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.aac.php // 12// module for analyzing AAC Audio files // 13// dependencies: NONE // 14// /// 15///////////////////////////////////////////////////////////////// 16 17if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers 18 exit; 19} 20 21class getid3_aac extends getid3_handler 22{ 23 /** 24 * @return bool 25 */ 26 public function Analyze() { 27 $info = &$this->getid3->info; 28 $this->fseek($info['avdataoffset']); 29 if ($this->fread(4) == 'ADIF') { 30 $this->getAACADIFheaderFilepointer(); 31 } else { 32 $this->getAACADTSheaderFilepointer(); 33 } 34 return true; 35 } 36 37 /** 38 * @return bool 39 */ 40 public function getAACADIFheaderFilepointer() { 41 $info = &$this->getid3->info; 42 $info['fileformat'] = 'aac'; 43 $info['audio']['dataformat'] = 'aac'; 44 $info['audio']['lossless'] = false; 45 46 $this->fseek($info['avdataoffset']); 47 $AACheader = $this->fread(1024); 48 $offset = 0; 49 50 if (substr($AACheader, 0, 4) == 'ADIF') { 51 52 // http://faac.sourceforge.net/wiki/index.php?page=ADIF 53 54 // http://libmpeg.org/mpeg4/doc/w2203tfs.pdf 55 // adif_header() { 56 // adif_id 32 57 // copyright_id_present 1 58 // if( copyright_id_present ) 59 // copyright_id 72 60 // original_copy 1 61 // home 1 62 // bitstream_type 1 63 // bitrate 23 64 // num_program_config_elements 4 65 // for (i = 0; i < num_program_config_elements + 1; i++ ) { 66 // if( bitstream_type == '0' ) 67 // adif_buffer_fullness 20 68 // program_config_element() 69 // } 70 // } 71 72 $AACheaderBitstream = getid3_lib::BigEndian2Bin($AACheader); 73 $bitoffset = 0; 74 75 $info['aac']['header_type'] = 'ADIF'; 76 $bitoffset += 32; 77 $info['aac']['header']['mpeg_version'] = 4; 78 79 $info['aac']['header']['copyright'] = substr($AACheaderBitstream, $bitoffset, 1) == '1'; 80 $bitoffset += 1; 81 if ($info['aac']['header']['copyright']) { 82 $info['aac']['header']['copyright_id'] = getid3_lib::Bin2String(substr($AACheaderBitstream, $bitoffset, 72)); 83 $bitoffset += 72; 84 } 85 $info['aac']['header']['original_copy'] = substr($AACheaderBitstream, $bitoffset, 1) == '1'; 86 $bitoffset += 1; 87 $info['aac']['header']['home'] = substr($AACheaderBitstream, $bitoffset, 1) == '1'; 88 $bitoffset += 1; 89 $info['aac']['header']['is_vbr'] = substr($AACheaderBitstream, $bitoffset, 1) == '1'; 90 $bitoffset += 1; 91 if ($info['aac']['header']['is_vbr']) { 92 $info['audio']['bitrate_mode'] = 'vbr'; 93 $info['aac']['header']['bitrate_max'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23)); 94 $bitoffset += 23; 95 } else { 96 $info['audio']['bitrate_mode'] = 'cbr'; 97 $info['aac']['header']['bitrate'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 23)); 98 $bitoffset += 23; 99 $info['audio']['bitrate'] = $info['aac']['header']['bitrate']; 100 } 101 if ($info['audio']['bitrate'] == 0) { 102 $this->error('Corrupt AAC file: bitrate_audio == zero'); 103 return false; 104 } 105 $info['aac']['header']['num_program_configs'] = 1 + getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 106 $bitoffset += 4; 107 108 for ($i = 0; $i < $info['aac']['header']['num_program_configs']; $i++) { 109 // http://www.audiocoding.com/wiki/index.php?page=program_config_element 110 111 // buffer_fullness 20 112 113 // element_instance_tag 4 114 // object_type 2 115 // sampling_frequency_index 4 116 // num_front_channel_elements 4 117 // num_side_channel_elements 4 118 // num_back_channel_elements 4 119 // num_lfe_channel_elements 2 120 // num_assoc_data_elements 3 121 // num_valid_cc_elements 4 122 // mono_mixdown_present 1 123 // mono_mixdown_element_number 4 if mono_mixdown_present == 1 124 // stereo_mixdown_present 1 125 // stereo_mixdown_element_number 4 if stereo_mixdown_present == 1 126 // matrix_mixdown_idx_present 1 127 // matrix_mixdown_idx 2 if matrix_mixdown_idx_present == 1 128 // pseudo_surround_enable 1 if matrix_mixdown_idx_present == 1 129 // for (i = 0; i < num_front_channel_elements; i++) { 130 // front_element_is_cpe[i] 1 131 // front_element_tag_select[i] 4 132 // } 133 // for (i = 0; i < num_side_channel_elements; i++) { 134 // side_element_is_cpe[i] 1 135 // side_element_tag_select[i] 4 136 // } 137 // for (i = 0; i < num_back_channel_elements; i++) { 138 // back_element_is_cpe[i] 1 139 // back_element_tag_select[i] 4 140 // } 141 // for (i = 0; i < num_lfe_channel_elements; i++) { 142 // lfe_element_tag_select[i] 4 143 // } 144 // for (i = 0; i < num_assoc_data_elements; i++) { 145 // assoc_data_element_tag_select[i] 4 146 // } 147 // for (i = 0; i < num_valid_cc_elements; i++) { 148 // cc_element_is_ind_sw[i] 1 149 // valid_cc_element_tag_select[i] 4 150 // } 151 // byte_alignment() VAR 152 // comment_field_bytes 8 153 // for (i = 0; i < comment_field_bytes; i++) { 154 // comment_field_data[i] 8 155 // } 156 157 if (!$info['aac']['header']['is_vbr']) { 158 $info['aac']['program_configs'][$i]['buffer_fullness'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 20)); 159 $bitoffset += 20; 160 } 161 $info['aac']['program_configs'][$i]['element_instance_tag'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 162 $bitoffset += 4; 163 $info['aac']['program_configs'][$i]['object_type'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 164 $bitoffset += 2; 165 $info['aac']['program_configs'][$i]['sampling_frequency_index'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 166 $bitoffset += 4; 167 $info['aac']['program_configs'][$i]['num_front_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 168 $bitoffset += 4; 169 $info['aac']['program_configs'][$i]['num_side_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 170 $bitoffset += 4; 171 $info['aac']['program_configs'][$i]['num_back_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 172 $bitoffset += 4; 173 $info['aac']['program_configs'][$i]['num_lfe_channel_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 174 $bitoffset += 2; 175 $info['aac']['program_configs'][$i]['num_assoc_data_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 3)); 176 $bitoffset += 3; 177 $info['aac']['program_configs'][$i]['num_valid_cc_elements'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 178 $bitoffset += 4; 179 $info['aac']['program_configs'][$i]['mono_mixdown_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 180 $bitoffset += 1; 181 if ($info['aac']['program_configs'][$i]['mono_mixdown_present']) { 182 $info['aac']['program_configs'][$i]['mono_mixdown_element_number'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 183 $bitoffset += 4; 184 } 185 $info['aac']['program_configs'][$i]['stereo_mixdown_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 186 $bitoffset += 1; 187 if ($info['aac']['program_configs'][$i]['stereo_mixdown_present']) { 188 $info['aac']['program_configs'][$i]['stereo_mixdown_element_number'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 189 $bitoffset += 4; 190 } 191 $info['aac']['program_configs'][$i]['matrix_mixdown_idx_present'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 192 $bitoffset += 1; 193 if ($info['aac']['program_configs'][$i]['matrix_mixdown_idx_present']) { 194 $info['aac']['program_configs'][$i]['matrix_mixdown_idx'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 2)); 195 $bitoffset += 2; 196 $info['aac']['program_configs'][$i]['pseudo_surround_enable'] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 197 $bitoffset += 1; 198 } 199 for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_front_channel_elements']; $j++) { 200 $info['aac']['program_configs'][$i]['front_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 201 $bitoffset += 1; 202 $info['aac']['program_configs'][$i]['front_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 203 $bitoffset += 4; 204 } 205 for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_side_channel_elements']; $j++) { 206 $info['aac']['program_configs'][$i]['side_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 207 $bitoffset += 1; 208 $info['aac']['program_configs'][$i]['side_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 209 $bitoffset += 4; 210 } 211 for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_back_channel_elements']; $j++) { 212 $info['aac']['program_configs'][$i]['back_element_is_cpe'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 213 $bitoffset += 1; 214 $info['aac']['program_configs'][$i]['back_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 215 $bitoffset += 4; 216 } 217 for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_lfe_channel_elements']; $j++) { 218 $info['aac']['program_configs'][$i]['lfe_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 219 $bitoffset += 4; 220 } 221 for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_assoc_data_elements']; $j++) { 222 $info['aac']['program_configs'][$i]['assoc_data_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 223 $bitoffset += 4; 224 } 225 for ($j = 0; $j < $info['aac']['program_configs'][$i]['num_valid_cc_elements']; $j++) { 226 $info['aac']['program_configs'][$i]['cc_element_is_ind_sw'][$j] = (bool) getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 1)); 227 $bitoffset += 1; 228 $info['aac']['program_configs'][$i]['valid_cc_element_tag_select'][$j] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 4)); 229 $bitoffset += 4; 230 } 231 232 $bitoffset = ceil($bitoffset / 8) * 8; 233 234 $info['aac']['program_configs'][$i]['comment_field_bytes'] = getid3_lib::Bin2Dec(substr($AACheaderBitstream, $bitoffset, 8)); 235 $bitoffset += 8; 236 $info['aac']['program_configs'][$i]['comment_field'] = getid3_lib::Bin2String(substr($AACheaderBitstream, $bitoffset, 8 * $info['aac']['program_configs'][$i]['comment_field_bytes'])); 237 $bitoffset += 8 * $info['aac']['program_configs'][$i]['comment_field_bytes']; 238 239 240 $info['aac']['header']['profile'] = self::AACprofileLookup($info['aac']['program_configs'][$i]['object_type'], $info['aac']['header']['mpeg_version']); 241 $info['aac']['program_configs'][$i]['sampling_frequency'] = self::AACsampleRateLookup($info['aac']['program_configs'][$i]['sampling_frequency_index']); 242 $info['audio']['sample_rate'] = $info['aac']['program_configs'][$i]['sampling_frequency']; 243 $info['audio']['channels'] = self::AACchannelCountCalculate($info['aac']['program_configs'][$i]); 244 if ($info['aac']['program_configs'][$i]['comment_field']) { 245 $info['aac']['comments'][] = $info['aac']['program_configs'][$i]['comment_field']; 246 } 247 } 248 $info['playtime_seconds'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['audio']['bitrate']; 249 250 $info['audio']['encoder_options'] = $info['aac']['header_type'].' '.$info['aac']['header']['profile']; 251 252 253 254 return true; 255 256 } else { 257 258 unset($info['fileformat']); 259 unset($info['aac']); 260 $this->error('AAC-ADIF synch not found at offset '.$info['avdataoffset'].' (expected "ADIF", found "'.substr($AACheader, 0, 4).'" instead)'); 261 return false; 262 263 } 264 265 } 266 267 /** 268 * @param int $MaxFramesToScan 269 * @param bool $ReturnExtendedInfo 270 * 271 * @return bool 272 */ 273 public function getAACADTSheaderFilepointer($MaxFramesToScan=1000000, $ReturnExtendedInfo=false) { 274 $info = &$this->getid3->info; 275 276 // based loosely on code from AACfile by Jurgen Faul <jfaulØgmx.de> 277 // http://jfaul.de/atl or http://j-faul.virtualave.net/atl/atl.html 278 279 280 // http://faac.sourceforge.net/wiki/index.php?page=ADTS // dead link 281 // http://wiki.multimedia.cx/index.php?title=ADTS 282 283 // * ADTS Fixed Header: these don't change from frame to frame 284 // syncword 12 always: '111111111111' 285 // ID 1 0: MPEG-4, 1: MPEG-2 286 // MPEG layer 2 If you send AAC in MPEG-TS, set to 0 287 // protection_absent 1 0: CRC present; 1: no CRC 288 // profile 2 0: AAC Main; 1: AAC LC (Low Complexity); 2: AAC SSR (Scalable Sample Rate); 3: AAC LTP (Long Term Prediction) 289 // sampling_frequency_index 4 15 not allowed 290 // private_bit 1 usually 0 291 // channel_configuration 3 292 // original/copy 1 0: original; 1: copy 293 // home 1 usually 0 294 // emphasis 2 only if ID == 0 (ie MPEG-4) // not present in some documentation? 295 296 // * ADTS Variable Header: these can change from frame to frame 297 // copyright_identification_bit 1 298 // copyright_identification_start 1 299 // aac_frame_length 13 length of the frame including header (in bytes) 300 // adts_buffer_fullness 11 0x7FF indicates VBR 301 // no_raw_data_blocks_in_frame 2 302 303 // * ADTS Error check 304 // crc_check 16 only if protection_absent == 0 305 306 $byteoffset = $info['avdataoffset']; 307 $framenumber = 0; 308 309 // Init bit pattern array 310 static $decbin = array(); 311 312 // Populate $bindec 313 for ($i = 0; $i < 256; $i++) { 314 $decbin[chr($i)] = str_pad(decbin($i), 8, '0', STR_PAD_LEFT); 315 } 316 317 // used to calculate bitrate below 318 $BitrateCache = array(); 319 320 321 while (true) { 322 // breaks out when end-of-file encountered, or invalid data found, 323 // or MaxFramesToScan frames have been scanned 324 325 if (!getid3_lib::intValueSupported($byteoffset)) { 326 $this->warning('Unable to parse AAC file beyond '.$this->ftell().' (PHP does not support file operations beyond '.round(PHP_INT_MAX / 1073741824).'GB)'); 327 return false; 328 } 329 $this->fseek($byteoffset); 330 331 // First get substring 332 $substring = $this->fread(9); // header is 7 bytes (or 9 if CRC is present) 333 $substringlength = strlen($substring); 334 if ($substringlength != 9) { 335 $this->error('Failed to read 7 bytes at offset '.($this->ftell() - $substringlength).' (only read '.$substringlength.' bytes)'); 336 return false; 337 } 338 // this would be easier with 64-bit math, but split it up to allow for 32-bit: 339 $header1 = getid3_lib::BigEndian2Int(substr($substring, 0, 2)); 340 $header2 = getid3_lib::BigEndian2Int(substr($substring, 2, 4)); 341 $header3 = getid3_lib::BigEndian2Int(substr($substring, 6, 1)); 342 343 $info['aac']['header']['raw']['syncword'] = ($header1 & 0xFFF0) >> 4; 344 if ($info['aac']['header']['raw']['syncword'] != 0x0FFF) { 345 $this->error('Synch pattern (0x0FFF) not found at offset '.($this->ftell() - $substringlength).' (found 0x0'.strtoupper(dechex($info['aac']['header']['raw']['syncword'])).' instead)'); 346 //if ($info['fileformat'] == 'aac') { 347 // return true; 348 //} 349 unset($info['aac']); 350 return false; 351 } 352 353 // Gather info for first frame only - this takes time to do 1000 times! 354 if ($framenumber == 0) { 355 $info['aac']['header_type'] = 'ADTS'; 356 $info['fileformat'] = 'aac'; 357 $info['audio']['dataformat'] = 'aac'; 358 359 $info['aac']['header']['raw']['mpeg_version'] = ($header1 & 0x0008) >> 3; 360 $info['aac']['header']['raw']['mpeg_layer'] = ($header1 & 0x0006) >> 1; 361 $info['aac']['header']['raw']['protection_absent'] = ($header1 & 0x0001) >> 0; 362 363 $info['aac']['header']['raw']['profile_code'] = ($header2 & 0xC0000000) >> 30; 364 $info['aac']['header']['raw']['sample_rate_code'] = ($header2 & 0x3C000000) >> 26; 365 $info['aac']['header']['raw']['private_stream'] = ($header2 & 0x02000000) >> 25; 366 $info['aac']['header']['raw']['channels_code'] = ($header2 & 0x01C00000) >> 22; 367 $info['aac']['header']['raw']['original'] = ($header2 & 0x00200000) >> 21; 368 $info['aac']['header']['raw']['home'] = ($header2 & 0x00100000) >> 20; 369 $info['aac']['header']['raw']['copyright_stream'] = ($header2 & 0x00080000) >> 19; 370 $info['aac']['header']['raw']['copyright_start'] = ($header2 & 0x00040000) >> 18; 371 $info['aac']['header']['raw']['frame_length'] = ($header2 & 0x0003FFE0) >> 5; 372 373 $info['aac']['header']['mpeg_version'] = ($info['aac']['header']['raw']['mpeg_version'] ? 2 : 4); 374 $info['aac']['header']['crc_present'] = ($info['aac']['header']['raw']['protection_absent'] ? false: true); 375 $info['aac']['header']['profile'] = self::AACprofileLookup($info['aac']['header']['raw']['profile_code'], $info['aac']['header']['mpeg_version']); 376 $info['aac']['header']['sample_frequency'] = self::AACsampleRateLookup($info['aac']['header']['raw']['sample_rate_code']); 377 $info['aac']['header']['private'] = (bool) $info['aac']['header']['raw']['private_stream']; 378 $info['aac']['header']['original'] = (bool) $info['aac']['header']['raw']['original']; 379 $info['aac']['header']['home'] = (bool) $info['aac']['header']['raw']['home']; 380 $info['aac']['header']['channels'] = (($info['aac']['header']['raw']['channels_code'] == 7) ? 8 : $info['aac']['header']['raw']['channels_code']); 381 if ($ReturnExtendedInfo) { 382 $info['aac'][$framenumber]['copyright_id_bit'] = (bool) $info['aac']['header']['raw']['copyright_stream']; 383 $info['aac'][$framenumber]['copyright_id_start'] = (bool) $info['aac']['header']['raw']['copyright_start']; 384 } 385 386 if ($info['aac']['header']['raw']['mpeg_layer'] != 0) { 387 $this->warning('Layer error - expected "0", found "'.$info['aac']['header']['raw']['mpeg_layer'].'" instead'); 388 } 389 if ($info['aac']['header']['sample_frequency'] == 0) { 390 $this->error('Corrupt AAC file: sample_frequency == zero'); 391 return false; 392 } 393 394 $info['audio']['sample_rate'] = $info['aac']['header']['sample_frequency']; 395 $info['audio']['channels'] = $info['aac']['header']['channels']; 396 } 397 398 $FrameLength = ($header2 & 0x0003FFE0) >> 5; 399 400 if (!isset($BitrateCache[$FrameLength])) { 401 $BitrateCache[$FrameLength] = ($info['aac']['header']['sample_frequency'] / 1024) * $FrameLength * 8; 402 } 403 getid3_lib::safe_inc($info['aac']['bitrate_distribution'][$BitrateCache[$FrameLength]], 1); 404 405 $info['aac'][$framenumber]['aac_frame_length'] = $FrameLength; 406 407 $info['aac'][$framenumber]['adts_buffer_fullness'] = (($header2 & 0x0000001F) << 6) & (($header3 & 0xFC) >> 2); 408 if ($info['aac'][$framenumber]['adts_buffer_fullness'] == 0x07FF) { 409 $info['audio']['bitrate_mode'] = 'vbr'; 410 } else { 411 $info['audio']['bitrate_mode'] = 'cbr'; 412 } 413 $info['aac'][$framenumber]['num_raw_data_blocks'] = (($header3 & 0x03) >> 0); 414 415 if ($info['aac']['header']['crc_present']) { 416 //$info['aac'][$framenumber]['crc'] = getid3_lib::BigEndian2Int(substr($substring, 7, 2); 417 } 418 419 if (!$ReturnExtendedInfo) { 420 unset($info['aac'][$framenumber]); 421 } 422 423 /* 424 $rounded_precision = 5000; 425 $info['aac']['bitrate_distribution_rounded'] = array(); 426 foreach ($info['aac']['bitrate_distribution'] as $bitrate => $count) { 427 $rounded_bitrate = round($bitrate / $rounded_precision) * $rounded_precision; 428 getid3_lib::safe_inc($info['aac']['bitrate_distribution_rounded'][$rounded_bitrate], $count); 429 } 430 ksort($info['aac']['bitrate_distribution_rounded']); 431 */ 432 433 $byteoffset += $FrameLength; 434 if ((++$framenumber < $MaxFramesToScan) && (($byteoffset + 10) < $info['avdataend'])) { 435 436 // keep scanning 437 438 } else { 439 440 $info['aac']['frames'] = $framenumber; 441 $info['playtime_seconds'] = ($info['avdataend'] / $byteoffset) * (($framenumber * 1024) / $info['aac']['header']['sample_frequency']); // (1 / % of file scanned) * (samples / (samples/sec)) = seconds 442 if ($info['playtime_seconds'] == 0) { 443 $this->error('Corrupt AAC file: playtime_seconds == zero'); 444 return false; 445 } 446 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds']; 447 ksort($info['aac']['bitrate_distribution']); 448 449 $info['audio']['encoder_options'] = $info['aac']['header_type'].' '.$info['aac']['header']['profile']; 450 451 return true; 452 453 } 454 } 455 // should never get here. 456 } 457 458 /** 459 * @param int $samplerateid 460 * 461 * @return int|string 462 */ 463 public static function AACsampleRateLookup($samplerateid) { 464 static $AACsampleRateLookup = array(); 465 if (empty($AACsampleRateLookup)) { 466 $AACsampleRateLookup[0] = 96000; 467 $AACsampleRateLookup[1] = 88200; 468 $AACsampleRateLookup[2] = 64000; 469 $AACsampleRateLookup[3] = 48000; 470 $AACsampleRateLookup[4] = 44100; 471 $AACsampleRateLookup[5] = 32000; 472 $AACsampleRateLookup[6] = 24000; 473 $AACsampleRateLookup[7] = 22050; 474 $AACsampleRateLookup[8] = 16000; 475 $AACsampleRateLookup[9] = 12000; 476 $AACsampleRateLookup[10] = 11025; 477 $AACsampleRateLookup[11] = 8000; 478 $AACsampleRateLookup[12] = 0; 479 $AACsampleRateLookup[13] = 0; 480 $AACsampleRateLookup[14] = 0; 481 $AACsampleRateLookup[15] = 0; 482 } 483 return (isset($AACsampleRateLookup[$samplerateid]) ? $AACsampleRateLookup[$samplerateid] : 'invalid'); 484 } 485 486 /** 487 * @param int $profileid 488 * @param int $mpegversion 489 * 490 * @return string 491 */ 492 public static function AACprofileLookup($profileid, $mpegversion) { 493 static $AACprofileLookup = array(); 494 if (empty($AACprofileLookup)) { 495 $AACprofileLookup[2][0] = 'Main profile'; 496 $AACprofileLookup[2][1] = 'Low Complexity profile (LC)'; 497 $AACprofileLookup[2][2] = 'Scalable Sample Rate profile (SSR)'; 498 $AACprofileLookup[2][3] = '(reserved)'; 499 $AACprofileLookup[4][0] = 'AAC_MAIN'; 500 $AACprofileLookup[4][1] = 'AAC_LC'; 501 $AACprofileLookup[4][2] = 'AAC_SSR'; 502 $AACprofileLookup[4][3] = 'AAC_LTP'; 503 } 504 return (isset($AACprofileLookup[$mpegversion][$profileid]) ? $AACprofileLookup[$mpegversion][$profileid] : 'invalid'); 505 } 506 507 /** 508 * @param array $program_configs 509 * 510 * @return int 511 */ 512 public static function AACchannelCountCalculate($program_configs) { 513 $channels = 0; 514 for ($i = 0; $i < $program_configs['num_front_channel_elements']; $i++) { 515 $channels++; 516 if ($program_configs['front_element_is_cpe'][$i]) { 517 // each front element is channel pair (CPE = Channel Pair Element) 518 $channels++; 519 } 520 } 521 for ($i = 0; $i < $program_configs['num_side_channel_elements']; $i++) { 522 $channels++; 523 if ($program_configs['side_element_is_cpe'][$i]) { 524 // each side element is channel pair (CPE = Channel Pair Element) 525 $channels++; 526 } 527 } 528 for ($i = 0; $i < $program_configs['num_back_channel_elements']; $i++) { 529 $channels++; 530 if ($program_configs['back_element_is_cpe'][$i]) { 531 // each back element is channel pair (CPE = Channel Pair Element) 532 $channels++; 533 } 534 } 535 for ($i = 0; $i < $program_configs['num_lfe_channel_elements']; $i++) { 536 $channels++; 537 } 538 return $channels; 539 } 540 541} 542