/src/Zend/Media/Mpeg/Abs/Frame.php
http://php-reader.googlecode.com/ · PHP · 574 lines · 235 code · 52 blank · 287 comment · 14 complexity · 24215485382dc635a4ff0e0bfbbb0ae9 MD5 · raw file
- <?php
- /**
- * Zend Framework
- *
- * LICENSE
- *
- * This source file is subject to the new BSD license that is bundled
- * with this package in the file LICENSE.txt.
- * It is also available through the world-wide-web at this URL:
- * http://framework.zend.com/license/new-bsd
- * If you did not receive a copy of the license and are unable to
- * obtain it through the world-wide-web, please send an email
- * to license@zend.com so we can send you a copy immediately.
- *
- * @category Zend
- * @package Zend_Media
- * @subpackage MPEG
- * @copyright Copyright (c) 2005-2010 Zend Technologies USA Inc. (http://www.zend.com)
- * @license http://framework.zend.com/license/new-bsd New BSD License
- * @version $Id: Frame.php 261 2012-03-05 20:43:15Z svollbehr $
- */
- /**#@+ @ignore */
- require_once 'Zend/Bit/Twiddling.php';
- require_once 'Zend/Media/Mpeg/Abs/Object.php';
- /**#@-*/
- /**
- * This class represents an MPEG Audio Bit Stream frame as described in
- * ISO/IEC 11172-3 and ISO/IEC 13818-3 standards.
- *
- * To accommodate fast header processing the error checking data and the audio
- * data are lazy fetch by default. You can change this behaviour by giving a
- * proper option to the {@link Zend_Media_Mpeg_Abs} class.
- *
- * @category Zend
- * @package Zend_Media
- * @subpackage MPEG
- * @author Ryan Butterfield <buttza@gmail.com>
- * @author Sven Vollbehr <sven@vollbehr.eu>
- * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
- * @license http://framework.zend.com/license/new-bsd New BSD License
- * @version $Id: Frame.php 261 2012-03-05 20:43:15Z svollbehr $
- */
- final class Zend_Media_Mpeg_Abs_Frame extends Zend_Media_Mpeg_Abs_Object
- {
- /**
- * The bitrate lookup table. The table has the following format.
- *
- * <code>
- * array (
- * SAMPLING_FREQUENCY_HIGH | SAMPLING_FREQUENCY_LOW => array (
- * LAYER_ONE | LAYER_TWO | LAYER_TREE => array ( <bitrates> )
- * )
- * )
- * </code>
- *
- * @var Array
- */
- private static $bitrates = array (
- self::SAMPLING_FREQUENCY_HIGH => array (
- self::LAYER_ONE => array (
- 1 => 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384,
- 416, 448
- ),
- self::LAYER_TWO => array (
- 1 => 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320,
- 384
- ),
- self::LAYER_THREE => array (
- 1 => 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,
- 320
- )
- ),
- self::SAMPLING_FREQUENCY_LOW => array (
- self::LAYER_ONE => array (
- 1 => 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224,
- 256
- ),
- self::LAYER_TWO => array (
- 1 => 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160
- ),
- self::LAYER_THREE => array (
- 1 => 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160
- )
- )
- );
- /**
- * Sample rate lookup table. The table has the following format.
- *
- * <code>
- * array (
- * LAYER_ONE | LAYER_TWO | LAYER_TREE => array ( <sample rates> )
- * )
- * </code>
- *
- * @var Array
- */
- private static $samplingFrequencies = array (
- self::VERSION_ONE => array (44100, 48000, 32000),
- self::VERSION_TWO => array (22050, 24000, 16000),
- self::VERSION_TWO_FIVE => array (11025, 12000, 8000)
- );
- /**
- * Samples per frame lookup table. The table has the following format.
- *
- * <code>
- * array (
- * SAMPLING_FREQUENCY_HIGH | SAMPLING_FREQUENCY_LOW => array (
- * LAYER_ONE | LAYER_TWO | LAYER_TREE => <sample count>
- * )
- * )
- * </code>
- *
- * @var Array
- */
- private static $samples = array (
- self::SAMPLING_FREQUENCY_HIGH => array (
- self::LAYER_ONE => 384,
- self::LAYER_TWO => 1152,
- self::LAYER_THREE => 1152),
- self::SAMPLING_FREQUENCY_LOW => array (
- self::LAYER_ONE => 384,
- self::LAYER_TWO => 1152,
- self::LAYER_THREE => 576));
- /**
- * Coefficient lookup table. The table has the following format.
- *
- * <code>
- * array (
- * SAMPLING_FREQUENCY_HIGH | SAMPLING_FREQUENCY_LOW => array (
- * LAYER_ONE | LAYER_TWO | LAYER_TREE => array ( <coefficient> )
- * )
- * )
- * </code>
- *
- * @var Array
- */
- private static $coefficients = array (
- self::SAMPLING_FREQUENCY_HIGH => array (
- self::LAYER_ONE => 12, self::LAYER_TWO => 144,
- self::LAYER_THREE => 144
- ),
- self::SAMPLING_FREQUENCY_LOW => array (
- self::LAYER_ONE => 12, self::LAYER_TWO => 144,
- self::LAYER_THREE => 72
- )
- );
- /**
- * Slot size per layer lookup table. The table has the following format.
- *
- * <code>
- * array (
- * LAYER_ONE | LAYER_TWO | LAYER_TREE => <size>
- * )
- * </code>
- *
- * @var Array
- */
- private static $slotsizes = array (
- self::LAYER_ONE => 4, self::LAYER_TWO => 1, self::LAYER_THREE => 1
- );
- /** @var integer */
- private $_offset;
- /** @var integer */
- private $_version;
- /** @var integer */
- private $_frequencyType;
- /** @var integer */
- private $_layer;
- /** @var integer */
- private $_redundancy;
- /** @var integer */
- private $_bitrate;
- /** @var integer */
- private $_samplingFrequency;
- /** @var integer */
- private $_padding;
- /** @var integer */
- private $_mode;
- /** @var integer */
- private $_modeExtension;
- /** @var integer */
- private $_copyright;
- /** @var integer */
- private $_original;
- /** @var integer */
- private $_emphasis;
- /** @var integer */
- private $_length;
- /** @var integer */
- private $_samples;
- /** @var integer */
- private $_crc = false;
- /** @var string */
- private $_data = false;
- /**
- * Constructs the class with given parameters and reads object related data
- * from the frame.
- *
- * @param Zend_Io_Reader $reader The reader object.
- * @param Array $options Array of options.
- */
- public function __construct($reader, &$options = array())
- {
- parent::__construct($reader, $options);
- $this->_offset = $this->_reader->getOffset();
-
- $header = null;
- for ($i = 0; $i < 5775 /* max attempts: max frame size x2 */; $i++) {
- $header = $this->_reader->readUInt32BE();
- if (Zend_Bit_Twiddling::testAllBits(Zend_Bit_Twiddling::getValue($header, 21, 32), 0xffe)) {
- break;
- }
- $this->_reader->setOffset(++$this->_offset + 1);
- if ($this->_offset == $this->_reader->getSize() || $i == (5775 - 1)) {
- require_once 'Zend/Media/Mpeg/Exception.php';
- throw new Zend_Media_Mpeg_Exception
- ('File does not contain a valid MPEG Audio Bit Stream (Invalid frame sync and resynchronization failed)');
- }
- }
-
- $this->_version = Zend_Bit_Twiddling::getValue($header, 19, 20);
- $this->_frequencyType = Zend_Bit_Twiddling::testBit($header, 19);
- $this->_layer = Zend_Bit_Twiddling::getValue($header, 17, 18);
- $this->_redundancy = !Zend_Bit_Twiddling::testBit($header, 16);
- $this->_bitrate = isset
- (self::$bitrates[$this->_frequencyType][$this->_layer]
- [$index = Zend_Bit_Twiddling::getValue($header, 12, 15)]) ?
- self::$bitrates[$this->_frequencyType][$this->_layer][$index] :
- false;
- $this->_samplingFrequency = isset
- (self::$samplingFrequencies[$this->_version]
- [$index = Zend_Bit_Twiddling::getValue($header, 10, 11)]) ?
- self::$samplingFrequencies[$this->_version][$index] : false;
- $this->_padding = Zend_Bit_Twiddling::testBit($header, 9);
- $this->_mode = Zend_Bit_Twiddling::getValue($header, 6, 7);
- $this->_modeExtension = Zend_Bit_Twiddling::getValue($header, 4, 5);
- $this->_copyright = Zend_Bit_Twiddling::testBit($header, 3);
- $this->_original = Zend_Bit_Twiddling::testBit($header, 2);
- $this->_emphasis = Zend_Bit_Twiddling::getValue($header, 0, 1);
- $this->_length = (int)
- ((self::$coefficients[$this->_frequencyType][$this->_layer] *
- ($this->_bitrate * 1000) / $this->_samplingFrequency) +
- ($this->_padding ? 1 : 0)) * self::$slotsizes[$this->_layer];
- $this->_samples = self::$samples[$this->_frequencyType][$this->_layer];
- if ($this->getOption('readmode', 'lazy') == 'full') {
- $this->_readCrc();
- $this->_readData();
- }
- $this->_reader->skip($this->_length - 4);
- }
- /**
- * Returns the offset where the frame actually begins (stream error may
- * cause resynchronization).
- *
- * @return integer
- */
- public function getOffset()
- {
- return $this->_offset;
- }
- /**
- * Returns the version identifier of the algorithm.
- *
- * @see VERSION_ONE, VERSION_TWO, VERSION_TWO_FIVE
- * @return integer
- */
- public function getVersion()
- {
- return $this->_version;
- }
- /**
- * Returns the sampling frequency type. This can be one of the following
- * values.
- *
- * o <b>{@link SAMPLING_FREQUENCY_HIGH}</b> -- Higher Sampling Frequency
- * (Version 1)
- * o <b>{@link SAMPLING_FREQUENCY_LOW}</b> -- Lower Sampling Frequency
- * (Version 2 and 2.5)
- *
- * @see SAMPLING_FREQUENCY_LOW, SAMPLING_FREQUENCY_HIGH
- * @return integer
- */
- public function getFrequencyType()
- {
- return $this->_frequencyType;
- }
- /**
- * Returns the type of layer used.
- *
- * @see LAYER_ONE, LAYER_TWO, LAYER_THREE
- * @return integer
- */
- public function getLayer()
- {
- return $this->_layer;
- }
- /**
- * An alias to getRedundancy().
- *
- * @see getRedundancy
- * @return boolean
- */
- public function hasRedundancy()
- {
- return $this->getRedundancy();
- }
- /**
- * Returns boolean corresponding to whether redundancy has been added in the
- * audio bitstream to facilitate error detection and concealment. Equals
- * <var>false</var> if no redundancy has been added, <var>true</var> if
- * redundancy has been added.
- *
- * @return boolean
- */
- public function getRedundancy()
- {
- return $this->_redundancy;
- }
- /**
- * Returns the bitrate in kbps. The returned value indicates the total bitrate
- * irrespective of the mode (stereo, joint_stereo, dual_channel,
- * single_channel).
- *
- * @return integer
- */
- public function getBitrate()
- {
- return $this->_bitrate;
- }
- /**
- * Returns the sampling frequency in Hz.
- *
- * @return integer
- */
- public function getSamplingFrequency()
- {
- return $this->_samplingFrequency;
- }
- /**
- * An alias to getPadding().
- *
- * @see getPadding
- * @return boolean
- */
- public function hasPadding()
- {
- return $this->getPadding();
- }
- /**
- * Returns boolean corresponding the frame contains an additional slot to
- * adjust the mean bitrate to the sampling frequency. Equals to
- * <var>true</var> if padding has been added, <var>false</var> otherwise.
- *
- * Padding is only necessary with a sampling frequency of 44.1kHz.
- *
- * @return boolean
- */
- public function getPadding()
- {
- return $this->_padding;
- }
- /**
- * Returns the mode. In Layer I and II the CHANNEL_JOINT_STEREO mode is
- * intensity_stereo, in Layer III it is intensity_stereo and/or ms_stereo.
- *
- * @see CHANNEL_STEREO, CHANNEL_JOINT_STEREO, CHANNEL_DUAL_CHANNEL,
- * CHANNEL_SINGLE_CHANNEL
- * @return integer
- */
- public function getMode()
- {
- return $this->_mode;
- }
- /**
- * Returns the mode extension used in CHANNEL_JOINT_STEREO mode.
- *
- * In Layer I and II the return type indicates which subbands are in
- * intensity_stereo. All other subbands are coded in stereo.
- *
- * o <b>{@link MODE_SUBBAND_4_TO_31}</b> -- subbands 4-31 in
- * intensity_stereo, bound==4
- * o <b>{@link MODE_SUBBAND_8_TO_31}</b> -- subbands 8-31 in
- * intensity_stereo, bound==8
- * o <b>{@link MODE_SUBBAND_12_TO_31}</b> -- subbands 12-31 in
- * intensity_stereo, bound==12
- * o <b>{@link MODE_SUBBAND_16_TO_31}</b> -- subbands 16-31 in
- * intensity_stereo, bound==16
- *
- * In Layer III they indicate which type of joint stereo coding method is
- * applied. The frequency ranges over which the intensity_stereo and
- * ms_stereo modes are applied are implicit in the algorithm. Please see
- * {@link MODE_ISOFF_MSSOFF}, {@link MODE_ISON_MSSOFF},
- * {@link MODE_ISOFF_MSSON}, and {@link MODE_ISON_MSSON}.
- *
- * @return integer
- */
- public function getModeExtension()
- {
- return $this->_modeExtension;
- }
- /**
- * An alias to getCopyright().
- *
- * @see getCopyright
- * @return boolean
- */
- public function hasCopyright()
- {
- return $this->getCopyright();
- }
- /**
- * Returns <var>true</var> if the coded bitstream is copyright protected,
- * <var>false</var> otherwise.
- *
- * @return boolean
- */
- public function getCopyright()
- {
- return $this->_copyright;
- }
- /**
- * An alias to getOriginal().
- *
- * @see getOriginal
- * @return boolean
- */
- public function isOriginal()
- {
- return $this->getOriginal();
- }
- /**
- * Returns whether the bitstream is original or home made.
- *
- * @return boolean
- */
- public function getOriginal()
- {
- return $this->_original;
- }
- /**
- * Returns the type of de-emphasis that shall be used. The value is one of
- * the following.
- *
- * o <b>{@link EMPHASIS_NONE}</b> -- No emphasis
- * o <b>{@link EMPHASIS_50_15}</b> -- 50/15 microsec. emphasis
- * o <b>{@link EMPHASIS_CCIT_J17}</b> -- CCITT J.17
- *
- * @see EMPHASIS_NONE, EMPHASIS_50_15, EMPHASIS_CCIT_J17
- * @return integer
- */
- public function getEmphasis()
- {
- return $this->_emphasis;
- }
- /**
- * Returns the length of the frame based on the current layer, bit rate,
- * sampling frequency and padding, in bytes.
- *
- * @return integer
- */
- public function getLength()
- {
- return $this->_length;
- }
- /**
- * Returns the number of samples contained in the frame.
- *
- * @return integer
- */
- public function getSamples()
- {
- return $this->_samples;
- }
- /**
- * Returns the 16-bit CRC of the frame or <var>false</var> if not present.
- *
- * @return integer
- */
- public function getCrc()
- {
- if ($this->getOption('readmode', 'lazy') == 'lazy' &&
- $this->hasRedundancy() && $this->_crc === false) {
- $this->_readCrc();
- }
- return $this->_crc;
- }
- /**
- * Reads the CRC data.
- */
- private function _readCrc()
- {
- if ($this->hasRedundancy()) {
- $offset = $this->_reader->getOffset();
- $this->_reader->setOffset($this->_offset + 4);
- $this->_crc = $this->_reader->readUInt16BE();
- $this->_reader->setOffset($offset);
- }
- }
- /**
- * Returns the audio data.
- *
- * @return string
- */
- public function getData()
- {
- if ($this->getOption('readmode', 'lazy') == 'lazy' &&
- $this->_data === false) {
- $this->_readData();
- }
- return $this->_data;
- }
- /**
- * Reads the frame data.
- */
- private function _readData()
- {
- $offset = $this->_reader->getOffset();
- $this->_reader->setOffset
- ($this->_offset + 4 + ($this->hasRedundancy() ? 2 : 0));
- $this->_data = $this->_reader->read
- ($this->getLength() - 4 - ($this->hasRedundancy() ? 2 : 0));
- $this->_reader->setOffset($offset);
- }
- }