Файл: core/PEAR/Ogg/Vorbis.php
Строк: 723
<?php
/* vim: set expandtab tabstop=4 shiftwidth=4: */
// +----------------------------------------------------------------------------+
// | File_Ogg PEAR Package for Accessing Ogg Bitstreams |
// | Copyright (c) 2005-2007 |
// | David Grant <david@grant.org.uk> |
// | Tim Starling <tstarling@wikimedia.org> |
// +----------------------------------------------------------------------------+
// | This library is free software; you can redistribute it and/or |
// | modify it under the terms of the GNU Lesser General Public |
// | License as published by the Free Software Foundation; either |
// | version 2.1 of the License, or (at your option) any later version. |
// | |
// | This library is distributed in the hope that it will be useful, |
// | but WITHOUT ANY WARRANTY; without even the implied warranty of |
// | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
// | Lesser General Public License for more details. |
// | |
// | You should have received a copy of the GNU Lesser General Public |
// | License along with this library; if not, write to the Free Software |
// | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
// +----------------------------------------------------------------------------+
require_once('Bitstream.php');
/**
* Check number for the first header in a Vorbis stream.
*
* @access private
*/
define("OGG_VORBIS_IDENTIFICATION_HEADER", 1);
/**
* Check number for the second header in a Vorbis stream.
*
* @access private
*/
define("OGG_VORBIS_COMMENTS_HEADER", 3);
/**
* Check number for the third header in a Vorbis stream.
*
* @access private
*/
define("OGG_VORBIS_SETUP_HEADER", 5);
/**
* Error thrown if the stream appears to be corrupted.
*
* @access private
*/
define("OGG_VORBIS_ERROR_UNDECODABLE", OGG_ERROR_UNDECODABLE);
/**
* Error thrown if the user attempts to extract a comment using a comment key
* that does not exist.
*
* @access private
*/
define("OGG_VORBIS_ERROR_INVALID_COMMENT", 2);
define("OGG_VORBIS_IDENTIFICATION_PAGE_OFFSET", 0);
define("OGG_VORBIS_COMMENTS_PAGE_OFFSET", 1);
/**
* Error thrown if the user attempts to write a comment containing an illegal
* character
*
* @access private
*/
define("OGG_VORBIS_ERROR_ILLEGAL_COMMENT", 3);
/**
* Extract the contents of a Vorbis logical stream.
*
* This class provides an interface to a Vorbis logical stream found within
* a Ogg stream. A variety of information may be extracted, including comment
* tags, running time, and bitrate. For more information, please see the following
* links.
*
* @author David Grant <david@grant.org.uk>, Tim Starling <tstarling@wikimedia.org>
* @category File
* @copyright David Grant <david@grant.org.uk>, Tim Starling <tstarling@wikimedia.org>
* @license http://www.gnu.org/copyleft/lesser.html GNU LGPL
* @link http://pear.php.net/package/File_Ogg
* @link http://www.xiph.org/vorbis/doc/
* @package File_Ogg
* @version CVS: $Id: Vorbis.php,v 1.14 2008/01/31 04:41:44 tstarling Exp $
*/
class File_Ogg_Vorbis extends File_Ogg_Media
{
/**
* Version of vorbis specification used.
*
* @access private
* @var int
*/
var $_version;
/**
* Number of channels in the vorbis stream.
*
* @access private
* @var int
*/
var $_channels;
/**
* Number of samples per second in the vorbis stream.
*
* @access private
* @var int
*/
var $_sampleRate;
/**
* Minimum bitrate for the vorbis stream.
*
* @access private
* @var int
*/
var $_minBitrate;
/**
* Maximum bitrate for the vorbis stream.
*
* @access private
* @var int
*/
var $_maxBitrate;
/**
* Nominal bitrate for the vorbis stream.
*
* @access private
* @var int
*/
var $_nomBitrate;
/**
* Average bitrate for the vorbis stream.
*
* @access private
* @var float
*/
var $_avgBitrate;
/**
* The length of this stream in seconds.
*
* @access private
* @var int
*/
var $_streamLength;
/**
* Constructor for accessing a Vorbis logical stream.
*
* This method is the constructor for the native-PHP interface to a Vorbis logical
* stream, embedded within an Ogg physical stream.
*
* @param int $streamSerial Serial number of the logical stream.
* @param array $streamData Data for the requested logical stream.
* @param string $filePath Location of a file on the filesystem.
* @param pointer $filePointer File pointer for the current physical stream.
* @access private
*/
function File_Ogg_Vorbis($streamSerial, $streamData, $filePointer)
{
File_Ogg_Bitstream::File_Ogg_Bitstream($streamSerial, $streamData, $filePointer);
$this->_decodeIdentificationHeader();
$this->_decodeCommentsHeader(OGG_VORBIS_COMMENTS_HEADER, OGG_VORBIS_COMMENTS_PAGE_OFFSET);
$this->_streamLength =
(( '0x' . substr( $this->_lastGranulePos, 0, 8 ) ) * pow(2, 32)
+ ( '0x' . substr( $this->_lastGranulePos, 8, 8 ) ))
/ $this->_idHeader['audio_sample_rate'];
$this->_avgBitrate = $this->_streamLength ? ($this->_streamSize * 8) / $this->_streamLength : 0;
}
/**
* Get a short string describing the type of the stream
*/
function getType()
{
return 'Vorbis';
}
/**
* Parse the identification header (the first of three headers) in a Vorbis stream.
*
* This function parses the identification header. The identification header
* contains simple audio characteristics, such as sample rate and number of
* channels. There are a number of error-checking provisions laid down in the Vorbis
* specification to ensure the stream is pure.
*
* @access private
*/
function _decodeIdentificationHeader()
{
$this->_decodeCommonHeader(OGG_VORBIS_IDENTIFICATION_HEADER, OGG_VORBIS_IDENTIFICATION_PAGE_OFFSET);
$h = File_Ogg::_readLittleEndian($this->_filePointer, array(
'vorbis_version' => 32,
'audio_channels' => 8,
'audio_sample_rate' => 32,
'bitrate_maximum' => 32,
'bitrate_nominal' => 32,
'bitrate_minimum' => 32,
'blocksize_0' => 4,
'blocksize_1' => 4,
'framing_flag' => 1
));
// The Vorbis stream version must be 0.
if ($h['vorbis_version'] == 0)
$this->_version = $h['vorbis_version'];
else
throw new PEAR_Exception("Stream is undecodable due to an invalid vorbis stream version.", OGG_VORBIS_ERROR_UNDECODABLE);
// The number of channels MUST be greater than 0.
if ($h['audio_channels'] == 0)
throw new PEAR_Exception("Stream is undecodable due to zero channels.", OGG_VORBIS_ERROR_UNDECODABLE);
else
$this->_channels = $h['audio_channels'];
// The sample rate MUST be greater than 0.
if ($h['audio_sample_rate'] == 0)
throw new PEAR_Exception("Stream is undecodable due to a zero sample rate.", OGG_VORBIS_ERROR_UNDECODABLE);
else
$this->_sampleRate = $h['audio_sample_rate'];
// Extract the various bitrates
$this->_maxBitrate = $h['bitrate_maximum'];
$this->_nomBitrate = $h['bitrate_nominal'];
$this->_minBitrate = $h['bitrate_minimum'];
// Powers of two between 6 and 13 inclusive.
$valid_block_sizes = array(64, 128, 256, 512, 1024, 2048, 4096, 8192);
// blocksize_0 MUST be a valid blocksize.
$blocksize_0 = pow(2, $h['blocksize_0']);
if (FALSE == in_array($blocksize_0, $valid_block_sizes))
throw new PEAR_Exception("Stream is undecodable because blocksize_0 is $blocksize_0, which is not a valid size.", OGG_VORBIS_ERROR_UNDECODABLE);
// Extract bits 5 to 8 from the character data.
// blocksize_1 MUST be a valid blocksize.
$blocksize_1 = pow(2, $h['blocksize_1']);
if (FALSE == in_array($blocksize_1, $valid_block_sizes))
throw new PEAR_Exception("Stream is undecodable because blocksize_1 is not a valid size.", OGG_VORBIS_ERROR_UNDECODABLE);
// blocksize 0 MUST be less than or equal to blocksize 1.
if ($blocksize_0 > $blocksize_1)
throw new PEAR_Exception("Stream is undecodable because blocksize_0 is not less than or equal to blocksize_1.", OGG_VORBIS_ERROR_UNDECODABLE);
// The framing bit MUST be set to mark the end of the identification header.
// Some encoders are broken though -- TS
/*
if ($h['framing_flag'] == 0)
throw new PEAR_Exception("Stream in undecodable because the framing bit is not non-zero.", OGG_VORBIS_ERROR_UNDECODABLE);
*/
$this->_idHeader = $h;
}
/**
* Decode the comments header
* @access private
* @param int $packetType
* @param int $pageOffset
*/
function _decodeCommentsHeader($packetType, $pageOffset)
{
$this->_decodeCommonHeader($packetType, $pageOffset);
$this->_decodeBareCommentsHeader();
// The framing bit MUST be set to mark the end of the comments header.
$framing_bit = unpack("Cdata", fread($this->_filePointer, 1));
if ($framing_bit['data'] != 1)
throw new PEAR_Exception("Stream Undecodable", OGG_VORBIS_ERROR_UNDECODABLE);
}
/**
* Get the 6-byte identification string expected in the common header
*/
function getIdentificationString() {
return OGG_STREAM_CAPTURE_VORBIS;
}
/**
* Version of the Vorbis specification referred to in the encoding of this stream.
*
* This method returns the version of the Vorbis specification (currently 0 (ZERO))
* referred to by the encoder of this stream. The Vorbis specification is well-
* defined, and thus one does not expect this value to change on a frequent basis.
*
* @access public
* @return int
*/
function getEncoderVersion()
{
return ($this->_version);
}
/**
* Number of channels used in this stream
*
* This function returns the number of channels used in this stream. This
* can range from 1 to 255, but will likely be 2 (stereo) or 1 (mono).
*
* @access public
* @return int
* @see File_Ogg_Vorbis::isMono()
* @see File_Ogg_Vorbis::isStereo()
* @see File_Ogg_Vorbis::isQuadrophonic()
*/
function getChannels()
{
return ($this->_channels);
}
/**
* Samples per second.
*
* This function returns the number of samples used per second in this
* recording. Probably the most common value here is 44,100.
*
* @return int
* @access public
*/
function getSampleRate()
{
return ($this->_sampleRate);
}
/**
* Various bitrate measurements
*
* Gives an array of the values of four different types of bitrates for this
* stream. The nominal, maximum and minimum values are found within the file,
* whereas the average value is computed.
*
* @access public
* @return array
*/
function getBitrates()
{
return (array("nom" => $this->_nomBitrate, "max" => $this->_maxBitrate, "min" => $this->_minBitrate, "avg" => $this->_avgBitrate));
}
/**
* Gives the most accurate bitrate measurement from this stream.
*
* This function returns the most accurate bitrate measurement for this
* recording, depending on values set in the stream header.
*
* @access public
* @return float
*/
function getBitrate()
{
if ($this->_avgBitrate != 0)
return ($this->_avgBitrate);
elseif ($this->_nomBitrate != 0)
return ($this->_nomBitrate);
else
return (($this->_minBitrate + $this->_maxBitrate) / 2);
}
/**
* Gives the length (in seconds) of this stream.
*
* @access public
* @return int
*/
function getLength()
{
return ($this->_streamLength);
}
/**
* States whether this logical stream was encoded in mono.
*
* @access public
* @return boolean
*/
function isMono()
{
return ($this->_channels == 1);
}
/**
* States whether this logical stream was encoded in stereo.
*
* @access public
* @return boolean
*/
function isStereo()
{
return ($this->_channels == 2);
}
/**
* States whether this logical stream was encoded in quadrophonic sound.
*
* @access public
* @return boolean
*/
function isQuadrophonic()
{
return ($this->_channels == 4);
}
/**
* The title of this track, e.g. "What's Up Pussycat?".
*
* @access public
* @return string
*/
function getTitle()
{
return ($this->getField("TITLE"));
}
/**
* Set the title of this track.
*
* @access public
* @param string $title
* @param boolean $replace
*/
function setTitle($title, $replace = true)
{
$this->setField("TITLE", $title, $replace);
}
/**
* The version of the track, such as a remix.
*
* @access public
* @return string
*/
function getVersion()
{
return $this->getField("VERSION");
}
/**
* Set the version of this track.
*
* @access public
* @param string $version
* @param boolean $replace
*/
function setVersion($version, $replace = true)
{
$this->setField("VERSION", $version, $replace);
}
/**
* The album or collection from which this track comes.
*
* @access public
* @return string
*/
function getAlbum()
{
return ($this->getField("ALBUM"));
}
/**
* Set the album or collection for this track.
*
* @access public
* @param string $album
* @param boolean $replace
*/
function setAlbum($album, $replace = true)
{
$this->setField("ALBUM", $album, $replace);
}
/**
* The number of this track if it is part of a larger collection.
*
* @access public
* @return string
*/
function getTrackNumber()
{
return ($this->getField("TRACKNUMBER"));
}
/**
* Set the number of this relative to the collection.
*
* @access public
* @param int $number
* @param boolean $replace
*/
function setTrackNumber($number, $replace = true)
{
$this->setField("TRACKNUMBER", $number, $replace);
}
/**
* The artist responsible for this track.
*
* This function returns the name of the artist responsible for this
* recording, which may be either a solo-artist, duet or group.
*
* @access public
* @return string
*/
function getArtist()
{
return ($this->getField("ARTIST"));
}
/**
* Set the artist of this track.
*
* @access public
* @param string $artist
* @param boolean $replace
*/
function setArtist($artist, $replace = true)
{
$this->setField("ARTIST", $artist, $replace = true);
}
/**
* The performer of this track, such as an orchestra
*
* @access public
* @return string
*/
function getPerformer()
{
return ($this->getField("PERFORMER"));
}
/**
* Set the performer of this track.
*
* @access public
* @param string $performer
* @param boolean $replace
*/
function setPerformer($performer, $replace = true)
{
$this->setField("PERFORMER", $performer, $replace);
}
/**
* The copyright attribution for this track.
*
* @access public
* @return string
*/
function getCopyright()
{
return ($this->getField("COPYRIGHT"));
}
/**
* Set the copyright attribution for this track.
*
* @access public
* @param string $copyright
* @param boolean $replace
*/
function setCopyright($copyright, $replace = true)
{
$this->setField("COPYRIGHT", $copyright, $replace);
}
/**
* The rights of distribution for this track.
*
* This funtion returns the license for this track, and may include
* copyright information, or a creative commons statement.
*
* @access public
* @return string
*/
function getLicense()
{
return ($this->getField("LICENSE"));
}
/**
* Set the distribution rights for this track.
*
* @access public
* @param string $license
* @param boolean $replace
*/
function setLicense($license, $replace = true)
{
$this->setField("LICENSE", $license, $replace);
}
/**
* The organisation responsible for this track.
*
* This function returns the name of the organisation responsible for
* the production of this track, such as the record label.
*
* @access public
* @return string
*/
function getOrganization()
{
return ($this->getField("ORGANIZATION"));
}
/**
* Set the organisation responsible for this track.
*
* @access public
* @param string $organization
* @param boolean $replace
*/
function setOrganziation($organization, $replace = true)
{
$this->setField("ORGANIZATION", $organization, $replace);
}
/**
* A short description of the contents of this track.
*
* This function returns a short description of this track, which might
* contain extra information that doesn't fit anywhere else.
*
* @access public
* @return string
*/
function getDescription()
{
return ($this->getField("DESCRIPTION"));
}
/**
* Set the description of this track.
*
* @access public
* @param string $description
* @param boolean $replace
*/
function setDescription($description, $replace = true)
{
$this->setField("DESCRIPTION", $replace);
}
/**
* The genre of this recording (e.g. Rock)
*
* This function returns the genre of this recording. There are no pre-
* defined genres, so this is completely up to the tagging software.
*
* @access public
* @return string
*/
function getGenre()
{
return ($this->getField("GENRE"));
}
/**
* Set the genre of this track.
*
* @access public
* @param string $genre
* @param boolean $replace
*/
function setGenre($genre, $replace = true)
{
$this->setField("GENRE", $genre, $replace);
}
/**
* The date of the recording of this track.
*
* This function returns the date on which this recording was made. There
* is no specification for the format of this date.
*
* @access public
* @return string
*/
function getDate()
{
return ($this->getField("DATE"));
}
/**
* Set the date of recording for this track.
*
* @access public
* @param string $date
* @param boolean $replace
*/
function setDate($date, $replace = true)
{
$this->setField("DATE", $date, $replace);
}
/**
* Where this recording was made.
*
* This function returns where this recording was made, such as a recording
* studio, or concert venue.
*
* @access public
* @return string
*/
function getLocation()
{
return ($this->getField("LOCATION"));
}
/**
* Set the location of the recording of this track.
*
* @access public
* @param string $location
* @param boolean $replace
*/
function setLocation($location, $replace = true)
{
$this->setField("LOCATION", $location, $replace);
}
/**
* @access public
* @return string
*/
function getContact()
{
return ($this->getField("CONTACT"));
}
/**
* Set the contact information for this track.
*
* @access public
* @param string $contact
* @param boolean $replace
*/
function setContact($contact, $replace = true)
{
$this->setField("CONTACT", $contact, $replace);
}
/**
* International Standard Recording Code.
*
* Returns the International Standard Recording Code. This code can be
* validated using the Validate_ISPN package.
*
* @access public
* @return string
*/
function getIsrc()
{
return ($this->getField("ISRC"));
}
/**
* Set the ISRC for this track.
*
* @access public
* @param string $isrc
* @param boolean $replace
*/
function setIsrc($isrc, $replace = true)
{
$this->setField("ISRC", $isrc, $replace);
}
/**
* Get an associative array containing header information about the stream
* @access public
* @return array
*/
function getHeader() {
return $this->_idHeader;
}
}
?>