source: flacrip/trunk/flactrack @ 7

#!/usr/bin/perl -w
use strict;

# extract one or more tracks from a FLAC file using its embedded cuesheet
# save those tracks as wav or mp3 files
# can also run them through a sox filter
# TODO: separate sox filter for each track!

use Getopt::Long qw{:config no_ignore_case};
use File::Spec::Functions qw{catfile};
use File::Path;
use Audio::FLAC::Header;
#TODO: put the MusicBrainz lib in a more common location
use lib qw{/home/peter/projects/flacrip};
use MusicBrainz;

GetOptions(
    'D=s' => \my %TRACKS,
    't=s' => \my $TYPE,
    'x=s' => \my $SOX_FILTER,
    'all|a' => \my $ALL,
    'dir|d=s' => \my $DIRECTORY,
);

my $FLAC_FILE = shift or die "Need a flac file to decode";

# default to mp3
$TYPE ||= 'mp3';

# default the directory to be named like the flac file
($DIRECTORY ||= $FLAC_FILE) =~ s/\.flac$//;

my $flac = Audio::FLAC::Header->new($FLAC_FILE) or die "Can't read FLAC header from $FLAC_FILE\n";

# for getting track metadata from MusicBrainz
my $info;
if ($ALL || $TYPE eq 'mp3') {
    my $discid = $flac->tags('MBZ_DISCID') or warn "No MBZ_DISCID tag in $FLAC_FILE\n" if $flac;
    #TODO: calculate TOC and DISCID from cuesheet if there is no MBZ_DISCID tag present

    #TODO: also get the year from MBZ
    $info = get_musicbrainz_info($discid);
}

if ($ALL) {
    die "Use of --all requires a --directory\n" unless $DIRECTORY;
    die "No track info found on MusicBrainz for $FLAC_FILE\n" unless $info;
    use YAML;
    my $cuesheet = $flac->cuesheet;
    my $count = scalar grep { /TRACK \d\d/ } @{ $flac->cuesheet };
    print "Found $count tracks\n";
    #TODO: default to just 01, 02, etc. if there is no $info
    %TRACKS = map {
        $_ => catfile($DIRECTORY, sprintf('%02d.%s', $_, to_filename($info->{TRACKS}[$_]{TITLE})))
    } (1 .. $count);
    #print Dump(\%TRACKS);
    for my $tracknum (sort { $a <=> $b } keys %TRACKS) {
        printf "%2d: %s\n", $tracknum, $TRACKS{$tracknum};
    }
    mkpath($DIRECTORY);
}

#TODO: all the option of sorting by tracknum or not
#while (my ($tracknum, $title) = each %TRACKS) {
for my $tracknum (sort { $a <=> $b } keys %TRACKS) {
    if ($tracknum !~ /^\d+$/) {
        warn "Don't know what to do with track number '$tracknum'";
        next;
    }
    my $start = $tracknum . '.1';
    my $end = $tracknum + 1 . '.1';
    my $cmd = qq{flac -d --cue $start-$end $FLAC_FILE -o - };

    if ($SOX_FILTER) {
        $cmd .= qq{| sox -t wav - -t wav - $SOX_FILTER };
    }

    my $title = quotemeta($TRACKS{$tracknum});
    if ($TYPE eq 'mp3') {
        # bitrate of 192
        $cmd .= qq{| lame -b 192};
        # if there is track info, add it as ID3 tags
        if ($info) {
            my $track = $info->{TRACKS}[$tracknum];
            $cmd .= sprintf q{ --tt %s --ta %s --tl %s --tn %d},
                quote($track->{TITLE}),
                quote($track->{ARTIST}),
                quote($info->{ALBUM}),
                $tracknum;
        }
        $cmd .= qq{ - $title.mp3};
    } elsif ($TYPE eq 'wav') {
        $cmd .= qq{> $title.wav};
    } else {
        die "Unknown type: $TYPE\n";
    }
    #die $cmd;
    system $cmd;
    die "\nFLAC decoding canceled\n" if ($? & 127);

    print "\n" if $SOX_FILTER;
}

sub quote {
    my ($string) = @_;
    $string =~ s/"/\\"/g;
    return qq{"$string"};
}

sub to_filename {
    my @strings = @_;
    #TODO: deal with non-ascii characters (unidecode) e.g. ü --> ue
    return map {
        s/[^a-z0-9-_ ]+//gi;
        s/ +/_/g;
        lc;
    } @strings;
}