###############################################################################
#
# Mp3IdOf:   Shows the MP3 Id tags of a mp3 file
#
# Parameter: MP3-Filename
#
#
# @Filetype: Perl scipt
# @Author:   Werner Puenter 
# @Date:     06.10.2001
# @Version:  1.1
#
# @History:
# Version 1.0: Initial Version
# Version 1.1: Add Genre
# Version 1.2: Add "use strict"
#              -> use of my
#              -> correct mistake of missing input_file
#
###############################################################################
use strict;

my $input_file = $ARGV[0];                              # must read from file(?)

if ($input_file)
{
  my @Genre = qw( Blues            Classic_Rock     Country          Dance 
                  Disco            Funk             Grunge           Hip-Hop 
                  Jazz             Metal            NewAge           Oldies 
                  Other            Pop              R&B              Rap 
                  Reggae           Rock             Techno           Industrial 
                  Alternative      Ska              DeathMetal       Pranks 
                  Soundtrack       Euro-Techno      Ambient          Trip-Hop 
                  Vocal            Jazz+Funk        Fusion           Trance 
                  Classical        Instrumental     Acid             House 
                  Game             SoundClip        Gospel           Noise
                  Alt.Rock         Bass             Soul             Punk
                  Space            Meditative       Instrumental_Pop Instrumental_Rock
                  Ethnic           Gothic           Darkwave         Techno-Industrial
                  Electronic       Pop-Folk         Eurodance        Dream
                  Southern_Rock    Comedy           Cult             Gangsta
                  Top40            Christian_Rap    Pop/Funk         Jungle
                  Native_American  Cabaret          New_Wave         Psychadelic
                  Rave             Showtunes        Trailer          Lo-Fi
                  Tribal           Acid_Punk        Acid_Jazz        Polka
                  Retro            Musical          Rock&Roll        Hard_Rock
                  Folk             Folk/Rock        National_Folk    Swing
                  Fusion           Bebob            Latin            Revival
                  Celtic           Bluegrass        Avantgarde       Gothic_Rock
                  Progressive_Rock Psychedelic_Rock Symphonic_Rock   Slow_Rock
                  Big_Band         Chorus           Easy_Listening   Acoustic
                  Humour           Speech           Chanson          Opera
                  Chamber_Music    Sonata           Symphony         Booty_Bass
                  Primus           Porn_Groove      Satire           Slow_Jam
                  Club             Tango            Samba            Folklore
                  Unknown
             );                                           # Folklore=115, Unknown=116-255

  open(INPUT_FILE,"<$input_file") or die "*** ERROR *** Not able to open $input_file.\n$!\n$^E";
  binmode(INPUT_FILE);                                    # Set file type to binary

  my @lines = reverse <INPUT_FILE>;                       # Read file from in reverse order 
                                                          # (Last row first)
  # The last 128 bytes of a MP3 file contains the ID-Tags

  my $MP3_Tag = 0;                                        # 3  Bytes = "TAG"
  my $MP3_Titel = 0;                                      # 30 Bytes = Titel des Stueckes
  my $MP3_Interpret = 0;                                  # 30 Bytes = Interpret
  my $MP3_CD_Name = 0;                                    # 30 Bytes = CD-Titel
  my $MP3_Jahr = 0;                                       # 4  Bytes = Erscheinungsjahr
  my $MP3_Comment = 0;                                    # 30 Bytes = Kommentar
  my $MP3_GenreByte = 255;                                # 1  Byte  = Genre
                                                        
  my $i = 0;
  foreach my $line(@lines)
  {
    $i=$i+1;

    if ($line =~ /.*(TAG.*)/)
    {
      my $Total = $1;

      $MP3_Tag       =     substr($Total,0,3);            # 0/1/2     -> 3  Char
      $MP3_Titel     =     substr($Total,3,30);           # 3/../32   -> 30 Char
      $MP3_Interpret =     substr($Total,33,30);          # 33/../62  -> 30 Char
      $MP3_CD_Name   =     substr($Total,63,30);          # 63/../92  -> 30 Char
      $MP3_Jahr      =     substr($Total,93,4);           # 93/../96  -> 4  Char
      $MP3_Comment   =     substr($Total,97,30);          # 97/../126 -> 30 Char
      $MP3_GenreByte = ord(substr($Total,127,1));         # 127/      -> 1  Char

      if ( $MP3_GenreByte > 115 )
      {
        $MP3_GenreByte = 116;     # UnKnown
      }

      print "MP3_Tag       = $MP3_Tag\n";
      print "MP3_Titel     = $MP3_Titel\n";
      print "MP3_Interpret = $MP3_Interpret\n";
      print "MP3_CD_Name   = $MP3_CD_Name\n";
      print "MP3_Jahr      = $MP3_Jahr\n";
      print "MP3_Comment   = $MP3_Comment\n";
      print "MP3_Genre     = $Genre[$MP3_GenreByte]\n";

      last;
    }
    else
    {
      print "No MP3 IdTag available.";
      last;
    }
    if ($i > 1)  
    { 
      print " *** WARNING *** - Unexspected EndOfLine found\n";
      last;                                               # Sicherheitshalber -> NotAus
    } 
  }
  close (INPUT_FILE);
}
else
{
  print "*** ERROR *** - Please use Mp3IdOf with Parameter <MP3 filename>\n";
}