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Code source de LifeType 1.2.4 |
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 ///////////////////////////////////////////////////////////////// 7 // See readme.txt for more details // 8 ///////////////////////////////////////////////////////////////// 9 // // 10 // module.audio.aac.php // 11 // module for analyzing AAC Audio files // 12 // dependencies: NONE // 13 // /// 14 ///////////////////////////////////////////////////////////////// 15 16 17 class getid3_aac 18 { 19 20 // new combined constructor 21 function getid3_aac(&$fd, &$ThisFileInfo, $option) { 22 23 if ($option === 'adif') { 24 $this->getAACADIFheaderFilepointer($fd, $ThisFileInfo); 25 } 26 elseif ($option === 'adts') { 27 $this->getAACADTSheaderFilepointer($fd, $ThisFileInfo); 28 } 29 } 30 31 32 33 function getAACADIFheaderFilepointer(&$fd, &$ThisFileInfo) { 34 $ThisFileInfo['fileformat'] = 'aac'; 35 $ThisFileInfo['audio']['dataformat'] = 'aac'; 36 $ThisFileInfo['audio']['lossless'] = false; 37 38 fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); 39 $AACheader = fread($fd, 1024); 40 $offset = 0; 41 42 if (substr($AACheader, 0, 4) == 'ADIF') { 43 44 // http://faac.sourceforge.net/wiki/index.php?page=ADIF 45 46 // http://libmpeg.org/mpeg4/doc/w2203tfs.pdf 47 // adif_header() { 48 // adif_id 32 49 // copyright_id_present 1 50 // if( copyright_id_present ) 51 // copyright_id 72 52 // original_copy 1 53 // home 1 54 // bitstream_type 1 55 // bitrate 23 56 // num_program_config_elements 4 57 // for (i = 0; i < num_program_config_elements + 1; i++ ) { 58 // if( bitstream_type == '0' ) 59 // adif_buffer_fullness 20 60 // program_config_element() 61 // } 62 // } 63 64 $AACheaderBitstream = getid3_lib::BigEndian2Bin($AACheader); 65 $bitoffset = 0; 66 67 $ThisFileInfo['aac']['header_type'] = 'ADIF'; 68 $bitoffset += 32; 69 $ThisFileInfo['aac']['header']['mpeg_version'] = 4; 70 71 $ThisFileInfo['aac']['header']['copyright'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1'); 72 $bitoffset += 1; 73 if ($ThisFileInfo['aac']['header']['copyright']) { 74 $ThisFileInfo['aac']['header']['copyright_id'] = getid3_lib::Bin2String(substr($AACheaderBitstream, $bitoffset, 72)); 75 $bitoffset += 72; 76 } 77 $ThisFileInfo['aac']['header']['original_copy'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1'); 78 $bitoffset += 1; 79 $ThisFileInfo['aac']['header']['home'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1'); 80 $bitoffset += 1; 81 $ThisFileInfo['aac']['header']['is_vbr'] = (bool) (substr($AACheaderBitstream, $bitoffset, 1) == '1'); 82 $bitoffset += 1; 83 if ($ThisFileInfo['aac']['header']['is_vbr']) { 84 $ThisFileInfo['audio']['bitrate_mode'] = 'vbr'; 85 $ThisFileInfo['aac']['header']['bitrate_max'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23)); 86 $bitoffset += 23; 87 } else { 88 $ThisFileInfo['audio']['bitrate_mode'] = 'cbr'; 89 $ThisFileInfo['aac']['header']['bitrate'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23)); 90 $bitoffset += 23; 91 $ThisFileInfo['audio']['bitrate'] = $ThisFileInfo['aac']['header']['bitrate']; 92 } 93 if ($ThisFileInfo['audio']['bitrate'] == 0) { 94 $ThisFileInfo['error'][] = 'Corrupt AAC file: bitrate_audio == zero'; 95 return false; 96 } 97 $ThisFileInfo['aac']['header']['num_program_configs'] = 1 + getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 98 $bitoffset += 4; 99 100 for ($i = 0; $i < $ThisFileInfo['aac']['header']['num_program_configs']; $i++) { 101 // http://www.audiocoding.com/wiki/index.php?page=program_config_element 102 103 // buffer_fullness 20 104 105 // element_instance_tag 4 106 // object_type 2 107 // sampling_frequency_index 4 108 // num_front_channel_elements 4 109 // num_side_channel_elements 4 110 // num_back_channel_elements 4 111 // num_lfe_channel_elements 2 112 // num_assoc_data_elements 3 113 // num_valid_cc_elements 4 114 // mono_mixdown_present 1 115 // mono_mixdown_element_number 4 if mono_mixdown_present == 1 116 // stereo_mixdown_present 1 117 // stereo_mixdown_element_number 4 if stereo_mixdown_present == 1 118 // matrix_mixdown_idx_present 1 119 // matrix_mixdown_idx 2 if matrix_mixdown_idx_present == 1 120 // pseudo_surround_enable 1 if matrix_mixdown_idx_present == 1 121 // for (i = 0; i < num_front_channel_elements; i++) { 122 // front_element_is_cpe[i] 1 123 // front_element_tag_select[i] 4 124 // } 125 // for (i = 0; i < num_side_channel_elements; i++) { 126 // side_element_is_cpe[i] 1 127 // side_element_tag_select[i] 4 128 // } 129 // for (i = 0; i < num_back_channel_elements; i++) { 130 // back_element_is_cpe[i] 1 131 // back_element_tag_select[i] 4 132 // } 133 // for (i = 0; i < num_lfe_channel_elements; i++) { 134 // lfe_element_tag_select[i] 4 135 // } 136 // for (i = 0; i < num_assoc_data_elements; i++) { 137 // assoc_data_element_tag_select[i] 4 138 // } 139 // for (i = 0; i < num_valid_cc_elements; i++) { 140 // cc_element_is_ind_sw[i] 1 141 // valid_cc_element_tag_select[i] 4 142 // } 143 // byte_alignment() VAR 144 // comment_field_bytes 8 145 // for (i = 0; i < comment_field_bytes; i++) { 146 // comment_field_data[i] 8 147 // } 148 149 if (!$ThisFileInfo['aac']['header']['is_vbr']) { 150 $ThisFileInfo['aac']['program_configs'][$i]['buffer_fullness'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 20)); 151 $bitoffset += 20; 152 } 153 $ThisFileInfo['aac']['program_configs'][$i]['element_instance_tag'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 154 $bitoffset += 4; 155 $ThisFileInfo['aac']['program_configs'][$i]['object_type'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 156 $bitoffset += 2; 157 $ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency_index'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 158 $bitoffset += 4; 159 $ThisFileInfo['aac']['program_configs'][$i]['num_front_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 160 $bitoffset += 4; 161 $ThisFileInfo['aac']['program_configs'][$i]['num_side_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 162 $bitoffset += 4; 163 $ThisFileInfo['aac']['program_configs'][$i]['num_back_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 164 $bitoffset += 4; 165 $ThisFileInfo['aac']['program_configs'][$i]['num_lfe_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 166 $bitoffset += 2; 167 $ThisFileInfo['aac']['program_configs'][$i]['num_assoc_data_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 3)); 168 $bitoffset += 3; 169 $ThisFileInfo['aac']['program_configs'][$i]['num_valid_cc_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 170 $bitoffset += 4; 171 $ThisFileInfo['aac']['program_configs'][$i]['mono_mixdown_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 172 $bitoffset += 1; 173 if ($ThisFileInfo['aac']['program_configs'][$i]['mono_mixdown_present']) { 174 $ThisFileInfo['aac']['program_configs'][$i]['mono_mixdown_element_number'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 175 $bitoffset += 4; 176 } 177 $ThisFileInfo['aac']['program_configs'][$i]['stereo_mixdown_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 178 $bitoffset += 1; 179 if ($ThisFileInfo['aac']['program_configs'][$i]['stereo_mixdown_present']) { 180 $ThisFileInfo['aac']['program_configs'][$i]['stereo_mixdown_element_number'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 181 $bitoffset += 4; 182 } 183 $ThisFileInfo['aac']['program_configs'][$i]['matrix_mixdown_idx_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 184 $bitoffset += 1; 185 if ($ThisFileInfo['aac']['program_configs'][$i]['matrix_mixdown_idx_present']) { 186 $ThisFileInfo['aac']['program_configs'][$i]['matrix_mixdown_idx'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 187 $bitoffset += 2; 188 $ThisFileInfo['aac']['program_configs'][$i]['pseudo_surround_enable'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 189 $bitoffset += 1; 190 } 191 for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_front_channel_elements']; $j++) { 192 $ThisFileInfo['aac']['program_configs'][$i]['front_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 193 $bitoffset += 1; 194 $ThisFileInfo['aac']['program_configs'][$i]['front_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 195 $bitoffset += 4; 196 } 197 for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_side_channel_elements']; $j++) { 198 $ThisFileInfo['aac']['program_configs'][$i]['side_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 199 $bitoffset += 1; 200 $ThisFileInfo['aac']['program_configs'][$i]['side_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 201 $bitoffset += 4; 202 } 203 for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_back_channel_elements']; $j++) { 204 $ThisFileInfo['aac']['program_configs'][$i]['back_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 205 $bitoffset += 1; 206 $ThisFileInfo['aac']['program_configs'][$i]['back_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 207 $bitoffset += 4; 208 } 209 for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_lfe_channel_elements']; $j++) { 210 $ThisFileInfo['aac']['program_configs'][$i]['lfe_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 211 $bitoffset += 4; 212 } 213 for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_assoc_data_elements']; $j++) { 214 $ThisFileInfo['aac']['program_configs'][$i]['assoc_data_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 215 $bitoffset += 4; 216 } 217 for ($j = 0; $j < $ThisFileInfo['aac']['program_configs'][$i]['num_valid_cc_elements']; $j++) { 218 $ThisFileInfo['aac']['program_configs'][$i]['cc_element_is_ind_sw'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 219 $bitoffset += 1; 220 $ThisFileInfo['aac']['program_configs'][$i]['valid_cc_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 221 $bitoffset += 4; 222 } 223 224 $bitoffset = ceil($bitoffset / 8) * 8; 225 226 $ThisFileInfo['aac']['program_configs'][$i]['comment_field_bytes'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 8)); 227 $bitoffset += 8; 228 $ThisFileInfo['aac']['program_configs'][$i]['comment_field'] = getid3_lib::Bin2String(substr($AACheaderBitstream, $bitoffset, 8 * $ThisFileInfo['aac']['program_configs'][$i]['comment_field_bytes'])); 229 $bitoffset += 8 * $ThisFileInfo['aac']['program_configs'][$i]['comment_field_bytes']; 230 231 232 $ThisFileInfo['aac']['header']['profile_text'] = $this->AACprofileLookup($ThisFileInfo['aac']['program_configs'][$i]['object_type'], $ThisFileInfo['aac']['header']['mpeg_version']); 233 $ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency'] = $this->AACsampleRateLookup($ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency_index']); 234 $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['aac']['program_configs'][$i]['sampling_frequency']; 235 $ThisFileInfo['audio']['channels'] = $this->AACchannelCountCalculate($ThisFileInfo['aac']['program_configs'][$i]); 236 if ($ThisFileInfo['aac']['program_configs'][$i]['comment_field']) { 237 $ThisFileInfo['aac']['comments'][] = $ThisFileInfo['aac']['program_configs'][$i]['comment_field']; 238 } 239 } 240 $ThisFileInfo['playtime_seconds'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['audio']['bitrate']; 241 242 $ThisFileInfo['audio']['encoder_options'] = $ThisFileInfo['aac']['header_type'].' '.$ThisFileInfo['aac']['header']['profile_text']; 243 244 245 246 return true; 247 248 } else { 249 250 unset($ThisFileInfo['fileformat']); 251 unset($ThisFileInfo['aac']); 252 $ThisFileInfo['error'][] = 'AAC-ADIF synch not found at offset '.$ThisFileInfo['avdataoffset'].' (expected "ADIF", found "'.substr($AACheader, 0, 4).'" instead)'; 253 return false; 254 255 } 256 257 } 258 259 260 function getAACADTSheaderFilepointer(&$fd, &$ThisFileInfo, $MaxFramesToScan=1000000, $ReturnExtendedInfo=false) { 261 // based loosely on code from AACfile by Jurgen Faul <jfaulØgmx.de> 262 // http://jfaul.de/atl or http://j-faul.virtualave.net/atl/atl.html 263 264 265 // http://faac.sourceforge.net/wiki/index.php?page=ADTS 266 267 // * ADTS Fixed Header: these don't change from frame to frame 268 // syncword 12 always: '111111111111' 269 // ID 1 0: MPEG-4, 1: MPEG-2 270 // layer 2 always: '00' 271 // protection_absent 1 272 // profile 2 273 // sampling_frequency_index 4 274 // private_bit 1 275 // channel_configuration 3 276 // original/copy 1 277 // home 1 278 // emphasis 2 only if ID == 0 (ie MPEG-4) 279 280 // * ADTS Variable Header: these can change from frame to frame 281 // copyright_identification_bit 1 282 // copyright_identification_start 1 283 // aac_frame_length 13 length of the frame including header (in bytes) 284 // adts_buffer_fullness 11 0x7FF indicates VBR 285 // no_raw_data_blocks_in_frame 2 286 287 // * ADTS Error check 288 // crc_check 16 only if protection_absent == 0 289 290 $byteoffset = 0; 291 $framenumber = 0; 292 293 // Init bit pattern array 294 static $decbin = array(); 295 296 // Populate $bindec 297 for ($i = 0; $i < 256; $i++) { 298 $decbin[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT); 299 } 300 301 // used to calculate bitrate below 302 $BitrateCache = array(); 303 304 305 while (true) { 306 // breaks out when end-of-file encountered, or invalid data found, 307 // or MaxFramesToScan frames have been scanned 308 309 fseek($fd, $byteoffset, SEEK_SET); 310 311 // First get substring 312 $substring = fread($fd, 10); 313 $substringlength = strlen($substring); 314 if ($substringlength != 10) { 315 $ThisFileInfo['error'][] = 'Failed to read 10 bytes at offset '.(ftell($fd) - $substringlength).' (only read '.$substringlength.' bytes)'; 316 return false; 317 } 318 319 // Initialise $AACheaderBitstream 320 $AACheaderBitstream = ''; 321 322 // Loop thru substring chars 323 for ($i = 0; $i < 10; $i++) { 324 $AACheaderBitstream .= $decbin[$substring{$i}]; 325 } 326 327 $bitoffset = 0; 328 329 $synctest = bindec(substr($AACheaderBitstream, $bitoffset, 12)); 330 331 $bitoffset += 12; 332 if ($synctest != 0x0FFF) { 333 $ThisFileInfo['error'][] = 'Synch pattern (0x0FFF) not found at offset '.(ftell($fd) - 10).' (found 0x0'.strtoupper(dechex($synctest)).' instead)'; 334 if ($ThisFileInfo['fileformat'] == 'aac') { 335 return true; 336 } 337 return false; 338 } 339 340 // Gather info for first frame only - this takes time to do 1000 times! 341 if ($framenumber > 0) { 342 343 if (!$AACheaderBitstream[$bitoffset]) { 344 345 // MPEG-4 346 $bitoffset += 20; 347 348 } else { 349 350 // MPEG-2 351 $bitoffset += 18; 352 353 } 354 355 } else { 356 357 $ThisFileInfo['aac']['header_type'] = 'ADTS'; 358 $ThisFileInfo['aac']['header']['synch'] = $synctest; 359 $ThisFileInfo['fileformat'] = 'aac'; 360 $ThisFileInfo['audio']['dataformat'] = 'aac'; 361 362 $ThisFileInfo['aac']['header']['mpeg_version'] = ((substr($AACheaderBitstream, $bitoffset, 1) == '0') ? 4 : 2); 363 $bitoffset += 1; 364 $ThisFileInfo['aac']['header']['layer'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 365 $bitoffset += 2; 366 if ($ThisFileInfo['aac']['header']['layer'] != 0) { 367 $ThisFileInfo['error'][] = 'Layer error - expected 0x00, found 0x'.dechex($ThisFileInfo['aac']['header']['layer']).' instead'; 368 return false; 369 } 370 $ThisFileInfo['aac']['header']['crc_present'] = ((substr($AACheaderBitstream, $bitoffset, 1) == '0') ? true : false); 371 $bitoffset += 1; 372 $ThisFileInfo['aac']['header']['profile_id'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 373 $bitoffset += 2; 374 $ThisFileInfo['aac']['header']['profile_text'] = $this->AACprofileLookup($ThisFileInfo['aac']['header']['profile_id'], $ThisFileInfo['aac']['header']['mpeg_version']); 375 376 $ThisFileInfo['aac']['header']['sample_frequency_index'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 377 $bitoffset += 4; 378 $ThisFileInfo['aac']['header']['sample_frequency'] = $this->AACsampleRateLookup($ThisFileInfo['aac']['header']['sample_frequency_index']); 379 if ($ThisFileInfo['aac']['header']['sample_frequency'] == 0) { 380 $ThisFileInfo['error'][] = 'Corrupt AAC file: sample_frequency == zero'; 381 return false; 382 } 383 $ThisFileInfo['audio']['sample_rate'] = $ThisFileInfo['aac']['header']['sample_frequency']; 384 385 $ThisFileInfo['aac']['header']['private'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 386 $bitoffset += 1; 387 $ThisFileInfo['aac']['header']['channel_configuration'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 3)); 388 $bitoffset += 3; 389 $ThisFileInfo['audio']['channels'] = $ThisFileInfo['aac']['header']['channel_configuration']; 390 $ThisFileInfo['aac']['header']['original'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 391 $bitoffset += 1; 392 $ThisFileInfo['aac']['header']['home'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 393 $bitoffset += 1; 394 395 if ($ThisFileInfo['aac']['header']['mpeg_version'] == 4) { 396 $ThisFileInfo['aac']['header']['emphasis'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 397 $bitoffset += 2; 398 } 399 400 if ($ReturnExtendedInfo) { 401 402 $ThisFileInfo['aac'][$framenumber]['copyright_id_bit'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 403 $bitoffset += 1; 404 $ThisFileInfo['aac'][$framenumber]['copyright_id_start'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 405 $bitoffset += 1; 406 407 } else { 408 409 $bitoffset += 2; 410 411 } 412 413 } 414 415 $FrameLength = bindec(substr($AACheaderBitstream, $bitoffset, 13)); 416 417 if (!isset($BitrateCache[$FrameLength])) { 418 $BitrateCache[$FrameLength] = ($ThisFileInfo['aac']['header']['sample_frequency'] / 1024) * $FrameLength * 8; 419 } 420 @$ThisFileInfo['aac']['bitrate_distribution'][$BitrateCache[$FrameLength]]++; 421 422 $ThisFileInfo['aac'][$framenumber]['aac_frame_length'] = $FrameLength; 423 $bitoffset += 13; 424 $ThisFileInfo['aac'][$framenumber]['adts_buffer_fullness'] = bindec(substr($AACheaderBitstream, $bitoffset, 11)); 425 $bitoffset += 11; 426 if ($ThisFileInfo['aac'][$framenumber]['adts_buffer_fullness'] == 0x07FF) { 427 $ThisFileInfo['audio']['bitrate_mode'] = 'vbr'; 428 } else { 429 $ThisFileInfo['audio']['bitrate_mode'] = 'cbr'; 430 } 431 $ThisFileInfo['aac'][$framenumber]['num_raw_data_blocks'] = bindec(substr($AACheaderBitstream, $bitoffset, 2)); 432 $bitoffset += 2; 433 434 if ($ThisFileInfo['aac']['header']['crc_present']) { 435 //$ThisFileInfo['aac'][$framenumber]['crc'] = bindec(substr($AACheaderBitstream, $bitoffset, 16)); 436 $bitoffset += 16; 437 } 438 439 if (!$ReturnExtendedInfo) { 440 unset($ThisFileInfo['aac'][$framenumber]); 441 } 442 443 $byteoffset += $FrameLength; 444 if ((++$framenumber < $MaxFramesToScan) && (($byteoffset + 10) < $ThisFileInfo['avdataend'])) { 445 446 // keep scanning 447 448 } else { 449 450 $ThisFileInfo['aac']['frames'] = $framenumber; 451 $ThisFileInfo['playtime_seconds'] = ($ThisFileInfo['avdataend'] / $byteoffset) * (($framenumber * 1024) / $ThisFileInfo['aac']['header']['sample_frequency']); // (1 / % of file scanned) * (samples / (samples/sec)) = seconds 452 if ($ThisFileInfo['playtime_seconds'] == 0) { 453 $ThisFileInfo['error'][] = 'Corrupt AAC file: playtime_seconds == zero'; 454 return false; 455 } 456 $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds']; 457 ksort($ThisFileInfo['aac']['bitrate_distribution']); 458 459 $ThisFileInfo['audio']['encoder_options'] = $ThisFileInfo['aac']['header_type'].' '.$ThisFileInfo['aac']['header']['profile_text']; 460 461 return true; 462 463 } 464 } 465 // should never get here. 466 } 467 468 function AACsampleRateLookup($samplerateid) { 469 static $AACsampleRateLookup = array(); 470 if (empty($AACsampleRateLookup)) { 471 $AACsampleRateLookup[0] = 96000; 472 $AACsampleRateLookup[1] = 88200; 473 $AACsampleRateLookup[2] = 64000; 474 $AACsampleRateLookup[3] = 48000; 475 $AACsampleRateLookup[4] = 44100; 476 $AACsampleRateLookup[5] = 32000; 477 $AACsampleRateLookup[6] = 24000; 478 $AACsampleRateLookup[7] = 22050; 479 $AACsampleRateLookup[8] = 16000; 480 $AACsampleRateLookup[9] = 12000; 481 $AACsampleRateLookup[10] = 11025; 482 $AACsampleRateLookup[11] = 8000; 483 $AACsampleRateLookup[12] = 0; 484 $AACsampleRateLookup[13] = 0; 485 $AACsampleRateLookup[14] = 0; 486 $AACsampleRateLookup[15] = 0; 487 } 488 return (isset($AACsampleRateLookup[$samplerateid]) ? $AACsampleRateLookup[$samplerateid] : 'invalid'); 489 } 490 491 function AACprofileLookup($profileid, $mpegversion) { 492 static $AACprofileLookup = array(); 493 if (empty($AACprofileLookup)) { 494 $AACprofileLookup[2][0] = 'Main profile'; 495 $AACprofileLookup[2][1] = 'Low Complexity profile (LC)'; 496 $AACprofileLookup[2][2] = 'Scalable Sample Rate profile (SSR)'; 497 $AACprofileLookup[2][3] = '(reserved)'; 498 $AACprofileLookup[4][0] = 'AAC_MAIN'; 499 $AACprofileLookup[4][1] = 'AAC_LC'; 500 $AACprofileLookup[4][2] = 'AAC_SSR'; 501 $AACprofileLookup[4][3] = 'AAC_LTP'; 502 } 503 return (isset($AACprofileLookup[$mpegversion][$profileid]) ? $AACprofileLookup[$mpegversion][$profileid] : 'invalid'); 504 } 505 506 function AACchannelCountCalculate($program_configs) { 507 $channels = 0; 508 for ($i = 0; $i < $program_configs['num_front_channel_elements']; $i++) { 509 $channels++; 510 if ($program_configs['front_element_is_cpe'][$i]) { 511 // each front element is channel pair (CPE = Channel Pair Element) 512 $channels++; 513 } 514 } 515 for ($i = 0; $i < $program_configs['num_side_channel_elements']; $i++) { 516 $channels++; 517 if ($program_configs['side_element_is_cpe'][$i]) { 518 // each side element is channel pair (CPE = Channel Pair Element) 519 $channels++; 520 } 521 } 522 for ($i = 0; $i < $program_configs['num_back_channel_elements']; $i++) { 523 $channels++; 524 if ($program_configs['back_element_is_cpe'][$i]) { 525 // each back element is channel pair (CPE = Channel Pair Element) 526 $channels++; 527 } 528 } 529 for ($i = 0; $i < $program_configs['num_lfe_channel_elements']; $i++) { 530 $channels++; 531 } 532 return $channels; 533 } 534 535 } 536 537 538 ?>
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| Généré le : Mon Nov 26 21:04:15 2007 | par Balluche grâce à PHPXref 0.7 |
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