1<?php 2///////////////////////////////////////////////////////////////// 3/// getID3() by James Heinrich <info@getid3.org> // 4// available at http://getid3.sourceforge.net // 5// or http://www.getid3.org // 6// also https://github.com/JamesHeinrich/getID3 // 7///////////////////////////////////////////////////////////////// 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 18class getid3_mpc extends getid3_handler 19{ 20 21 public function Analyze() { 22 $info = &$this->getid3->info; 23 24 $info['mpc']['header'] = array(); 25 $thisfile_mpc_header = &$info['mpc']['header']; 26 27 $info['fileformat'] = 'mpc'; 28 $info['audio']['dataformat'] = 'mpc'; 29 $info['audio']['bitrate_mode'] = 'vbr'; 30 $info['audio']['channels'] = 2; // up to SV7 the format appears to have been hardcoded for stereo only 31 $info['audio']['lossless'] = false; 32 33 $this->fseek($info['avdataoffset']); 34 $MPCheaderData = $this->fread(4); 35 $info['mpc']['header']['preamble'] = substr($MPCheaderData, 0, 4); // should be 'MPCK' (SV8) or 'MP+' (SV7), otherwise possible stream data (SV4-SV6) 36 if (preg_match('#^MPCK#', $info['mpc']['header']['preamble'])) { 37 38 // this is SV8 39 return $this->ParseMPCsv8(); 40 41 } elseif (preg_match('#^MP\+#', $info['mpc']['header']['preamble'])) { 42 43 // this is SV7 44 return $this->ParseMPCsv7(); 45 46 } 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)) { 47 48 // this is SV4 - SV6, handle seperately 49 return $this->ParseMPCsv6(); 50 51 } else { 52 53 $this->error('Expecting "MP+" or "MPCK" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes(substr($MPCheaderData, 0, 4)).'"'); 54 unset($info['fileformat']); 55 unset($info['mpc']); 56 return false; 57 58 } 59 return false; 60 } 61 62 63 public function ParseMPCsv8() { 64 // this is SV8 65 // http://trac.musepack.net/trac/wiki/SV8Specification 66 67 $info = &$this->getid3->info; 68 $thisfile_mpc_header = &$info['mpc']['header']; 69 70 $keyNameSize = 2; 71 $maxHandledPacketLength = 9; // specs say: "n*8; 0 < n < 10" 72 73 $offset = $this->ftell(); 74 while ($offset < $info['avdataend']) { 75 $thisPacket = array(); 76 $thisPacket['offset'] = $offset; 77 $packet_offset = 0; 78 79 // Size is a variable-size field, could be 1-4 bytes (possibly more?) 80 // read enough data in and figure out the exact size later 81 $MPCheaderData = $this->fread($keyNameSize + $maxHandledPacketLength); 82 $packet_offset += $keyNameSize; 83 $thisPacket['key'] = substr($MPCheaderData, 0, $keyNameSize); 84 $thisPacket['key_name'] = $this->MPCsv8PacketName($thisPacket['key']); 85 if ($thisPacket['key'] == $thisPacket['key_name']) { 86 $this->error('Found unexpected key value "'.$thisPacket['key'].'" at offset '.$thisPacket['offset']); 87 return false; 88 } 89 $packetLength = 0; 90 $thisPacket['packet_size'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $keyNameSize), $packetLength); // includes keyname and packet_size field 91 if ($thisPacket['packet_size'] === false) { 92 $this->error('Did not find expected packet length within '.$maxHandledPacketLength.' bytes at offset '.($thisPacket['offset'] + $keyNameSize)); 93 return false; 94 } 95 $packet_offset += $packetLength; 96 $offset += $thisPacket['packet_size']; 97 98 switch ($thisPacket['key']) { 99 case 'SH': // Stream Header 100 $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength; 101 if ($moreBytesToRead > 0) { 102 $MPCheaderData .= $this->fread($moreBytesToRead); 103 } 104 $thisPacket['crc'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 4)); 105 $packet_offset += 4; 106 $thisPacket['stream_version'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1)); 107 $packet_offset += 1; 108 109 $packetLength = 0; 110 $thisPacket['sample_count'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength); 111 $packet_offset += $packetLength; 112 113 $packetLength = 0; 114 $thisPacket['beginning_silence'] = $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength); 115 $packet_offset += $packetLength; 116 117 $otherUsefulData = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2)); 118 $packet_offset += 2; 119 $thisPacket['sample_frequency_raw'] = (($otherUsefulData & 0xE000) >> 13); 120 $thisPacket['max_bands_used'] = (($otherUsefulData & 0x1F00) >> 8); 121 $thisPacket['channels'] = (($otherUsefulData & 0x00F0) >> 4) + 1; 122 $thisPacket['ms_used'] = (bool) (($otherUsefulData & 0x0008) >> 3); 123 $thisPacket['audio_block_frames'] = (($otherUsefulData & 0x0007) >> 0); 124 $thisPacket['sample_frequency'] = $this->MPCfrequencyLookup($thisPacket['sample_frequency_raw']); 125 126 $thisfile_mpc_header['mid_side_stereo'] = $thisPacket['ms_used']; 127 $thisfile_mpc_header['sample_rate'] = $thisPacket['sample_frequency']; 128 $thisfile_mpc_header['samples'] = $thisPacket['sample_count']; 129 $thisfile_mpc_header['stream_version_major'] = $thisPacket['stream_version']; 130 131 $info['audio']['channels'] = $thisPacket['channels']; 132 $info['audio']['sample_rate'] = $thisPacket['sample_frequency']; 133 $info['playtime_seconds'] = $thisPacket['sample_count'] / $thisPacket['sample_frequency']; 134 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds']; 135 break; 136 137 case 'RG': // Replay Gain 138 $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength; 139 if ($moreBytesToRead > 0) { 140 $MPCheaderData .= $this->fread($moreBytesToRead); 141 } 142 $thisPacket['replaygain_version'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1)); 143 $packet_offset += 1; 144 $thisPacket['replaygain_title_gain'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2)); 145 $packet_offset += 2; 146 $thisPacket['replaygain_title_peak'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2)); 147 $packet_offset += 2; 148 $thisPacket['replaygain_album_gain'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2)); 149 $packet_offset += 2; 150 $thisPacket['replaygain_album_peak'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 2)); 151 $packet_offset += 2; 152 153 if ($thisPacket['replaygain_title_gain']) { $info['replay_gain']['title']['gain'] = $thisPacket['replaygain_title_gain']; } 154 if ($thisPacket['replaygain_title_peak']) { $info['replay_gain']['title']['peak'] = $thisPacket['replaygain_title_peak']; } 155 if ($thisPacket['replaygain_album_gain']) { $info['replay_gain']['album']['gain'] = $thisPacket['replaygain_album_gain']; } 156 if ($thisPacket['replaygain_album_peak']) { $info['replay_gain']['album']['peak'] = $thisPacket['replaygain_album_peak']; } 157 break; 158 159 case 'EI': // Encoder Info 160 $moreBytesToRead = $thisPacket['packet_size'] - $keyNameSize - $maxHandledPacketLength; 161 if ($moreBytesToRead > 0) { 162 $MPCheaderData .= $this->fread($moreBytesToRead); 163 } 164 $profile_pns = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1)); 165 $packet_offset += 1; 166 $quality_int = (($profile_pns & 0xF0) >> 4); 167 $quality_dec = (($profile_pns & 0x0E) >> 3); 168 $thisPacket['quality'] = (float) $quality_int + ($quality_dec / 8); 169 $thisPacket['pns_tool'] = (bool) (($profile_pns & 0x01) >> 0); 170 $thisPacket['version_major'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1)); 171 $packet_offset += 1; 172 $thisPacket['version_minor'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1)); 173 $packet_offset += 1; 174 $thisPacket['version_build'] = getid3_lib::BigEndian2Int(substr($MPCheaderData, $packet_offset, 1)); 175 $packet_offset += 1; 176 $thisPacket['version'] = $thisPacket['version_major'].'.'.$thisPacket['version_minor'].'.'.$thisPacket['version_build']; 177 178 $info['audio']['encoder'] = 'MPC v'.$thisPacket['version'].' ('.(($thisPacket['version_minor'] % 2) ? 'unstable' : 'stable').')'; 179 $thisfile_mpc_header['encoder_version'] = $info['audio']['encoder']; 180 //$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 10.0 181 $thisfile_mpc_header['quality'] = (float) ($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 10.0 182 break; 183 184 case 'SO': // Seek Table Offset 185 $packetLength = 0; 186 $thisPacket['seek_table_offset'] = $thisPacket['offset'] + $this->SV8variableLengthInteger(substr($MPCheaderData, $packet_offset, $maxHandledPacketLength), $packetLength); 187 $packet_offset += $packetLength; 188 break; 189 190 case 'ST': // Seek Table 191 case 'SE': // Stream End 192 case 'AP': // Audio Data 193 // nothing useful here, just skip this packet 194 $thisPacket = array(); 195 break; 196 197 default: 198 $this->error('Found unhandled key type "'.$thisPacket['key'].'" at offset '.$thisPacket['offset']); 199 return false; 200 break; 201 } 202 if (!empty($thisPacket)) { 203 $info['mpc']['packets'][] = $thisPacket; 204 } 205 $this->fseek($offset); 206 } 207 $thisfile_mpc_header['size'] = $offset; 208 return true; 209 } 210 211 public function ParseMPCsv7() { 212 // this is SV7 213 // http://www.uni-jena.de/~pfk/mpp/sv8/header.html 214 215 $info = &$this->getid3->info; 216 $thisfile_mpc_header = &$info['mpc']['header']; 217 $offset = 0; 218 219 $thisfile_mpc_header['size'] = 28; 220 $MPCheaderData = $info['mpc']['header']['preamble']; 221 $MPCheaderData .= $this->fread($thisfile_mpc_header['size'] - strlen($info['mpc']['header']['preamble'])); 222 $offset = strlen('MP+'); 223 224 $StreamVersionByte = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1)); 225 $offset += 1; 226 $thisfile_mpc_header['stream_version_major'] = ($StreamVersionByte & 0x0F) >> 0; 227 $thisfile_mpc_header['stream_version_minor'] = ($StreamVersionByte & 0xF0) >> 4; // should always be 0, subversions no longer exist in SV8 228 $thisfile_mpc_header['frame_count'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4)); 229 $offset += 4; 230 231 if ($thisfile_mpc_header['stream_version_major'] != 7) { 232 $this->error('Only Musepack SV7 supported (this file claims to be v'.$thisfile_mpc_header['stream_version_major'].')'); 233 return false; 234 } 235 236 $FlagsDWORD1 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4)); 237 $offset += 4; 238 $thisfile_mpc_header['intensity_stereo'] = (bool) (($FlagsDWORD1 & 0x80000000) >> 31); 239 $thisfile_mpc_header['mid_side_stereo'] = (bool) (($FlagsDWORD1 & 0x40000000) >> 30); 240 $thisfile_mpc_header['max_subband'] = ($FlagsDWORD1 & 0x3F000000) >> 24; 241 $thisfile_mpc_header['raw']['profile'] = ($FlagsDWORD1 & 0x00F00000) >> 20; 242 $thisfile_mpc_header['begin_loud'] = (bool) (($FlagsDWORD1 & 0x00080000) >> 19); 243 $thisfile_mpc_header['end_loud'] = (bool) (($FlagsDWORD1 & 0x00040000) >> 18); 244 $thisfile_mpc_header['raw']['sample_rate'] = ($FlagsDWORD1 & 0x00030000) >> 16; 245 $thisfile_mpc_header['max_level'] = ($FlagsDWORD1 & 0x0000FFFF); 246 247 $thisfile_mpc_header['raw']['title_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2)); 248 $offset += 2; 249 $thisfile_mpc_header['raw']['title_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true); 250 $offset += 2; 251 252 $thisfile_mpc_header['raw']['album_peak'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2)); 253 $offset += 2; 254 $thisfile_mpc_header['raw']['album_gain'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 2), true); 255 $offset += 2; 256 257 $FlagsDWORD2 = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 4)); 258 $offset += 4; 259 $thisfile_mpc_header['true_gapless'] = (bool) (($FlagsDWORD2 & 0x80000000) >> 31); 260 $thisfile_mpc_header['last_frame_length'] = ($FlagsDWORD2 & 0x7FF00000) >> 20; 261 262 263 $thisfile_mpc_header['raw']['not_sure_what'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 3)); 264 $offset += 3; 265 $thisfile_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, $offset, 1)); 266 $offset += 1; 267 268 $thisfile_mpc_header['profile'] = $this->MPCprofileNameLookup($thisfile_mpc_header['raw']['profile']); 269 $thisfile_mpc_header['sample_rate'] = $this->MPCfrequencyLookup($thisfile_mpc_header['raw']['sample_rate']); 270 if ($thisfile_mpc_header['sample_rate'] == 0) { 271 $this->error('Corrupt MPC file: frequency == zero'); 272 return false; 273 } 274 $info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate']; 275 $thisfile_mpc_header['samples'] = ((($thisfile_mpc_header['frame_count'] - 1) * 1152) + $thisfile_mpc_header['last_frame_length']) * $info['audio']['channels']; 276 277 $info['playtime_seconds'] = ($thisfile_mpc_header['samples'] / $info['audio']['channels']) / $info['audio']['sample_rate']; 278 if ($info['playtime_seconds'] == 0) { 279 $this->error('Corrupt MPC file: playtime_seconds == zero'); 280 return false; 281 } 282 283 // add size of file header to avdataoffset - calc bitrate correctly + MD5 data 284 $info['avdataoffset'] += $thisfile_mpc_header['size']; 285 286 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds']; 287 288 $thisfile_mpc_header['title_peak'] = $thisfile_mpc_header['raw']['title_peak']; 289 $thisfile_mpc_header['title_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['title_peak']); 290 if ($thisfile_mpc_header['raw']['title_gain'] < 0) { 291 $thisfile_mpc_header['title_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['title_gain']) / -100; 292 } else { 293 $thisfile_mpc_header['title_gain_db'] = (float) $thisfile_mpc_header['raw']['title_gain'] / 100; 294 } 295 296 $thisfile_mpc_header['album_peak'] = $thisfile_mpc_header['raw']['album_peak']; 297 $thisfile_mpc_header['album_peak_db'] = $this->MPCpeakDBLookup($thisfile_mpc_header['album_peak']); 298 if ($thisfile_mpc_header['raw']['album_gain'] < 0) { 299 $thisfile_mpc_header['album_gain_db'] = (float) (32768 + $thisfile_mpc_header['raw']['album_gain']) / -100; 300 } else { 301 $thisfile_mpc_header['album_gain_db'] = (float) $thisfile_mpc_header['raw']['album_gain'] / 100;; 302 } 303 $thisfile_mpc_header['encoder_version'] = $this->MPCencoderVersionLookup($thisfile_mpc_header['raw']['encoder_version']); 304 305 $info['replay_gain']['track']['adjustment'] = $thisfile_mpc_header['title_gain_db']; 306 $info['replay_gain']['album']['adjustment'] = $thisfile_mpc_header['album_gain_db']; 307 308 if ($thisfile_mpc_header['title_peak'] > 0) { 309 $info['replay_gain']['track']['peak'] = $thisfile_mpc_header['title_peak']; 310 } elseif (round($thisfile_mpc_header['max_level'] * 1.18) > 0) { 311 $info['replay_gain']['track']['peak'] = getid3_lib::CastAsInt(round($thisfile_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c 312 } 313 if ($thisfile_mpc_header['album_peak'] > 0) { 314 $info['replay_gain']['album']['peak'] = $thisfile_mpc_header['album_peak']; 315 } 316 317 //$info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major'].'.'.$thisfile_mpc_header['stream_version_minor'].', '.$thisfile_mpc_header['encoder_version']; 318 $info['audio']['encoder'] = $thisfile_mpc_header['encoder_version']; 319 $info['audio']['encoder_options'] = $thisfile_mpc_header['profile']; 320 $thisfile_mpc_header['quality'] = (float) ($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 10.0 321 322 return true; 323 } 324 325 public function ParseMPCsv6() { 326 // this is SV4 - SV6 327 328 $info = &$this->getid3->info; 329 $thisfile_mpc_header = &$info['mpc']['header']; 330 $offset = 0; 331 332 $thisfile_mpc_header['size'] = 8; 333 $this->fseek($info['avdataoffset']); 334 $MPCheaderData = $this->fread($thisfile_mpc_header['size']); 335 336 // add size of file header to avdataoffset - calc bitrate correctly + MD5 data 337 $info['avdataoffset'] += $thisfile_mpc_header['size']; 338 339 // Most of this code adapted from Jurgen Faul's MPEGplus source code - thanks Jurgen! :) 340 $HeaderDWORD[0] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 0, 4)); 341 $HeaderDWORD[1] = getid3_lib::LittleEndian2Int(substr($MPCheaderData, 4, 4)); 342 343 344 // DDDD DDDD CCCC CCCC BBBB BBBB AAAA AAAA 345 // aaaa aaaa abcd dddd dddd deee eeff ffff 346 // 347 // a = bitrate = anything 348 // b = IS = anything 349 // c = MS = anything 350 // d = streamversion = 0000000004 or 0000000005 or 0000000006 351 // e = maxband = anything 352 // f = blocksize = 000001 for SV5+, anything(?) for SV4 353 354 $thisfile_mpc_header['target_bitrate'] = (($HeaderDWORD[0] & 0xFF800000) >> 23); 355 $thisfile_mpc_header['intensity_stereo'] = (bool) (($HeaderDWORD[0] & 0x00400000) >> 22); 356 $thisfile_mpc_header['mid_side_stereo'] = (bool) (($HeaderDWORD[0] & 0x00200000) >> 21); 357 $thisfile_mpc_header['stream_version_major'] = ($HeaderDWORD[0] & 0x001FF800) >> 11; 358 $thisfile_mpc_header['stream_version_minor'] = 0; // no sub-version numbers before SV7 359 $thisfile_mpc_header['max_band'] = ($HeaderDWORD[0] & 0x000007C0) >> 6; // related to lowpass frequency, not sure how it translates exactly 360 $thisfile_mpc_header['block_size'] = ($HeaderDWORD[0] & 0x0000003F); 361 362 switch ($thisfile_mpc_header['stream_version_major']) { 363 case 4: 364 $thisfile_mpc_header['frame_count'] = ($HeaderDWORD[1] >> 16); 365 break; 366 367 case 5: 368 case 6: 369 $thisfile_mpc_header['frame_count'] = $HeaderDWORD[1]; 370 break; 371 372 default: 373 $info['error'] = 'Expecting 4, 5 or 6 in version field, found '.$thisfile_mpc_header['stream_version_major'].' instead'; 374 unset($info['mpc']); 375 return false; 376 break; 377 } 378 379 if (($thisfile_mpc_header['stream_version_major'] > 4) && ($thisfile_mpc_header['block_size'] != 1)) { 380 $this->warning('Block size expected to be 1, actual value found: '.$thisfile_mpc_header['block_size']); 381 } 382 383 $thisfile_mpc_header['sample_rate'] = 44100; // AB: used by all files up to SV7 384 $info['audio']['sample_rate'] = $thisfile_mpc_header['sample_rate']; 385 $thisfile_mpc_header['samples'] = $thisfile_mpc_header['frame_count'] * 1152 * $info['audio']['channels']; 386 387 if ($thisfile_mpc_header['target_bitrate'] == 0) { 388 $info['audio']['bitrate_mode'] = 'vbr'; 389 } else { 390 $info['audio']['bitrate_mode'] = 'cbr'; 391 } 392 393 $info['mpc']['bitrate'] = ($info['avdataend'] - $info['avdataoffset']) * 8 * 44100 / $thisfile_mpc_header['frame_count'] / 1152; 394 $info['audio']['bitrate'] = $info['mpc']['bitrate']; 395 $info['audio']['encoder'] = 'SV'.$thisfile_mpc_header['stream_version_major']; 396 397 return true; 398 } 399 400 401 public function MPCprofileNameLookup($profileid) { 402 static $MPCprofileNameLookup = array( 403 0 => 'no profile', 404 1 => 'Experimental', 405 2 => 'unused', 406 3 => 'unused', 407 4 => 'unused', 408 5 => 'below Telephone (q = 0.0)', 409 6 => 'below Telephone (q = 1.0)', 410 7 => 'Telephone (q = 2.0)', 411 8 => 'Thumb (q = 3.0)', 412 9 => 'Radio (q = 4.0)', 413 10 => 'Standard (q = 5.0)', 414 11 => 'Extreme (q = 6.0)', 415 12 => 'Insane (q = 7.0)', 416 13 => 'BrainDead (q = 8.0)', 417 14 => 'above BrainDead (q = 9.0)', 418 15 => 'above BrainDead (q = 10.0)' 419 ); 420 return (isset($MPCprofileNameLookup[$profileid]) ? $MPCprofileNameLookup[$profileid] : 'invalid'); 421 } 422 423 public function MPCfrequencyLookup($frequencyid) { 424 static $MPCfrequencyLookup = array( 425 0 => 44100, 426 1 => 48000, 427 2 => 37800, 428 3 => 32000 429 ); 430 return (isset($MPCfrequencyLookup[$frequencyid]) ? $MPCfrequencyLookup[$frequencyid] : 'invalid'); 431 } 432 433 public function MPCpeakDBLookup($intvalue) { 434 if ($intvalue > 0) { 435 return ((log10($intvalue) / log10(2)) - 15) * 6; 436 } 437 return false; 438 } 439 440 public function MPCencoderVersionLookup($encoderversion) { 441 //Encoder version * 100 (106 = 1.06) 442 //EncoderVersion % 10 == 0 Release (1.0) 443 //EncoderVersion % 2 == 0 Beta (1.06) 444 //EncoderVersion % 2 == 1 Alpha (1.05a...z) 445 446 if ($encoderversion == 0) { 447 // very old version, not known exactly which 448 return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05'; 449 } 450 451 if (($encoderversion % 10) == 0) { 452 453 // release version 454 return number_format($encoderversion / 100, 2); 455 456 } elseif (($encoderversion % 2) == 0) { 457 458 // beta version 459 return number_format($encoderversion / 100, 2).' beta'; 460 461 } 462 463 // alpha version 464 return number_format($encoderversion / 100, 2).' alpha'; 465 } 466 467 public function SV8variableLengthInteger($data, &$packetLength, $maxHandledPacketLength=9) { 468 $packet_size = 0; 469 for ($packetLength = 1; $packetLength <= $maxHandledPacketLength; $packetLength++) { 470 // variable-length size field: 471 // bits, big-endian 472 // 0xxx xxxx - value 0 to 2^7-1 473 // 1xxx xxxx 0xxx xxxx - value 0 to 2^14-1 474 // 1xxx xxxx 1xxx xxxx 0xxx xxxx - value 0 to 2^21-1 475 // 1xxx xxxx 1xxx xxxx 1xxx xxxx 0xxx xxxx - value 0 to 2^28-1 476 // ... 477 $thisbyte = ord(substr($data, ($packetLength - 1), 1)); 478 // look through bytes until find a byte with MSB==0 479 $packet_size = ($packet_size << 7); 480 $packet_size = ($packet_size | ($thisbyte & 0x7F)); 481 if (($thisbyte & 0x80) === 0) { 482 break; 483 } 484 if ($packetLength >= $maxHandledPacketLength) { 485 return false; 486 } 487 } 488 return $packet_size; 489 } 490 491 public function MPCsv8PacketName($packetKey) { 492 static $MPCsv8PacketName = array(); 493 if (empty($MPCsv8PacketName)) { 494 $MPCsv8PacketName = array( 495 'AP' => 'Audio Packet', 496 'CT' => 'Chapter Tag', 497 'EI' => 'Encoder Info', 498 'RG' => 'Replay Gain', 499 'SE' => 'Stream End', 500 'SH' => 'Stream Header', 501 'SO' => 'Seek Table Offset', 502 'ST' => 'Seek Table', 503 ); 504 } 505 return (isset($MPCsv8PacketName[$packetKey]) ? $MPCsv8PacketName[$packetKey] : $packetKey); 506 } 507} 508