public function Analyze() {
    $info = &$this->getid3->info;

    ///AH
    $info['ac3']['raw']['bsi'] = array();
    $thisfile_ac3              = &$info['ac3'];
    $thisfile_ac3_raw          = &$thisfile_ac3['raw'];
    $thisfile_ac3_raw_bsi      = &$thisfile_ac3_raw['bsi'];


    // http://www.atsc.org/standards/a_52a.pdf

    $info['fileformat'] = 'ac3';

    // An AC-3 serial coded audio bit stream is made up of a sequence of synchronization frames
    // Each synchronization frame contains 6 coded audio blocks (AB), each of which represent 256
    // new audio samples per channel. A synchronization information (SI) header at the beginning
    // of each frame contains information needed to acquire and maintain synchronization. A
    // bit stream information (BSI) header follows SI, and contains parameters describing the coded
    // audio service. The coded audio blocks may be followed by an auxiliary data (Aux) field. At the
    // end of each frame is an error check field that includes a CRC word for error detection. An
    // additional CRC word is located in the SI header, the use of which, by a decoder, is optional.
    //
    // syncinfo() | bsi() | AB0 | AB1 | AB2 | AB3 | AB4 | AB5 | Aux | CRC

    // syncinfo() {
    // 	 syncword    16
    // 	 crc1        16
    // 	 fscod        2
    // 	 frmsizecod   6
    // } /* end of syncinfo */

    $this->fseek($info['avdataoffset']);
    $tempAC3header = $this->fread(100); // should be enough to cover all data, there are some variable-length fields...?
    $this->AC3header['syncinfo']  =     getid3_lib::BigEndian2Int(substr($tempAC3header, 0, 2));
    $this->AC3header['bsi']       =     getid3_lib::BigEndian2Bin(substr($tempAC3header, 2));
    $thisfile_ac3_raw_bsi['bsid'] = (getid3_lib::LittleEndian2Int(substr($tempAC3header, 5, 1)) & 0xF8) >> 3; // AC3 and E-AC3 put the "bsid" version identifier in the same place, but unfortnately the 4 bytes between the syncword and the version identifier are interpreted differently, so grab it here so the following code structure can make sense
    unset($tempAC3header);

    if ($this->AC3header['syncinfo'] !== self::syncword) {
      if (!$this->isDependencyFor('matroska')) {
        unset($info['fileformat'], $info['ac3']);
        return $this->error('Expecting "'.dechex(self::syncword).'" at offset '.$info['avdataoffset'].', found "'.dechex($this->AC3header['syncinfo']).'"');
      }
    }

    $info['audio']['dataformat']   = 'ac3';
    $info['audio']['bitrate_mode'] = 'cbr';
    $info['audio']['lossless']     = false;

    if ($thisfile_ac3_raw_bsi['bsid'] <= 8) {

      $thisfile_ac3_raw_bsi['crc1']       = getid3_lib::Bin2Dec($this->getid3_ac3::readHeaderBSI(16));
      $thisfile_ac3_raw_bsi['fscod']      =                     $this->getid3_ac3::readHeaderBSI(2);   // 5.4.1.3
      $thisfile_ac3_raw_bsi['frmsizecod'] =                     $this->getid3_ac3::readHeaderBSI(6);   // 5.4.1.4
      if ($thisfile_ac3_raw_bsi['frmsizecod'] > 37) { // binary: 100101 - see Table 5.18 Frame Size Code Table (1 word = 16 bits)
        $this->warning('Unexpected ac3.bsi.frmsizecod value: '.$thisfile_ac3_raw_bsi['frmsizecod'].', bitrate not set correctly');
      }

      $thisfile_ac3_raw_bsi['bsid']  = $this->getid3_ac3::readHeaderBSI(5); // we already know this from pre-parsing the version identifier, but re-read it to let the bitstream flow as intended
      $thisfile_ac3_raw_bsi['bsmod'] = $this->getid3_ac3::readHeaderBSI(3);
      $thisfile_ac3_raw_bsi['acmod'] = $this->getid3_ac3::readHeaderBSI(3);

      if ($thisfile_ac3_raw_bsi['acmod'] & 0x01) {
        // If the lsb of acmod is a 1, center channel is in use and cmixlev follows in the bit stream.
        $thisfile_ac3_raw_bsi['cmixlev'] = $this->getid3_ac3::readHeaderBSI(2);
        $thisfile_ac3['center_mix_level'] = self::centerMixLevelLookup($thisfile_ac3_raw_bsi['cmixlev']);
      }

      if ($thisfile_ac3_raw_bsi['acmod'] & 0x04) {
        // If the msb of acmod is a 1, surround channels are in use and surmixlev follows in the bit stream.
        $thisfile_ac3_raw_bsi['surmixlev'] = $this->getid3_ac3::readHeaderBSI(2);
        $thisfile_ac3['surround_mix_level'] = self::surroundMixLevelLookup($thisfile_ac3_raw_bsi['surmixlev']);
      }

      if ($thisfile_ac3_raw_bsi['acmod'] == 0x02) {
        // When operating in the two channel mode, this 2-bit code indicates whether or not the program has been encoded in Dolby Surround.
        $thisfile_ac3_raw_bsi['dsurmod'] = $this->getid3_ac3::readHeaderBSI(2);
        $thisfile_ac3['dolby_surround_mode'] = self::dolbySurroundModeLookup($thisfile_ac3_raw_bsi['dsurmod']);
      }

      $thisfile_ac3_raw_bsi['flags']['lfeon'] = (bool) $this->getid3_ac3::readHeaderBSI(1);

      // This indicates how far the average dialogue level is below digital 100 percent. Valid values are 1-31.
      // The value of 0 is reserved. The values of 1 to 31 are interpreted as -1 dB to -31 dB with respect to digital 100 percent.
      $thisfile_ac3_raw_bsi['dialnorm'] = $this->getid3_ac3::readHeaderBSI(5);                 // 5.4.2.8 dialnorm: Dialogue Normalization, 5 Bits

      $thisfile_ac3_raw_bsi['flags']['compr'] = (bool) $this->getid3_ac3::readHeaderBSI(1);       // 5.4.2.9 compre: Compression Gain Word Exists, 1 Bit
      if ($thisfile_ac3_raw_bsi['flags']['compr']) {
        $thisfile_ac3_raw_bsi['compr'] = $this->getid3_ac3::readHeaderBSI(8);                // 5.4.2.10 compr: Compression Gain Word, 8 Bits
        $thisfile_ac3['heavy_compression'] = self::heavyCompression($thisfile_ac3_raw_bsi['compr']);
      }

      $thisfile_ac3_raw_bsi['flags']['langcod'] = (bool) $this->getid3_ac3::readHeaderBSI(1);     // 5.4.2.11 langcode: Language Code Exists, 1 Bit
      if ($thisfile_ac3_raw_bsi['flags']['langcod']) {
        $thisfile_ac3_raw_bsi['langcod'] = $this->getid3_ac3::readHeaderBSI(8);              // 5.4.2.12 langcod: Language Code, 8 Bits
      }

      $thisfile_ac3_raw_bsi['flags']['audprodinfo'] = (bool) $this->getid3_ac3::readHeaderBSI(1);  // 5.4.2.13 audprodie: Audio Production Information Exists, 1 Bit
      if ($thisfile_ac3_raw_bsi['flags']['audprodinfo']) {
        $thisfile_ac3_raw_bsi['mixlevel'] = $this->getid3_ac3::readHeaderBSI(5);             // 5.4.2.14 mixlevel: Mixing Level, 5 Bits
        $thisfile_ac3_raw_bsi['roomtyp']  = $this->getid3_ac3::readHeaderBSI(2);             // 5.4.2.15 roomtyp: Room Type, 2 Bits

        $thisfile_ac3['mixing_level'] = (80 + $thisfile_ac3_raw_bsi['mixlevel']).'dB';
        $thisfile_ac3['room_type']    = self::roomTypeLookup($thisfile_ac3_raw_bsi['roomtyp']);
      }


      $thisfile_ac3_raw_bsi['dialnorm2'] = $this->getid3_ac3::readHeaderBSI(5);                // 5.4.2.16 dialnorm2: Dialogue Normalization, ch2, 5 Bits
      $thisfile_ac3['dialogue_normalization2'] = '-'.$thisfile_ac3_raw_bsi['dialnorm2'].'dB';  // This indicates how far the average dialogue level is below digital 100 percent. Valid values are 1-31. The value of 0 is reserved. The values of 1 to 31 are interpreted as -1 dB to -31 dB with respect to digital 100 percent.

      $thisfile_ac3_raw_bsi['flags']['compr2'] = (bool) $this->getid3_ac3::readHeaderBSI(1);       // 5.4.2.17 compr2e: Compression Gain Word Exists, ch2, 1 Bit
      if ($thisfile_ac3_raw_bsi['flags']['compr2']) {
        $thisfile_ac3_raw_bsi['compr2'] = $this->getid3_ac3::readHeaderBSI(8);               // 5.4.2.18 compr2: Compression Gain Word, ch2, 8 Bits
        $thisfile_ac3['heavy_compression2'] = self::heavyCompression($thisfile_ac3_raw_bsi['compr2']);
      }

      $thisfile_ac3_raw_bsi['flags']['langcod2'] = (bool) $this->getid3_ac3::readHeaderBSI(1);    // 5.4.2.19 langcod2e: Language Code Exists, ch2, 1 Bit
      if ($thisfile_ac3_raw_bsi['flags']['langcod2']) {
        $thisfile_ac3_raw_bsi['langcod2'] = $this->getid3_ac3::readHeaderBSI(8);             // 5.4.2.20 langcod2: Language Code, ch2, 8 Bits
      }

      $thisfile_ac3_raw_bsi['flags']['audprodinfo2'] = (bool) $this->getid3_ac3::readHeaderBSI(1); // 5.4.2.21 audprodi2e: Audio Production Information Exists, ch2, 1 Bit
      if ($thisfile_ac3_raw_bsi['flags']['audprodinfo2']) {
        $thisfile_ac3_raw_bsi['mixlevel2'] = $this->getid3_ac3::readHeaderBSI(5);            // 5.4.2.22 mixlevel2: Mixing Level, ch2, 5 Bits
        $thisfile_ac3_raw_bsi['roomtyp2']  = $this->getid3_ac3::readHeaderBSI(2);            // 5.4.2.23 roomtyp2: Room Type, ch2, 2 Bits

        $thisfile_ac3['mixing_level2'] = (80 + $thisfile_ac3_raw_bsi['mixlevel2']).'dB';
        $thisfile_ac3['room_type2']    = self::roomTypeLookup($thisfile_ac3_raw_bsi['roomtyp2']);
      }

      $thisfile_ac3_raw_bsi['copyright'] = (bool) $this->getid3_ac3::readHeaderBSI(1);         // 5.4.2.24 copyrightb: Copyright Bit, 1 Bit

      $thisfile_ac3_raw_bsi['original']  = (bool) $this->getid3_ac3::readHeaderBSI(1);         // 5.4.2.25 origbs: Original Bit Stream, 1 Bit

      $thisfile_ac3_raw_bsi['flags']['timecod1'] = $this->getid3_ac3::readHeaderBSI(2);            // 5.4.2.26 timecod1e, timcode2e: Time Code (first and second) Halves Exist, 2 Bits
      if ($thisfile_ac3_raw_bsi['flags']['timecod1'] & 0x01) {
        $thisfile_ac3_raw_bsi['timecod1'] = $this->getid3_ac3::readHeaderBSI(14);            // 5.4.2.27 timecod1: Time code first half, 14 bits
        $thisfile_ac3['timecode1'] = 0;
        $thisfile_ac3['timecode1'] += (($thisfile_ac3_raw_bsi['timecod1'] & 0x3E00) >>  9) * 3600;  // The first 5 bits of this 14-bit field represent the time in hours, with valid values of 0�23
        $thisfile_ac3['timecode1'] += (($thisfile_ac3_raw_bsi['timecod1'] & 0x01F8) >>  3) *   60;  // The next 6 bits represent the time in minutes, with valid values of 0�59
        $thisfile_ac3['timecode1'] += (($thisfile_ac3_raw_bsi['timecod1'] & 0x0003) >>  0) *    8;  // The final 3 bits represents the time in 8 second increments, with valid values of 0�7 (representing 0, 8, 16, ... 56 seconds)
      }
      if ($thisfile_ac3_raw_bsi['flags']['timecod1'] & 0x02) {
        $thisfile_ac3_raw_bsi['timecod2'] = $this->getid3_ac3::readHeaderBSI(14);            // 5.4.2.28 timecod2: Time code second half, 14 bits
        $thisfile_ac3['timecode2'] = 0;
        $thisfile_ac3['timecode2'] += (($thisfile_ac3_raw_bsi['timecod2'] & 0x3800) >> 11) *   1;              // The first 3 bits of this 14-bit field represent the time in seconds, with valid values from 0�7 (representing 0-7 seconds)
        $thisfile_ac3['timecode2'] += (($thisfile_ac3_raw_bsi['timecod2'] & 0x07C0) >>  6) *  (1 / 30);        // The next 5 bits represents the time in frames, with valid values from 0�29 (one frame = 1/30th of a second)
        $thisfile_ac3['timecode2'] += (($thisfile_ac3_raw_bsi['timecod2'] & 0x003F) >>  0) * ((1 / 30) / 60);  // The final 6 bits represents fractions of 1/64 of a frame, with valid values from 0�63
      }

      $thisfile_ac3_raw_bsi['flags']['addbsi'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
      if ($thisfile_ac3_raw_bsi['flags']['addbsi']) {
        $thisfile_ac3_raw_bsi['addbsi_length'] = $this->getid3_ac3::readHeaderBSI(6) + 1; // This 6-bit code, which exists only if addbside is a 1, indicates the length in bytes of additional bit stream information. The valid range of addbsil is 0�63, indicating 1�64 additional bytes, respectively.

        $this->AC3header['bsi'] .= getid3_lib::BigEndian2Bin($this->fread($thisfile_ac3_raw_bsi['addbsi_length']));

        $thisfile_ac3_raw_bsi['addbsi_data'] = substr($this->AC3header['bsi'], $this->BSIoffset, $thisfile_ac3_raw_bsi['addbsi_length'] * 8);
        $this->BSIoffset += $thisfile_ac3_raw_bsi['addbsi_length'] * 8;
      }


    } elseif ($thisfile_ac3_raw_bsi['bsid'] <= 16) { // E-AC3


      $this->error('E-AC3 parsing is incomplete and experimental in this version of getID3 ('.$this->getid3->version().'). Notably the bitrate calculations are wrong -- value might (or not) be correct, but it is not calculated correctly. Email info@getid3.org if you know how to calculate EAC3 bitrate correctly.');
      $info['audio']['dataformat'] = 'eac3';

      $thisfile_ac3_raw_bsi['strmtyp']          =        $this->getid3_ac3::readHeaderBSI(2);
      $thisfile_ac3_raw_bsi['substreamid']      =        $this->getid3_ac3::readHeaderBSI(3);
      $thisfile_ac3_raw_bsi['frmsiz']           =        $this->getid3_ac3::readHeaderBSI(11);
      $thisfile_ac3_raw_bsi['fscod']            =        $this->getid3_ac3::readHeaderBSI(2);
      if ($thisfile_ac3_raw_bsi['fscod'] == 3) {
        $thisfile_ac3_raw_bsi['fscod2']       =        $this->getid3_ac3::readHeaderBSI(2);
        $thisfile_ac3_raw_bsi['numblkscod'] = 3; // six blocks per syncframe
      } else {
        $thisfile_ac3_raw_bsi['numblkscod']   =        $this->getid3_ac3::readHeaderBSI(2);
      }
      $thisfile_ac3['bsi']['blocks_per_sync_frame'] = self::blocksPerSyncFrame($thisfile_ac3_raw_bsi['numblkscod']);
      $thisfile_ac3_raw_bsi['acmod']            =        $this->getid3_ac3::readHeaderBSI(3);
      $thisfile_ac3_raw_bsi['flags']['lfeon']   = (bool) $this->getid3_ac3::readHeaderBSI(1);
      $thisfile_ac3_raw_bsi['bsid']             =        $this->getid3_ac3::readHeaderBSI(5); // we already know this from pre-parsing the version identifier, but re-read it to let the bitstream flow as intended
      $thisfile_ac3_raw_bsi['dialnorm']         =        $this->getid3_ac3::readHeaderBSI(5);
      $thisfile_ac3_raw_bsi['flags']['compr']       = (bool) $this->getid3_ac3::readHeaderBSI(1);
      if ($thisfile_ac3_raw_bsi['flags']['compr']) {
        $thisfile_ac3_raw_bsi['compr']        =        $this->getid3_ac3::readHeaderBSI(8);
      }
      if ($thisfile_ac3_raw_bsi['acmod'] == 0) { // if 1+1 mode (dual mono, so some items need a second value)
        $thisfile_ac3_raw_bsi['dialnorm2']    =        $this->getid3_ac3::readHeaderBSI(5);
        $thisfile_ac3_raw_bsi['flags']['compr2']  = (bool) $this->getid3_ac3::readHeaderBSI(1);
        if ($thisfile_ac3_raw_bsi['flags']['compr2']) {
          $thisfile_ac3_raw_bsi['compr2']   =        $this->getid3_ac3::readHeaderBSI(8);
        }
      }
      if ($thisfile_ac3_raw_bsi['strmtyp'] == 1) { // if dependent stream
        $thisfile_ac3_raw_bsi['flags']['chanmap'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
        if ($thisfile_ac3_raw_bsi['flags']['chanmap']) {
          $thisfile_ac3_raw_bsi['chanmap']  =        $this->getid3_ac3::readHeaderBSI(8);
        }
      }
      $thisfile_ac3_raw_bsi['flags']['mixmdat']     = (bool) $this->getid3_ac3::readHeaderBSI(1);
      if ($thisfile_ac3_raw_bsi['flags']['mixmdat']) { // Mixing metadata
        if ($thisfile_ac3_raw_bsi['acmod'] > 2) { // if more than 2 channels
          $thisfile_ac3_raw_bsi['dmixmod']  =        $this->getid3_ac3::readHeaderBSI(2);
        }
        if (($thisfile_ac3_raw_bsi['acmod'] & 0x01) && ($thisfile_ac3_raw_bsi['acmod'] > 2)) { // if three front channels exist
          $thisfile_ac3_raw_bsi['ltrtcmixlev'] =        $this->getid3_ac3::readHeaderBSI(3);
          $thisfile_ac3_raw_bsi['lorocmixlev'] =        $this->getid3_ac3::readHeaderBSI(3);
        }
        if ($thisfile_ac3_raw_bsi['acmod'] & 0x04) { // if a surround channel exists
          $thisfile_ac3_raw_bsi['ltrtsurmixlev'] =        $this->getid3_ac3::readHeaderBSI(3);
          $thisfile_ac3_raw_bsi['lorosurmixlev'] =        $this->getid3_ac3::readHeaderBSI(3);
        }
        if ($thisfile_ac3_raw_bsi['flags']['lfeon']) { // if the LFE channel exists
          $thisfile_ac3_raw_bsi['flags']['lfemixlevcod'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
          if ($thisfile_ac3_raw_bsi['flags']['lfemixlevcod']) {
            $thisfile_ac3_raw_bsi['lfemixlevcod']  =        $this->getid3_ac3::readHeaderBSI(5);
          }
        }
        if ($thisfile_ac3_raw_bsi['strmtyp'] == 0) { // if independent stream
          $thisfile_ac3_raw_bsi['flags']['pgmscl'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
          if ($thisfile_ac3_raw_bsi['flags']['pgmscl']) {
            $thisfile_ac3_raw_bsi['pgmscl']  =        $this->getid3_ac3::readHeaderBSI(6);
          }
          if ($thisfile_ac3_raw_bsi['acmod'] == 0) { // if 1+1 mode (dual mono, so some items need a second value)
            $thisfile_ac3_raw_bsi['flags']['pgmscl2'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
            if ($thisfile_ac3_raw_bsi['flags']['pgmscl2']) {
              $thisfile_ac3_raw_bsi['pgmscl2']  =        $this->getid3_ac3::readHeaderBSI(6);
            }
          }
          $thisfile_ac3_raw_bsi['flags']['extpgmscl'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
          if ($thisfile_ac3_raw_bsi['flags']['extpgmscl']) {
            $thisfile_ac3_raw_bsi['extpgmscl']  =        $this->getid3_ac3::readHeaderBSI(6);
          }
          $thisfile_ac3_raw_bsi['mixdef']  =        $this->getid3_ac3::readHeaderBSI(2);
          if ($thisfile_ac3_raw_bsi['mixdef'] == 1) { // mixing option 2
            $thisfile_ac3_raw_bsi['premixcmpsel']  = (bool) $this->getid3_ac3::readHeaderBSI(1);
            $thisfile_ac3_raw_bsi['drcsrc']        = (bool) $this->getid3_ac3::readHeaderBSI(1);
            $thisfile_ac3_raw_bsi['premixcmpscl']  =        $this->getid3_ac3::readHeaderBSI(3);
          } elseif ($thisfile_ac3_raw_bsi['mixdef'] == 2) { // mixing option 3
            $thisfile_ac3_raw_bsi['mixdata']       =        $this->getid3_ac3::readHeaderBSI(12);
          } elseif ($thisfile_ac3_raw_bsi['mixdef'] == 3) { // mixing option 4
            $mixdefbitsread = 0;
            $thisfile_ac3_raw_bsi['mixdeflen']     =        $this->getid3_ac3::readHeaderBSI(5); $mixdefbitsread += 5;
            $thisfile_ac3_raw_bsi['flags']['mixdata2'] = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
            if ($thisfile_ac3_raw_bsi['flags']['mixdata2']) {
              $thisfile_ac3_raw_bsi['premixcmpsel']  = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              $thisfile_ac3_raw_bsi['drcsrc']        = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              $thisfile_ac3_raw_bsi['premixcmpscl']  =        $this->getid3_ac3::readHeaderBSI(3); $mixdefbitsread += 3;
              $thisfile_ac3_raw_bsi['flags']['extpgmlscl']   = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['extpgmlscl']) {
                $thisfile_ac3_raw_bsi['extpgmlscl']    =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
              }
              $thisfile_ac3_raw_bsi['flags']['extpgmcscl']   = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['extpgmcscl']) {
                $thisfile_ac3_raw_bsi['extpgmcscl']    =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
              }
              $thisfile_ac3_raw_bsi['flags']['extpgmrscl']   = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['extpgmrscl']) {
                $thisfile_ac3_raw_bsi['extpgmrscl']    =        $this->getid3_ac3::readHeaderBSI(4);
              }
              $thisfile_ac3_raw_bsi['flags']['extpgmlsscl']  = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['extpgmlsscl']) {
                $thisfile_ac3_raw_bsi['extpgmlsscl']   =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
              }
              $thisfile_ac3_raw_bsi['flags']['extpgmrsscl']  = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['extpgmrsscl']) {
                $thisfile_ac3_raw_bsi['extpgmrsscl']   =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
              }
              $thisfile_ac3_raw_bsi['flags']['extpgmlfescl'] = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['extpgmlfescl']) {
                $thisfile_ac3_raw_bsi['extpgmlfescl']  =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
              }
              $thisfile_ac3_raw_bsi['flags']['dmixscl']      = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['dmixscl']) {
                $thisfile_ac3_raw_bsi['dmixscl']       =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
              }
              $thisfile_ac3_raw_bsi['flags']['addch']        = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['addch']) {
                $thisfile_ac3_raw_bsi['flags']['extpgmaux1scl']   = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
                if ($thisfile_ac3_raw_bsi['flags']['extpgmaux1scl']) {
                  $thisfile_ac3_raw_bsi['extpgmaux1scl']    =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
                }
                $thisfile_ac3_raw_bsi['flags']['extpgmaux2scl']   = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
                if ($thisfile_ac3_raw_bsi['flags']['extpgmaux2scl']) {
                  $thisfile_ac3_raw_bsi['extpgmaux2scl']    =        $this->getid3_ac3::readHeaderBSI(4); $mixdefbitsread += 4;
                }
              }
            }
            $thisfile_ac3_raw_bsi['flags']['mixdata3'] = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
            if ($thisfile_ac3_raw_bsi['flags']['mixdata3']) {
              $thisfile_ac3_raw_bsi['spchdat']   =        $this->getid3_ac3::readHeaderBSI(5); $mixdefbitsread += 5;
              $thisfile_ac3_raw_bsi['flags']['addspchdat'] = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
              if ($thisfile_ac3_raw_bsi['flags']['addspchdat']) {
                $thisfile_ac3_raw_bsi['spchdat1']   =         $this->getid3_ac3::readHeaderBSI(5); $mixdefbitsread += 5;
                $thisfile_ac3_raw_bsi['spchan1att'] =         $this->getid3_ac3::readHeaderBSI(2); $mixdefbitsread += 2;
                $thisfile_ac3_raw_bsi['flags']['addspchdat1'] = (bool) $this->getid3_ac3::readHeaderBSI(1); $mixdefbitsread += 1;
                if ($thisfile_ac3_raw_bsi['flags']['addspchdat1']) {
                  $thisfile_ac3_raw_bsi['spchdat2']   =         $this->getid3_ac3::readHeaderBSI(5); $mixdefbitsread += 5;
                  $thisfile_ac3_raw_bsi['spchan2att'] =         $this->getid3_ac3::readHeaderBSI(3); $mixdefbitsread += 3;
                }
              }
            }
            $mixdata_bits = (8 * ($thisfile_ac3_raw_bsi['mixdeflen'] + 2)) - $mixdefbitsread;
            $mixdata_fill = (($mixdata_bits % 8) ? 8 - ($mixdata_bits % 8) : 0);
            $thisfile_ac3_raw_bsi['mixdata']     =        $this->getid3_ac3::readHeaderBSI($mixdata_bits);
            $thisfile_ac3_raw_bsi['mixdatafill'] =        $this->getid3_ac3::readHeaderBSI($mixdata_fill);
            unset($mixdefbitsread, $mixdata_bits, $mixdata_fill);
          }
          if ($thisfile_ac3_raw_bsi['acmod'] < 2) { // if mono or dual mono source
            $thisfile_ac3_raw_bsi['flags']['paninfo'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
            if ($thisfile_ac3_raw_bsi['flags']['paninfo']) {
              $thisfile_ac3_raw_bsi['panmean']   =        $this->getid3_ac3::readHeaderBSI(8);
              $thisfile_ac3_raw_bsi['paninfo']   =        $this->getid3_ac3::readHeaderBSI(6);
            }
            if ($thisfile_ac3_raw_bsi['acmod'] == 0) { // if 1+1 mode (dual mono, so some items need a second value)
              $thisfile_ac3_raw_bsi['flags']['paninfo2'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
              if ($thisfile_ac3_raw_bsi['flags']['paninfo2']) {
                $thisfile_ac3_raw_bsi['panmean2']   =        $this->getid3_ac3::readHeaderBSI(8);
                $thisfile_ac3_raw_bsi['paninfo2']   =        $this->getid3_ac3::readHeaderBSI(6);
              }
            }
          }
          $thisfile_ac3_raw_bsi['flags']['frmmixcfginfo'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
          if ($thisfile_ac3_raw_bsi['flags']['frmmixcfginfo']) { // mixing configuration information
            if ($thisfile_ac3_raw_bsi['numblkscod'] == 0) {
              $thisfile_ac3_raw_bsi['blkmixcfginfo'][0]  =        $this->getid3_ac3::readHeaderBSI(5);
            } else {
              for ($blk = 0; $blk < $thisfile_ac3_raw_bsi['numblkscod']; $blk++) {
                $thisfile_ac3_raw_bsi['flags']['blkmixcfginfo'.$blk] = (bool) $this->getid3_ac3::readHeaderBSI(1);
                if ($thisfile_ac3_raw_bsi['flags']['blkmixcfginfo'.$blk]) { // mixing configuration information
                  $thisfile_ac3_raw_bsi['blkmixcfginfo'][$blk]  =        $this->getid3_ac3::readHeaderBSI(5);
                }
              }
            }
          }
        }
      }
      $thisfile_ac3_raw_bsi['flags']['infomdat']          = (bool) $this->getid3_ac3::readHeaderBSI(1);
      if ($thisfile_ac3_raw_bsi['flags']['infomdat']) { // Informational metadata
        $thisfile_ac3_raw_bsi['bsmod']                  =        $this->getid3_ac3::readHeaderBSI(3);
        $thisfile_ac3_raw_bsi['flags']['copyrightb']    = (bool) $this->getid3_ac3::readHeaderBSI(1);
        $thisfile_ac3_raw_bsi['flags']['origbs']        = (bool) $this->getid3_ac3::readHeaderBSI(1);
        if ($thisfile_ac3_raw_bsi['acmod'] == 2) { //  if in 2/0 mode
          $thisfile_ac3_raw_bsi['dsurmod']            =        $this->getid3_ac3::readHeaderBSI(2);
          $thisfile_ac3_raw_bsi['dheadphonmod']       =        $this->getid3_ac3::readHeaderBSI(2);
        }
        if ($thisfile_ac3_raw_bsi['acmod'] >= 6) { //  if both surround channels exist
          $thisfile_ac3_raw_bsi['dsurexmod']          =        $this->getid3_ac3::readHeaderBSI(2);
        }
        $thisfile_ac3_raw_bsi['flags']['audprodi']      = (bool) $this->getid3_ac3::readHeaderBSI(1);
        if ($thisfile_ac3_raw_bsi['flags']['audprodi']) {
          $thisfile_ac3_raw_bsi['mixlevel']           =        $this->getid3_ac3::readHeaderBSI(5);
          $thisfile_ac3_raw_bsi['roomtyp']            =        $this->getid3_ac3::readHeaderBSI(2);
          $thisfile_ac3_raw_bsi['flags']['adconvtyp'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
        }
        if ($thisfile_ac3_raw_bsi['acmod'] == 0) { //  if 1+1 mode (dual mono, so some items need a second value)
          $thisfile_ac3_raw_bsi['flags']['audprodi2']      = (bool) $this->getid3_ac3::readHeaderBSI(1);
          if ($thisfile_ac3_raw_bsi['flags']['audprodi2']) {
            $thisfile_ac3_raw_bsi['mixlevel2']           =        $this->getid3_ac3::readHeaderBSI(5);
            $thisfile_ac3_raw_bsi['roomtyp2']            =        $this->getid3_ac3::readHeaderBSI(2);
            $thisfile_ac3_raw_bsi['flags']['adconvtyp2'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
          }
        }
        if ($thisfile_ac3_raw_bsi['fscod'] < 3) { // if not half sample rate
          $thisfile_ac3_raw_bsi['flags']['sourcefscod'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
        }
      }
      if (($thisfile_ac3_raw_bsi['strmtyp'] == 0) && ($thisfile_ac3_raw_bsi['numblkscod'] != 3)) { //  if both surround channels exist
        $thisfile_ac3_raw_bsi['flags']['convsync'] = (bool) $this->getid3_ac3::readHeaderBSI(1);
      }
      if ($thisfile_ac3_raw_bsi['strmtyp'] == 2) { //  if bit stream converted from AC-3
        if ($thisfile_ac3_raw_bsi['numblkscod'] != 3) { // 6 blocks per syncframe
          $thisfile_ac3_raw_bsi['flags']['blkid']  = 1;
        } else {
          $thisfile_ac3_raw_bsi['flags']['blkid']  = (bool) $this->getid3_ac3::readHeaderBSI(1);
        }
        if ($thisfile_ac3_raw_bsi['flags']['blkid']) {
          $thisfile_ac3_raw_bsi['frmsizecod']  =        $this->getid3_ac3::readHeaderBSI(6);
        }
      }
      $thisfile_ac3_raw_bsi['flags']['addbsi']  = (bool) $this->getid3_ac3::readHeaderBSI(1);
      if ($thisfile_ac3_raw_bsi['flags']['addbsi']) {
        $thisfile_ac3_raw_bsi['addbsil']  =        $this->getid3_ac3::readHeaderBSI(6);
        $thisfile_ac3_raw_bsi['addbsi']   =        $this->getid3_ac3::readHeaderBSI(($thisfile_ac3_raw_bsi['addbsil'] + 1) * 8);
      }

    } else {

      $this->error('Bit stream identification is version '.$thisfile_ac3_raw_bsi['bsid'].', but getID3() only understands up to version 16. Please submit a support ticket with a sample file.');
      unset($info['ac3']);
      return false;

    }

    if (isset($thisfile_ac3_raw_bsi['fscod2'])) {
      $thisfile_ac3['sample_rate'] = self::sampleRateCodeLookup2($thisfile_ac3_raw_bsi['fscod2']);
    } else {
      $thisfile_ac3['sample_rate'] = self::sampleRateCodeLookup($thisfile_ac3_raw_bsi['fscod']);
    }
    if ($thisfile_ac3_raw_bsi['fscod'] <= 3) {
      $info['audio']['sample_rate'] = $thisfile_ac3['sample_rate'];
    } else {
      $this->warning('Unexpected ac3.bsi.fscod value: '.$thisfile_ac3_raw_bsi['fscod']);
    }
    if (isset($thisfile_ac3_raw_bsi['frmsizecod'])) {
      $thisfile_ac3['frame_length'] = self::frameSizeLookup($thisfile_ac3_raw_bsi['frmsizecod'], $thisfile_ac3_raw_bsi['fscod']);
      $thisfile_ac3['bitrate']      = self::bitrateLookup($thisfile_ac3_raw_bsi['frmsizecod']);
    } elseif (!empty($thisfile_ac3_raw_bsi['frmsiz'])) {
      // this isn't right, but it's (usually) close, roughly 5% less than it should be.
      // but WHERE is the actual bitrate value stored in EAC3?? email info@getid3.org if you know!
      $thisfile_ac3['bitrate']      = ($thisfile_ac3_raw_bsi['frmsiz'] + 1) * 16 * 30; // The frmsiz field shall contain a value one less than the overall size of the coded syncframe in 16-bit words. That is, this field may assume a value ranging from 0 to 2047, and these values correspond to syncframe sizes ranging from 1 to 2048.
      // kludge-fix to make it approximately the expected value, still not "right":
      $thisfile_ac3['bitrate'] = round(($thisfile_ac3['bitrate'] * 1.05) / 16000) * 16000;
    }
    $info['audio']['bitrate'] = $thisfile_ac3['bitrate'];

    if (isset($thisfile_ac3_raw_bsi['bsmod']) && isset($thisfile_ac3_raw_bsi['acmod'])) {
      $thisfile_ac3['service_type'] = self::serviceTypeLookup($thisfile_ac3_raw_bsi['bsmod'], $thisfile_ac3_raw_bsi['acmod']);
    }
    $ac3_coding_mode = self::audioCodingModeLookup($thisfile_ac3_raw_bsi['acmod']);
    foreach($ac3_coding_mode as $key => $value) {
      $thisfile_ac3[$key] = $value;
    }
    switch ($thisfile_ac3_raw_bsi['acmod']) {
      case 0:
      case 1:
        $info['audio']['channelmode'] = 'mono';
        break;
      case 3:
      case 4:
        $info['audio']['channelmode'] = 'stereo';
        break;
      default:
        $info['audio']['channelmode'] = 'surround';
        break;
    }
    $info['audio']['channels'] = $thisfile_ac3['num_channels'];

    $thisfile_ac3['lfe_enabled'] = $thisfile_ac3_raw_bsi['flags']['lfeon'];
    if ($thisfile_ac3_raw_bsi['flags']['lfeon']) {
      $info['audio']['channels'] .= '.1';
    }

    $thisfile_ac3['channels_enabled'] = self::channelsEnabledLookup($thisfile_ac3_raw_bsi['acmod'], $thisfile_ac3_raw_bsi['flags']['lfeon']);
    $thisfile_ac3['dialogue_normalization'] = '-'.$thisfile_ac3_raw_bsi['dialnorm'].'dB';

    return true;
  }