/src/Zend/Media/Mpeg/Abs/Frame.php
PHP | 574 lines | 235 code | 52 blank | 287 comment | 14 complexity | 24215485382dc635a4ff0e0bfbbb0ae9 MD5 | raw file
1<?php 2/** 3 * Zend Framework 4 * 5 * LICENSE 6 * 7 * This source file is subject to the new BSD license that is bundled 8 * with this package in the file LICENSE.txt. 9 * It is also available through the world-wide-web at this URL: 10 * http://framework.zend.com/license/new-bsd 11 * If you did not receive a copy of the license and are unable to 12 * obtain it through the world-wide-web, please send an email 13 * to license@zend.com so we can send you a copy immediately. 14 * 15 * @category Zend 16 * @package Zend_Media 17 * @subpackage MPEG 18 * @copyright Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com) 19 * @license http://framework.zend.com/license/new-bsd New BSD License 20 * @version $Id: Frame.php 261 2012-03-05 20:43:15Z svollbehr $ 21 */ 22 23/**#@+ @ignore */ 24require_once 'Zend/Bit/Twiddling.php'; 25require_once 'Zend/Media/Mpeg/Abs/Object.php'; 26/**#@-*/ 27 28/** 29 * This class represents an MPEG Audio Bit Stream frame as described in 30 * ISO/IEC 11172-3 and ISO/IEC 13818-3 standards. 31 * 32 * To accommodate fast header processing the error checking data and the audio 33 * data are lazy fetch by default. You can change this behaviour by giving a 34 * proper option to the {@link Zend_Media_Mpeg_Abs} class. 35 * 36 * @category Zend 37 * @package Zend_Media 38 * @subpackage MPEG 39 * @author Ryan Butterfield <buttza@gmail.com> 40 * @author Sven Vollbehr <sven@vollbehr.eu> 41 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com) 42 * @license http://framework.zend.com/license/new-bsd New BSD License 43 * @version $Id: Frame.php 261 2012-03-05 20:43:15Z svollbehr $ 44 */ 45final class Zend_Media_Mpeg_Abs_Frame extends Zend_Media_Mpeg_Abs_Object 46{ 47 /** 48 * The bitrate lookup table. The table has the following format. 49 * 50 * <code> 51 * array ( 52 * SAMPLING_FREQUENCY_HIGH | SAMPLING_FREQUENCY_LOW => array ( 53 * LAYER_ONE | LAYER_TWO | LAYER_TREE => array ( <bitrates> ) 54 * ) 55 * ) 56 * </code> 57 * 58 * @var Array 59 */ 60 private static $bitrates = array ( 61 self::SAMPLING_FREQUENCY_HIGH => array ( 62 self::LAYER_ONE => array ( 63 1 => 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 64 416, 448 65 ), 66 self::LAYER_TWO => array ( 67 1 => 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 68 384 69 ), 70 self::LAYER_THREE => array ( 71 1 => 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 72 320 73 ) 74 ), 75 self::SAMPLING_FREQUENCY_LOW => array ( 76 self::LAYER_ONE => array ( 77 1 => 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 78 256 79 ), 80 self::LAYER_TWO => array ( 81 1 => 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 82 ), 83 self::LAYER_THREE => array ( 84 1 => 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160 85 ) 86 ) 87 ); 88 89 /** 90 * Sample rate lookup table. The table has the following format. 91 * 92 * <code> 93 * array ( 94 * LAYER_ONE | LAYER_TWO | LAYER_TREE => array ( <sample rates> ) 95 * ) 96 * </code> 97 * 98 * @var Array 99 */ 100 private static $samplingFrequencies = array ( 101 self::VERSION_ONE => array (44100, 48000, 32000), 102 self::VERSION_TWO => array (22050, 24000, 16000), 103 self::VERSION_TWO_FIVE => array (11025, 12000, 8000) 104 ); 105 106 /** 107 * Samples per frame lookup table. The table has the following format. 108 * 109 * <code> 110 * array ( 111 * SAMPLING_FREQUENCY_HIGH | SAMPLING_FREQUENCY_LOW => array ( 112 * LAYER_ONE | LAYER_TWO | LAYER_TREE => <sample count> 113 * ) 114 * ) 115 * </code> 116 * 117 * @var Array 118 */ 119 private static $samples = array ( 120 self::SAMPLING_FREQUENCY_HIGH => array ( 121 self::LAYER_ONE => 384, 122 self::LAYER_TWO => 1152, 123 self::LAYER_THREE => 1152), 124 self::SAMPLING_FREQUENCY_LOW => array ( 125 self::LAYER_ONE => 384, 126 self::LAYER_TWO => 1152, 127 self::LAYER_THREE => 576)); 128 129 /** 130 * Coefficient lookup table. The table has the following format. 131 * 132 * <code> 133 * array ( 134 * SAMPLING_FREQUENCY_HIGH | SAMPLING_FREQUENCY_LOW => array ( 135 * LAYER_ONE | LAYER_TWO | LAYER_TREE => array ( <coefficient> ) 136 * ) 137 * ) 138 * </code> 139 * 140 * @var Array 141 */ 142 private static $coefficients = array ( 143 self::SAMPLING_FREQUENCY_HIGH => array ( 144 self::LAYER_ONE => 12, self::LAYER_TWO => 144, 145 self::LAYER_THREE => 144 146 ), 147 self::SAMPLING_FREQUENCY_LOW => array ( 148 self::LAYER_ONE => 12, self::LAYER_TWO => 144, 149 self::LAYER_THREE => 72 150 ) 151 ); 152 153 /** 154 * Slot size per layer lookup table. The table has the following format. 155 * 156 * <code> 157 * array ( 158 * LAYER_ONE | LAYER_TWO | LAYER_TREE => <size> 159 * ) 160 * </code> 161 * 162 * @var Array 163 */ 164 private static $slotsizes = array ( 165 self::LAYER_ONE => 4, self::LAYER_TWO => 1, self::LAYER_THREE => 1 166 ); 167 168 /** @var integer */ 169 private $_offset; 170 171 /** @var integer */ 172 private $_version; 173 174 /** @var integer */ 175 private $_frequencyType; 176 177 /** @var integer */ 178 private $_layer; 179 180 /** @var integer */ 181 private $_redundancy; 182 183 /** @var integer */ 184 private $_bitrate; 185 186 /** @var integer */ 187 private $_samplingFrequency; 188 189 /** @var integer */ 190 private $_padding; 191 192 /** @var integer */ 193 private $_mode; 194 195 /** @var integer */ 196 private $_modeExtension; 197 198 /** @var integer */ 199 private $_copyright; 200 201 /** @var integer */ 202 private $_original; 203 204 /** @var integer */ 205 private $_emphasis; 206 207 /** @var integer */ 208 private $_length; 209 210 /** @var integer */ 211 private $_samples; 212 213 /** @var integer */ 214 private $_crc = false; 215 216 /** @var string */ 217 private $_data = false; 218 219 /** 220 * Constructs the class with given parameters and reads object related data 221 * from the frame. 222 * 223 * @param Zend_Io_Reader $reader The reader object. 224 * @param Array $options Array of options. 225 */ 226 public function __construct($reader, &$options = array()) 227 { 228 parent::__construct($reader, $options); 229 230 $this->_offset = $this->_reader->getOffset(); 231 232 $header = null; 233 for ($i = 0; $i < 5775 /* max attempts: max frame size x2 */; $i++) { 234 $header = $this->_reader->readUInt32BE(); 235 if (Zend_Bit_Twiddling::testAllBits(Zend_Bit_Twiddling::getValue($header, 21, 32), 0xffe)) { 236 break; 237 } 238 $this->_reader->setOffset(++$this->_offset + 1); 239 if ($this->_offset == $this->_reader->getSize() || $i == (5775 - 1)) { 240 require_once 'Zend/Media/Mpeg/Exception.php'; 241 throw new Zend_Media_Mpeg_Exception 242 ('File does not contain a valid MPEG Audio Bit Stream (Invalid frame sync and resynchronization failed)'); 243 } 244 } 245 246 $this->_version = Zend_Bit_Twiddling::getValue($header, 19, 20); 247 $this->_frequencyType = Zend_Bit_Twiddling::testBit($header, 19); 248 $this->_layer = Zend_Bit_Twiddling::getValue($header, 17, 18); 249 $this->_redundancy = !Zend_Bit_Twiddling::testBit($header, 16); 250 $this->_bitrate = isset 251 (self::$bitrates[$this->_frequencyType][$this->_layer] 252 [$index = Zend_Bit_Twiddling::getValue($header, 12, 15)]) ? 253 self::$bitrates[$this->_frequencyType][$this->_layer][$index] : 254 false; 255 $this->_samplingFrequency = isset 256 (self::$samplingFrequencies[$this->_version] 257 [$index = Zend_Bit_Twiddling::getValue($header, 10, 11)]) ? 258 self::$samplingFrequencies[$this->_version][$index] : false; 259 $this->_padding = Zend_Bit_Twiddling::testBit($header, 9); 260 $this->_mode = Zend_Bit_Twiddling::getValue($header, 6, 7); 261 $this->_modeExtension = Zend_Bit_Twiddling::getValue($header, 4, 5); 262 $this->_copyright = Zend_Bit_Twiddling::testBit($header, 3); 263 $this->_original = Zend_Bit_Twiddling::testBit($header, 2); 264 $this->_emphasis = Zend_Bit_Twiddling::getValue($header, 0, 1); 265 266 $this->_length = (int) 267 ((self::$coefficients[$this->_frequencyType][$this->_layer] * 268 ($this->_bitrate * 1000) / $this->_samplingFrequency) + 269 ($this->_padding ? 1 : 0)) * self::$slotsizes[$this->_layer]; 270 $this->_samples = self::$samples[$this->_frequencyType][$this->_layer]; 271 272 if ($this->getOption('readmode', 'lazy') == 'full') { 273 $this->_readCrc(); 274 $this->_readData(); 275 } 276 $this->_reader->skip($this->_length - 4); 277 } 278 279 /** 280 * Returns the offset where the frame actually begins (stream error may 281 * cause resynchronization). 282 * 283 * @return integer 284 */ 285 public function getOffset() 286 { 287 return $this->_offset; 288 } 289 290 /** 291 * Returns the version identifier of the algorithm. 292 * 293 * @see VERSION_ONE, VERSION_TWO, VERSION_TWO_FIVE 294 * @return integer 295 */ 296 public function getVersion() 297 { 298 return $this->_version; 299 } 300 301 /** 302 * Returns the sampling frequency type. This can be one of the following 303 * values. 304 * 305 * o <b>{@link SAMPLING_FREQUENCY_HIGH}</b> -- Higher Sampling Frequency 306 * (Version 1) 307 * o <b>{@link SAMPLING_FREQUENCY_LOW}</b> -- Lower Sampling Frequency 308 * (Version 2 and 2.5) 309 * 310 * @see SAMPLING_FREQUENCY_LOW, SAMPLING_FREQUENCY_HIGH 311 * @return integer 312 */ 313 public function getFrequencyType() 314 { 315 return $this->_frequencyType; 316 } 317 318 /** 319 * Returns the type of layer used. 320 * 321 * @see LAYER_ONE, LAYER_TWO, LAYER_THREE 322 * @return integer 323 */ 324 public function getLayer() 325 { 326 return $this->_layer; 327 } 328 329 /** 330 * An alias to getRedundancy(). 331 * 332 * @see getRedundancy 333 * @return boolean 334 */ 335 public function hasRedundancy() 336 { 337 return $this->getRedundancy(); 338 } 339 340 /** 341 * Returns boolean corresponding to whether redundancy has been added in the 342 * audio bitstream to facilitate error detection and concealment. Equals 343 * <var>false</var> if no redundancy has been added, <var>true</var> if 344 * redundancy has been added. 345 * 346 * @return boolean 347 */ 348 public function getRedundancy() 349 { 350 return $this->_redundancy; 351 } 352 353 /** 354 * Returns the bitrate in kbps. The returned value indicates the total bitrate 355 * irrespective of the mode (stereo, joint_stereo, dual_channel, 356 * single_channel). 357 * 358 * @return integer 359 */ 360 public function getBitrate() 361 { 362 return $this->_bitrate; 363 } 364 365 /** 366 * Returns the sampling frequency in Hz. 367 * 368 * @return integer 369 */ 370 public function getSamplingFrequency() 371 { 372 return $this->_samplingFrequency; 373 } 374 375 /** 376 * An alias to getPadding(). 377 * 378 * @see getPadding 379 * @return boolean 380 */ 381 public function hasPadding() 382 { 383 return $this->getPadding(); 384 } 385 386 /** 387 * Returns boolean corresponding the frame contains an additional slot to 388 * adjust the mean bitrate to the sampling frequency. Equals to 389 * <var>true</var> if padding has been added, <var>false</var> otherwise. 390 * 391 * Padding is only necessary with a sampling frequency of 44.1kHz. 392 * 393 * @return boolean 394 */ 395 public function getPadding() 396 { 397 return $this->_padding; 398 } 399 400 /** 401 * Returns the mode. In Layer I and II the CHANNEL_JOINT_STEREO mode is 402 * intensity_stereo, in Layer III it is intensity_stereo and/or ms_stereo. 403 * 404 * @see CHANNEL_STEREO, CHANNEL_JOINT_STEREO, CHANNEL_DUAL_CHANNEL, 405 * CHANNEL_SINGLE_CHANNEL 406 * @return integer 407 */ 408 public function getMode() 409 { 410 return $this->_mode; 411 } 412 413 /** 414 * Returns the mode extension used in CHANNEL_JOINT_STEREO mode. 415 * 416 * In Layer I and II the return type indicates which subbands are in 417 * intensity_stereo. All other subbands are coded in stereo. 418 * 419 * o <b>{@link MODE_SUBBAND_4_TO_31}</b> -- subbands 4-31 in 420 * intensity_stereo, bound==4 421 * o <b>{@link MODE_SUBBAND_8_TO_31}</b> -- subbands 8-31 in 422 * intensity_stereo, bound==8 423 * o <b>{@link MODE_SUBBAND_12_TO_31}</b> -- subbands 12-31 in 424 * intensity_stereo, bound==12 425 * o <b>{@link MODE_SUBBAND_16_TO_31}</b> -- subbands 16-31 in 426 * intensity_stereo, bound==16 427 * 428 * In Layer III they indicate which type of joint stereo coding method is 429 * applied. The frequency ranges over which the intensity_stereo and 430 * ms_stereo modes are applied are implicit in the algorithm. Please see 431 * {@link MODE_ISOFF_MSSOFF}, {@link MODE_ISON_MSSOFF}, 432 * {@link MODE_ISOFF_MSSON}, and {@link MODE_ISON_MSSON}. 433 * 434 * @return integer 435 */ 436 public function getModeExtension() 437 { 438 return $this->_modeExtension; 439 } 440 441 /** 442 * An alias to getCopyright(). 443 * 444 * @see getCopyright 445 * @return boolean 446 */ 447 public function hasCopyright() 448 { 449 return $this->getCopyright(); 450 } 451 452 /** 453 * Returns <var>true</var> if the coded bitstream is copyright protected, 454 * <var>false</var> otherwise. 455 * 456 * @return boolean 457 */ 458 public function getCopyright() 459 { 460 return $this->_copyright; 461 } 462 463 /** 464 * An alias to getOriginal(). 465 * 466 * @see getOriginal 467 * @return boolean 468 */ 469 public function isOriginal() 470 { 471 return $this->getOriginal(); 472 } 473 474 /** 475 * Returns whether the bitstream is original or home made. 476 * 477 * @return boolean 478 */ 479 public function getOriginal() 480 { 481 return $this->_original; 482 } 483 484 /** 485 * Returns the type of de-emphasis that shall be used. The value is one of 486 * the following. 487 * 488 * o <b>{@link EMPHASIS_NONE}</b> -- No emphasis 489 * o <b>{@link EMPHASIS_50_15}</b> -- 50/15 microsec. emphasis 490 * o <b>{@link EMPHASIS_CCIT_J17}</b> -- CCITT J.17 491 * 492 * @see EMPHASIS_NONE, EMPHASIS_50_15, EMPHASIS_CCIT_J17 493 * @return integer 494 */ 495 public function getEmphasis() 496 { 497 return $this->_emphasis; 498 } 499 500 /** 501 * Returns the length of the frame based on the current layer, bit rate, 502 * sampling frequency and padding, in bytes. 503 * 504 * @return integer 505 */ 506 public function getLength() 507 { 508 return $this->_length; 509 } 510 511 /** 512 * Returns the number of samples contained in the frame. 513 * 514 * @return integer 515 */ 516 public function getSamples() 517 { 518 return $this->_samples; 519 } 520 521 /** 522 * Returns the 16-bit CRC of the frame or <var>false</var> if not present. 523 * 524 * @return integer 525 */ 526 public function getCrc() 527 { 528 if ($this->getOption('readmode', 'lazy') == 'lazy' && 529 $this->hasRedundancy() && $this->_crc === false) { 530 $this->_readCrc(); 531 } 532 return $this->_crc; 533 } 534 535 /** 536 * Reads the CRC data. 537 */ 538 private function _readCrc() 539 { 540 if ($this->hasRedundancy()) { 541 $offset = $this->_reader->getOffset(); 542 $this->_reader->setOffset($this->_offset + 4); 543 $this->_crc = $this->_reader->readUInt16BE(); 544 $this->_reader->setOffset($offset); 545 } 546 } 547 548 /** 549 * Returns the audio data. 550 * 551 * @return string 552 */ 553 public function getData() 554 { 555 if ($this->getOption('readmode', 'lazy') == 'lazy' && 556 $this->_data === false) { 557 $this->_readData(); 558 } 559 return $this->_data; 560 } 561 562 /** 563 * Reads the frame data. 564 */ 565 private function _readData() 566 { 567 $offset = $this->_reader->getOffset(); 568 $this->_reader->setOffset 569 ($this->_offset + 4 + ($this->hasRedundancy() ? 2 : 0)); 570 $this->_data = $this->_reader->read 571 ($this->getLength() - 4 - ($this->hasRedundancy() ? 2 : 0)); 572 $this->_reader->setOffset($offset); 573 } 574}