIR));
		closedir(DIR);
		select(FILE);
		foreach my $file (@files) {
			print "$file\n";
		}
		select(STDOUT);
		close(FILE);
	}
	
	print "\nEncoding with $lame_option finished...\n";

	# Move over any other files using rsync
	if ($move_other) {
		my $rsync_comm = "rsync -a --exclude \"*.flac\" --exclude \"*.log\" \"$flac_dir/\" \"$mp3_dir/\"";
		`$rsync_comm`;
	}

	# Create .torrent file with what.cd parameters, if tags are present, if configured by user
	if($torrent_output_directory ne '') {
		print "\nCreating torrent...\n";
		my $torrent_create = "mktorrent -a http://tracker.what.cd:34000/$torrent_passkey/announce -o \"$torrent_output_directory$output_name ($lame_option).torrent\" \"$mp3_dir\"";
		`$torrent_create`;
		print "'$torrent_create'";
	}
}
print "\nAll Done...\n";