public static function GenerateID3v1Tag($title, $artist, $album, $year, $genreid, $comment, $track='') {
    $ID3v1Tag  = 'TAG';
    $ID3v1Tag .= str_pad(trim(substr($title,  0, 30)), 30, "\x00", STR_PAD_RIGHT);
    $ID3v1Tag .= str_pad(trim(substr($artist, 0, 30)), 30, "\x00", STR_PAD_RIGHT);
    $ID3v1Tag .= str_pad(trim(substr($album,  0, 30)), 30, "\x00", STR_PAD_RIGHT);
    $ID3v1Tag .= str_pad(trim(substr($year,   0,  4)),  4, "\x00", STR_PAD_LEFT);
    if (!empty($track) && ($track > 0) && ($track <= 255)) {
      $ID3v1Tag .= str_pad(trim(substr($comment, 0, 28)), 28, "\x00", STR_PAD_RIGHT);
      $ID3v1Tag .= "\x00";
      if (gettype($track) == 'string') {
        $track = (int) $track;
      }
      $ID3v1Tag .= chr($track);
    } else {
      $ID3v1Tag .= str_pad(trim(substr($comment, 0, 30)), 30, "\x00", STR_PAD_RIGHT);
    }
    if (($genreid < 0) || ($genreid > 147)) {
      $genreid = 255; // 'unknown' genre
    }
    switch (gettype($genreid)) {
      case 'string':
      case 'integer':
        $ID3v1Tag .= chr(intval($genreid));
        break;
      default:
        $ID3v1Tag .= chr(255); // 'unknown' genre
        break;
    }

    return $ID3v1Tag;
  }