www/plugins-dist/medias/lib/getid3/module.audio.wavpack.php

   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.wavpack.php                                    //
  12 // module for analyzing WavPack v4.0+ Audio files              //
  13 // dependencies: NONE                                          //
  14 //                                                            ///
  15 /////////////////////////////////////////////////////////////////
  16
  17
  18 class getid3_wavpack extends getid3_handler
  19 {
  20         /**
  21          * @return bool
  22          */
  23         public function Analyze() {
  24                 $info = &$this->getid3->info;
  25
  26                 $this->fseek($info['avdataoffset']);
  27
  28                 while (true) {
  29
  30                         $wavpackheader = $this->fread(32);
  31
  32                         if ($this->ftell() >= $info['avdataend']) {
  33                                 break;
  34                         } elseif (feof($this->getid3->fp)) {
  35                                 break;
  36                         } elseif (
  37                                 isset($info['wavpack']['blockheader']['total_samples']) &&
  38                                 isset($info['wavpack']['blockheader']['block_samples']) &&
  39                                 ($info['wavpack']['blockheader']['total_samples'] > 0) &&
  40                                 ($info['wavpack']['blockheader']['block_samples'] > 0) &&
  41                                 (!isset($info['wavpack']['riff_trailer_size']) || ($info['wavpack']['riff_trailer_size'] <= 0)) &&
  42                                 ((isset($info['wavpack']['config_flags']['md5_checksum']) && ($info['wavpack']['config_flags']['md5_checksum'] === false)) || !empty($info['md5_data_source']))) {
  43                                         break;
  44                         }
  45
  46                         $blockheader_offset = $this->ftell() - 32;
  47                         $blockheader_magic  =                              substr($wavpackheader,  0,  4);
  48                         $blockheader_size   = getid3_lib::LittleEndian2Int(substr($wavpackheader,  4,  4));
  49
  50                         $magic = 'wvpk';
  51                         if ($blockheader_magic != $magic) {
  52                                 $this->error('Expecting "'.getid3_lib::PrintHexBytes($magic).'" at offset '.$blockheader_offset.', found "'.getid3_lib::PrintHexBytes($blockheader_magic).'"');
  53                                 switch (isset($info['audio']['dataformat']) ? $info['audio']['dataformat'] : '') {
  54                                         case 'wavpack':
  55                                         case 'wvc':
  56                                                 break;
  57                                         default:
  58                                                 unset($info['fileformat']);
  59                                                 unset($info['audio']);
  60                                                 unset($info['wavpack']);
  61                                                 break;
  62                                 }
  63                                 return false;
  64                         }
  65
  66                         if (empty($info['wavpack']['blockheader']['block_samples']) ||
  67                                 empty($info['wavpack']['blockheader']['total_samples']) ||
  68                                 ($info['wavpack']['blockheader']['block_samples'] <= 0) ||
  69                                 ($info['wavpack']['blockheader']['total_samples'] <= 0)) {
  70                                 // Also, it is possible that the first block might not have
  71                                 // any samples (block_samples == 0) and in this case you should skip blocks
  72                                 // until you find one with samples because the other information (like
  73                                 // total_samples) are not guaranteed to be correct until (block_samples > 0)
  74
  75                                 // Finally, I have defined a format for files in which the length is not known
  76                                 // (for example when raw files are created using pipes). In these cases
  77                                 // total_samples will be -1 and you must seek to the final block to determine
  78                                 // the total number of samples.
  79
  80
  81                                 $info['audio']['dataformat']   = 'wavpack';
  82                                 $info['fileformat']            = 'wavpack';
  83                                 $info['audio']['lossless']     = true;
  84                                 $info['audio']['bitrate_mode'] = 'vbr';
  85
  86                                 $info['wavpack']['blockheader']['offset'] = $blockheader_offset;
  87                                 $info['wavpack']['blockheader']['magic']  = $blockheader_magic;
  88                                 $info['wavpack']['blockheader']['size']   = $blockheader_size;
  89
  90                                 if ($info['wavpack']['blockheader']['size'] >= 0x100000) {
  91                                         $this->error('Expecting WavPack block size less than "0x100000", found "'.$info['wavpack']['blockheader']['size'].'" at offset '.$info['wavpack']['blockheader']['offset']);
  92                                         switch (isset($info['audio']['dataformat']) ? $info['audio']['dataformat'] : '') {
  93                                                 case 'wavpack':
  94                                                 case 'wvc':
  95                                                         break;
  96                                                 default:
  97                                                         unset($info['fileformat']);
  98                                                         unset($info['audio']);
  99                                                         unset($info['wavpack']);
 100                                                         break;
 101                                         }
 102                                         return false;
 103                                 }
 104
 105                                 $info['wavpack']['blockheader']['minor_version'] = ord($wavpackheader{8});
 106                                 $info['wavpack']['blockheader']['major_version'] = ord($wavpackheader{9});
 107
 108                                 if (($info['wavpack']['blockheader']['major_version'] != 4) ||
 109                                         (($info['wavpack']['blockheader']['minor_version'] < 4) &&
 110                                         ($info['wavpack']['blockheader']['minor_version'] > 16))) {
 111                                                 $this->error('Expecting WavPack version between "4.2" and "4.16", found version "'.$info['wavpack']['blockheader']['major_version'].'.'.$info['wavpack']['blockheader']['minor_version'].'" at offset '.$info['wavpack']['blockheader']['offset']);
 112                                                 switch (isset($info['audio']['dataformat']) ? $info['audio']['dataformat'] : '') {
 113                                                         case 'wavpack':
 114                                                         case 'wvc':
 115                                                                 break;
 116                                                         default:
 117                                                                 unset($info['fileformat']);
 118                                                                 unset($info['audio']);
 119                                                                 unset($info['wavpack']);
 120                                                                 break;
 121                                                 }
 122                                                 return false;
 123                                 }
 124
 125                                 $info['wavpack']['blockheader']['track_number']  = ord($wavpackheader{10}); // unused
 126                                 $info['wavpack']['blockheader']['index_number']  = ord($wavpackheader{11}); // unused
 127                                 $info['wavpack']['blockheader']['total_samples'] = getid3_lib::LittleEndian2Int(substr($wavpackheader, 12,  4));
 128                                 $info['wavpack']['blockheader']['block_index']   = getid3_lib::LittleEndian2Int(substr($wavpackheader, 16,  4));
 129                                 $info['wavpack']['blockheader']['block_samples'] = getid3_lib::LittleEndian2Int(substr($wavpackheader, 20,  4));
 130                                 $info['wavpack']['blockheader']['flags_raw']     = getid3_lib::LittleEndian2Int(substr($wavpackheader, 24,  4));
 131                                 $info['wavpack']['blockheader']['crc']           = getid3_lib::LittleEndian2Int(substr($wavpackheader, 28,  4));
 132
 133                                 $info['wavpack']['blockheader']['flags']['bytes_per_sample']     =    1 + ($info['wavpack']['blockheader']['flags_raw'] & 0x00000003);
 134                                 $info['wavpack']['blockheader']['flags']['mono']                 = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000004);
 135                                 $info['wavpack']['blockheader']['flags']['hybrid']               = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000008);
 136                                 $info['wavpack']['blockheader']['flags']['joint_stereo']         = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000010);
 137                                 $info['wavpack']['blockheader']['flags']['cross_decorrelation']  = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000020);
 138                                 $info['wavpack']['blockheader']['flags']['hybrid_noiseshape']    = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000040);
 139                                 $info['wavpack']['blockheader']['flags']['ieee_32bit_float']     = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000080);
 140                                 $info['wavpack']['blockheader']['flags']['int_32bit']            = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000100);
 141                                 $info['wavpack']['blockheader']['flags']['hybrid_bitrate_noise'] = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000200);
 142                                 $info['wavpack']['blockheader']['flags']['hybrid_balance_noise'] = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000400);
 143                                 $info['wavpack']['blockheader']['flags']['multichannel_initial'] = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00000800);
 144                                 $info['wavpack']['blockheader']['flags']['multichannel_final']   = (bool) ($info['wavpack']['blockheader']['flags_raw'] & 0x00001000);
 145
 146                                 $info['audio']['lossless'] = !$info['wavpack']['blockheader']['flags']['hybrid'];
 147                         }
 148
 149                         while (!feof($this->getid3->fp) && ($this->ftell() < ($blockheader_offset + $blockheader_size + 8))) {
 150
 151                                 $metablock = array('offset'=>$this->ftell());
 152                                 $metablockheader = $this->fread(2);
 153                                 if (feof($this->getid3->fp)) {
 154                                         break;
 155                                 }
 156                                 $metablock['id'] = ord($metablockheader{0});
 157                                 $metablock['function_id'] = ($metablock['id'] & 0x3F);
 158                                 $metablock['function_name'] = $this->WavPackMetablockNameLookup($metablock['function_id']);
 159
 160                                 // The 0x20 bit in the id of the meta subblocks (which is defined as
 161                                 // ID_OPTIONAL_DATA) is a permanent part of the id. The idea is that
 162                                 // if a decoder encounters an id that it does not know about, it uses
 163                                 // that "ID_OPTIONAL_DATA" flag to determine what to do. If it is set
 164                                 // then the decoder simply ignores the metadata, but if it is zero
 165                                 // then the decoder should quit because it means that an understanding
 166                                 // of the metadata is required to correctly decode the audio.
 167                                 $metablock['non_decoder'] = (bool) ($metablock['id'] & 0x20);
 168
 169                                 $metablock['padded_data'] = (bool) ($metablock['id'] & 0x40);
 170                                 $metablock['large_block'] = (bool) ($metablock['id'] & 0x80);
 171                                 if ($metablock['large_block']) {
 172                                         $metablockheader .= $this->fread(2);
 173                                 }
 174                                 $metablock['size'] = getid3_lib::LittleEndian2Int(substr($metablockheader, 1)) * 2; // size is stored in words
 175                                 $metablock['data'] = null;
 176
 177                                 if ($metablock['size'] > 0) {
 178
 179                                         switch ($metablock['function_id']) {
 180                                                 case 0x21: // ID_RIFF_HEADER
 181                                                 case 0x22: // ID_RIFF_TRAILER
 182                                                 case 0x23: // ID_REPLAY_GAIN
 183                                                 case 0x24: // ID_CUESHEET
 184                                                 case 0x25: // ID_CONFIG_BLOCK
 185                                                 case 0x26: // ID_MD5_CHECKSUM
 186                                                         $metablock['data'] = $this->fread($metablock['size']);
 187
 188                                                         if ($metablock['padded_data']) {
 189                                                                 // padded to the nearest even byte
 190                                                                 $metablock['size']--;
 191                                                                 $metablock['data'] = substr($metablock['data'], 0, -1);
 192                                                         }
 193                                                         break;
 194
 195                                                 case 0x00: // ID_DUMMY
 196                                                 case 0x01: // ID_ENCODER_INFO
 197                                                 case 0x02: // ID_DECORR_TERMS
 198                                                 case 0x03: // ID_DECORR_WEIGHTS
 199                                                 case 0x04: // ID_DECORR_SAMPLES
 200                                                 case 0x05: // ID_ENTROPY_VARS
 201                                                 case 0x06: // ID_HYBRID_PROFILE
 202                                                 case 0x07: // ID_SHAPING_WEIGHTS
 203                                                 case 0x08: // ID_FLOAT_INFO
 204                                                 case 0x09: // ID_INT32_INFO
 205                                                 case 0x0A: // ID_WV_BITSTREAM
 206                                                 case 0x0B: // ID_WVC_BITSTREAM
 207                                                 case 0x0C: // ID_WVX_BITSTREAM
 208                                                 case 0x0D: // ID_CHANNEL_INFO
 209                                                         $this->fseek($metablock['offset'] + ($metablock['large_block'] ? 4 : 2) + $metablock['size']);
 210                                                         break;
 211
 212                                                 default:
 213                                                         $this->warning('Unexpected metablock type "0x'.str_pad(dechex($metablock['function_id']), 2, '0', STR_PAD_LEFT).'" at offset '.$metablock['offset']);
 214                                                         $this->fseek($metablock['offset'] + ($metablock['large_block'] ? 4 : 2) + $metablock['size']);
 215                                                         break;
 216                                         }
 217
 218                                         switch ($metablock['function_id']) {
 219                                                 case 0x21: // ID_RIFF_HEADER
 220                                                         getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true);
 221                                                         $original_wav_filesize = getid3_lib::LittleEndian2Int(substr($metablock['data'], 4, 4));
 222
 223                                                         $getid3_temp = new getID3();
 224                                                         $getid3_temp->openfile($this->getid3->filename);
 225                                                         $getid3_riff = new getid3_riff($getid3_temp);
 226                                                         $getid3_riff->ParseRIFFdata($metablock['data']);
 227                                                         $metablock['riff']            = $getid3_temp->info['riff'];
 228                                                         $info['audio']['sample_rate'] = $getid3_temp->info['riff']['raw']['fmt ']['nSamplesPerSec'];
 229                                                         unset($getid3_riff, $getid3_temp);
 230
 231                                                         $metablock['riff']['original_filesize'] = $original_wav_filesize;
 232                                                         $info['wavpack']['riff_trailer_size'] = $original_wav_filesize - $metablock['riff']['WAVE']['data'][0]['size'] - $metablock['riff']['header_size'];
 233                                                         $info['playtime_seconds'] = $info['wavpack']['blockheader']['total_samples'] / $info['audio']['sample_rate'];
 234
 235                                                         // Safe RIFF header in case there's a RIFF footer later
 236                                                         $metablockRIFFheader = $metablock['data'];
 237                                                         break;
 238
 239
 240                                                 case 0x22: // ID_RIFF_TRAILER
 241                                                         $metablockRIFFfooter = isset($metablockRIFFheader) ? $metablockRIFFheader : ''.$metablock['data'];
 242                                                         getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true);
 243
 244                                                         $startoffset = $metablock['offset'] + ($metablock['large_block'] ? 4 : 2);
 245                                                         $getid3_temp = new getID3();
 246                                                         $getid3_temp->openfile($this->getid3->filename);
 247                                                         $getid3_temp->info['avdataend']  = $info['avdataend'];
 248                                                         //$getid3_temp->info['fileformat'] = 'riff';
 249                                                         $getid3_riff = new getid3_riff($getid3_temp);
 250                                                         $metablock['riff'] = $getid3_riff->ParseRIFF($startoffset, $startoffset + $metablock['size']);
 251
 252                                                         if (!empty($metablock['riff']['INFO'])) {
 253                                                                 getid3_riff::parseComments($metablock['riff']['INFO'], $metablock['comments']);
 254                                                                 $info['tags']['riff'] = $metablock['comments'];
 255                                                         }
 256                                                         unset($getid3_temp, $getid3_riff);
 257                                                         break;
 258
 259
 260                                                 case 0x23: // ID_REPLAY_GAIN
 261                                                         $this->warning('WavPack "Replay Gain" contents not yet handled by getID3() in metablock at offset '.$metablock['offset']);
 262                                                         break;
 263
 264
 265                                                 case 0x24: // ID_CUESHEET
 266                                                         $this->warning('WavPack "Cuesheet" contents not yet handled by getID3() in metablock at offset '.$metablock['offset']);
 267                                                         break;
 268
 269
 270                                                 case 0x25: // ID_CONFIG_BLOCK
 271                                                         $metablock['flags_raw'] = getid3_lib::LittleEndian2Int(substr($metablock['data'], 0, 3));
 272
 273                                                         $metablock['flags']['adobe_mode']     = (bool) ($metablock['flags_raw'] & 0x000001); // "adobe" mode for 32-bit floats
 274                                                         $metablock['flags']['fast_flag']      = (bool) ($metablock['flags_raw'] & 0x000002); // fast mode
 275                                                         $metablock['flags']['very_fast_flag'] = (bool) ($metablock['flags_raw'] & 0x000004); // double fast
 276                                                         $metablock['flags']['high_flag']      = (bool) ($metablock['flags_raw'] & 0x000008); // high quality mode
 277                                                         $metablock['flags']['very_high_flag'] = (bool) ($metablock['flags_raw'] & 0x000010); // double high (not used yet)
 278                                                         $metablock['flags']['bitrate_kbps']   = (bool) ($metablock['flags_raw'] & 0x000020); // bitrate is kbps, not bits / sample
 279                                                         $metablock['flags']['auto_shaping']   = (bool) ($metablock['flags_raw'] & 0x000040); // automatic noise shaping
 280                                                         $metablock['flags']['shape_override'] = (bool) ($metablock['flags_raw'] & 0x000080); // shaping mode specified
 281                                                         $metablock['flags']['joint_override'] = (bool) ($metablock['flags_raw'] & 0x000100); // joint-stereo mode specified
 282                                                         $metablock['flags']['copy_time']      = (bool) ($metablock['flags_raw'] & 0x000200); // copy file-time from source
 283                                                         $metablock['flags']['create_exe']     = (bool) ($metablock['flags_raw'] & 0x000400); // create executable
 284                                                         $metablock['flags']['create_wvc']     = (bool) ($metablock['flags_raw'] & 0x000800); // create correction file
 285                                                         $metablock['flags']['optimize_wvc']   = (bool) ($metablock['flags_raw'] & 0x001000); // maximize bybrid compression
 286                                                         $metablock['flags']['quality_mode']   = (bool) ($metablock['flags_raw'] & 0x002000); // psychoacoustic quality mode
 287                                                         $metablock['flags']['raw_flag']       = (bool) ($metablock['flags_raw'] & 0x004000); // raw mode (not implemented yet)
 288                                                         $metablock['flags']['calc_noise']     = (bool) ($metablock['flags_raw'] & 0x008000); // calc noise in hybrid mode
 289                                                         $metablock['flags']['lossy_mode']     = (bool) ($metablock['flags_raw'] & 0x010000); // obsolete (for information)
 290                                                         $metablock['flags']['extra_mode']     = (bool) ($metablock['flags_raw'] & 0x020000); // extra processing mode
 291                                                         $metablock['flags']['skip_wvx']       = (bool) ($metablock['flags_raw'] & 0x040000); // no wvx stream w/ floats & big ints
 292                                                         $metablock['flags']['md5_checksum']   = (bool) ($metablock['flags_raw'] & 0x080000); // compute & store MD5 signature
 293                                                         $metablock['flags']['quiet_mode']     = (bool) ($metablock['flags_raw'] & 0x100000); // don't report progress %
 294
 295                                                         $info['wavpack']['config_flags'] = $metablock['flags'];
 296
 297
 298                                                         $info['audio']['encoder_options'] = '';
 299                                                         if ($info['wavpack']['blockheader']['flags']['hybrid']) {
 300                                                                 $info['audio']['encoder_options'] .= ' -b???';
 301                                                         }
 302                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['adobe_mode']     ? ' -a' : '');
 303                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['optimize_wvc']   ? ' -cc' : '');
 304                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['create_exe']     ? ' -e' : '');
 305                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['fast_flag']      ? ' -f' : '');
 306                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['joint_override'] ? ' -j?' : '');
 307                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['high_flag']      ? ' -h' : '');
 308                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['md5_checksum']   ? ' -m' : '');
 309                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['calc_noise']     ? ' -n' : '');
 310                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['shape_override'] ? ' -s?' : '');
 311                                                         $info['audio']['encoder_options'] .= ($metablock['flags']['extra_mode']     ? ' -x?' : '');
 312                                                         if (!empty($info['audio']['encoder_options'])) {
 313                                                                 $info['audio']['encoder_options'] = trim($info['audio']['encoder_options']);
 314                                                         } elseif (isset($info['audio']['encoder_options'])) {
 315                                                                 unset($info['audio']['encoder_options']);
 316                                                         }
 317                                                         break;
 318
 319
 320                                                 case 0x26: // ID_MD5_CHECKSUM
 321                                                         if (strlen($metablock['data']) == 16) {
 322                                                                 $info['md5_data_source'] = strtolower(getid3_lib::PrintHexBytes($metablock['data'], true, false, false));
 323                                                         } else {
 324                                                                 $this->warning('Expecting 16 bytes of WavPack "MD5 Checksum" in metablock at offset '.$metablock['offset'].', but found '.strlen($metablock['data']).' bytes');
 325                                                         }
 326                                                         break;
 327
 328
 329                                                 case 0x00: // ID_DUMMY
 330                                                 case 0x01: // ID_ENCODER_INFO
 331                                                 case 0x02: // ID_DECORR_TERMS
 332                                                 case 0x03: // ID_DECORR_WEIGHTS
 333                                                 case 0x04: // ID_DECORR_SAMPLES
 334                                                 case 0x05: // ID_ENTROPY_VARS
 335                                                 case 0x06: // ID_HYBRID_PROFILE
 336                                                 case 0x07: // ID_SHAPING_WEIGHTS
 337                                                 case 0x08: // ID_FLOAT_INFO
 338                                                 case 0x09: // ID_INT32_INFO
 339                                                 case 0x0A: // ID_WV_BITSTREAM
 340                                                 case 0x0B: // ID_WVC_BITSTREAM
 341                                                 case 0x0C: // ID_WVX_BITSTREAM
 342                                                 case 0x0D: // ID_CHANNEL_INFO
 343                                                         unset($metablock);
 344                                                         break;
 345                                         }
 346
 347                                 }
 348                                 if (!empty($metablock)) {
 349                                         $info['wavpack']['metablocks'][] = $metablock;
 350                                 }
 351
 352                         }
 353
 354                 }
 355
 356                 $info['audio']['encoder']         = 'WavPack v'.$info['wavpack']['blockheader']['major_version'].'.'.str_pad($info['wavpack']['blockheader']['minor_version'], 2, '0', STR_PAD_LEFT);
 357                 $info['audio']['bits_per_sample'] = $info['wavpack']['blockheader']['flags']['bytes_per_sample'] * 8;
 358                 $info['audio']['channels']        = ($info['wavpack']['blockheader']['flags']['mono'] ? 1 : 2);
 359
 360                 if (!empty($info['playtime_seconds'])) {
 361
 362                         $info['audio']['bitrate']     = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
 363
 364                 } else {
 365
 366                         $info['audio']['dataformat']  = 'wvc';
 367
 368                 }
 369
 370                 return true;
 371         }
 372
 373         /**
 374          * @param int $id
 375          *
 376          * @return string
 377          */
 378         public function WavPackMetablockNameLookup(&$id) {
 379                 static $WavPackMetablockNameLookup = array(
 380                         0x00 => 'Dummy',
 381                         0x01 => 'Encoder Info',
 382                         0x02 => 'Decorrelation Terms',
 383                         0x03 => 'Decorrelation Weights',
 384                         0x04 => 'Decorrelation Samples',
 385                         0x05 => 'Entropy Variables',
 386                         0x06 => 'Hybrid Profile',
 387                         0x07 => 'Shaping Weights',
 388                         0x08 => 'Float Info',
 389                         0x09 => 'Int32 Info',
 390                         0x0A => 'WV Bitstream',
 391                         0x0B => 'WVC Bitstream',
 392                         0x0C => 'WVX Bitstream',
 393                         0x0D => 'Channel Info',
 394                         0x21 => 'RIFF header',
 395                         0x22 => 'RIFF trailer',
 396                         0x23 => 'Replay Gain',
 397                         0x24 => 'Cuesheet',
 398                         0x25 => 'Config Block',
 399                         0x26 => 'MD5 Checksum',
 400                 );
 401                 return (isset($WavPackMetablockNameLookup[$id]) ? $WavPackMetablockNameLookup[$id] : '');
 402         }
 403
 404 }