bin/mpd-dynamic

   1 #!/usr/bin/perl
   2 #
   3 # This file is part of Audio::MPD
   4 # Copyright (c) 2007-2008 Jerome Quelin, all rights reserved.
   5 #
   6 # This program is free software; you can redistribute it and/or modify
   7 # it under the same terms as Perl itself.
   8 #
   9 #
  10
  11 use strict;
  12 use warnings;
  13
  14 use Audio::MPD;
  15 use DB_File;
  16 use Encode;
  17 use Getopt::Euclid qw[ :minimal_keys ];
  18 use Proc::Daemon;
  19 use Time::HiRes    qw[ usleep ];
  20
  21
  22 #
  23 my $song     = 0; # song currently playing
  24 my $playlist = 0; # playlist version
  25 my $mpd = Audio::MPD->new;
  26
  27 Proc::Daemon::Init unless $ARGV{debug};
  28
  29 # fetch list of songs known by mpd.
  30 my @files = $mpd->collection->all_pathes;
  31
  32
  33 while (1) { # endless loop
  34     my $status;
  35     eval { $status = $mpd->status };
  36     next if $@; # error while peaking status
  37
  38     # do playlist and/or current song have changed?
  39     next unless $status->playlist > $playlist
  40         || defined $status->song && $status->song != $song;
  41     debug("checking playlist...\n");
  42
  43     # yup - update playlist & song.
  44     $playlist = $status->playlist;
  45     $song     = $status->song;
  46
  47     # keep at most $ARGV{old} songs.
  48     if ( $song > $ARGV{old} ) {
  49         my $old = $song - $ARGV{old};
  50         debug( "need to remove $old songs\n" );
  51         eval { $mpd->playlist->delete(0) for 1..$old };
  52     }
  53
  54     # add at most $ARGV{new} songs.
  55     my @pl = $mpd->playlist->as_items;
  56     if ( $#pl - $song < $ARGV{new} ) {
  57         my $new = $ARGV{new} - ( $#pl - $song );
  58         debug("need to add $new songs\n");
  59
  60         my %ratings;
  61         my $istied =
  62             tie( %ratings, 'DB_File', $ARGV{ratings}, O_RDONLY )
  63             ? 1 : 0;
  64
  65         PICK_ONE:
  66         for (1..$new) {
  67             my $random = encode('utf-8', $files[ rand @files ]);
  68             if ( $istied && exists $ratings{$random}
  69                  && $ratings{$random} != 0
  70                  && $ratings{$random} < $ARGV{min} ) {
  71                 debug("rating too low: $ratings{$random} [$random]\n");
  72                 redo PICK_ONE;
  73             }
  74             debug("adding [$random]\n");
  75             eval { $mpd->playlist->add( decode('utf-8', $random) ) };
  76             debug("error: $@\n") if $@;
  77         }
  78         untie %ratings if $istied;
  79     }
  80
  81 } continue {
  82     usleep $ARGV{sleep} * 1000 * 1000; # microseconds
  83 }
  84
  85 exit; # should not be there...
  86
  87 sub debug {
  88     return unless $ARGV{debug};
  89     my ($msg) = @_;
  90     my ($s,$m,$h) = ( localtime(time) )[0,1,2,3,6];
  91     my $date = sprintf "%02d:%02d:%02d", $h, $m, $s;
  92     warn "$date $msg";
  93 }
  94
  95 __END__
  96
  97
  98 =head1 NAME
  99
 100 mpd-dynamic - a dynamic playlist for mpd
 101
 102
 103 =head1 USAGE
 104
 105     mpd-dynamic [options]
 106
 107
 108 =head1 VERSION
 109
 110 This is mpd-dynamic version 0.4
 111
 112
 113 =head1 DESCRIPTION
 114
 115 This program implements a dynamic playlist for MPD, build on top of the
 116 C<Audio::MPD> perl module.
 117
 118 MPD (music player daemon) is a cool music player, but it lacks a dynamic
 119 playlist. A dynamic playlist is a playlist that will change
 120 automatically over time. In particular, it will remove already played
 121 songs (keeping at most a given number of songs) and add new songs to the
 122 playlist so it never fall short of songs.
 123
 124 Note that since mpd is a daemon needing no gui to work, C<mpd-dynamic> is
 125 also a daemon. That is, it will fork and do all its work from the background.
 126 This way, you can fire C<mpd> and C<mpd-dynamic> and forget completely
 127 about your music (especially since C<mpd-dynamic> is a low-resource program):
 128 it will just be there! :-)
 129
 130
 131 =head1 OPTIONS
 132
 133 =head2 General behaviour
 134
 135 You can customize the usage of mpd-dynamic with the following options:
 136
 137
 138 =over 4
 139
 140 =item -o[ld] <old>
 141
 142 Number of old tracks to keep in the backlog. Defaults to 10.
 143
 144 =for Euclid:
 145     old.type:     integer >= 0
 146     old.default:  10
 147
 148
 149 =item -n[ew] <new>
 150
 151 Number of new tracks to keep in the to-be-played playlist. Defaults to 10.
 152
 153 =for Euclid:
 154     new.type:     integer > 0
 155     new.default:  10
 156
 157
 158 =item -s[leep] <sleep>
 159
 160 Time spent sleeping (in seconds) before checking if playlist should be
 161 updated. Default to 5 seconds.
 162
 163 =for Euclid:
 164     sleep.type:     number > 0
 165     sleep.default:  5
 166
 167
 168 =item -d[ebug]
 169
 170 Run mpd-dynamic in debug mode. In particular, the program will not daemonize
 171 itself. Default to false.
 172
 173
 174 =item -e[ncoding] <encoding>
 175
 176 Print debug messages with this encoding. Since mpd-dynamic is meant to be a
 177 silent daemon, this option will not be used outside of debug mode. Default
 178 to C<utf-8>.
 179
 180 =for Euclid:
 181     encoding.type:     string
 182     encoding.default:  'utf-8'
 183
 184
 185 =item --version
 186
 187 =item --usage
 188
 189 =item --help
 190
 191 =item --man
 192
 193 Print the usual program information
 194
 195
 196 =back
 197
 198 Note however that those flags are optional: since C<mpd-dynamic> comes with
 199 some sane defaults, you can fire C<mpd-dynamic> as is.
 200
 201
 202 =head2 Ratings
 203
 204 You can also take advantage of ratings if you want. With those options, songs
 205 need to have at least a given rating (or no rating yet) to be inserted: this
 206 way, you will only listen to your favorite songs!
 207
 208 Note that if you supply a non-existant rating db-file, the rating mechanism
 209 will be ignored. The following options control the rating mechanism:
 210
 211
 212 =over 4
 213
 214 =item -r[atings] <ratings>
 215
 216 The path of a db file with the ratings per song. The keys are the song path
 217 (relative to MPD root), and the value is an integer (the rating). Default to
 218 C<~/.mpd/ratings.db>.
 219
 220 =for Euclid:
 221     ratings.type:     readable
 222     ratings.default:  "$ENV{HOME}/.mpd/ratings.db"
 223
 224
 225 =item -m[in[imum]] <min>
 226
 227 The minimum rating for a song to be inserted in the playlist. Default to 4.
 228
 229 =for Euclid:
 230     min.type:     integer > 0
 231     min.default:  4
 232
 233
 234 =back
 235
 236
 237 =head1 AUTHOR
 238
 239 Jerome Quelin, C<< <jquelin@cpan.org> >>
 240
 241
 242 =head1 COPYRIGHT & LICENSE
 243
 244 Copyright (c) 2007-2008 Jerome Quelin, all rights reserved.
 245
 246 This program is free software; you can redistribute it and/or modify
 247 it under the same terms as Perl itself.
 248
 249 =cut