Re: [Bug-gnupod] Patch to support ReplayGain / mp3gain

[Richard van den Berg]

Hello Henrik,

I finally found some time to make a proper patch for the ReplayGain 
support. Let me know if this is acceptable, or if it needs some more 
tweaking. I've added the following options to gnupod_addsong.pl:

--disable-ape                Do not read APE Tags (MP3 Only) 
--disable-v1 with --disable-v2 implies --disable-ape
--replaygain-album           Use the ReplayGain album value instead of 
the ReplayGain track value (default)


On 4/20/09 3:32 PM, H. Langos wrote:
> - Change the call to something like this: (I'm improvising here so don't
>   use it as it is...)
>
>   $soundcheck = ( _parse_ReplayGain($hs->{REPLAYGAIN_TRACK_GAIN}) || 
> _parse_iTunNORM($hs->{COMM} || $hs->{COM} || $h->{COMMENT}) )
>
>   This will probably fail if _parse_ReplayGain() ever returns a valid value
>   of 0. So you might have to write a more elaborate version like this:
>
>   $soundcheck = _parse_iTunNORM($hs->{COMM} || $hs->{COM} || $h->{COMMENT})  
> unless defined ($soundcheck = _parse_ReplayGain($hs->{REPLAYGAIN_TRACK_GAIN})) ;
>
>   But taking a second look at that sub, it probably never does. So the first
>   and easier to understand version should be ok.
>   

Actually, if the ReplayGain value is anything above 33.01 dB 
_parse_ReplayGain() will return 0. It's not very likely, but possible. 
So I went with the second form which seems to work well.

Cheers,

Richard

? .gnupod_version
? Makefile
? autom4te.cache
? config.log
? config.status
? configure
? src/ext/FileMagic.pm.org
Index: src/gnupod_addsong.pl
===================================================================
RCS file: /sources/gnupod/gnupod/src/gnupod_addsong.pl,v
retrieving revision 1.104
diff -u -r1.104 gnupod_addsong.pl
--- src/gnupod_addsong.pl       25 Mar 2009 13:43:27 -0000      1.104
+++ src/gnupod_addsong.pl       6 May 2009 10:17:49 -0000
@@ -44,14 +44,14 @@
 $opts{mount} = $ENV{IPOD_MOUNTPOINT};
 #Don't add xml and itunes opts.. we *NEED* the mount opt to be set..
 GetOptions(\%opts, "version", "help|h", "mount|m=s", "decode|x=s", 
"restore|r", "duplicate|d", "disable-v2", "disable-v1",
-                   "set-title|t=s", "set-artist|a=s", "set-album|l=s", 
"set-genre|g=s", "set-rating=i", "set-playcount=i",
-                   "set-bookmarkable|b", "set-shuffleskip", "artwork=s",
+                   "disable-ape", "set-title|t=s", "set-artist|a=s", 
"set-album|l=s", "set-genre|g=s", "set-rating=i",
+                   "set-playcount=i", "set-bookmarkable|b", "set-shuffleskip", 
"artwork=s", "replaygain-album",
                    "set-songnum", "playlist|p=s@", "reencode|e=i",
                    "min-vol-adj=i", "max-vol-adj=i", "playlist-is-podcast", 
"podcast-files-limit=i", "podcast-cache-dir=s",
                    "podcast-artwork", "set-compilation");
 
-GNUpod::FooBar::GetConfig(\%opts, {'decode'=>'s', mount=>'s', duplicate=>'b', 
model=>'s',
-                                   'disable-v1'=>'b', 'disable-v2'=>'b', 
'set-songnum'=>'b',
+GNUpod::FooBar::GetConfig(\%opts, {'decode'=>'s', mount=>'s', duplicate=>'b', 
model=>'s', 'replaygain-album'=>'b',
+                                   'disable-v1'=>'b', 'disable-v2'=>'b', 
'disable-ape'=>'b', 'set-songnum'=>'b',
                                    'min-vol-adj'=>'i', 'max-vol-adj'=>'i', 
'automktunes'=>'b', 
                                    'podcast-files-limit'=>'i', 
'podcast-cache-dir'=>'s', 'podcast-artwork'=>'b' },
                                    "gnupod_addsong");
@@ -157,6 +157,8 @@
                #Get the filetype
                my ($fh,$media_h,$converter) =  
GNUpod::FileMagic::wtf_is($file, {noIDv1=>$opts{'disable-v1'}, 
                                                                                
  noIDv2=>$opts{'disable-v2'},
+                                                                               
  noAPE=>$opts{'disable-ape'},
+                                                                               
  rgalbum=>$opts{'replaygain-album'},
                                                                                
  decode=>$opts{'decode'}},$con);
                
                unless($fh) {
@@ -734,6 +736,8 @@
                                     0 = download all (default), -X = download 
X oldest items, X = download X newest items
        --disable-v1                 Do not read ID3v1 Tags (MP3 Only)
        --disable-v2                 Do not read ID3v2 Tags (MP3 Only)
+       --disable-ape                Do not read APE Tags (MP3 Only) 
--disable-v1 with --disable-v2 implies --disable-ape
+       --replaygain-album           Use the ReplayGain album value instead of 
the ReplayGain track value (default)
    -x  --decode=pcm|mp3|aac|aacbm   Convert FLAC Files to WAVE/MP3 or AAC 
'on-the-fly'. Use '-e' to specify a quality/bitrate
    -x  --decode=video               Convert .avi Files into iPod video 
'on-the-fly' (needs ffmpeg with AAC support)
    -x  --decode=alac                Convert FLAC Files into Apple Lossless 
'on-the-fly' (needs ffmpeg with ALAC support)
Index: src/ext/FileMagic.pm
===================================================================
RCS file: /sources/gnupod/gnupod/src/ext/FileMagic.pm,v
retrieving revision 1.81
diff -u -r1.81 FileMagic.pm
--- src/ext/FileMagic.pm        17 Sep 2008 09:41:55 -0000      1.81
+++ src/ext/FileMagic.pm        6 May 2009 10:17:49 -0000
@@ -75,8 +75,13 @@
 and converters to convert the $file into something iPod compatible and to
 extract the meta/media information.
 
-FLAGS is a hash that may contain a true value for the keys 'noIDv1' and 
'noIDv2' if
-you want to skip the extraction of ID3v1 or ID3v2 tags from MP3 files.
+FLAGS is a hash that may contain a true value for the keys 'noIDv1', 'noIDv2'
+and 'noAPE' if you want to skip the extraction of ID3v1, ID3v2 or APE tags
+from MP3 files. APE tags are always read in conjunction with ID3 tags.
+Disabling the use of both ID3v1 and ID3v2 tags also disables the reading
+of APE tags from MP3 files. Set a true value for the key 'rgalbum' if you
+want to use the album ReplayGain value instead of the track ReplayGain
+value (default).
 
 Returns:
 
@@ -482,8 +487,8 @@
        $rh{time}     = int($h->{SECS}*1000);
        $rh{fdesc}    = "MPEG ${$h}{VERSION} layer ${$h}{LAYER} file";
        
-       $h  = MP3::Info::get_mp3tag($file,1)    unless $flags->{'noIDv1'};  
#Get the IDv1 tag
-       $hs = MP3::Info::get_mp3tag($file,2,2)  unless $flags->{'noIDv2'};  
#Get the IDv2 tag
+       $h  = MP3::Info::get_mp3tag($file,1,0,$flags->{'noAPE'}?0:1) unless 
$flags->{'noIDv1'};  #Get the IDv1 tag
+       $hs = MP3::Info::get_mp3tag($file,2,2,$flags->{'noAPE'}?0:1) unless 
$flags->{'noIDv2'};  #Get the IDv2 tag
        
        my $nonitunescomment = undef;
        #The IDv2 Hashref may return arrays.. kill them :)
@@ -505,6 +510,10 @@
        #Try to parse things like 01/01
        my @songa = pss($hs->{TRCK} || $hs->{TRK} || $h->{TRACKNUM});
        my @cda   = pss($hs->{TPOS});
+
+       # Use track ReplayGain by default, use album ReplayGain if requested
+       my $rgtag = "REPLAYGAIN_TRACK_GAIN";
+       $rgtag = "REPLAYGAIN_ALBUM_GAIN" if($flags->{'rgalbum'});
        
        $rh{songs}      = int($songa[1]);
        $rh{songnum}    = int($songa[0]);
@@ -519,7 +528,7 @@
        $rh{desc}       = __merge_strings({joinby => " ", wspace => "norm", 
case => "ignore"},($hs->{USLT} || $hs->{ULT}),($nonitunescomment || 
$h->{COMMENT}));
        $rh{composer}   = ($hs->{TCOM} || $hs->{TCM} || "");
        $rh{playcount}  = int($hs->{PCNT} || $hs->{CNT}) || 0;
-       $rh{soundcheck} = _parse_iTunNORM($hs->{COMM} || $hs->{COM} || 
$h->{COMMENT});
+       $rh{soundcheck} = _parse_iTunNORM($hs->{COMM} || $hs->{COM} || 
$h->{COMMENT}) unless defined($rh{soundcheck} = _parse_ReplayGain($hs->{$rgtag} 
|| $h->{$rgtag}));
        $rh{mediatype}  = MEDIATYPE_AUDIO;
 
        # Handle volume adjustment information
@@ -789,6 +798,32 @@
 
 =cut
 
+#########################################################
+# Convert ReplayGain to SoundCheck
+# Code adapted from http://projects.robinbowes.com/flac2mp3/trac/ticket/30
+
+=item _parse_ReplayGain(VALUE)
+
+Converts ReplayGain VALUE in dB to iTunes Sound Check value. Anything
+outside the range of -18.16 dB to 33.01 dB will be rounded to those values.
+For more information on ReplayGain see http://replaygain.hydrogenaudio.org/
+
+=cut
+
+sub _parse_ReplayGain {
+       my ($gain) = @_;
+       return undef unless defined($gain);
+       if($gain =~ /(.*)\s+dB$/) {
+               $gain = $1
+       }
+       return undef unless ($gain =~ /^\s*-?\d+\.?\d*\s*$/);
+       my $result = int((10 ** (-$gain / 10)) * 1000 + .5);
+       if ($result > 65534) {
+               $result = 65534;
+       }
+       return oct(sprintf("0x%08X",$result));
+}
+
 1;