www/plugins-dist/medias/lib/getid3/module.audio.mpc.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.mpc.php                                        //
  12 // module for analyzing Musepack/MPEG+ Audio files             //
  13 // dependencies: NONE                                          //
  14 //                                                            ///
  15 /////////////////////////////////////////////////////////////////
  16
  17
  18 class getid3_mpc extends getid3_handler
  19 {
  20         /**
  21          * @return bool
  22          */
  23         public function Analyze() {
  24                 $info = &$this->getid3->info;
  25
  26                 $info['mpc']['header'] = array();
  27                 $thisfile_mpc_header   = &$info['mpc']['header'];
  28
  29                 $info['fileformat']               = 'mpc';
  30                 $info['audio']['dataformat']      = 'mpc';
  31                 $info['audio']['bitrate_mode']    = 'vbr';
  32                 $info['audio']['channels']        = 2;  // up to SV7 the format appears to have been hardcoded for stereo only
  33                 $info['audio']['lossless']        = false;
  34
  35                 $this->fseek($info['avdataoffset']);
  36                 $MPCheaderData = $this->fread(4);
  37                 $info['mpc']['header']['preamble'] = substr($MPCheaderData, 0, 4); // should be 'MPCK' (SV8) or 'MP+' (SV7), otherwise possible stream data (SV4-SV6)
  38                 if (preg_match('#^MPCK#', $info['mpc']['header']['preamble'])) {
  39
  40                         // this is SV8
  41                         return $this->ParseMPCsv8();
  42
  43                 } elseif (preg_match('#^MP\+#', $info['mpc']['header']['preamble'])) {
  44
  45                         // this is SV7
  46                         return $this->ParseMPCsv7();
  47
  48                 } elseif (preg_match('/^[\x00\x01\x10\x11\x40\x41\x50\x51\x80\x81\x90\x91\xC0\xC1\xD0\xD1][\x20-37][\x00\x20\x40\x60\x80\xA0\xC0\xE0]/s', $MPCheaderData)) {
  49
  50                         // this is SV4 - SV6, handle seperately
  51                         return $this->ParseMPCsv6();
  52
  53                 } else {
  54
  55                         $this->error('Expecting "MP+" or "MPCK" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($MPCheaderData, 0, 4)).'"');
  56                         unset($info['fileformat']);
  57                         unset($info['mpc']);
  58                         return false;
  59
  60                 }
  61         }
  62
  63         /**
  64          * @return bool
  65          */
  66         public function ParseMPCsv8() {
  67                 // this is SV8
  68                 // http://trac.musepack.net/trac/wiki/SV8Specification
  69
  70                 $info = &$this->getid3->info;
  71                 $thisfile_mpc_header = &$info['mpc']['header'];
  72
  73                 $keyNameSize            = 2;
  74                 $maxHandledPacketLength = 9; // specs say: "n*8; 0 < n < 10"
  75
  76                 $offset = $this->ftell();
  77                 while ($offset < $info['avdataend']) {
  78                         $thisPacket = array();
  79                         $thisPacket['offset'] = $offset;
  80                         $packet_offset = 0;
  81
  82                         // Size is a variable-size field, could be 1-4 bytes (possibly more?)
  83                         // read enough data in and figure out the exact size later
  84                         $MPCheaderData = $this->fread($keyNameSize + $maxHandledPacketLength);
  85                         $packet_offset += $keyNameSize;
  86                         $thisPacket['key']      = substr($MPCheaderData, 0, $keyNameSize);
  87                         $thisPacket['key_name'] = $this->MPCsv8PacketName($thisPacket['key']);
  88                         if ($thisPacket['key'] == $thisPacket['key_name']) {
  89                                 $this->error('Found unexpected key value "'.$thisPacket['key'].'" at offset '.$thisPacket['offset']);
  90                                 return false;
  91                         }
  92                         $packetLength = 0;
  93                         $thisPacket['packet_size'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $keyNameSize), $packetLength); // includes keyname and packet_size field
  94                         if ($thisPacket['packet_size'] === false) {
  95                                 $this->error('Did not find expected packet length within '.$maxHandledPacketLength.' bytes at offset '.($thisPacket['offset'] + $keyNameSize));
  96                                 return false;
  97                         }
  98                         $packet_offset += $packetLength;
  99                         $offset += $thisPacket['packet_size'];
 100
 101                         switch ($thisPacket['key']) {
 102                                 case 'SH': // Stream Header
 103                                         $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
 104                                         if ($moreBytesToRead > 0) {
 105                                                 $MPCheaderData .= $this->fread($moreBytesToRead);
 106                                         }
 107                                         $thisPacket['crc']               =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 4));
 108                                         $packet_offset += 4;
 109                                         $thisPacket['stream_version']    =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
 110                                         $packet_offset += 1;
 111
 112                                         $packetLength = 0;
 113                                         $thisPacket['sample_count']      = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
 114                                         $packet_offset += $packetLength;
 115
 116                                         $packetLength = 0;
 117                                         $thisPacket['beginning_silence'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
 118                                         $packet_offset += $packetLength;
 119
 120                                         $otherUsefulData                 =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
 121                                         $packet_offset += 2;
 122                                         $thisPacket['sample_frequency_raw'] =        (($otherUsefulData & 0xE000) >> 13);
 123                                         $thisPacket['max_bands_used']       =        (($otherUsefulData & 0x1F00) >>  8);
 124                                         $thisPacket['channels']             =        (($otherUsefulData & 0x00F0) >>  4) + 1;
 125                                         $thisPacket['ms_used']              = (bool) (($otherUsefulData & 0x0008) >>  3);
 126                                         $thisPacket['audio_block_frames']   =        (($otherUsefulData & 0x0007) >>  0);
 127                                         $thisPacket['sample_frequency']     = $this->MPCfrequencyLookup($thisPacket['sample_frequency_raw']);
 128
 129                                         $thisfile_mpc_header['mid_side_stereo']      = $thisPacket['ms_used'];
 130                                         $thisfile_mpc_header['sample_rate']          = $thisPacket['sample_frequency'];
 131                                         $thisfile_mpc_header['samples']              = $thisPacket['sample_count'];
 132                                         $thisfile_mpc_header['stream_version_major'] = $thisPacket['stream_version'];
 133
 134                                         $info['audio']['channels']    = $thisPacket['channels'];
 135                                         $info['audio']['sample_rate'] = $thisPacket['sample_frequency'];
 136                                         $info['playtime_seconds'] = $thisPacket['sample_count'] / $thisPacket['sample_frequency'];
 137                                         $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
 138                                         break;
 139
 140                                 case 'RG': // Replay Gain
 141                                         $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
 142                                         if ($moreBytesToRead > 0) {
 143                                                 $MPCheaderData .= $this->fread($moreBytesToRead);
 144                                         }
 145                                         $thisPacket['replaygain_version']     =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
 146                                         $packet_offset += 1;
 147                                         $thisPacket['replaygain_title_gain']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
 148                                         $packet_offset += 2;
 149                                         $thisPacket['replaygain_title_peak']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
 150                                         $packet_offset += 2;
 151                                         $thisPacket['replaygain_album_gain']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
 152                                         $packet_offset += 2;
 153                                         $thisPacket['replaygain_album_peak']  =       getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2));
 154                                         $packet_offset += 2;
 155
 156                                         if ($thisPacket['replaygain_title_gain']) { $info['replay_gain']['title']['gain'] = $thisPacket['replaygain_title_gain']; }
 157                                         if ($thisPacket['replaygain_title_peak']) { $info['replay_gain']['title']['peak'] = $thisPacket['replaygain_title_peak']; }
 158                                         if ($thisPacket['replaygain_album_gain']) { $info['replay_gain']['album']['gain'] = $thisPacket['replaygain_album_gain']; }
 159                                         if ($thisPacket['replaygain_album_peak']) { $info['replay_gain']['album']['peak'] = $thisPacket['replaygain_album_peak']; }
 160                                         break;
 161
 162                                 case 'EI': // Encoder Info
 163                                         $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength;
 164                                         if ($moreBytesToRead > 0) {
 165                                                 $MPCheaderData .= $this->fread($moreBytesToRead);
 166                                         }
 167                                         $profile_pns                 = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
 168                                         $packet_offset += 1;
 169                                         $quality_int =                   (($profile_pns & 0xF0) >> 4);
 170                                         $quality_dec =                   (($profile_pns & 0x0E) >> 3);
 171                                         $thisPacket['quality'] = (float) $quality_int + ($quality_dec / 8);
 172                                         $thisPacket['pns_tool'] = (bool) (($profile_pns & 0x01) >> 0);
 173                                         $thisPacket['version_major'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
 174                                         $packet_offset += 1;
 175                                         $thisPacket['version_minor'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
 176                                         $packet_offset += 1;
 177                                         $thisPacket['version_build'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1));
 178                                         $packet_offset += 1;
 179                                         $thisPacket['version'] = $thisPacket['version_major'].'.'.$thisPacket['version_minor'].'.'.$thisPacket['version_build'];
 180
 181                                         $info['audio']['encoder'] = 'MPC v'.$thisPacket['version'].' ('.(($thisPacket['version_minor'] % 2) ? 'unstable' : 'stable').')';
 182                                         $thisfile_mpc_header['encoder_version'] = $info['audio']['encoder'];
 183                                         //$thisfile_mpc_header['quality']         = (float) ($thisPacket['quality'] / 1.5875); // values can range from 0.000 to 15.875, mapped to qualities of 0.0 to 10.0
 184                                         $thisfile_mpc_header['quality']         = (float) ($thisPacket['quality'] - 5); // values can range from 0.000 to 15.875, of which 0..4 are "reserved/experimental", and 5..15 are mapped to qualities of 0.0 to 10.0
 185                                         break;
 186
 187                                 case 'SO': // Seek Table Offset
 188                                         $packetLength = 0;
 189                                         $thisPacket['seek_table_offset'] = $thisPacket['offset'] + $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength);
 190                                         $packet_offset += $packetLength;
 191                                         break;
 192
 193                                 case 'ST': // Seek Table
 194                                 case 'SE': // Stream End
 195                                 case 'AP': // Audio Data
 196                                         // nothing useful here, just skip this packet
 197                                         $thisPacket = array();
 198                                         break;
 199
 200                                 default:
 201                                         $this->error('Found unhandled key type "'.$thisPacket['key'].'" at offset '.$thisPacket['offset']);
 202                                         return false;
 203                                         break;
 204                         }
 205                         if (!empty($thisPacket)) {
 206                                 $info['mpc']['packets'][] = $thisPacket;
 207                         }
 208                         $this->fseek($offset);
 209                 }
 210                 $thisfile_mpc_header['size'] = $offset;
 211                 return true;
 212         }
 213
 214         /**
 215          * @return bool
 216          */
 217         public function ParseMPCsv7() {
 218                 // this is SV7
 219                 // http://www.uni-jena.de/~pfk/mpp/sv8/header.html
 220
 221                 $info = &$this->getid3->info;
 222                 $thisfile_mpc_header = &$info['mpc']['header'];
 223                 $offset = 0;
 224
 225                 $thisfile_mpc_header['size'] = 28;
 226                 $MPCheaderData  = $info['mpc']['header']['preamble'];
 227                 $MPCheaderData .= $this->fread($thisfile_mpc_header['size'] - strlen($info['mpc']['header']['preamble']));
 228                 $offset = strlen('MP+');
 229
 230                 $StreamVersionByte                           = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
 231                 $offset += 1;
 232                 $thisfile_mpc_header['stream_version_major'] = ($StreamVersionByte & 0x0F) >> 0;
 233                 $thisfile_mpc_header['stream_version_minor'] = ($StreamVersionByte & 0xF0) >> 4; // should always be 0, subversions no longer exist in SV8
 234                 $thisfile_mpc_header['frame_count']          = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
 235                 $offset += 4;
 236
 237                 if ($thisfile_mpc_header['stream_version_major'] != 7) {
 238                         $this->error('Only Musepack SV7 supported (this file claims to be v'.$thisfile_mpc_header['stream_version_major'].')');
 239                         return false;
 240                 }
 241
 242                 $FlagsDWORD1                                   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
 243                 $offset += 4;
 244                 $thisfile_mpc_header['intensity_stereo']       = (bool) (($FlagsDWORD1 & 0x80000000) >> 31);
 245                 $thisfile_mpc_header['mid_side_stereo']        = (bool) (($FlagsDWORD1 & 0x40000000) >> 30);
 246                 $thisfile_mpc_header['max_subband']            =         ($FlagsDWORD1 & 0x3F000000) >> 24;
 247                 $thisfile_mpc_header['raw']['profile']         =         ($FlagsDWORD1 & 0x00F00000) >> 20;
 248                 $thisfile_mpc_header['begin_loud']             = (bool) (($FlagsDWORD1 & 0x00080000) >> 19);
 249                 $thisfile_mpc_header['end_loud']               = (bool) (($FlagsDWORD1 & 0x00040000) >> 18);
 250                 $thisfile_mpc_header['raw']['sample_rate']     =         ($FlagsDWORD1 & 0x00030000) >> 16;
 251                 $thisfile_mpc_header['max_level']              =         ($FlagsDWORD1 & 0x0000FFFF);
 252
 253                 $thisfile_mpc_header['raw']['title_peak']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
 254                 $offset += 2;
 255                 $thisfile_mpc_header['raw']['title_gain']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
 256                 $offset += 2;
 257
 258                 $thisfile_mpc_header['raw']['album_peak']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2));
 259                 $offset += 2;
 260                 $thisfile_mpc_header['raw']['album_gain']      = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true);
 261                 $offset += 2;
 262
 263                 $FlagsDWORD2                                   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4));
 264                 $offset += 4;
 265                 $thisfile_mpc_header['true_gapless']           = (bool) (($FlagsDWORD2 & 0x80000000) >> 31);
 266                 $thisfile_mpc_header['last_frame_length']      =         ($FlagsDWORD2 & 0x7FF00000) >> 20;
 267
 268
 269                 $thisfile_mpc_header['raw']['not_sure_what']   = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3));
 270                 $offset += 3;
 271                 $thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1));
 272                 $offset += 1;
 273
 274                 $thisfile_mpc_header['profile']     = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']);
 275                 $thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']);
 276                 if ($thisfile_mpc_header['sample_rate'] == 0) {
 277                         $this->error('Corrupt MPC file: frequency == zero');
 278                         return false;
 279                 }
 280                 $info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
 281                 $thisfile_mpc_header['samples']       = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $info['audio']['channels'];
 282
 283                 $info['playtime_seconds']     = ($thisfile_mpc_header['samples'] / $info['audio']['channels']) / $info['audio']['sample_rate'];
 284                 if ($info['playtime_seconds'] == 0) {
 285                         $this->error('Corrupt MPC file: playtime_seconds == zero');
 286                         return false;
 287                 }
 288
 289                 // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
 290                 $info['avdataoffset'] += $thisfile_mpc_header['size'];
 291
 292                 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
 293
 294                 $thisfile_mpc_header['title_peak']        = $thisfile_mpc_header['raw']['title_peak'];
 295                 $thisfile_mpc_header['title_peak_db']     = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']);
 296                 if ($thisfile_mpc_header['raw']['title_gain'] < 0) {
 297                         $thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100;
 298                 } else {
 299                         $thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100;
 300                 }
 301
 302                 $thisfile_mpc_header['album_peak']        = $thisfile_mpc_header['raw']['album_peak'];
 303                 $thisfile_mpc_header['album_peak_db']     = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']);
 304                 if ($thisfile_mpc_header['raw']['album_gain'] < 0) {
 305                         $thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100;
 306                 } else {
 307                         $thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;;
 308                 }
 309                 $thisfile_mpc_header['encoder_version']   = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']);
 310
 311                 $info['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db'];
 312                 $info['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db'];
 313
 314                 if ($thisfile_mpc_header['title_peak'] > 0) {
 315                         $info['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak'];
 316                 } elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) {
 317                         $info['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c
 318                 }
 319                 if ($thisfile_mpc_header['album_peak'] > 0) {
 320                         $info['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak'];
 321                 }
 322
 323                 //$info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'].'.'.$thisfile_mpc_header['stream_version_minor'].', '.$thisfile_mpc_header['encoder_version'];
 324                 $info['audio']['encoder'] = $thisfile_mpc_header['encoder_version'];
 325                 $info['audio']['encoder_options'] = $thisfile_mpc_header['profile'];
 326                 $thisfile_mpc_header['quality'] = (float) ($thisfile_mpc_header['raw']['profile'] - 5); // values can range from 0 to 15, of which 0..4 are "reserved/experimental", and 5..15 are mapped to qualities of 0.0 to 10.0
 327
 328                 return true;
 329         }
 330
 331         /**
 332          * @return bool
 333          */
 334         public function ParseMPCsv6() {
 335                 // this is SV4 - SV6
 336
 337                 $info = &$this->getid3->info;
 338                 $thisfile_mpc_header = &$info['mpc']['header'];
 339                 $offset = 0;
 340
 341                 $thisfile_mpc_header['size'] = 8;
 342                 $this->fseek($info['avdataoffset']);
 343                 $MPCheaderData = $this->fread($thisfile_mpc_header['size']);
 344
 345                 // add size of file header to avdataoffset - calc bitrate correctly + MD5 data
 346                 $info['avdataoffset'] += $thisfile_mpc_header['size'];
 347
 348                 // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :)
 349                 $HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4));
 350                 $HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4));
 351
 352
 353                 // DDDD DDDD  CCCC CCCC  BBBB BBBB  AAAA AAAA
 354                 // aaaa aaaa  abcd dddd  dddd deee  eeff ffff
 355                 //
 356                 // a = bitrate       = anything
 357                 // b = IS            = anything
 358                 // c = MS            = anything
 359                 // d = streamversion = 0000000004 or 0000000005 or 0000000006
 360                 // e = maxband       = anything
 361                 // f = blocksize     = 000001 for SV5+, anything(?) for SV4
 362
 363                 $thisfile_mpc_header['target_bitrate']       =        (($HeaderDWORD[0] & 0xFF800000) >> 23);
 364                 $thisfile_mpc_header['intensity_stereo']     = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22);
 365                 $thisfile_mpc_header['mid_side_stereo']      = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21);
 366                 $thisfile_mpc_header['stream_version_major'] =         ($HeaderDWORD[0] & 0x001FF800) >> 11;
 367                 $thisfile_mpc_header['stream_version_minor'] = 0; // no sub-version numbers before SV7
 368                 $thisfile_mpc_header['max_band']             =         ($HeaderDWORD[0] & 0x000007C0) >>  6;  // related to lowpass frequency, not sure how it translates exactly
 369                 $thisfile_mpc_header['block_size']           =         ($HeaderDWORD[0] & 0x0000003F);
 370
 371                 switch ($thisfile_mpc_header['stream_version_major']) {
 372                         case 4:
 373                                 $thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16);
 374                                 break;
 375
 376                         case 5:
 377                         case 6:
 378                                 $thisfile_mpc_header['frame_count'] =  $HeaderDWORD[1];
 379                                 break;
 380
 381                         default:
 382                                 $info['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_version_major'].' instead';
 383                                 unset($info['mpc']);
 384                                 return false;
 385                                 break;
 386                 }
 387
 388                 if (($thisfile_mpc_header['stream_version_major'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) {
 389                         $this->warning('Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size']);
 390                 }
 391
 392                 $thisfile_mpc_header['sample_rate']   = 44100; // AB: used by all files up to SV7
 393                 $info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate'];
 394                 $thisfile_mpc_header['samples']       = $thisfile_mpc_header['frame_count'] * 1152 * $info['audio']['channels'];
 395
 396                 if ($thisfile_mpc_header['target_bitrate'] == 0) {
 397                         $info['audio']['bitrate_mode'] = 'vbr';
 398                 } else {
 399                         $info['audio']['bitrate_mode'] = 'cbr';
 400                 }
 401
 402                 $info['mpc']['bitrate']   = ($info['avdataend'] - $info['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152;
 403                 $info['audio']['bitrate'] = $info['mpc']['bitrate'];
 404                 $info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'];
 405
 406                 return true;
 407         }
 408
 409         /**
 410          * @param int $profileid
 411          *
 412          * @return string
 413          */
 414         public function MPCprofileNameLookup($profileid) {
 415                 static $MPCprofileNameLookup = array(
 416                         0  => 'no profile',
 417                         1  => 'Experimental',
 418                         2  => 'unused',
 419                         3  => 'unused',
 420                         4  => 'unused',
 421                         5  => 'below Telephone (q = 0.0)',
 422                         6  => 'below Telephone (q = 1.0)',
 423                         7  => 'Telephone (q = 2.0)',
 424                         8  => 'Thumb (q = 3.0)',
 425                         9  => 'Radio (q = 4.0)',
 426                         10 => 'Standard (q = 5.0)',
 427                         11 => 'Extreme (q = 6.0)',
 428                         12 => 'Insane (q = 7.0)',
 429                         13 => 'BrainDead (q = 8.0)',
 430                         14 => 'above BrainDead (q = 9.0)',
 431                         15 => 'above BrainDead (q = 10.0)'
 432                 );
 433                 return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid');
 434         }
 435
 436         /**
 437          * @param int $frequencyid
 438          *
 439          * @return int|string
 440          */
 441         public function MPCfrequencyLookup($frequencyid) {
 442                 static $MPCfrequencyLookup = array(
 443                         0 => 44100,
 444                         1 => 48000,
 445                         2 => 37800,
 446                         3 => 32000
 447                 );
 448                 return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid');
 449         }
 450
 451         /**
 452          * @param int $intvalue
 453          *
 454          * @return float|false
 455          */
 456         public function MPCpeakDBLookup($intvalue) {
 457                 if ($intvalue > 0) {
 458                         return ((log10($intvalue) / log10(2)) - 15) * 6;
 459                 }
 460                 return false;
 461         }
 462
 463         /**
 464          * @param int $encoderversion
 465          *
 466          * @return string
 467          */
 468         public function MPCencoderVersionLookup($encoderversion) {
 469                 //Encoder version * 100  (106 = 1.06)
 470                 //EncoderVersion % 10 == 0        Release (1.0)
 471                 //EncoderVersion %  2 == 0        Beta (1.06)
 472                 //EncoderVersion %  2 == 1        Alpha (1.05a...z)
 473
 474                 if ($encoderversion == 0) {
 475                         // very old version, not known exactly which
 476                         return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';
 477                 }
 478
 479                 if (($encoderversion % 10) == 0) {
 480
 481                         // release version
 482                         return number_format($encoderversion / 100, 2);
 483
 484                 } elseif (($encoderversion % 2) == 0) {
 485
 486                         // beta version
 487                         return number_format($encoderversion / 100, 2).' beta';
 488
 489                 }
 490
 491                 // alpha version
 492                 return number_format($encoderversion / 100, 2).' alpha';
 493         }
 494
 495         /**
 496          * @param string $data
 497          * @param int    $packetLength
 498          * @param int    $maxHandledPacketLength
 499          *
 500          * @return int|false
 501          */
 502         public function SV8variableLengthInteger($data, &$packetLength, $maxHandledPacketLength=9) {
 503                 $packet_size = 0;
 504                 for ($packetLength = 1; $packetLength <= $maxHandledPacketLength; $packetLength++) {
 505                         // variable-length size field:
 506                         //  bits, big-endian
 507                         //  0xxx xxxx                                           - value 0 to  2^7-1
 508                         //  1xxx xxxx  0xxx xxxx                                - value 0 to 2^14-1
 509                         //  1xxx xxxx  1xxx xxxx  0xxx xxxx                     - value 0 to 2^21-1
 510                         //  1xxx xxxx  1xxx xxxx  1xxx xxxx  0xxx xxxx          - value 0 to 2^28-1
 511                         //  ...
 512                         $thisbyte = ord(substr($data, ($packetLength - 1), 1));
 513                         // look through bytes until find a byte with MSB==0
 514                         $packet_size = ($packet_size << 7);
 515                         $packet_size = ($packet_size | ($thisbyte & 0x7F));
 516                         if (($thisbyte & 0x80) === 0) {
 517                                 break;
 518                         }
 519                         if ($packetLength >= $maxHandledPacketLength) {
 520                                 return false;
 521                         }
 522                 }
 523                 return $packet_size;
 524         }
 525
 526         /**
 527          * @param string $packetKey
 528          *
 529          * @return string
 530          */
 531         public function MPCsv8PacketName($packetKey) {
 532                 static $MPCsv8PacketName = array();
 533                 if (empty($MPCsv8PacketName)) {
 534                         $MPCsv8PacketName = array(
 535                                 'AP' => 'Audio Packet',
 536                                 'CT' => 'Chapter Tag',
 537                                 'EI' => 'Encoder Info',
 538                                 'RG' => 'Replay Gain',
 539                                 'SE' => 'Stream End',
 540                                 'SH' => 'Stream Header',
 541                                 'SO' => 'Seek Table Offset',
 542                                 'ST' => 'Seek Table',
 543                         );
 544                 }
 545                 return (isset($MPCsv8PacketName[$packetKey]) ? $MPCsv8PacketName[$packetKey] : $packetKey);
 546         }
 547 }