[ Index ]

PHP Cross Reference of WordPress

title

Body

[close]

/wp-includes/ID3/ -> module.audio.mp3.php (source)

   1  <?php
   2  
   3  /////////////////////////////////////////////////////////////////
   4  /// getID3() by James Heinrich <info@getid3.org>               //
   5  //  available at https://github.com/JamesHeinrich/getID3       //
   6  //            or https://www.getid3.org                        //
   7  //            or http://getid3.sourceforge.net                 //
   8  //  see readme.txt for more details                            //
   9  /////////////////////////////////////////////////////////////////
  10  //                                                             //
  11  // module.audio.mp3.php                                        //
  12  // module for analyzing MP3 files                              //
  13  // dependencies: NONE                                          //
  14  //                                                            ///
  15  /////////////////////////////////////////////////////////////////
  16  
  17  
  18  // number of frames to scan to determine if MPEG-audio sequence is valid
  19  // Lower this number to 5-20 for faster scanning
  20  // Increase this number to 50+ for most accurate detection of valid VBR/CBR
  21  // mpeg-audio streams
  22  define('GETID3_MP3_VALID_CHECK_FRAMES', 35);
  23  
  24  
  25  class getid3_mp3 extends getid3_handler
  26  {
  27      /**
  28       * Forces getID3() to scan the file byte-by-byte and log all the valid audio frame headers - extremely slow,
  29       * unrecommended, but may provide data from otherwise-unusable files.
  30       *
  31       * @var bool
  32       */
  33      public $allow_bruteforce = false;
  34  
  35      /**
  36       * @return bool
  37       */
  38  	public function Analyze() {
  39          $info = &$this->getid3->info;
  40  
  41          $initialOffset = $info['avdataoffset'];
  42  
  43          if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {
  44              if ($this->allow_bruteforce) {
  45                  $this->error('Rescanning file in BruteForce mode');
  46                  $this->getOnlyMPEGaudioInfoBruteForce();
  47              }
  48          }
  49  
  50  
  51          if (isset($info['mpeg']['audio']['bitrate_mode'])) {
  52              $info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);
  53          }
  54  
  55          if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {
  56  
  57              $synchoffsetwarning = 'Unknown data before synch ';
  58              if (isset($info['id3v2']['headerlength'])) {
  59                  $synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';
  60              } elseif ($initialOffset > 0) {
  61                  $synchoffsetwarning .= '(should be at '.$initialOffset.', ';
  62              } else {
  63                  $synchoffsetwarning .= '(should be at beginning of file, ';
  64              }
  65              $synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';
  66              if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {
  67  
  68                  if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {
  69  
  70                      $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';
  71                      $info['audio']['codec'] = 'LAME';
  72                      $CurrentDataLAMEversionString = 'LAME3.';
  73  
  74                  } elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {
  75  
  76                      $synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';
  77                      $info['audio']['codec'] = 'LAME';
  78                      $CurrentDataLAMEversionString = 'LAME3.';
  79  
  80                  }
  81  
  82              }
  83              $this->warning($synchoffsetwarning);
  84  
  85          }
  86  
  87          if (isset($info['mpeg']['audio']['LAME'])) {
  88              $info['audio']['codec'] = 'LAME';
  89              if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {
  90                  $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");
  91              } elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {
  92                  $info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");
  93              }
  94          }
  95  
  96          $CurrentDataLAMEversionString = (!empty($CurrentDataLAMEversionString) ? $CurrentDataLAMEversionString : (isset($info['audio']['encoder']) ? $info['audio']['encoder'] : ''));
  97          if (!empty($CurrentDataLAMEversionString) && (substr($CurrentDataLAMEversionString, 0, 6) == 'LAME3.') && !preg_match('[0-9\)]', substr($CurrentDataLAMEversionString, -1))) {
  98              // a version number of LAME that does not end with a number like "LAME3.92"
  99              // or with a closing parenthesis like "LAME3.88 (alpha)"
 100              // or a version of LAME with the LAMEtag-not-filled-in-DLL-mode bug (3.90-3.92)
 101  
 102              // not sure what the actual last frame length will be, but will be less than or equal to 1441
 103              $PossiblyLongerLAMEversion_FrameLength = 1441;
 104  
 105              // Not sure what version of LAME this is - look in padding of last frame for longer version string
 106              $PossibleLAMEversionStringOffset = $info['avdataend'] - $PossiblyLongerLAMEversion_FrameLength;
 107              $this->fseek($PossibleLAMEversionStringOffset);
 108              $PossiblyLongerLAMEversion_Data = $this->fread($PossiblyLongerLAMEversion_FrameLength);
 109              switch (substr($CurrentDataLAMEversionString, -1)) {
 110                  case 'a':
 111                  case 'b':
 112                      // "LAME3.94a" will have a longer version string of "LAME3.94 (alpha)" for example
 113                      // need to trim off "a" to match longer string
 114                      $CurrentDataLAMEversionString = substr($CurrentDataLAMEversionString, 0, -1);
 115                      break;
 116              }
 117              if (($PossiblyLongerLAMEversion_String = strstr($PossiblyLongerLAMEversion_Data, $CurrentDataLAMEversionString)) !== false) {
 118                  if (substr($PossiblyLongerLAMEversion_String, 0, strlen($CurrentDataLAMEversionString)) == $CurrentDataLAMEversionString) {
 119                      $PossiblyLongerLAMEversion_NewString = substr($PossiblyLongerLAMEversion_String, 0, strspn($PossiblyLongerLAMEversion_String, 'LAME0123456789., (abcdefghijklmnopqrstuvwxyzJFSOND)')); //"LAME3.90.3"  "LAME3.87 (beta 1, Sep 27 2000)" "LAME3.88 (beta)"
 120                      if (empty($info['audio']['encoder']) || (strlen($PossiblyLongerLAMEversion_NewString) > strlen($info['audio']['encoder']))) {
 121                          $info['audio']['encoder'] = $PossiblyLongerLAMEversion_NewString;
 122                      }
 123                  }
 124              }
 125          }
 126          if (!empty($info['audio']['encoder'])) {
 127              $info['audio']['encoder'] = rtrim($info['audio']['encoder'], "\x00 ");
 128          }
 129  
 130          switch (isset($info['mpeg']['audio']['layer']) ? $info['mpeg']['audio']['layer'] : '') {
 131              case 1:
 132              case 2:
 133                  $info['audio']['dataformat'] = 'mp'.$info['mpeg']['audio']['layer'];
 134                  break;
 135          }
 136          if (isset($info['fileformat']) && ($info['fileformat'] == 'mp3')) {
 137              switch ($info['audio']['dataformat']) {
 138                  case 'mp1':
 139                  case 'mp2':
 140                  case 'mp3':
 141                      $info['fileformat'] = $info['audio']['dataformat'];
 142                      break;
 143  
 144                  default:
 145                      $this->warning('Expecting [audio][dataformat] to be mp1/mp2/mp3 when fileformat == mp3, [audio][dataformat] actually "'.$info['audio']['dataformat'].'"');
 146                      break;
 147              }
 148          }
 149  
 150          if (empty($info['fileformat'])) {
 151              unset($info['fileformat']);
 152              unset($info['audio']['bitrate_mode']);
 153              unset($info['avdataoffset']);
 154              unset($info['avdataend']);
 155              return false;
 156          }
 157  
 158          $info['mime_type']         = 'audio/mpeg';
 159          $info['audio']['lossless'] = false;
 160  
 161          // Calculate playtime
 162          if (!isset($info['playtime_seconds']) && isset($info['audio']['bitrate']) && ($info['audio']['bitrate'] > 0)) {
 163              // https://github.com/JamesHeinrich/getID3/issues/161
 164              // VBR header frame contains ~0.026s of silent audio data, but is not actually part of the original encoding and should be ignored
 165              $xingVBRheaderFrameLength = ((isset($info['mpeg']['audio']['VBR_frames']) && isset($info['mpeg']['audio']['framelength'])) ? $info['mpeg']['audio']['framelength'] : 0);
 166  
 167              $info['playtime_seconds'] = ($info['avdataend'] - $info['avdataoffset'] - $xingVBRheaderFrameLength) * 8 / $info['audio']['bitrate'];
 168          }
 169  
 170          $info['audio']['encoder_options'] = $this->GuessEncoderOptions();
 171  
 172          return true;
 173      }
 174  
 175      /**
 176       * @return string
 177       */
 178  	public function GuessEncoderOptions() {
 179          // shortcuts
 180          $info = &$this->getid3->info;
 181          $thisfile_mpeg_audio = array();
 182          $thisfile_mpeg_audio_lame = array();
 183          if (!empty($info['mpeg']['audio'])) {
 184              $thisfile_mpeg_audio = &$info['mpeg']['audio'];
 185              if (!empty($thisfile_mpeg_audio['LAME'])) {
 186                  $thisfile_mpeg_audio_lame = &$thisfile_mpeg_audio['LAME'];
 187              }
 188          }
 189  
 190          $encoder_options = '';
 191          static $NamedPresetBitrates = array(16, 24, 40, 56, 112, 128, 160, 192, 256);
 192  
 193          if (isset($thisfile_mpeg_audio['VBR_method']) && ($thisfile_mpeg_audio['VBR_method'] == 'Fraunhofer') && !empty($thisfile_mpeg_audio['VBR_quality'])) {
 194  
 195              $encoder_options = 'VBR q'.$thisfile_mpeg_audio['VBR_quality'];
 196  
 197          } elseif (!empty($thisfile_mpeg_audio_lame['preset_used']) && isset($thisfile_mpeg_audio_lame['preset_used_id']) && (!in_array($thisfile_mpeg_audio_lame['preset_used_id'], $NamedPresetBitrates))) {
 198  
 199              $encoder_options = $thisfile_mpeg_audio_lame['preset_used'];
 200  
 201          } elseif (!empty($thisfile_mpeg_audio_lame['vbr_quality'])) {
 202  
 203              static $KnownEncoderValues = array();
 204              if (empty($KnownEncoderValues)) {
 205  
 206                  //$KnownEncoderValues[abrbitrate_minbitrate][vbr_quality][raw_vbr_method][raw_noise_shaping][raw_stereo_mode][ath_type][lowpass_frequency] = 'preset name';
 207                  $KnownEncoderValues[0xFF][58][1][1][3][2][20500] = '--alt-preset insane';        // 3.90,   3.90.1, 3.92
 208                  $KnownEncoderValues[0xFF][58][1][1][3][2][20600] = '--alt-preset insane';        // 3.90.2, 3.90.3, 3.91
 209                  $KnownEncoderValues[0xFF][57][1][1][3][4][20500] = '--alt-preset insane';        // 3.94,   3.95
 210                  $KnownEncoderValues['**'][78][3][2][3][2][19500] = '--alt-preset extreme';       // 3.90,   3.90.1, 3.92
 211                  $KnownEncoderValues['**'][78][3][2][3][2][19600] = '--alt-preset extreme';       // 3.90.2, 3.91
 212                  $KnownEncoderValues['**'][78][3][1][3][2][19600] = '--alt-preset extreme';       // 3.90.3
 213                  $KnownEncoderValues['**'][78][4][2][3][2][19500] = '--alt-preset fast extreme';  // 3.90,   3.90.1, 3.92
 214                  $KnownEncoderValues['**'][78][4][2][3][2][19600] = '--alt-preset fast extreme';  // 3.90.2, 3.90.3, 3.91
 215                  $KnownEncoderValues['**'][78][3][2][3][4][19000] = '--alt-preset standard';      // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
 216                  $KnownEncoderValues['**'][78][3][1][3][4][19000] = '--alt-preset standard';      // 3.90.3
 217                  $KnownEncoderValues['**'][78][4][2][3][4][19000] = '--alt-preset fast standard'; // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
 218                  $KnownEncoderValues['**'][78][4][1][3][4][19000] = '--alt-preset fast standard'; // 3.90.3
 219                  $KnownEncoderValues['**'][88][4][1][3][3][19500] = '--r3mix';                    // 3.90,   3.90.1, 3.92
 220                  $KnownEncoderValues['**'][88][4][1][3][3][19600] = '--r3mix';                    // 3.90.2, 3.90.3, 3.91
 221                  $KnownEncoderValues['**'][67][4][1][3][4][18000] = '--r3mix';                    // 3.94,   3.95
 222                  $KnownEncoderValues['**'][68][3][2][3][4][18000] = '--alt-preset medium';        // 3.90.3
 223                  $KnownEncoderValues['**'][68][4][2][3][4][18000] = '--alt-preset fast medium';   // 3.90.3
 224  
 225                  $KnownEncoderValues[0xFF][99][1][1][1][2][0]     = '--preset studio';            // 3.90,   3.90.1, 3.90.2, 3.91, 3.92
 226                  $KnownEncoderValues[0xFF][58][2][1][3][2][20600] = '--preset studio';            // 3.90.3, 3.93.1
 227                  $KnownEncoderValues[0xFF][58][2][1][3][2][20500] = '--preset studio';            // 3.93
 228                  $KnownEncoderValues[0xFF][57][2][1][3][4][20500] = '--preset studio';            // 3.94,   3.95
 229                  $KnownEncoderValues[0xC0][88][1][1][1][2][0]     = '--preset cd';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 230                  $KnownEncoderValues[0xC0][58][2][2][3][2][19600] = '--preset cd';                // 3.90.3, 3.93.1
 231                  $KnownEncoderValues[0xC0][58][2][2][3][2][19500] = '--preset cd';                // 3.93
 232                  $KnownEncoderValues[0xC0][57][2][1][3][4][19500] = '--preset cd';                // 3.94,   3.95
 233                  $KnownEncoderValues[0xA0][78][1][1][3][2][18000] = '--preset hifi';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 234                  $KnownEncoderValues[0xA0][58][2][2][3][2][18000] = '--preset hifi';              // 3.90.3, 3.93,   3.93.1
 235                  $KnownEncoderValues[0xA0][57][2][1][3][4][18000] = '--preset hifi';              // 3.94,   3.95
 236                  $KnownEncoderValues[0x80][67][1][1][3][2][18000] = '--preset tape';              // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 237                  $KnownEncoderValues[0x80][67][1][1][3][2][15000] = '--preset radio';             // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 238                  $KnownEncoderValues[0x70][67][1][1][3][2][15000] = '--preset fm';                // 3.90,   3.90.1, 3.90.2,   3.91, 3.92
 239                  $KnownEncoderValues[0x70][58][2][2][3][2][16000] = '--preset tape/radio/fm';     // 3.90.3, 3.93,   3.93.1
 240                  $KnownEncoderValues[0x70][57][2][1][3][4][16000] = '--preset tape/radio/fm';     // 3.94,   3.95
 241                  $KnownEncoderValues[0x38][58][2][2][0][2][10000] = '--preset voice';             // 3.90.3, 3.93,   3.93.1
 242                  $KnownEncoderValues[0x38][57][2][1][0][4][15000] = '--preset voice';             // 3.94,   3.95
 243                  $KnownEncoderValues[0x38][57][2][1][0][4][16000] = '--preset voice';             // 3.94a14
 244                  $KnownEncoderValues[0x28][65][1][1][0][2][7500]  = '--preset mw-us';             // 3.90,   3.90.1, 3.92
 245                  $KnownEncoderValues[0x28][65][1][1][0][2][7600]  = '--preset mw-us';             // 3.90.2, 3.91
 246                  $KnownEncoderValues[0x28][58][2][2][0][2][7000]  = '--preset mw-us';             // 3.90.3, 3.93,   3.93.1
 247                  $KnownEncoderValues[0x28][57][2][1][0][4][10500] = '--preset mw-us';             // 3.94,   3.95
 248                  $KnownEncoderValues[0x28][57][2][1][0][4][11200] = '--preset mw-us';             // 3.94a14
 249                  $KnownEncoderValues[0x28][57][2][1][0][4][8800]  = '--preset mw-us';             // 3.94a15
 250                  $KnownEncoderValues[0x18][58][2][2][0][2][4000]  = '--preset phon+/lw/mw-eu/sw'; // 3.90.3, 3.93.1
 251                  $KnownEncoderValues[0x18][58][2][2][0][2][3900]  = '--preset phon+/lw/mw-eu/sw'; // 3.93
 252                  $KnownEncoderValues[0x18][57][2][1][0][4][5900]  = '--preset phon+/lw/mw-eu/sw'; // 3.94,   3.95
 253                  $KnownEncoderValues[0x18][57][2][1][0][4][6200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a14
 254                  $KnownEncoderValues[0x18][57][2][1][0][4][3200]  = '--preset phon+/lw/mw-eu/sw'; // 3.94a15
 255                  $KnownEncoderValues[0x10][58][2][2][0][2][3800]  = '--preset phone';             // 3.90.3, 3.93.1
 256                  $KnownEncoderValues[0x10][58][2][2][0][2][3700]  = '--preset phone';             // 3.93
 257                  $KnownEncoderValues[0x10][57][2][1][0][4][5600]  = '--preset phone';             // 3.94,   3.95
 258              }
 259  
 260              if (isset($KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {
 261  
 262                  $encoder_options = $KnownEncoderValues[$thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate']][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
 263  
 264              } elseif (isset($KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']])) {
 265  
 266                  $encoder_options = $KnownEncoderValues['**'][$thisfile_mpeg_audio_lame['vbr_quality']][$thisfile_mpeg_audio_lame['raw']['vbr_method']][$thisfile_mpeg_audio_lame['raw']['noise_shaping']][$thisfile_mpeg_audio_lame['raw']['stereo_mode']][$thisfile_mpeg_audio_lame['ath_type']][$thisfile_mpeg_audio_lame['lowpass_frequency']];
 267  
 268              } elseif ($info['audio']['bitrate_mode'] == 'vbr') {
 269  
 270                  // http://gabriel.mp3-tech.org/mp3infotag.html
 271                  // int    Quality = (100 - 10 * gfp->VBR_q - gfp->quality)h
 272  
 273  
 274                  $LAME_V_value = 10 - ceil($thisfile_mpeg_audio_lame['vbr_quality'] / 10);
 275                  $LAME_q_value = 100 - $thisfile_mpeg_audio_lame['vbr_quality'] - ($LAME_V_value * 10);
 276                  $encoder_options = '-V'.$LAME_V_value.' -q'.$LAME_q_value;
 277  
 278              } elseif ($info['audio']['bitrate_mode'] == 'cbr') {
 279  
 280                  $encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
 281  
 282              } else {
 283  
 284                  $encoder_options = strtoupper($info['audio']['bitrate_mode']);
 285  
 286              }
 287  
 288          } elseif (!empty($thisfile_mpeg_audio_lame['bitrate_abr'])) {
 289  
 290              $encoder_options = 'ABR'.$thisfile_mpeg_audio_lame['bitrate_abr'];
 291  
 292          } elseif (!empty($info['audio']['bitrate'])) {
 293  
 294              if ($info['audio']['bitrate_mode'] == 'cbr') {
 295                  $encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
 296              } else {
 297                  $encoder_options = strtoupper($info['audio']['bitrate_mode']);
 298              }
 299  
 300          }
 301          if (!empty($thisfile_mpeg_audio_lame['bitrate_min'])) {
 302              $encoder_options .= ' -b'.$thisfile_mpeg_audio_lame['bitrate_min'];
 303          }
 304  
 305          if (!empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']) || !empty($thisfile_mpeg_audio_lame['encoding_flags']['nogap_next'])) {
 306              $encoder_options .= ' --nogap';
 307          }
 308  
 309          if (!empty($thisfile_mpeg_audio_lame['lowpass_frequency'])) {
 310              $ExplodedOptions = explode(' ', $encoder_options, 4);
 311              if ($ExplodedOptions[0] == '--r3mix') {
 312                  $ExplodedOptions[1] = 'r3mix';
 313              }
 314              switch ($ExplodedOptions[0]) {
 315                  case '--preset':
 316                  case '--alt-preset':
 317                  case '--r3mix':
 318                      if ($ExplodedOptions[1] == 'fast') {
 319                          $ExplodedOptions[1] .= ' '.$ExplodedOptions[2];
 320                      }
 321                      switch ($ExplodedOptions[1]) {
 322                          case 'portable':
 323                          case 'medium':
 324                          case 'standard':
 325                          case 'extreme':
 326                          case 'insane':
 327                          case 'fast portable':
 328                          case 'fast medium':
 329                          case 'fast standard':
 330                          case 'fast extreme':
 331                          case 'fast insane':
 332                          case 'r3mix':
 333                              static $ExpectedLowpass = array(
 334                                      'insane|20500'        => 20500,
 335                                      'insane|20600'        => 20600,  // 3.90.2, 3.90.3, 3.91
 336                                      'medium|18000'        => 18000,
 337                                      'fast medium|18000'   => 18000,
 338                                      'extreme|19500'       => 19500,  // 3.90,   3.90.1, 3.92, 3.95
 339                                      'extreme|19600'       => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
 340                                      'fast extreme|19500'  => 19500,  // 3.90,   3.90.1, 3.92, 3.95
 341                                      'fast extreme|19600'  => 19600,  // 3.90.2, 3.90.3, 3.91, 3.93.1
 342                                      'standard|19000'      => 19000,
 343                                      'fast standard|19000' => 19000,
 344                                      'r3mix|19500'         => 19500,  // 3.90,   3.90.1, 3.92
 345                                      'r3mix|19600'         => 19600,  // 3.90.2, 3.90.3, 3.91
 346                                      'r3mix|18000'         => 18000,  // 3.94,   3.95
 347                                  );
 348                              if (!isset($ExpectedLowpass[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio_lame['lowpass_frequency']]) && ($thisfile_mpeg_audio_lame['lowpass_frequency'] < 22050) && (round($thisfile_mpeg_audio_lame['lowpass_frequency'] / 1000) < round($thisfile_mpeg_audio['sample_rate'] / 2000))) {
 349                                  $encoder_options .= ' --lowpass '.$thisfile_mpeg_audio_lame['lowpass_frequency'];
 350                              }
 351                              break;
 352  
 353                          default:
 354                              break;
 355                      }
 356                      break;
 357              }
 358          }
 359  
 360          if (isset($thisfile_mpeg_audio_lame['raw']['source_sample_freq'])) {
 361              if (($thisfile_mpeg_audio['sample_rate'] == 44100) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 1)) {
 362                  $encoder_options .= ' --resample 44100';
 363              } elseif (($thisfile_mpeg_audio['sample_rate'] == 48000) && ($thisfile_mpeg_audio_lame['raw']['source_sample_freq'] != 2)) {
 364                  $encoder_options .= ' --resample 48000';
 365              } elseif ($thisfile_mpeg_audio['sample_rate'] < 44100) {
 366                  switch ($thisfile_mpeg_audio_lame['raw']['source_sample_freq']) {
 367                      case 0: // <= 32000
 368                          // may or may not be same as source frequency - ignore
 369                          break;
 370                      case 1: // 44100
 371                      case 2: // 48000
 372                      case 3: // 48000+
 373                          $ExplodedOptions = explode(' ', $encoder_options, 4);
 374                          switch ($ExplodedOptions[0]) {
 375                              case '--preset':
 376                              case '--alt-preset':
 377                                  switch ($ExplodedOptions[1]) {
 378                                      case 'fast':
 379                                      case 'portable':
 380                                      case 'medium':
 381                                      case 'standard':
 382                                      case 'extreme':
 383                                      case 'insane':
 384                                          $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
 385                                          break;
 386  
 387                                      default:
 388                                          static $ExpectedResampledRate = array(
 389                                                  'phon+/lw/mw-eu/sw|16000' => 16000,
 390                                                  'mw-us|24000'             => 24000, // 3.95
 391                                                  'mw-us|32000'             => 32000, // 3.93
 392                                                  'mw-us|16000'             => 16000, // 3.92
 393                                                  'phone|16000'             => 16000,
 394                                                  'phone|11025'             => 11025, // 3.94a15
 395                                                  'radio|32000'             => 32000, // 3.94a15
 396                                                  'fm/radio|32000'          => 32000, // 3.92
 397                                                  'fm|32000'                => 32000, // 3.90
 398                                                  'voice|32000'             => 32000);
 399                                          if (!isset($ExpectedResampledRate[$ExplodedOptions[1].'|'.$thisfile_mpeg_audio['sample_rate']])) {
 400                                              $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
 401                                          }
 402                                          break;
 403                                  }
 404                                  break;
 405  
 406                              case '--r3mix':
 407                              default:
 408                                  $encoder_options .= ' --resample '.$thisfile_mpeg_audio['sample_rate'];
 409                                  break;
 410                          }
 411                          break;
 412                  }
 413              }
 414          }
 415          if (empty($encoder_options) && !empty($info['audio']['bitrate']) && !empty($info['audio']['bitrate_mode'])) {
 416              //$encoder_options = strtoupper($info['audio']['bitrate_mode']).ceil($info['audio']['bitrate'] / 1000);
 417              $encoder_options = strtoupper($info['audio']['bitrate_mode']);
 418          }
 419  
 420          return $encoder_options;
 421      }
 422  
 423      /**
 424       * @param int   $offset
 425       * @param array $info
 426       * @param bool  $recursivesearch
 427       * @param bool  $ScanAsCBR
 428       * @param bool  $FastMPEGheaderScan
 429       *
 430       * @return bool
 431       */
 432  	public function decodeMPEGaudioHeader($offset, &$info, $recursivesearch=true, $ScanAsCBR=false, $FastMPEGheaderScan=false) {
 433          static $MPEGaudioVersionLookup;
 434          static $MPEGaudioLayerLookup;
 435          static $MPEGaudioBitrateLookup;
 436          static $MPEGaudioFrequencyLookup;
 437          static $MPEGaudioChannelModeLookup;
 438          static $MPEGaudioModeExtensionLookup;
 439          static $MPEGaudioEmphasisLookup;
 440          if (empty($MPEGaudioVersionLookup)) {
 441              $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
 442              $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
 443              $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
 444              $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
 445              $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
 446              $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
 447              $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
 448          }
 449  
 450          if ($this->fseek($offset) != 0) {
 451              $this->error('decodeMPEGaudioHeader() failed to seek to next offset at '.$offset);
 452              return false;
 453          }
 454          //$headerstring = $this->fread(1441); // worst-case max length = 32kHz @ 320kbps layer 3 = 1441 bytes/frame
 455          $headerstring = $this->fread(226); // LAME header at offset 36 + 190 bytes of Xing/LAME data
 456  
 457          // MP3 audio frame structure:
 458          // $aa $aa $aa $aa [$bb $bb] $cc...
 459          // where $aa..$aa is the four-byte mpeg-audio header (below)
 460          // $bb $bb is the optional 2-byte CRC
 461          // and $cc... is the audio data
 462  
 463          $head4 = substr($headerstring, 0, 4);
 464          $head4_key = getid3_lib::PrintHexBytes($head4, true, false, false);
 465          static $MPEGaudioHeaderDecodeCache = array();
 466          if (isset($MPEGaudioHeaderDecodeCache[$head4_key])) {
 467              $MPEGheaderRawArray = $MPEGaudioHeaderDecodeCache[$head4_key];
 468          } else {
 469              $MPEGheaderRawArray = self::MPEGaudioHeaderDecode($head4);
 470              $MPEGaudioHeaderDecodeCache[$head4_key] = $MPEGheaderRawArray;
 471          }
 472  
 473          static $MPEGaudioHeaderValidCache = array();
 474          if (!isset($MPEGaudioHeaderValidCache[$head4_key])) { // Not in cache
 475              //$MPEGaudioHeaderValidCache[$head4_key] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, true);  // allow badly-formatted freeformat (from LAME 3.90 - 3.93.1)
 476              $MPEGaudioHeaderValidCache[$head4_key] = self::MPEGaudioHeaderValid($MPEGheaderRawArray, false, false);
 477          }
 478  
 479          // shortcut
 480          if (!isset($info['mpeg']['audio'])) {
 481              $info['mpeg']['audio'] = array();
 482          }
 483          $thisfile_mpeg_audio = &$info['mpeg']['audio'];
 484  
 485          if ($MPEGaudioHeaderValidCache[$head4_key]) {
 486              $thisfile_mpeg_audio['raw'] = $MPEGheaderRawArray;
 487          } else {
 488              $this->error('Invalid MPEG audio header ('.getid3_lib::PrintHexBytes($head4).') at offset '.$offset);
 489              return false;
 490          }
 491  
 492          if (!$FastMPEGheaderScan) {
 493              $thisfile_mpeg_audio['version']       = $MPEGaudioVersionLookup[$thisfile_mpeg_audio['raw']['version']];
 494              $thisfile_mpeg_audio['layer']         = $MPEGaudioLayerLookup[$thisfile_mpeg_audio['raw']['layer']];
 495  
 496              $thisfile_mpeg_audio['channelmode']   = $MPEGaudioChannelModeLookup[$thisfile_mpeg_audio['raw']['channelmode']];
 497              $thisfile_mpeg_audio['channels']      = (($thisfile_mpeg_audio['channelmode'] == 'mono') ? 1 : 2);
 498              $thisfile_mpeg_audio['sample_rate']   = $MPEGaudioFrequencyLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['raw']['sample_rate']];
 499              $thisfile_mpeg_audio['protection']    = !$thisfile_mpeg_audio['raw']['protection'];
 500              $thisfile_mpeg_audio['private']       = (bool) $thisfile_mpeg_audio['raw']['private'];
 501              $thisfile_mpeg_audio['modeextension'] = $MPEGaudioModeExtensionLookup[$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['modeextension']];
 502              $thisfile_mpeg_audio['copyright']     = (bool) $thisfile_mpeg_audio['raw']['copyright'];
 503              $thisfile_mpeg_audio['original']      = (bool) $thisfile_mpeg_audio['raw']['original'];
 504              $thisfile_mpeg_audio['emphasis']      = $MPEGaudioEmphasisLookup[$thisfile_mpeg_audio['raw']['emphasis']];
 505  
 506              $info['audio']['channels']    = $thisfile_mpeg_audio['channels'];
 507              $info['audio']['sample_rate'] = $thisfile_mpeg_audio['sample_rate'];
 508  
 509              if ($thisfile_mpeg_audio['protection']) {
 510                  $thisfile_mpeg_audio['crc'] = getid3_lib::BigEndian2Int(substr($headerstring, 4, 2));
 511              }
 512          }
 513  
 514          if ($thisfile_mpeg_audio['raw']['bitrate'] == 15) {
 515              // http://www.hydrogenaudio.org/?act=ST&f=16&t=9682&st=0
 516              $this->warning('Invalid bitrate index (15), this is a known bug in free-format MP3s encoded by LAME v3.90 - 3.93.1');
 517              $thisfile_mpeg_audio['raw']['bitrate'] = 0;
 518          }
 519          $thisfile_mpeg_audio['padding'] = (bool) $thisfile_mpeg_audio['raw']['padding'];
 520          $thisfile_mpeg_audio['bitrate'] = $MPEGaudioBitrateLookup[$thisfile_mpeg_audio['version']][$thisfile_mpeg_audio['layer']][$thisfile_mpeg_audio['raw']['bitrate']];
 521  
 522          if (($thisfile_mpeg_audio['bitrate'] == 'free') && ($offset == $info['avdataoffset'])) {
 523              // only skip multiple frame check if free-format bitstream found at beginning of file
 524              // otherwise is quite possibly simply corrupted data
 525              $recursivesearch = false;
 526          }
 527  
 528          // For Layer 2 there are some combinations of bitrate and mode which are not allowed.
 529          if (!$FastMPEGheaderScan && ($thisfile_mpeg_audio['layer'] == '2')) {
 530  
 531              $info['audio']['dataformat'] = 'mp2';
 532              switch ($thisfile_mpeg_audio['channelmode']) {
 533  
 534                  case 'mono':
 535                      if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] <= 192000)) {
 536                          // these are ok
 537                      } else {
 538                          $this->error($thisfile_mpeg_audio['bitrate'].'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.');
 539                          return false;
 540                      }
 541                      break;
 542  
 543                  case 'stereo':
 544                  case 'joint stereo':
 545                  case 'dual channel':
 546                      if (($thisfile_mpeg_audio['bitrate'] == 'free') || ($thisfile_mpeg_audio['bitrate'] == 64000) || ($thisfile_mpeg_audio['bitrate'] >= 96000)) {
 547                          // these are ok
 548                      } else {
 549                          $this->error(intval(round($thisfile_mpeg_audio['bitrate'] / 1000)).'kbps not allowed in Layer 2, '.$thisfile_mpeg_audio['channelmode'].'.');
 550                          return false;
 551                      }
 552                      break;
 553  
 554              }
 555  
 556          }
 557  
 558  
 559          if ($info['audio']['sample_rate'] > 0) {
 560              $thisfile_mpeg_audio['framelength'] = self::MPEGaudioFrameLength($thisfile_mpeg_audio['bitrate'], $thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['layer'], (int) $thisfile_mpeg_audio['padding'], $info['audio']['sample_rate']);
 561          }
 562  
 563          $nextframetestoffset = $offset + 1;
 564          if ($thisfile_mpeg_audio['bitrate'] != 'free') {
 565  
 566              $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
 567  
 568              if (isset($thisfile_mpeg_audio['framelength'])) {
 569                  $nextframetestoffset = $offset + $thisfile_mpeg_audio['framelength'];
 570              } else {
 571                  $this->error('Frame at offset('.$offset.') is has an invalid frame length.');
 572                  return false;
 573              }
 574  
 575          }
 576  
 577          $ExpectedNumberOfAudioBytes = 0;
 578  
 579          ////////////////////////////////////////////////////////////////////////////////////
 580          // Variable-bitrate headers
 581  
 582          if (substr($headerstring, 4 + 32, 4) == 'VBRI') {
 583              // Fraunhofer VBR header is hardcoded 'VBRI' at offset 0x24 (36)
 584              // specs taken from http://minnie.tuhs.org/pipermail/mp3encoder/2001-January/001800.html
 585  
 586              $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
 587              $thisfile_mpeg_audio['VBR_method']   = 'Fraunhofer';
 588              $info['audio']['codec']              = 'Fraunhofer';
 589  
 590              $SideInfoData = substr($headerstring, 4 + 2, 32);
 591  
 592              $FraunhoferVBROffset = 36;
 593  
 594              $thisfile_mpeg_audio['VBR_encoder_version']     = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  4, 2)); // VbriVersion
 595              $thisfile_mpeg_audio['VBR_encoder_delay']       = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  6, 2)); // VbriDelay
 596              $thisfile_mpeg_audio['VBR_quality']             = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset +  8, 2)); // VbriQuality
 597              $thisfile_mpeg_audio['VBR_bytes']               = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 10, 4)); // VbriStreamBytes
 598              $thisfile_mpeg_audio['VBR_frames']              = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 14, 4)); // VbriStreamFrames
 599              $thisfile_mpeg_audio['VBR_seek_offsets']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 18, 2)); // VbriTableSize
 600              $thisfile_mpeg_audio['VBR_seek_scale']          = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 20, 2)); // VbriTableScale
 601              $thisfile_mpeg_audio['VBR_entry_bytes']         = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 22, 2)); // VbriEntryBytes
 602              $thisfile_mpeg_audio['VBR_entry_frames']        = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset + 24, 2)); // VbriEntryFrames
 603  
 604              $ExpectedNumberOfAudioBytes = $thisfile_mpeg_audio['VBR_bytes'];
 605  
 606              $previousbyteoffset = $offset;
 607              for ($i = 0; $i < $thisfile_mpeg_audio['VBR_seek_offsets']; $i++) {
 608                  $Fraunhofer_OffsetN = getid3_lib::BigEndian2Int(substr($headerstring, $FraunhoferVBROffset, $thisfile_mpeg_audio['VBR_entry_bytes']));
 609                  $FraunhoferVBROffset += $thisfile_mpeg_audio['VBR_entry_bytes'];
 610                  $thisfile_mpeg_audio['VBR_offsets_relative'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']);
 611                  $thisfile_mpeg_audio['VBR_offsets_absolute'][$i] = ($Fraunhofer_OffsetN * $thisfile_mpeg_audio['VBR_seek_scale']) + $previousbyteoffset;
 612                  $previousbyteoffset += $Fraunhofer_OffsetN;
 613              }
 614  
 615  
 616          } else {
 617  
 618              // Xing VBR header is hardcoded 'Xing' at a offset 0x0D (13), 0x15 (21) or 0x24 (36)
 619              // depending on MPEG layer and number of channels
 620  
 621              $VBRidOffset = self::XingVBRidOffset($thisfile_mpeg_audio['version'], $thisfile_mpeg_audio['channelmode']);
 622              $SideInfoData = substr($headerstring, 4 + 2, $VBRidOffset - 4);
 623  
 624              if ((substr($headerstring, $VBRidOffset, strlen('Xing')) == 'Xing') || (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Info')) {
 625                  // 'Xing' is traditional Xing VBR frame
 626                  // 'Info' is LAME-encoded CBR (This was done to avoid CBR files to be recognized as traditional Xing VBR files by some decoders.)
 627                  // 'Info' *can* legally be used to specify a VBR file as well, however.
 628  
 629                  // http://www.multiweb.cz/twoinches/MP3inside.htm
 630                  //00..03 = "Xing" or "Info"
 631                  //04..07 = Flags:
 632                  //  0x01  Frames Flag     set if value for number of frames in file is stored
 633                  //  0x02  Bytes Flag      set if value for filesize in bytes is stored
 634                  //  0x04  TOC Flag        set if values for TOC are stored
 635                  //  0x08  VBR Scale Flag  set if values for VBR scale is stored
 636                  //08..11  Frames: Number of frames in file (including the first Xing/Info one)
 637                  //12..15  Bytes:  File length in Bytes
 638                  //16..115  TOC (Table of Contents):
 639                  //  Contains of 100 indexes (one Byte length) for easier lookup in file. Approximately solves problem with moving inside file.
 640                  //  Each Byte has a value according this formula:
 641                  //  (TOC[i] / 256) * fileLenInBytes
 642                  //  So if song lasts eg. 240 sec. and you want to jump to 60. sec. (and file is 5 000 000 Bytes length) you can use:
 643                  //  TOC[(60/240)*100] = TOC[25]
 644                  //  and corresponding Byte in file is then approximately at:
 645                  //  (TOC[25]/256) * 5000000
 646                  //116..119  VBR Scale
 647  
 648  
 649                  // should be safe to leave this at 'vbr' and let it be overriden to 'cbr' if a CBR preset/mode is used by LAME
 650  //                if (substr($headerstring, $VBRidOffset, strlen('Info')) == 'Xing') {
 651                      $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
 652                      $thisfile_mpeg_audio['VBR_method']   = 'Xing';
 653  //                } else {
 654  //                    $ScanAsCBR = true;
 655  //                    $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 656  //                }
 657  
 658                  $thisfile_mpeg_audio['xing_flags_raw'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 4, 4));
 659  
 660                  $thisfile_mpeg_audio['xing_flags']['frames']    = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000001);
 661                  $thisfile_mpeg_audio['xing_flags']['bytes']     = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000002);
 662                  $thisfile_mpeg_audio['xing_flags']['toc']       = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000004);
 663                  $thisfile_mpeg_audio['xing_flags']['vbr_scale'] = (bool) ($thisfile_mpeg_audio['xing_flags_raw'] & 0x00000008);
 664  
 665                  if ($thisfile_mpeg_audio['xing_flags']['frames']) {
 666                      $thisfile_mpeg_audio['VBR_frames'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset +  8, 4));
 667                      //$thisfile_mpeg_audio['VBR_frames']--; // don't count header Xing/Info frame
 668                  }
 669                  if ($thisfile_mpeg_audio['xing_flags']['bytes']) {
 670                      $thisfile_mpeg_audio['VBR_bytes']  = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 12, 4));
 671                  }
 672  
 673                  //if (($thisfile_mpeg_audio['bitrate'] == 'free') && !empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
 674                  //if (!empty($thisfile_mpeg_audio['VBR_frames']) && !empty($thisfile_mpeg_audio['VBR_bytes'])) {
 675                  if (!empty($thisfile_mpeg_audio['VBR_frames'])) {
 676                      $used_filesize  = 0;
 677                      if (!empty($thisfile_mpeg_audio['VBR_bytes'])) {
 678                          $used_filesize = $thisfile_mpeg_audio['VBR_bytes'];
 679                      } elseif (!empty($info['filesize'])) {
 680                          $used_filesize  = $info['filesize'];
 681                          $used_filesize -= (isset($info['id3v2']['headerlength']) ? intval($info['id3v2']['headerlength']) : 0);
 682                          $used_filesize -= (isset($info['id3v1']) ? 128 : 0);
 683                          $used_filesize -= (isset($info['tag_offset_end']) ? $info['tag_offset_end'] - $info['tag_offset_start'] : 0);
 684                          $this->warning('MP3.Xing header missing VBR_bytes, assuming MPEG audio portion of file is '.number_format($used_filesize).' bytes');
 685                      }
 686  
 687                      $framelengthfloat = $used_filesize / $thisfile_mpeg_audio['VBR_frames'];
 688  
 689                      if ($thisfile_mpeg_audio['layer'] == '1') {
 690                          // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
 691                          //$info['audio']['bitrate'] = ((($framelengthfloat / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
 692                          $info['audio']['bitrate'] = ($framelengthfloat / 4) * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 12;
 693                      } else {
 694                          // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
 695                          //$info['audio']['bitrate'] = (($framelengthfloat - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
 696                          $info['audio']['bitrate'] = $framelengthfloat * $thisfile_mpeg_audio['sample_rate'] * (2 / $info['audio']['channels']) / 144;
 697                      }
 698                      $thisfile_mpeg_audio['framelength'] = floor($framelengthfloat);
 699                  }
 700  
 701                  if ($thisfile_mpeg_audio['xing_flags']['toc']) {
 702                      $LAMEtocData = substr($headerstring, $VBRidOffset + 16, 100);
 703                      for ($i = 0; $i < 100; $i++) {
 704                          $thisfile_mpeg_audio['toc'][$i] = ord($LAMEtocData[$i]);
 705                      }
 706                  }
 707                  if ($thisfile_mpeg_audio['xing_flags']['vbr_scale']) {
 708                      $thisfile_mpeg_audio['VBR_scale'] = getid3_lib::BigEndian2Int(substr($headerstring, $VBRidOffset + 116, 4));
 709                  }
 710  
 711  
 712                  // http://gabriel.mp3-tech.org/mp3infotag.html
 713                  if (substr($headerstring, $VBRidOffset + 120, 4) == 'LAME') {
 714  
 715                      // shortcut
 716                      $thisfile_mpeg_audio['LAME'] = array();
 717                      $thisfile_mpeg_audio_lame    = &$thisfile_mpeg_audio['LAME'];
 718  
 719  
 720                      $thisfile_mpeg_audio_lame['long_version']  = substr($headerstring, $VBRidOffset + 120, 20);
 721                      $thisfile_mpeg_audio_lame['short_version'] = substr($thisfile_mpeg_audio_lame['long_version'], 0, 9);
 722  
 723                      if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.90') {
 724  
 725                          // extra 11 chars are not part of version string when LAMEtag present
 726                          unset($thisfile_mpeg_audio_lame['long_version']);
 727  
 728                          // It the LAME tag was only introduced in LAME v3.90
 729                          // http://www.hydrogenaudio.org/?act=ST&f=15&t=9933
 730  
 731                          // Offsets of various bytes in http://gabriel.mp3-tech.org/mp3infotag.html
 732                          // are assuming a 'Xing' identifier offset of 0x24, which is the case for
 733                          // MPEG-1 non-mono, but not for other combinations
 734                          $LAMEtagOffsetContant = $VBRidOffset - 0x24;
 735  
 736                          // shortcuts
 737                          $thisfile_mpeg_audio_lame['RGAD']    = array('track'=>array(), 'album'=>array());
 738                          $thisfile_mpeg_audio_lame_RGAD       = &$thisfile_mpeg_audio_lame['RGAD'];
 739                          $thisfile_mpeg_audio_lame_RGAD_track = &$thisfile_mpeg_audio_lame_RGAD['track'];
 740                          $thisfile_mpeg_audio_lame_RGAD_album = &$thisfile_mpeg_audio_lame_RGAD['album'];
 741                          $thisfile_mpeg_audio_lame['raw'] = array();
 742                          $thisfile_mpeg_audio_lame_raw    = &$thisfile_mpeg_audio_lame['raw'];
 743  
 744                          // byte $9B  VBR Quality
 745                          // This field is there to indicate a quality level, although the scale was not precised in the original Xing specifications.
 746                          // Actually overwrites original Xing bytes
 747                          unset($thisfile_mpeg_audio['VBR_scale']);
 748                          $thisfile_mpeg_audio_lame['vbr_quality'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0x9B, 1));
 749  
 750                          // bytes $9C-$A4  Encoder short VersionString
 751                          $thisfile_mpeg_audio_lame['short_version'] = substr($headerstring, $LAMEtagOffsetContant + 0x9C, 9);
 752  
 753                          // byte $A5  Info Tag revision + VBR method
 754                          $LAMEtagRevisionVBRmethod = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA5, 1));
 755  
 756                          $thisfile_mpeg_audio_lame['tag_revision']   = ($LAMEtagRevisionVBRmethod & 0xF0) >> 4;
 757                          $thisfile_mpeg_audio_lame_raw['vbr_method'] =  $LAMEtagRevisionVBRmethod & 0x0F;
 758                          $thisfile_mpeg_audio_lame['vbr_method']     = self::LAMEvbrMethodLookup($thisfile_mpeg_audio_lame_raw['vbr_method']);
 759                          $thisfile_mpeg_audio['bitrate_mode']        = substr($thisfile_mpeg_audio_lame['vbr_method'], 0, 3); // usually either 'cbr' or 'vbr', but truncates 'vbr-old / vbr-rh' to 'vbr'
 760  
 761                          // byte $A6  Lowpass filter value
 762                          $thisfile_mpeg_audio_lame['lowpass_frequency'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA6, 1)) * 100;
 763  
 764                          // bytes $A7-$AE  Replay Gain
 765                          // http://privatewww.essex.ac.uk/~djmrob/replaygain/rg_data_format.html
 766                          // bytes $A7-$AA : 32 bit floating point "Peak signal amplitude"
 767                          if ($thisfile_mpeg_audio_lame['short_version'] >= 'LAME3.94b') {
 768                              // LAME 3.94a16 and later - 9.23 fixed point
 769                              // ie 0x0059E2EE / (2^23) = 5890798 / 8388608 = 0.7022378444671630859375
 770                              $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = (float) ((getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4))) / 8388608);
 771                          } else {
 772                              // LAME 3.94a15 and earlier - 32-bit floating point
 773                              // Actually 3.94a16 will fall in here too and be WRONG, but is hard to detect 3.94a16 vs 3.94a15
 774                              $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] = getid3_lib::LittleEndian2Float(substr($headerstring, $LAMEtagOffsetContant + 0xA7, 4));
 775                          }
 776                          if ($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'] == 0) {
 777                              unset($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
 778                          } else {
 779                              $thisfile_mpeg_audio_lame_RGAD['peak_db'] = getid3_lib::RGADamplitude2dB($thisfile_mpeg_audio_lame_RGAD['peak_amplitude']);
 780                          }
 781  
 782                          $thisfile_mpeg_audio_lame_raw['RGAD_track']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAB, 2));
 783                          $thisfile_mpeg_audio_lame_raw['RGAD_album']      =   getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAD, 2));
 784  
 785  
 786                          if ($thisfile_mpeg_audio_lame_raw['RGAD_track'] != 0) {
 787  
 788                              $thisfile_mpeg_audio_lame_RGAD_track['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0xE000) >> 13;
 789                              $thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x1C00) >> 10;
 790                              $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x0200) >> 9;
 791                              $thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'] =  $thisfile_mpeg_audio_lame_raw['RGAD_track'] & 0x01FF;
 792                              $thisfile_mpeg_audio_lame_RGAD_track['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['name']);
 793                              $thisfile_mpeg_audio_lame_RGAD_track['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['originator']);
 794                              $thisfile_mpeg_audio_lame_RGAD_track['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_track['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_track['raw']['sign_bit']);
 795  
 796                              if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
 797                                  $info['replay_gain']['track']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
 798                              }
 799                              $info['replay_gain']['track']['originator'] = $thisfile_mpeg_audio_lame_RGAD_track['originator'];
 800                              $info['replay_gain']['track']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_track['gain_db'];
 801                          } else {
 802                              unset($thisfile_mpeg_audio_lame_RGAD['track']);
 803                          }
 804                          if ($thisfile_mpeg_audio_lame_raw['RGAD_album'] != 0) {
 805  
 806                              $thisfile_mpeg_audio_lame_RGAD_album['raw']['name']        = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0xE000) >> 13;
 807                              $thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']  = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x1C00) >> 10;
 808                              $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']    = ($thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x0200) >> 9;
 809                              $thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'] = $thisfile_mpeg_audio_lame_raw['RGAD_album'] & 0x01FF;
 810                              $thisfile_mpeg_audio_lame_RGAD_album['name']       = getid3_lib::RGADnameLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['name']);
 811                              $thisfile_mpeg_audio_lame_RGAD_album['originator'] = getid3_lib::RGADoriginatorLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['originator']);
 812                              $thisfile_mpeg_audio_lame_RGAD_album['gain_db']    = getid3_lib::RGADadjustmentLookup($thisfile_mpeg_audio_lame_RGAD_album['raw']['gain_adjust'], $thisfile_mpeg_audio_lame_RGAD_album['raw']['sign_bit']);
 813  
 814                              if (!empty($thisfile_mpeg_audio_lame_RGAD['peak_amplitude'])) {
 815                                  $info['replay_gain']['album']['peak']   = $thisfile_mpeg_audio_lame_RGAD['peak_amplitude'];
 816                              }
 817                              $info['replay_gain']['album']['originator'] = $thisfile_mpeg_audio_lame_RGAD_album['originator'];
 818                              $info['replay_gain']['album']['adjustment'] = $thisfile_mpeg_audio_lame_RGAD_album['gain_db'];
 819                          } else {
 820                              unset($thisfile_mpeg_audio_lame_RGAD['album']);
 821                          }
 822                          if (empty($thisfile_mpeg_audio_lame_RGAD)) {
 823                              unset($thisfile_mpeg_audio_lame['RGAD']);
 824                          }
 825  
 826  
 827                          // byte $AF  Encoding flags + ATH Type
 828                          $EncodingFlagsATHtype = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xAF, 1));
 829                          $thisfile_mpeg_audio_lame['encoding_flags']['nspsytune']   = (bool) ($EncodingFlagsATHtype & 0x10);
 830                          $thisfile_mpeg_audio_lame['encoding_flags']['nssafejoint'] = (bool) ($EncodingFlagsATHtype & 0x20);
 831                          $thisfile_mpeg_audio_lame['encoding_flags']['nogap_next']  = (bool) ($EncodingFlagsATHtype & 0x40);
 832                          $thisfile_mpeg_audio_lame['encoding_flags']['nogap_prev']  = (bool) ($EncodingFlagsATHtype & 0x80);
 833                          $thisfile_mpeg_audio_lame['ath_type']                      =         $EncodingFlagsATHtype & 0x0F;
 834  
 835                          // byte $B0  if ABR {specified bitrate} else {minimal bitrate}
 836                          $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB0, 1));
 837                          if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 2) { // Average BitRate (ABR)
 838                              $thisfile_mpeg_audio_lame['bitrate_abr'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
 839                          } elseif ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) { // Constant BitRate (CBR)
 840                              // ignore
 841                          } elseif ($thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'] > 0) { // Variable BitRate (VBR) - minimum bitrate
 842                              $thisfile_mpeg_audio_lame['bitrate_min'] = $thisfile_mpeg_audio_lame['raw']['abrbitrate_minbitrate'];
 843                          }
 844  
 845                          // bytes $B1-$B3  Encoder delays
 846                          $EncoderDelays = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB1, 3));
 847                          $thisfile_mpeg_audio_lame['encoder_delay'] = ($EncoderDelays & 0xFFF000) >> 12;
 848                          $thisfile_mpeg_audio_lame['end_padding']   =  $EncoderDelays & 0x000FFF;
 849  
 850                          // byte $B4  Misc
 851                          $MiscByte = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB4, 1));
 852                          $thisfile_mpeg_audio_lame_raw['noise_shaping']       = ($MiscByte & 0x03);
 853                          $thisfile_mpeg_audio_lame_raw['stereo_mode']         = ($MiscByte & 0x1C) >> 2;
 854                          $thisfile_mpeg_audio_lame_raw['not_optimal_quality'] = ($MiscByte & 0x20) >> 5;
 855                          $thisfile_mpeg_audio_lame_raw['source_sample_freq']  = ($MiscByte & 0xC0) >> 6;
 856                          $thisfile_mpeg_audio_lame['noise_shaping']       = $thisfile_mpeg_audio_lame_raw['noise_shaping'];
 857                          $thisfile_mpeg_audio_lame['stereo_mode']         = self::LAMEmiscStereoModeLookup($thisfile_mpeg_audio_lame_raw['stereo_mode']);
 858                          $thisfile_mpeg_audio_lame['not_optimal_quality'] = (bool) $thisfile_mpeg_audio_lame_raw['not_optimal_quality'];
 859                          $thisfile_mpeg_audio_lame['source_sample_freq']  = self::LAMEmiscSourceSampleFrequencyLookup($thisfile_mpeg_audio_lame_raw['source_sample_freq']);
 860  
 861                          // byte $B5  MP3 Gain
 862                          $thisfile_mpeg_audio_lame_raw['mp3_gain'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB5, 1), false, true);
 863                          $thisfile_mpeg_audio_lame['mp3_gain_db']     = (getid3_lib::RGADamplitude2dB(2) / 4) * $thisfile_mpeg_audio_lame_raw['mp3_gain'];
 864                          $thisfile_mpeg_audio_lame['mp3_gain_factor'] = pow(2, ($thisfile_mpeg_audio_lame['mp3_gain_db'] / 6));
 865  
 866                          // bytes $B6-$B7  Preset and surround info
 867                          $PresetSurroundBytes = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB6, 2));
 868                          // Reserved                                                    = ($PresetSurroundBytes & 0xC000);
 869                          $thisfile_mpeg_audio_lame_raw['surround_info'] = ($PresetSurroundBytes & 0x3800);
 870                          $thisfile_mpeg_audio_lame['surround_info']     = self::LAMEsurroundInfoLookup($thisfile_mpeg_audio_lame_raw['surround_info']);
 871                          $thisfile_mpeg_audio_lame['preset_used_id']    = ($PresetSurroundBytes & 0x07FF);
 872                          $thisfile_mpeg_audio_lame['preset_used']       = self::LAMEpresetUsedLookup($thisfile_mpeg_audio_lame);
 873                          if (!empty($thisfile_mpeg_audio_lame['preset_used_id']) && empty($thisfile_mpeg_audio_lame['preset_used'])) {
 874                              $this->warning('Unknown LAME preset used ('.$thisfile_mpeg_audio_lame['preset_used_id'].') - please report to info@getid3.org');
 875                          }
 876                          if (($thisfile_mpeg_audio_lame['short_version'] == 'LAME3.90.') && !empty($thisfile_mpeg_audio_lame['preset_used_id'])) {
 877                              // this may change if 3.90.4 ever comes out
 878                              $thisfile_mpeg_audio_lame['short_version'] = 'LAME3.90.3';
 879                          }
 880  
 881                          // bytes $B8-$BB  MusicLength
 882                          $thisfile_mpeg_audio_lame['audio_bytes'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xB8, 4));
 883                          $ExpectedNumberOfAudioBytes = (($thisfile_mpeg_audio_lame['audio_bytes'] > 0) ? $thisfile_mpeg_audio_lame['audio_bytes'] : $thisfile_mpeg_audio['VBR_bytes']);
 884  
 885                          // bytes $BC-$BD  MusicCRC
 886                          $thisfile_mpeg_audio_lame['music_crc']    = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBC, 2));
 887  
 888                          // bytes $BE-$BF  CRC-16 of Info Tag
 889                          $thisfile_mpeg_audio_lame['lame_tag_crc'] = getid3_lib::BigEndian2Int(substr($headerstring, $LAMEtagOffsetContant + 0xBE, 2));
 890  
 891  
 892                          // LAME CBR
 893                          if ($thisfile_mpeg_audio_lame_raw['vbr_method'] == 1) {
 894  
 895                              $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 896                              $thisfile_mpeg_audio['bitrate'] = self::ClosestStandardMP3Bitrate($thisfile_mpeg_audio['bitrate']);
 897                              $info['audio']['bitrate'] = $thisfile_mpeg_audio['bitrate'];
 898                              //if (empty($thisfile_mpeg_audio['bitrate']) || (!empty($thisfile_mpeg_audio_lame['bitrate_min']) && ($thisfile_mpeg_audio_lame['bitrate_min'] != 255))) {
 899                              //    $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio_lame['bitrate_min'];
 900                              //}
 901  
 902                          }
 903  
 904                      }
 905                  }
 906  
 907              } else {
 908  
 909                  // not Fraunhofer or Xing VBR methods, most likely CBR (but could be VBR with no header)
 910                  $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 911                  if ($recursivesearch) {
 912                      $thisfile_mpeg_audio['bitrate_mode'] = 'vbr';
 913                      if ($this->RecursiveFrameScanning($offset, $nextframetestoffset, true)) {
 914                          $recursivesearch = false;
 915                          $thisfile_mpeg_audio['bitrate_mode'] = 'cbr';
 916                      }
 917                      if ($thisfile_mpeg_audio['bitrate_mode'] == 'vbr') {
 918                          $this->warning('VBR file with no VBR header. Bitrate values calculated from actual frame bitrates.');
 919                      }
 920                  }
 921  
 922              }
 923  
 924          }
 925  
 926          if (($ExpectedNumberOfAudioBytes > 0) && ($ExpectedNumberOfAudioBytes != ($info['avdataend'] - $info['avdataoffset']))) {
 927              if ($ExpectedNumberOfAudioBytes > ($info['avdataend'] - $info['avdataoffset'])) {
 928                  if ($this->isDependencyFor('matroska') || $this->isDependencyFor('riff')) {
 929                      // ignore, audio data is broken into chunks so will always be data "missing"
 930                  }
 931                  elseif (($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])) == 1) {
 932                      $this->warning('Last byte of data truncated (this is a known bug in Meracl ID3 Tag Writer before v1.3.5)');
 933                  }
 934                  else {
 935                      $this->warning('Probable truncated file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, only found '.($info['avdataend'] - $info['avdataoffset']).' (short by '.($ExpectedNumberOfAudioBytes - ($info['avdataend'] - $info['avdataoffset'])).' bytes)');
 936                  }
 937              } else {
 938                  if ((($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes) == 1) {
 939                  //    $prenullbytefileoffset = $this->ftell();
 940                  //    $this->fseek($info['avdataend']);
 941                  //    $PossibleNullByte = $this->fread(1);
 942                  //    $this->fseek($prenullbytefileoffset);
 943                  //    if ($PossibleNullByte === "\x00") {
 944                          $info['avdataend']--;
 945                  //        $this->warning('Extra null byte at end of MP3 data assumed to be RIFF padding and therefore ignored');
 946                  //    } else {
 947                  //        $this->warning('Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)');
 948                  //    }
 949                  } else {
 950                      $this->warning('Too much data in file: expecting '.$ExpectedNumberOfAudioBytes.' bytes of audio data, found '.($info['avdataend'] - $info['avdataoffset']).' ('.(($info['avdataend'] - $info['avdataoffset']) - $ExpectedNumberOfAudioBytes).' bytes too many)');
 951                  }
 952              }
 953          }
 954  
 955          if (($thisfile_mpeg_audio['bitrate'] == 'free') && empty($info['audio']['bitrate'])) {
 956              if (($offset == $info['avdataoffset']) && empty($thisfile_mpeg_audio['VBR_frames'])) {
 957                  $framebytelength = $this->FreeFormatFrameLength($offset, true);
 958                  if ($framebytelength > 0) {
 959                      $thisfile_mpeg_audio['framelength'] = $framebytelength;
 960                      if ($thisfile_mpeg_audio['layer'] == '1') {
 961                          // BitRate = (((FrameLengthInBytes / 4) - Padding) * SampleRate) / 12
 962                          $info['audio']['bitrate'] = ((($framebytelength / 4) - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 12;
 963                      } else {
 964                          // Bitrate = ((FrameLengthInBytes - Padding) * SampleRate) / 144
 965                          $info['audio']['bitrate'] = (($framebytelength - intval($thisfile_mpeg_audio['padding'])) * $thisfile_mpeg_audio['sample_rate']) / 144;
 966                      }
 967                  } else {
 968                      $this->error('Error calculating frame length of free-format MP3 without Xing/LAME header');
 969                  }
 970              }
 971          }
 972  
 973          if (isset($thisfile_mpeg_audio['VBR_frames']) ? $thisfile_mpeg_audio['VBR_frames'] : '') {
 974              switch ($thisfile_mpeg_audio['bitrate_mode']) {
 975                  case 'vbr':
 976                  case 'abr':
 977                      $bytes_per_frame = 1152;
 978                      if (($thisfile_mpeg_audio['version'] == '1') && ($thisfile_mpeg_audio['layer'] == 1)) {
 979                          $bytes_per_frame = 384;
 980                      } elseif ((($thisfile_mpeg_audio['version'] == '2') || ($thisfile_mpeg_audio['version'] == '2.5')) && ($thisfile_mpeg_audio['layer'] == 3)) {
 981                          $bytes_per_frame = 576;
 982                      }
 983                      $thisfile_mpeg_audio['VBR_bitrate'] = (isset($thisfile_mpeg_audio['VBR_bytes']) ? (($thisfile_mpeg_audio['VBR_bytes'] / $thisfile_mpeg_audio['VBR_frames']) * 8) * ($info['audio']['sample_rate'] / $bytes_per_frame) : 0);
 984                      if ($thisfile_mpeg_audio['VBR_bitrate'] > 0) {
 985                          $info['audio']['bitrate']       = $thisfile_mpeg_audio['VBR_bitrate'];
 986                          $thisfile_mpeg_audio['bitrate'] = $thisfile_mpeg_audio['VBR_bitrate']; // to avoid confusion
 987                      }
 988                      break;
 989              }
 990          }
 991  
 992          // End variable-bitrate headers
 993          ////////////////////////////////////////////////////////////////////////////////////
 994  
 995          if ($recursivesearch) {
 996  
 997              if (!$this->RecursiveFrameScanning($offset, $nextframetestoffset, $ScanAsCBR)) {
 998                  return false;
 999              }
1000  
1001          }
1002  
1003  
1004          //if (false) {
1005          //    // experimental side info parsing section - not returning anything useful yet
1006          //
1007          //    $SideInfoBitstream = getid3_lib::BigEndian2Bin($SideInfoData);
1008          //    $SideInfoOffset = 0;
1009          //
1010          //    if ($thisfile_mpeg_audio['version'] == '1') {
1011          //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
1012          //            // MPEG-1 (mono)
1013          //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1014          //            $SideInfoOffset += 9;
1015          //            $SideInfoOffset += 5;
1016          //        } else {
1017          //            // MPEG-1 (stereo, joint-stereo, dual-channel)
1018          //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1019          //            $SideInfoOffset += 9;
1020          //            $SideInfoOffset += 3;
1021          //        }
1022          //    } else { // 2 or 2.5
1023          //        if ($thisfile_mpeg_audio['channelmode'] == 'mono') {
1024          //            // MPEG-2, MPEG-2.5 (mono)
1025          //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1026          //            $SideInfoOffset += 8;
1027          //            $SideInfoOffset += 1;
1028          //        } else {
1029          //            // MPEG-2, MPEG-2.5 (stereo, joint-stereo, dual-channel)
1030          //            $thisfile_mpeg_audio['side_info']['main_data_begin'] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1031          //            $SideInfoOffset += 8;
1032          //            $SideInfoOffset += 2;
1033          //        }
1034          //    }
1035          //
1036          //    if ($thisfile_mpeg_audio['version'] == '1') {
1037          //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1038          //            for ($scfsi_band = 0; $scfsi_band < 4; $scfsi_band++) {
1039          //                $thisfile_mpeg_audio['scfsi'][$channel][$scfsi_band] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1040          //                $SideInfoOffset += 2;
1041          //            }
1042          //        }
1043          //    }
1044          //    for ($granule = 0; $granule < (($thisfile_mpeg_audio['version'] == '1') ? 2 : 1); $granule++) {
1045          //        for ($channel = 0; $channel < $info['audio']['channels']; $channel++) {
1046          //            $thisfile_mpeg_audio['part2_3_length'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 12);
1047          //            $SideInfoOffset += 12;
1048          //            $thisfile_mpeg_audio['big_values'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1049          //            $SideInfoOffset += 9;
1050          //            $thisfile_mpeg_audio['global_gain'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 8);
1051          //            $SideInfoOffset += 8;
1052          //            if ($thisfile_mpeg_audio['version'] == '1') {
1053          //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1054          //                $SideInfoOffset += 4;
1055          //            } else {
1056          //                $thisfile_mpeg_audio['scalefac_compress'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 9);
1057          //                $SideInfoOffset += 9;
1058          //            }
1059          //            $thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1060          //            $SideInfoOffset += 1;
1061          //
1062          //            if ($thisfile_mpeg_audio['window_switching_flag'][$granule][$channel] == '1') {
1063          //
1064          //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 2);
1065          //                $SideInfoOffset += 2;
1066          //                $thisfile_mpeg_audio['mixed_block_flag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1067          //                $SideInfoOffset += 1;
1068          //
1069          //                for ($region = 0; $region < 2; $region++) {
1070          //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1071          //                    $SideInfoOffset += 5;
1072          //                }
1073          //                $thisfile_mpeg_audio['table_select'][$granule][$channel][2] = 0;
1074          //
1075          //                for ($window = 0; $window < 3; $window++) {
1076          //                    $thisfile_mpeg_audio['subblock_gain'][$granule][$channel][$window] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1077          //                    $SideInfoOffset += 3;
1078          //                }
1079          //
1080          //            } else {
1081          //
1082          //                for ($region = 0; $region < 3; $region++) {
1083          //                    $thisfile_mpeg_audio['table_select'][$granule][$channel][$region] = substr($SideInfoBitstream, $SideInfoOffset, 5);
1084          //                    $SideInfoOffset += 5;
1085          //                }
1086          //
1087          //                $thisfile_mpeg_audio['region0_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 4);
1088          //                $SideInfoOffset += 4;
1089          //                $thisfile_mpeg_audio['region1_count'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 3);
1090          //                $SideInfoOffset += 3;
1091          //                $thisfile_mpeg_audio['block_type'][$granule][$channel] = 0;
1092          //            }
1093          //
1094          //            if ($thisfile_mpeg_audio['version'] == '1') {
1095          //                $thisfile_mpeg_audio['preflag'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1096          //                $SideInfoOffset += 1;
1097          //            }
1098          //            $thisfile_mpeg_audio['scalefac_scale'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1099          //            $SideInfoOffset += 1;
1100          //            $thisfile_mpeg_audio['count1table_select'][$granule][$channel] = substr($SideInfoBitstream, $SideInfoOffset, 1);
1101          //            $SideInfoOffset += 1;
1102          //        }
1103          //    }
1104          //}
1105  
1106          return true;
1107      }
1108  
1109      /**
1110       * @param int $offset
1111       * @param int $nextframetestoffset
1112       * @param bool $ScanAsCBR
1113       *
1114       * @return bool
1115       */
1116  	public function RecursiveFrameScanning(&$offset, &$nextframetestoffset, $ScanAsCBR) {
1117          $info = &$this->getid3->info;
1118          $firstframetestarray = array('error' => array(), 'warning'=> array(), 'avdataend' => $info['avdataend'], 'avdataoffset' => $info['avdataoffset']);
1119          $this->decodeMPEGaudioHeader($offset, $firstframetestarray, false);
1120  
1121          for ($i = 0; $i < GETID3_MP3_VALID_CHECK_FRAMES; $i++) {
1122              // check next GETID3_MP3_VALID_CHECK_FRAMES frames for validity, to make sure we haven't run across a false synch
1123              if (($nextframetestoffset + 4) >= $info['avdataend']) {
1124                  // end of file
1125                  return true;
1126              }
1127  
1128              $nextframetestarray = array('error' => array(), 'warning' => array(), 'avdataend' => $info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1129              if ($this->decodeMPEGaudioHeader($nextframetestoffset, $nextframetestarray, false)) {
1130                  if ($ScanAsCBR) {
1131                      // force CBR mode, used for trying to pick out invalid audio streams with valid(?) VBR headers, or VBR streams with no VBR header
1132                      if (!isset($nextframetestarray['mpeg']['audio']['bitrate']) || !isset($firstframetestarray['mpeg']['audio']['bitrate']) || ($nextframetestarray['mpeg']['audio']['bitrate'] != $firstframetestarray['mpeg']['audio']['bitrate'])) {
1133                          return false;
1134                      }
1135                  }
1136  
1137  
1138                  // next frame is OK, get ready to check the one after that
1139                  if (isset($nextframetestarray['mpeg']['audio']['framelength']) && ($nextframetestarray['mpeg']['audio']['framelength'] > 0)) {
1140                      $nextframetestoffset += $nextframetestarray['mpeg']['audio']['framelength'];
1141                  } else {
1142                      $this->error('Frame at offset ('.$offset.') is has an invalid frame length.');
1143                      return false;
1144                  }
1145  
1146              } elseif (!empty($firstframetestarray['mpeg']['audio']['framelength']) && (($nextframetestoffset + $firstframetestarray['mpeg']['audio']['framelength']) > $info['avdataend'])) {
1147  
1148                  // it's not the end of the file, but there's not enough data left for another frame, so assume it's garbage/padding and return OK
1149                  return true;
1150  
1151              } else {
1152  
1153                  // next frame is not valid, note the error and fail, so scanning can contiue for a valid frame sequence
1154                  $this->warning('Frame at offset ('.$offset.') is valid, but the next one at ('.$nextframetestoffset.') is not.');
1155  
1156                  return false;
1157              }
1158          }
1159          return true;
1160      }
1161  
1162      /**
1163       * @param int  $offset
1164       * @param bool $deepscan
1165       *
1166       * @return int|false
1167       */
1168  	public function FreeFormatFrameLength($offset, $deepscan=false) {
1169          $info = &$this->getid3->info;
1170  
1171          $this->fseek($offset);
1172          $MPEGaudioData = $this->fread(32768);
1173  
1174          $SyncPattern1 = substr($MPEGaudioData, 0, 4);
1175          // may be different pattern due to padding
1176          $SyncPattern2 = $SyncPattern1[0].$SyncPattern1[1].chr(ord($SyncPattern1[2]) | 0x02).$SyncPattern1[3];
1177          if ($SyncPattern2 === $SyncPattern1) {
1178              $SyncPattern2 = $SyncPattern1[0].$SyncPattern1[1].chr(ord($SyncPattern1[2]) & 0xFD).$SyncPattern1[3];
1179          }
1180  
1181          $framelength = false;
1182          $framelength1 = strpos($MPEGaudioData, $SyncPattern1, 4);
1183          $framelength2 = strpos($MPEGaudioData, $SyncPattern2, 4);
1184          if ($framelength1 > 4) {
1185              $framelength = $framelength1;
1186          }
1187          if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1188              $framelength = $framelength2;
1189          }
1190          if (!$framelength) {
1191  
1192              // LAME 3.88 has a different value for modeextension on the first frame vs the rest
1193              $framelength1 = strpos($MPEGaudioData, substr($SyncPattern1, 0, 3), 4);
1194              $framelength2 = strpos($MPEGaudioData, substr($SyncPattern2, 0, 3), 4);
1195  
1196              if ($framelength1 > 4) {
1197                  $framelength = $framelength1;
1198              }
1199              if (($framelength2 > 4) && ($framelength2 < $framelength1)) {
1200                  $framelength = $framelength2;
1201              }
1202              if (!$framelength) {
1203                  $this->error('Cannot find next free-format synch pattern ('.getid3_lib::PrintHexBytes($SyncPattern1).' or '.getid3_lib::PrintHexBytes($SyncPattern2).') after offset '.$offset);
1204                  return false;
1205              } else {
1206                  $this->warning('ModeExtension varies between first frame and other frames (known free-format issue in LAME 3.88)');
1207                  $info['audio']['codec']   = 'LAME';
1208                  $info['audio']['encoder'] = 'LAME3.88';
1209                  $SyncPattern1 = substr($SyncPattern1, 0, 3);
1210                  $SyncPattern2 = substr($SyncPattern2, 0, 3);
1211              }
1212          }
1213  
1214          if ($deepscan) {
1215  
1216              $ActualFrameLengthValues = array();
1217              $nextoffset = $offset + $framelength;
1218              while ($nextoffset < ($info['avdataend'] - 6)) {
1219                  $this->fseek($nextoffset - 1);
1220                  $NextSyncPattern = $this->fread(6);
1221                  if ((substr($NextSyncPattern, 1, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 1, strlen($SyncPattern2)) == $SyncPattern2)) {
1222                      // good - found where expected
1223                      $ActualFrameLengthValues[] = $framelength;
1224                  } elseif ((substr($NextSyncPattern, 0, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 0, strlen($SyncPattern2)) == $SyncPattern2)) {
1225                      // ok - found one byte earlier than expected (last frame wasn't padded, first frame was)
1226                      $ActualFrameLengthValues[] = ($framelength - 1);
1227                      $nextoffset--;
1228                  } elseif ((substr($NextSyncPattern, 2, strlen($SyncPattern1)) == $SyncPattern1) || (substr($NextSyncPattern, 2, strlen($SyncPattern2)) == $SyncPattern2)) {
1229                      // ok - found one byte later than expected (last frame was padded, first frame wasn't)
1230                      $ActualFrameLengthValues[] = ($framelength + 1);
1231                      $nextoffset++;
1232                  } else {
1233                      $this->error('Did not find expected free-format sync pattern at offset '.$nextoffset);
1234                      return false;
1235                  }
1236                  $nextoffset += $framelength;
1237              }
1238              if (count($ActualFrameLengthValues) > 0) {
1239                  $framelength = intval(round(array_sum($ActualFrameLengthValues) / count($ActualFrameLengthValues)));
1240              }
1241          }
1242          return $framelength;
1243      }
1244  
1245      /**
1246       * @return bool
1247       */
1248  	public function getOnlyMPEGaudioInfoBruteForce() {
1249          $MPEGaudioHeaderDecodeCache   = array();
1250          $MPEGaudioHeaderValidCache    = array();
1251          $MPEGaudioHeaderLengthCache   = array();
1252          $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1253          $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1254          $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1255          $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1256          $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1257          $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1258          $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1259          $LongMPEGversionLookup        = array();
1260          $LongMPEGlayerLookup          = array();
1261          $LongMPEGbitrateLookup        = array();
1262          $LongMPEGpaddingLookup        = array();
1263          $LongMPEGfrequencyLookup      = array();
1264          $Distribution['bitrate']      = array();
1265          $Distribution['frequency']    = array();
1266          $Distribution['layer']        = array();
1267          $Distribution['version']      = array();
1268          $Distribution['padding']      = array();
1269  
1270          $info = &$this->getid3->info;
1271          $this->fseek($info['avdataoffset']);
1272  
1273          $max_frames_scan = 5000;
1274          $frames_scanned  = 0;
1275  
1276          $previousvalidframe = $info['avdataoffset'];
1277          while ($this->ftell() < $info['avdataend']) {
1278              set_time_limit(30);
1279              $head4 = $this->fread(4);
1280              if (strlen($head4) < 4) {
1281                  break;
1282              }
1283              if ($head4[0] != "\xFF") {
1284                  for ($i = 1; $i < 4; $i++) {
1285                      if ($head4[$i] == "\xFF") {
1286                          $this->fseek($i - 4, SEEK_CUR);
1287                          continue 2;
1288                      }
1289                  }
1290                  continue;
1291              }
1292              if (!isset($MPEGaudioHeaderDecodeCache[$head4])) {
1293                  $MPEGaudioHeaderDecodeCache[$head4] = self::MPEGaudioHeaderDecode($head4);
1294              }
1295              if (!isset($MPEGaudioHeaderValidCache[$head4])) {
1296                  $MPEGaudioHeaderValidCache[$head4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$head4], false, false);
1297              }
1298              if ($MPEGaudioHeaderValidCache[$head4]) {
1299  
1300                  if (!isset($MPEGaudioHeaderLengthCache[$head4])) {
1301                      $LongMPEGversionLookup[$head4]   = $MPEGaudioVersionLookup[$MPEGaudioHeaderDecodeCache[$head4]['version']];
1302                      $LongMPEGlayerLookup[$head4]     = $MPEGaudioLayerLookup[$MPEGaudioHeaderDecodeCache[$head4]['layer']];
1303                      $LongMPEGbitrateLookup[$head4]   = $MPEGaudioBitrateLookup[$LongMPEGversionLookup[$head4]][$LongMPEGlayerLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['bitrate']];
1304                      $LongMPEGpaddingLookup[$head4]   = (bool) $MPEGaudioHeaderDecodeCache[$head4]['padding'];
1305                      $LongMPEGfrequencyLookup[$head4] = $MPEGaudioFrequencyLookup[$LongMPEGversionLookup[$head4]][$MPEGaudioHeaderDecodeCache[$head4]['sample_rate']];
1306                      $MPEGaudioHeaderLengthCache[$head4] = self::MPEGaudioFrameLength(
1307                          $LongMPEGbitrateLookup[$head4],
1308                          $LongMPEGversionLookup[$head4],
1309                          $LongMPEGlayerLookup[$head4],
1310                          $LongMPEGpaddingLookup[$head4],
1311                          $LongMPEGfrequencyLookup[$head4]);
1312                  }
1313                  if ($MPEGaudioHeaderLengthCache[$head4] > 4) {
1314                      $WhereWeWere = $this->ftell();
1315                      $this->fseek($MPEGaudioHeaderLengthCache[$head4] - 4, SEEK_CUR);
1316                      $next4 = $this->fread(4);
1317                      if ($next4[0] == "\xFF") {
1318                          if (!isset($MPEGaudioHeaderDecodeCache[$next4])) {
1319                              $MPEGaudioHeaderDecodeCache[$next4] = self::MPEGaudioHeaderDecode($next4);
1320                          }
1321                          if (!isset($MPEGaudioHeaderValidCache[$next4])) {
1322                              $MPEGaudioHeaderValidCache[$next4] = self::MPEGaudioHeaderValid($MPEGaudioHeaderDecodeCache[$next4], false, false);
1323                          }
1324                          if ($MPEGaudioHeaderValidCache[$next4]) {
1325                              $this->fseek(-4, SEEK_CUR);
1326  
1327                              getid3_lib::safe_inc($Distribution['bitrate'][$LongMPEGbitrateLookup[$head4]]);
1328                              getid3_lib::safe_inc($Distribution['layer'][$LongMPEGlayerLookup[$head4]]);
1329                              getid3_lib::safe_inc($Distribution['version'][$LongMPEGversionLookup[$head4]]);
1330                              getid3_lib::safe_inc($Distribution['padding'][intval($LongMPEGpaddingLookup[$head4])]);
1331                              getid3_lib::safe_inc($Distribution['frequency'][$LongMPEGfrequencyLookup[$head4]]);
1332                              if ($max_frames_scan && (++$frames_scanned >= $max_frames_scan)) {
1333                                  $pct_data_scanned = ($this->ftell() - $info['avdataoffset']) / ($info['avdataend'] - $info['avdataoffset']);
1334                                  $this->warning('too many MPEG audio frames to scan, only scanned first '.$max_frames_scan.' frames ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.');
1335                                  foreach ($Distribution as $key1 => $value1) {
1336                                      foreach ($value1 as $key2 => $value2) {
1337                                          $Distribution[$key1][$key2] = round($value2 / $pct_data_scanned);
1338                                      }
1339                                  }
1340                                  break;
1341                              }
1342                              continue;
1343                          }
1344                      }
1345                      unset($next4);
1346                      $this->fseek($WhereWeWere - 3);
1347                  }
1348  
1349              }
1350          }
1351          foreach ($Distribution as $key => $value) {
1352              ksort($Distribution[$key], SORT_NUMERIC);
1353          }
1354          ksort($Distribution['version'], SORT_STRING);
1355          $info['mpeg']['audio']['bitrate_distribution']   = $Distribution['bitrate'];
1356          $info['mpeg']['audio']['frequency_distribution'] = $Distribution['frequency'];
1357          $info['mpeg']['audio']['layer_distribution']     = $Distribution['layer'];
1358          $info['mpeg']['audio']['version_distribution']   = $Distribution['version'];
1359          $info['mpeg']['audio']['padding_distribution']   = $Distribution['padding'];
1360          if (count($Distribution['version']) > 1) {
1361              $this->error('Corrupt file - more than one MPEG version detected');
1362          }
1363          if (count($Distribution['layer']) > 1) {
1364              $this->error('Corrupt file - more than one MPEG layer detected');
1365          }
1366          if (count($Distribution['frequency']) > 1) {
1367              $this->error('Corrupt file - more than one MPEG sample rate detected');
1368          }
1369  
1370  
1371          $bittotal = 0;
1372          foreach ($Distribution['bitrate'] as $bitratevalue => $bitratecount) {
1373              if ($bitratevalue != 'free') {
1374                  $bittotal += ($bitratevalue * $bitratecount);
1375              }
1376          }
1377          $info['mpeg']['audio']['frame_count']  = array_sum($Distribution['bitrate']);
1378          if ($info['mpeg']['audio']['frame_count'] == 0) {
1379              $this->error('no MPEG audio frames found');
1380              return false;
1381          }
1382          $info['mpeg']['audio']['bitrate']      = ($bittotal / $info['mpeg']['audio']['frame_count']);
1383          $info['mpeg']['audio']['bitrate_mode'] = ((count($Distribution['bitrate']) > 0) ? 'vbr' : 'cbr');
1384          $info['mpeg']['audio']['sample_rate']  = getid3_lib::array_max($Distribution['frequency'], true);
1385  
1386          $info['audio']['bitrate']      = $info['mpeg']['audio']['bitrate'];
1387          $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1388          $info['audio']['sample_rate']  = $info['mpeg']['audio']['sample_rate'];
1389          $info['audio']['dataformat']   = 'mp'.getid3_lib::array_max($Distribution['layer'], true);
1390          $info['fileformat']            = $info['audio']['dataformat'];
1391  
1392          return true;
1393      }
1394  
1395      /**
1396       * @param int  $avdataoffset
1397       * @param bool $BitrateHistogram
1398       *
1399       * @return bool
1400       */
1401  	public function getOnlyMPEGaudioInfo($avdataoffset, $BitrateHistogram=false) {
1402          // looks for synch, decodes MPEG audio header
1403  
1404          $info = &$this->getid3->info;
1405  
1406          static $MPEGaudioVersionLookup;
1407          static $MPEGaudioLayerLookup;
1408          static $MPEGaudioBitrateLookup;
1409          if (empty($MPEGaudioVersionLookup)) {
1410              $MPEGaudioVersionLookup = self::MPEGaudioVersionArray();
1411              $MPEGaudioLayerLookup   = self::MPEGaudioLayerArray();
1412              $MPEGaudioBitrateLookup = self::MPEGaudioBitrateArray();
1413          }
1414  
1415          $this->fseek($avdataoffset);
1416          $sync_seek_buffer_size = min(128 * 1024, $info['avdataend'] - $avdataoffset);
1417          if ($sync_seek_buffer_size <= 0) {
1418              $this->error('Invalid $sync_seek_buffer_size at offset '.$avdataoffset);
1419              return false;
1420          }
1421          $header = $this->fread($sync_seek_buffer_size);
1422          $sync_seek_buffer_size = strlen($header);
1423          $SynchSeekOffset = 0;
1424          while ($SynchSeekOffset < $sync_seek_buffer_size) {
1425              if ((($avdataoffset + $SynchSeekOffset)  < $info['avdataend']) && !feof($this->getid3->fp)) {
1426  
1427                  if ($SynchSeekOffset > $sync_seek_buffer_size) {
1428                      // if a synch's not found within the first 128k bytes, then give up
1429                      $this->error('Could not find valid MPEG audio synch within the first '.round($sync_seek_buffer_size / 1024).'kB');
1430                      if (isset($info['audio']['bitrate'])) {
1431                          unset($info['audio']['bitrate']);
1432                      }
1433                      if (isset($info['mpeg']['audio'])) {
1434                          unset($info['mpeg']['audio']);
1435                      }
1436                      if (empty($info['mpeg'])) {
1437                          unset($info['mpeg']);
1438                      }
1439                      return false;
1440  
1441                  } elseif (feof($this->getid3->fp)) {
1442  
1443                      $this->error('Could not find valid MPEG audio synch before end of file');
1444                      if (isset($info['audio']['bitrate'])) {
1445                          unset($info['audio']['bitrate']);
1446                      }
1447                      if (isset($info['mpeg']['audio'])) {
1448                          unset($info['mpeg']['audio']);
1449                      }
1450                      if (isset($info['mpeg']) && (!is_array($info['mpeg']) || (count($info['mpeg']) == 0))) {
1451                          unset($info['mpeg']);
1452                      }
1453                      return false;
1454                  }
1455              }
1456  
1457              if (($SynchSeekOffset + 1) >= strlen($header)) {
1458                  $this->error('Could not find valid MPEG synch before end of file');
1459                  return false;
1460              }
1461  
1462              if (($header[$SynchSeekOffset] == "\xFF") && ($header[($SynchSeekOffset + 1)] > "\xE0")) { // synch detected
1463                  $FirstFrameAVDataOffset = null;
1464                  if (!isset($FirstFrameThisfileInfo) && !isset($info['mpeg']['audio'])) {
1465                      $FirstFrameThisfileInfo = $info;
1466                      $FirstFrameAVDataOffset = $avdataoffset + $SynchSeekOffset;
1467                      if (!$this->decodeMPEGaudioHeader($FirstFrameAVDataOffset, $FirstFrameThisfileInfo, false)) {
1468                          // if this is the first valid MPEG-audio frame, save it in case it's a VBR header frame and there's
1469                          // garbage between this frame and a valid sequence of MPEG-audio frames, to be restored below
1470                          unset($FirstFrameThisfileInfo);
1471                      }
1472                  }
1473  
1474                  $dummy = $info; // only overwrite real data if valid header found
1475                  if ($this->decodeMPEGaudioHeader($avdataoffset + $SynchSeekOffset, $dummy, true)) {
1476                      $info = $dummy;
1477                      $info['avdataoffset'] = $avdataoffset + $SynchSeekOffset;
1478                      switch (isset($info['fileformat']) ? $info['fileformat'] : '') {
1479                          case '':
1480                          case 'id3':
1481                          case 'ape':
1482                          case 'mp3':
1483                              $info['fileformat']          = 'mp3';
1484                              $info['audio']['dataformat'] = 'mp3';
1485                              break;
1486                      }
1487                      if (isset($FirstFrameThisfileInfo) && isset($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode']) && ($FirstFrameThisfileInfo['mpeg']['audio']['bitrate_mode'] == 'vbr')) {
1488                          if (!(abs($info['audio']['bitrate'] - $FirstFrameThisfileInfo['audio']['bitrate']) <= 1)) {
1489                              // If there is garbage data between a valid VBR header frame and a sequence
1490                              // of valid MPEG-audio frames the VBR data is no longer discarded.
1491                              $info = $FirstFrameThisfileInfo;
1492                              $info['avdataoffset']        = $FirstFrameAVDataOffset;
1493                              $info['fileformat']          = 'mp3';
1494                              $info['audio']['dataformat'] = 'mp3';
1495                              $dummy                       = $info;
1496                              unset($dummy['mpeg']['audio']);
1497                              $GarbageOffsetStart = $FirstFrameAVDataOffset + $FirstFrameThisfileInfo['mpeg']['audio']['framelength'];
1498                              $GarbageOffsetEnd   = $avdataoffset + $SynchSeekOffset;
1499                              if ($this->decodeMPEGaudioHeader($GarbageOffsetEnd, $dummy, true, true)) {
1500                                  $info = $dummy;
1501                                  $info['avdataoffset'] = $GarbageOffsetEnd;
1502                                  $this->warning('apparently-valid VBR header not used because could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.'), but did find valid CBR stream starting at '.$GarbageOffsetEnd);
1503                              } else {
1504                                  $this->warning('using data from VBR header even though could not find '.GETID3_MP3_VALID_CHECK_FRAMES.' consecutive MPEG-audio frames immediately after VBR header (garbage data for '.($GarbageOffsetEnd - $GarbageOffsetStart).' bytes between '.$GarbageOffsetStart.' and '.$GarbageOffsetEnd.')');
1505                              }
1506                          }
1507                      }
1508                      if (isset($info['mpeg']['audio']['bitrate_mode']) && ($info['mpeg']['audio']['bitrate_mode'] == 'vbr') && !isset($info['mpeg']['audio']['VBR_method'])) {
1509                          // VBR file with no VBR header
1510                          $BitrateHistogram = true;
1511                      }
1512  
1513                      if ($BitrateHistogram) {
1514  
1515                          $info['mpeg']['audio']['stereo_distribution']  = array('stereo'=>0, 'joint stereo'=>0, 'dual channel'=>0, 'mono'=>0);
1516                          $info['mpeg']['audio']['version_distribution'] = array('1'=>0, '2'=>0, '2.5'=>0);
1517  
1518                          if ($info['mpeg']['audio']['version'] == '1') {
1519                              if ($info['mpeg']['audio']['layer'] == 3) {
1520                                  $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0);
1521                              } elseif ($info['mpeg']['audio']['layer'] == 2) {
1522                                  $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 320000=>0, 384000=>0);
1523                              } elseif ($info['mpeg']['audio']['layer'] == 1) {
1524                                  $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 64000=>0, 96000=>0, 128000=>0, 160000=>0, 192000=>0, 224000=>0, 256000=>0, 288000=>0, 320000=>0, 352000=>0, 384000=>0, 416000=>0, 448000=>0);
1525                              }
1526                          } elseif ($info['mpeg']['audio']['layer'] == 1) {
1527                              $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 32000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 144000=>0, 160000=>0, 176000=>0, 192000=>0, 224000=>0, 256000=>0);
1528                          } else {
1529                              $info['mpeg']['audio']['bitrate_distribution'] = array('free'=>0, 8000=>0, 16000=>0, 24000=>0, 32000=>0, 40000=>0, 48000=>0, 56000=>0, 64000=>0, 80000=>0, 96000=>0, 112000=>0, 128000=>0, 144000=>0, 160000=>0);
1530                          }
1531  
1532                          $dummy = array('error'=>$info['error'], 'warning'=>$info['warning'], 'avdataend'=>$info['avdataend'], 'avdataoffset'=>$info['avdataoffset']);
1533                          $synchstartoffset = $info['avdataoffset'];
1534                          $this->fseek($info['avdataoffset']);
1535  
1536                          // you can play with these numbers:
1537                          $max_frames_scan  = 50000;
1538                          $max_scan_segments = 10;
1539  
1540                          // don't play with these numbers:
1541                          $FastMode = false;
1542                          $SynchErrorsFound = 0;
1543                          $frames_scanned   = 0;
1544                          $this_scan_segment = 0;
1545                          $frames_scan_per_segment = ceil($max_frames_scan / $max_scan_segments);
1546                          $pct_data_scanned = 0;
1547                          for ($current_segment = 0; $current_segment < $max_scan_segments; $current_segment++) {
1548                              $frames_scanned_this_segment = 0;
1549                              if ($this->ftell() >= $info['avdataend']) {
1550                                  break;
1551                              }
1552                              $scan_start_offset[$current_segment] = max($this->ftell(), $info['avdataoffset'] + round($current_segment * (($info['avdataend'] - $info['avdataoffset']) / $max_scan_segments)));
1553                              if ($current_segment > 0) {
1554                                  $this->fseek($scan_start_offset[$current_segment]);
1555                                  $buffer_4k = $this->fread(4096);
1556                                  for ($j = 0; $j < (strlen($buffer_4k) - 4); $j++) {
1557                                      if (($buffer_4k[$j] == "\xFF") && ($buffer_4k[($j + 1)] > "\xE0")) { // synch detected
1558                                          if ($this->decodeMPEGaudioHeader($scan_start_offset[$current_segment] + $j, $dummy, false, false, $FastMode)) {
1559                                              $calculated_next_offset = $scan_start_offset[$current_segment] + $j + $dummy['mpeg']['audio']['framelength'];
1560                                              if ($this->decodeMPEGaudioHeader($calculated_next_offset, $dummy, false, false, $FastMode)) {
1561                                                  $scan_start_offset[$current_segment] += $j;
1562                                                  break;
1563                                              }
1564                                          }
1565                                      }
1566                                  }
1567                              }
1568                              $synchstartoffset = $scan_start_offset[$current_segment];
1569                              while (($synchstartoffset < $info['avdataend']) && $this->decodeMPEGaudioHeader($synchstartoffset, $dummy, false, false, $FastMode)) {
1570                                  $FastMode = true;
1571                                  $thisframebitrate = $MPEGaudioBitrateLookup[$MPEGaudioVersionLookup[$dummy['mpeg']['audio']['raw']['version']]][$MPEGaudioLayerLookup[$dummy['mpeg']['audio']['raw']['layer']]][$dummy['mpeg']['audio']['raw']['bitrate']];
1572  
1573                                  if (empty($dummy['mpeg']['audio']['framelength'])) {
1574                                      $SynchErrorsFound++;
1575                                      $synchstartoffset++;
1576                                  } else {
1577                                      getid3_lib::safe_inc($info['mpeg']['audio']['bitrate_distribution'][$thisframebitrate]);
1578                                      getid3_lib::safe_inc($info['mpeg']['audio']['stereo_distribution'][$dummy['mpeg']['audio']['channelmode']]);
1579                                      getid3_lib::safe_inc($info['mpeg']['audio']['version_distribution'][$dummy['mpeg']['audio']['version']]);
1580                                      $synchstartoffset += $dummy['mpeg']['audio']['framelength'];
1581                                  }
1582                                  $frames_scanned++;
1583                                  if ($frames_scan_per_segment && (++$frames_scanned_this_segment >= $frames_scan_per_segment)) {
1584                                      $this_pct_scanned = ($this->ftell() - $scan_start_offset[$current_segment]) / ($info['avdataend'] - $info['avdataoffset']);
1585                                      if (($current_segment == 0) && (($this_pct_scanned * $max_scan_segments) >= 1)) {
1586                                          // file likely contains < $max_frames_scan, just scan as one segment
1587                                          $max_scan_segments = 1;
1588                                          $frames_scan_per_segment = $max_frames_scan;
1589                                      } else {
1590                                          $pct_data_scanned += $this_pct_scanned;
1591                                          break;
1592                                      }
1593                                  }
1594                              }
1595                          }
1596                          if ($pct_data_scanned > 0) {
1597                              $this->warning('too many MPEG audio frames to scan, only scanned '.$frames_scanned.' frames in '.$max_scan_segments.' segments ('.number_format($pct_data_scanned * 100, 1).'% of file) and extrapolated distribution, playtime and bitrate may be incorrect.');
1598                              foreach ($info['mpeg']['audio'] as $key1 => $value1) {
1599                                  if (!preg_match('#_distribution$#i', $key1)) {
1600                                      continue;
1601                                  }
1602                                  foreach ($value1 as $key2 => $value2) {
1603                                      $info['mpeg']['audio'][$key1][$key2] = round($value2 / $pct_data_scanned);
1604                                  }
1605                              }
1606                          }
1607  
1608                          if ($SynchErrorsFound > 0) {
1609                              $this->warning('Found '.$SynchErrorsFound.' synch errors in histogram analysis');
1610                              //return false;
1611                          }
1612  
1613                          $bittotal     = 0;
1614                          $framecounter = 0;
1615                          foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitratevalue => $bitratecount) {
1616                              $framecounter += $bitratecount;
1617                              if ($bitratevalue != 'free') {
1618                                  $bittotal += ($bitratevalue * $bitratecount);
1619                              }
1620                          }
1621                          if ($framecounter == 0) {
1622                              $this->error('Corrupt MP3 file: framecounter == zero');
1623                              return false;
1624                          }
1625                          $info['mpeg']['audio']['frame_count'] = getid3_lib::CastAsInt($framecounter);
1626                          $info['mpeg']['audio']['bitrate']     = ($bittotal / $framecounter);
1627  
1628                          $info['audio']['bitrate'] = $info['mpeg']['audio']['bitrate'];
1629  
1630  
1631                          // Definitively set VBR vs CBR, even if the Xing/LAME/VBRI header says differently
1632                          $distinct_bitrates = 0;
1633                          foreach ($info['mpeg']['audio']['bitrate_distribution'] as $bitrate_value => $bitrate_count) {
1634                              if ($bitrate_count > 0) {
1635                                  $distinct_bitrates++;
1636                              }
1637                          }
1638                          if ($distinct_bitrates > 1) {
1639                              $info['mpeg']['audio']['bitrate_mode'] = 'vbr';
1640                          } else {
1641                              $info['mpeg']['audio']['bitrate_mode'] = 'cbr';
1642                          }
1643                          $info['audio']['bitrate_mode'] = $info['mpeg']['audio']['bitrate_mode'];
1644  
1645                      }
1646  
1647                      break; // exit while()
1648                  }
1649              }
1650  
1651              $SynchSeekOffset++;
1652              if (($avdataoffset + $SynchSeekOffset) >= $info['avdataend']) {
1653                  // end of file/data
1654  
1655                  if (empty($info['mpeg']['audio'])) {
1656  
1657                      $this->error('could not find valid MPEG synch before end of file');
1658                      if (isset($info['audio']['bitrate'])) {
1659                          unset($info['audio']['bitrate']);
1660                      }
1661                      if (isset($info['mpeg']['audio'])) {
1662                          unset($info['mpeg']['audio']);
1663                      }
1664                      if (isset($info['mpeg']) && (!is_array($info['mpeg']) || empty($info['mpeg']))) {
1665                          unset($info['mpeg']);
1666                      }
1667                      return false;
1668  
1669                  }
1670                  break;
1671              }
1672  
1673          }
1674          $info['audio']['channels']        = $info['mpeg']['audio']['channels'];
1675          $info['audio']['channelmode']     = $info['mpeg']['audio']['channelmode'];
1676          $info['audio']['sample_rate']     = $info['mpeg']['audio']['sample_rate'];
1677          return true;
1678      }
1679  
1680      /**
1681       * @return array
1682       */
1683  	public static function MPEGaudioVersionArray() {
1684          static $MPEGaudioVersion = array('2.5', false, '2', '1');
1685          return $MPEGaudioVersion;
1686      }
1687  
1688      /**
1689       * @return array
1690       */
1691  	public static function MPEGaudioLayerArray() {
1692          static $MPEGaudioLayer = array(false, 3, 2, 1);
1693          return $MPEGaudioLayer;
1694      }
1695  
1696      /**
1697       * @return array
1698       */
1699  	public static function MPEGaudioBitrateArray() {
1700          static $MPEGaudioBitrate;
1701          if (empty($MPEGaudioBitrate)) {
1702              $MPEGaudioBitrate = array (
1703                  '1'  =>  array (1 => array('free', 32000, 64000, 96000, 128000, 160000, 192000, 224000, 256000, 288000, 320000, 352000, 384000, 416000, 448000),
1704                                  2 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000, 384000),
1705                                  3 => array('free', 32000, 40000, 48000,  56000,  64000,  80000,  96000, 112000, 128000, 160000, 192000, 224000, 256000, 320000)
1706                                 ),
1707  
1708                  '2'  =>  array (1 => array('free', 32000, 48000, 56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000, 176000, 192000, 224000, 256000),
1709                                  2 => array('free',  8000, 16000, 24000,  32000,  40000,  48000,  56000,  64000,  80000,  96000, 112000, 128000, 144000, 160000),
1710                                 )
1711              );
1712              $MPEGaudioBitrate['2'][3] = $MPEGaudioBitrate['2'][2];
1713              $MPEGaudioBitrate['2.5']  = $MPEGaudioBitrate['2'];
1714          }
1715          return $MPEGaudioBitrate;
1716      }
1717  
1718      /**
1719       * @return array
1720       */
1721  	public static function MPEGaudioFrequencyArray() {
1722          static $MPEGaudioFrequency;
1723          if (empty($MPEGaudioFrequency)) {
1724              $MPEGaudioFrequency = array (
1725                  '1'   => array(44100, 48000, 32000),
1726                  '2'   => array(22050, 24000, 16000),
1727                  '2.5' => array(11025, 12000,  8000)
1728              );
1729          }
1730          return $MPEGaudioFrequency;
1731      }
1732  
1733      /**
1734       * @return array
1735       */
1736  	public static function MPEGaudioChannelModeArray() {
1737          static $MPEGaudioChannelMode = array('stereo', 'joint stereo', 'dual channel', 'mono');
1738          return $MPEGaudioChannelMode;
1739      }
1740  
1741      /**
1742       * @return array
1743       */
1744  	public static function MPEGaudioModeExtensionArray() {
1745          static $MPEGaudioModeExtension;
1746          if (empty($MPEGaudioModeExtension)) {
1747              $MPEGaudioModeExtension = array (
1748                  1 => array('4-31', '8-31', '12-31', '16-31'),
1749                  2 => array('4-31', '8-31', '12-31', '16-31'),
1750                  3 => array('', 'IS', 'MS', 'IS+MS')
1751              );
1752          }
1753          return $MPEGaudioModeExtension;
1754      }
1755  
1756      /**
1757       * @return array
1758       */
1759  	public static function MPEGaudioEmphasisArray() {
1760          static $MPEGaudioEmphasis = array('none', '50/15ms', false, 'CCIT J.17');
1761          return $MPEGaudioEmphasis;
1762      }
1763  
1764      /**
1765       * @param string $head4
1766       * @param bool   $allowBitrate15
1767       *
1768       * @return bool
1769       */
1770  	public static function MPEGaudioHeaderBytesValid($head4, $allowBitrate15=false) {
1771          return self::MPEGaudioHeaderValid(self::MPEGaudioHeaderDecode($head4), false, $allowBitrate15);
1772      }
1773  
1774      /**
1775       * @param array $rawarray
1776       * @param bool  $echoerrors
1777       * @param bool  $allowBitrate15
1778       *
1779       * @return bool
1780       */
1781  	public static function MPEGaudioHeaderValid($rawarray, $echoerrors=false, $allowBitrate15=false) {
1782          if (($rawarray['synch'] & 0x0FFE) != 0x0FFE) {
1783              return false;
1784          }
1785  
1786          static $MPEGaudioVersionLookup;
1787          static $MPEGaudioLayerLookup;
1788          static $MPEGaudioBitrateLookup;
1789          static $MPEGaudioFrequencyLookup;
1790          static $MPEGaudioChannelModeLookup;
1791          static $MPEGaudioModeExtensionLookup;
1792          static $MPEGaudioEmphasisLookup;
1793          if (empty($MPEGaudioVersionLookup)) {
1794              $MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();
1795              $MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();
1796              $MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();
1797              $MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();
1798              $MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();
1799              $MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();
1800              $MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();
1801          }
1802  
1803          if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {
1804              $decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];
1805          } else {
1806              echo ($echoerrors ? "\n".'invalid Version ('.$rawarray['version'].')' : '');
1807              return false;
1808          }
1809          if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {
1810              $decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];
1811          } else {
1812              echo ($echoerrors ? "\n".'invalid Layer ('.$rawarray['layer'].')' : '');
1813              return false;
1814          }
1815          if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {
1816              echo ($echoerrors ? "\n".'invalid Bitrate ('.$rawarray['bitrate'].')' : '');
1817              if ($rawarray['bitrate'] == 15) {
1818                  // known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 0
1819                  // let it go through here otherwise file will not be identified
1820                  if (!$allowBitrate15) {
1821                      return false;
1822                  }
1823              } else {
1824                  return false;
1825              }
1826          }
1827          if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {
1828              echo ($echoerrors ? "\n".'invalid Frequency ('.$rawarray['sample_rate'].')' : '');
1829              return false;
1830          }
1831          if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {
1832              echo ($echoerrors ? "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')' : '');
1833              return false;
1834          }
1835          if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {
1836              echo ($echoerrors ? "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')' : '');
1837              return false;
1838          }
1839          if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {
1840              echo ($echoerrors ? "\n".'invalid Emphasis ('.$rawarray['emphasis'].')' : '');
1841              return false;
1842          }
1843          // These are just either set or not set, you can't mess that up :)
1844          // $rawarray['protection'];
1845          // $rawarray['padding'];
1846          // $rawarray['private'];
1847          // $rawarray['copyright'];
1848          // $rawarray['original'];
1849  
1850          return true;
1851      }
1852  
1853      /**
1854       * @param string $Header4Bytes
1855       *
1856       * @return array|false
1857       */
1858  	public static function MPEGaudioHeaderDecode($Header4Bytes) {
1859          // AAAA AAAA  AAAB BCCD  EEEE FFGH  IIJJ KLMM
1860          // A - Frame sync (all bits set)
1861          // B - MPEG Audio version ID
1862          // C - Layer description
1863          // D - Protection bit
1864          // E - Bitrate index
1865          // F - Sampling rate frequency index
1866          // G - Padding bit
1867          // H - Private bit
1868          // I - Channel Mode
1869          // J - Mode extension (Only if Joint stereo)
1870          // K - Copyright
1871          // L - Original
1872          // M - Emphasis
1873  
1874          if (strlen($Header4Bytes) != 4) {
1875              return false;
1876          }
1877  
1878          $MPEGrawHeader['synch']         = (getid3_lib::BigEndian2Int(substr($Header4Bytes, 0, 2)) & 0xFFE0) >> 4;
1879          $MPEGrawHeader['version']       = (ord($Header4Bytes[1]) & 0x18) >> 3; //    BB
1880          $MPEGrawHeader['layer']         = (ord($Header4Bytes[1]) & 0x06) >> 1; //      CC
1881          $MPEGrawHeader['protection']    = (ord($Header4Bytes[1]) & 0x01);      //        D
1882          $MPEGrawHeader['bitrate']       = (ord($Header4Bytes[2]) & 0xF0) >> 4; // EEEE
1883          $MPEGrawHeader['sample_rate']   = (ord($Header4Bytes[2]) & 0x0C) >> 2; //     FF
1884          $MPEGrawHeader['padding']       = (ord($Header4Bytes[2]) & 0x02) >> 1; //       G
1885          $MPEGrawHeader['private']       = (ord($Header4Bytes[2]) & 0x01);      //        H
1886          $MPEGrawHeader['channelmode']   = (ord($Header4Bytes[3]) & 0xC0) >> 6; // II
1887          $MPEGrawHeader['modeextension'] = (ord($Header4Bytes[3]) & 0x30) >> 4; //   JJ
1888          $MPEGrawHeader['copyright']     = (ord($Header4Bytes[3]) & 0x08) >> 3; //     K
1889          $MPEGrawHeader['original']      = (ord($Header4Bytes[3]) & 0x04) >> 2; //      L
1890          $MPEGrawHeader['emphasis']      = (ord($Header4Bytes[3]) & 0x03);      //       MM
1891  
1892          return $MPEGrawHeader;
1893      }
1894  
1895      /**
1896       * @param int|string $bitrate
1897       * @param string     $version
1898       * @param string     $layer
1899       * @param bool       $padding
1900       * @param int        $samplerate
1901       *
1902       * @return int|false
1903       */
1904  	public static function MPEGaudioFrameLength(&$bitrate, &$version, &$layer, $padding, &$samplerate) {
1905          static $AudioFrameLengthCache = array();
1906  
1907          if (!isset($AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate])) {
1908              $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = false;
1909              if ($bitrate != 'free') {
1910  
1911                  if ($version == '1') {
1912  
1913                      if ($layer == '1') {
1914  
1915                          // For Layer I slot is 32 bits long
1916                          $FrameLengthCoefficient = 48;
1917                          $SlotLength = 4;
1918  
1919                      } else { // Layer 2 / 3
1920  
1921                          // for Layer 2 and Layer 3 slot is 8 bits long.
1922                          $FrameLengthCoefficient = 144;
1923                          $SlotLength = 1;
1924  
1925                      }
1926  
1927                  } else { // MPEG-2 / MPEG-2.5
1928  
1929                      if ($layer == '1') {
1930  
1931                          // For Layer I slot is 32 bits long
1932                          $FrameLengthCoefficient = 24;
1933                          $SlotLength = 4;
1934  
1935                      } elseif ($layer == '2') {
1936  
1937                          // for Layer 2 and Layer 3 slot is 8 bits long.
1938                          $FrameLengthCoefficient = 144;
1939                          $SlotLength = 1;
1940  
1941                      } else { // layer 3
1942  
1943                          // for Layer 2 and Layer 3 slot is 8 bits long.
1944                          $FrameLengthCoefficient = 72;
1945                          $SlotLength = 1;
1946  
1947                      }
1948  
1949                  }
1950  
1951                  // FrameLengthInBytes = ((Coefficient * BitRate) / SampleRate) + Padding
1952                  if ($samplerate > 0) {
1953                      $NewFramelength  = ($FrameLengthCoefficient * $bitrate) / $samplerate;
1954                      $NewFramelength  = floor($NewFramelength / $SlotLength) * $SlotLength; // round to next-lower multiple of SlotLength (1 byte for Layer 2/3, 4 bytes for Layer I)
1955                      if ($padding) {
1956                          $NewFramelength += $SlotLength;
1957                      }
1958                      $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate] = (int) $NewFramelength;
1959                  }
1960              }
1961          }
1962          return $AudioFrameLengthCache[$bitrate][$version][$layer][$padding][$samplerate];
1963      }
1964  
1965      /**
1966       * @param float|int $bit_rate
1967       *
1968       * @return int|float|string
1969       */
1970  	public static function ClosestStandardMP3Bitrate($bit_rate) {
1971          static $standard_bit_rates = array (320000, 256000, 224000, 192000, 160000, 128000, 112000, 96000, 80000, 64000, 56000, 48000, 40000, 32000, 24000, 16000, 8000);
1972          static $bit_rate_table = array (0=>'-');
1973          $round_bit_rate = intval(round($bit_rate, -3));
1974          if (!isset($bit_rate_table[$round_bit_rate])) {
1975              if ($round_bit_rate > max($standard_bit_rates)) {
1976                  $bit_rate_table[$round_bit_rate] = round($bit_rate, 2 - strlen($bit_rate));
1977              } else {
1978                  $bit_rate_table[$round_bit_rate] = max($standard_bit_rates);
1979                  foreach ($standard_bit_rates as $standard_bit_rate) {
1980                      if ($round_bit_rate >= $standard_bit_rate + (($bit_rate_table[$round_bit_rate] - $standard_bit_rate) / 2)) {
1981                          break;
1982                      }
1983                      $bit_rate_table[$round_bit_rate] = $standard_bit_rate;
1984                  }
1985              }
1986          }
1987          return $bit_rate_table[$round_bit_rate];
1988      }
1989  
1990      /**
1991       * @param string $version
1992       * @param string $channelmode
1993       *
1994       * @return int
1995       */
1996  	public static function XingVBRidOffset($version, $channelmode) {
1997          static $XingVBRidOffsetCache = array();
1998          if (empty($XingVBRidOffsetCache)) {
1999              $XingVBRidOffsetCache = array (
2000                  '1'   => array ('mono'          => 0x15, // 4 + 17 = 21
2001                                  'stereo'        => 0x24, // 4 + 32 = 36
2002                                  'joint stereo'  => 0x24,
2003                                  'dual channel'  => 0x24
2004                                 ),
2005  
2006                  '2'   => array ('mono'          => 0x0D, // 4 +  9 = 13
2007                                  'stereo'        => 0x15, // 4 + 17 = 21
2008                                  'joint stereo'  => 0x15,
2009                                  'dual channel'  => 0x15
2010                                 ),
2011  
2012                  '2.5' => array ('mono'          => 0x15,
2013                                  'stereo'        => 0x15,
2014                                  'joint stereo'  => 0x15,
2015                                  'dual channel'  => 0x15
2016                                 )
2017              );
2018          }
2019          return $XingVBRidOffsetCache[$version][$channelmode];
2020      }
2021  
2022      /**
2023       * @param int $VBRmethodID
2024       *
2025       * @return string
2026       */
2027  	public static function LAMEvbrMethodLookup($VBRmethodID) {
2028          static $LAMEvbrMethodLookup = array(
2029              0x00 => 'unknown',
2030              0x01 => 'cbr',
2031              0x02 => 'abr',
2032              0x03 => 'vbr-old / vbr-rh',
2033              0x04 => 'vbr-new / vbr-mtrh',
2034              0x05 => 'vbr-mt',
2035              0x06 => 'vbr (full vbr method 4)',
2036              0x08 => 'cbr (constant bitrate 2 pass)',
2037              0x09 => 'abr (2 pass)',
2038              0x0F => 'reserved'
2039          );
2040          return (isset($LAMEvbrMethodLookup[$VBRmethodID]) ? $LAMEvbrMethodLookup[$VBRmethodID] : '');
2041      }
2042  
2043      /**
2044       * @param int $StereoModeID
2045       *
2046       * @return string
2047       */
2048  	public static function LAMEmiscStereoModeLookup($StereoModeID) {
2049          static $LAMEmiscStereoModeLookup = array(
2050              0 => 'mono',
2051              1 => 'stereo',
2052              2 => 'dual mono',
2053              3 => 'joint stereo',
2054              4 => 'forced stereo',
2055              5 => 'auto',
2056              6 => 'intensity stereo',
2057              7 => 'other'
2058          );
2059          return (isset($LAMEmiscStereoModeLookup[$StereoModeID]) ? $LAMEmiscStereoModeLookup[$StereoModeID] : '');
2060      }
2061  
2062      /**
2063       * @param int $SourceSampleFrequencyID
2064       *
2065       * @return string
2066       */
2067  	public static function LAMEmiscSourceSampleFrequencyLookup($SourceSampleFrequencyID) {
2068          static $LAMEmiscSourceSampleFrequencyLookup = array(
2069              0 => '<= 32 kHz',
2070              1 => '44.1 kHz',
2071              2 => '48 kHz',
2072              3 => '> 48kHz'
2073          );
2074          return (isset($LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID]) ? $LAMEmiscSourceSampleFrequencyLookup[$SourceSampleFrequencyID] : '');
2075      }
2076  
2077      /**
2078       * @param int $SurroundInfoID
2079       *
2080       * @return string
2081       */
2082  	public static function LAMEsurroundInfoLookup($SurroundInfoID) {
2083          static $LAMEsurroundInfoLookup = array(
2084              0 => 'no surround info',
2085              1 => 'DPL encoding',
2086              2 => 'DPL2 encoding',
2087              3 => 'Ambisonic encoding'
2088          );
2089          return (isset($LAMEsurroundInfoLookup[$SurroundInfoID]) ? $LAMEsurroundInfoLookup[$SurroundInfoID] : 'reserved');
2090      }
2091  
2092      /**
2093       * @param array $LAMEtag
2094       *
2095       * @return string
2096       */
2097  	public static function LAMEpresetUsedLookup($LAMEtag) {
2098  
2099          if ($LAMEtag['preset_used_id'] == 0) {
2100              // no preset used (LAME >=3.93)
2101              // no preset recorded (LAME <3.93)
2102              return '';
2103          }
2104          $LAMEpresetUsedLookup = array();
2105  
2106          /////  THIS PART CANNOT BE STATIC .
2107          for ($i = 8; $i <= 320; $i++) {
2108              switch ($LAMEtag['vbr_method']) {
2109                  case 'cbr':
2110                      $LAMEpresetUsedLookup[$i] = '--alt-preset '.$LAMEtag['vbr_method'].' '.$i;
2111                      break;
2112                  case 'abr':
2113                  default: // other VBR modes shouldn't be here(?)
2114                      $LAMEpresetUsedLookup[$i] = '--alt-preset '.$i;
2115                      break;
2116              }
2117          }
2118  
2119          // named old-style presets (studio, phone, voice, etc) are handled in GuessEncoderOptions()
2120  
2121          // named alt-presets
2122          $LAMEpresetUsedLookup[1000] = '--r3mix';
2123          $LAMEpresetUsedLookup[1001] = '--alt-preset standard';
2124          $LAMEpresetUsedLookup[1002] = '--alt-preset extreme';
2125          $LAMEpresetUsedLookup[1003] = '--alt-preset insane';
2126          $LAMEpresetUsedLookup[1004] = '--alt-preset fast standard';
2127          $LAMEpresetUsedLookup[1005] = '--alt-preset fast extreme';
2128          $LAMEpresetUsedLookup[1006] = '--alt-preset medium';
2129          $LAMEpresetUsedLookup[1007] = '--alt-preset fast medium';
2130  
2131          // LAME 3.94 additions/changes
2132          $LAMEpresetUsedLookup[1010] = '--preset portable';                                                           // 3.94a15 Oct 21 2003
2133          $LAMEpresetUsedLookup[1015] = '--preset radio';                                                              // 3.94a15 Oct 21 2003
2134  
2135          $LAMEpresetUsedLookup[320]  = '--preset insane';                                                             // 3.94a15 Nov 12 2003
2136          $LAMEpresetUsedLookup[410]  = '-V9';
2137          $LAMEpresetUsedLookup[420]  = '-V8';
2138          $LAMEpresetUsedLookup[440]  = '-V6';
2139          $LAMEpresetUsedLookup[430]  = '--preset radio';                                                              // 3.94a15 Nov 12 2003
2140          $LAMEpresetUsedLookup[450]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'portable';  // 3.94a15 Nov 12 2003
2141          $LAMEpresetUsedLookup[460]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'medium';    // 3.94a15 Nov 12 2003
2142          $LAMEpresetUsedLookup[470]  = '--r3mix';                                                                     // 3.94b1  Dec 18 2003
2143          $LAMEpresetUsedLookup[480]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'standard';  // 3.94a15 Nov 12 2003
2144          $LAMEpresetUsedLookup[490]  = '-V1';
2145          $LAMEpresetUsedLookup[500]  = '--preset '.(($LAMEtag['raw']['vbr_method'] == 4) ? 'fast ' : '').'extreme';   // 3.94a15 Nov 12 2003
2146  
2147          return (isset($LAMEpresetUsedLookup[$LAMEtag['preset_used_id']]) ? $LAMEpresetUsedLookup[$LAMEtag['preset_used_id']] : 'new/unknown preset: '.$LAMEtag['preset_used_id'].' - report to info@getid3.org');
2148      }
2149  
2150  }


Generated: Wed Nov 13 01:00:03 2019 Cross-referenced by PHPXref 0.7.1