Files
plibreader/src/MPEG/Audio/XINGHeader.php
2008-12-03 21:49:43 +00:00

137 lines
4.4 KiB
PHP

<?php
/**
* PHP Reader Library
*
* Copyright (c) 2008 The PHP Reader Project Workgroup. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* - Neither the name of the project workgroup nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* @package php-reader
* @subpackage MPEG
* @copyright Copyright (c) 2008 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Id: XINGHeader.php 1 2008-07-06 10:43:41Z rbutterfield $
*/
/**#@+ @ignore */
require_once("Reader.php");
require_once("Twiddling.php");
require_once("MPEG/Object.php");
/**#@-*/
/**
* This class represents the Xing VBR header which is often found in the first
* frame of an MPEG stream.
*
* @package php-reader
* @subpackage MPEG
* @author Ryan Butterfield <buttza@gmail.com>
* @author Sven Vollbehr <svollbehr@gmail.com>
* @copyright Copyright (c) 2008 The PHP Reader Project Workgroup
* @license http://code.google.com/p/php-reader/wiki/License New BSD License
* @version $Rev: 1 $
*/
class MPEG_Audio_XINGHeader extends MPEG_Object
{
/** @var integer */
private $_frames = false;
/** @var integer */
private $_bytes = false;
/** @var Array */
private $_toc = array();
/** @var integer */
private $_qualityIndicator = false;
/**
* Constructs the class with given parameters and reads object related data
* from the bitstream.
*
* @param Reader $reader The reader object.
* @param Array $options Array of options.
*/
public function __construct($reader, &$options = array())
{
parent::__construct($reader, $options);
$flags = $reader->readUInt32BE();
if (Twiddling::testAnyBits($flags, 0x1))
$this->_frames = $this->_reader->readUInt32BE();
if (Twiddling::testAnyBits($flags, 0x2))
$this->_bytes = $this->_reader->readUInt32BE();
if (Twiddling::testAnyBits($flags, 0x4))
$this->_toc = array_merge(unpack("C*", $this->_reader->read(100)));
if (Twiddling::testAnyBits($flags, 0x8))
$this->_qualityIndicator = $this->_reader->readUInt32BE();
}
/**
* Returns the number of frames in the file.
*
* @return integer
*/
public function getFrames() { return $this->_frames; }
/**
* Returns the number of bytes in the file.
*
* @return integer
*/
public function getBytes() { return $this->_bytes; }
/**
* Returns the table of contents array. The returned array has a fixed amount
* of 100 seek points to the file.
*
* @return Array
*/
public function getToc() { return $this->_toc; }
/**
* Returns the quality indicator. The indicator is from 0 (best quality) to
* 100 (worst quality).
*
* @return integer
*/
public function getQualityIndicator() { return $this->_qualityIndicator; }
/**
* Returns the length of the header in bytes.
*
* @return integer
*/
public function getLength()
{
return 4 +
($this->_frames !== false ? 4 : 0) +
($this->_bytes !== false ? 4 : 0) +
(empty($this->_toc) ? 0 : 100) +
($this->_qualityIndicator !== false ? 4 : 0);
}
}