diff options
Diffstat (limited to 'extensions/TimedMediaHandler/handlers/OggHandler/File_Ogg/File/Ogg/Flac.php')
-rw-r--r-- | extensions/TimedMediaHandler/handlers/OggHandler/File_Ogg/File/Ogg/Flac.php | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/extensions/TimedMediaHandler/handlers/OggHandler/File_Ogg/File/Ogg/Flac.php b/extensions/TimedMediaHandler/handlers/OggHandler/File_Ogg/File/Ogg/Flac.php new file mode 100644 index 00000000..6838ba68 --- /dev/null +++ b/extensions/TimedMediaHandler/handlers/OggHandler/File_Ogg/File/Ogg/Flac.php @@ -0,0 +1,133 @@ +<?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 | +// +----------------------------------------------------------------------------+ + + +/** + * @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://flac.sourceforge.net/documentation.html + * @package File_Ogg + * @version CVS: $Id: Flac.php,v 1.9 2005/11/16 20:43:27 djg Exp $ + */ +class File_Ogg_Flac extends File_Ogg_Media +{ + /** + * @access private + */ + function __construct($streamSerial, $streamData, $filePointer) + { + parent::__construct($streamSerial, $streamData, $filePointer); + $this->_decodeHeader(); + $this->_decodeCommentsHeader(); + $this->_streamLength = $this->_streamInfo['total_samples'] + / $this->_streamInfo['sample_rate']; + } + + /** + * Get a short string describing the type of the stream + * @return string + */ + function getType() { + return 'FLAC'; + } + + /** + * @access private + * @param int $packetType + * @param int $pageOffset + */ + function _decodeHeader() + { + fseek($this->_filePointer, $this->_streamData['pages'][0]['body_offset'], SEEK_SET); + // Check if this is the correct header. + $packet = unpack("Cdata", fread($this->_filePointer, 1)); + if ($packet['data'] != 0x7f) + throw new OggException("Stream Undecodable", OGG_ERROR_UNDECODABLE); + + // The following four characters should be "FLAC". + if (fread($this->_filePointer, 4) != 'FLAC') + throw new OggException("Stream is undecodable due to a malformed header.", OGG_ERROR_UNDECODABLE); + + $version = unpack("Cmajor/Cminor", fread($this->_filePointer, 2)); + $this->_version = "{$version['major']}.{$version['minor']}"; + if ($version['major'] > 1) { + throw new OggException("Cannot decode a version {$version['major']} FLAC stream", OGG_ERROR_UNDECODABLE); + } + $h = File_Ogg::_readBigEndian( $this->_filePointer, + array( + // Ogg-specific + 'num_headers' => 16, + 'flac_native_sig' => 32, + // METADATA_BLOCK_HEADER + 'is_last' => 1, + 'type' => 7, + 'length' => 24, + )); + + // METADATA_BLOCK_STREAMINFO + // The variable names are canonical, and come from the FLAC source (format.h) + $this->_streamInfo = File_Ogg::_readBigEndian( $this->_filePointer, + array( + 'min_blocksize' => 16, + 'max_blocksize' => 16, + 'min_framesize' => 24, + 'max_framesize' => 24, + 'sample_rate' => 20, + 'channels' => 3, + 'bits_per_sample' => 5, + 'total_samples' => 36, + )); + $this->_streamInfo['md5sum'] = bin2hex(fread($this->_filePointer, 16)); + } + + /** + * Get an associative array containing header information about the stream + * @access public + * @return array + */ + function getHeader() + { + return $this->_streamInfo; + } + + function _decodeCommentsHeader() + { + fseek($this->_filePointer, $this->_streamData['pages'][1]['body_offset'], SEEK_SET); + $blockHeader = File_Ogg::_readBigEndian( $this->_filePointer, + array( + 'last_block' => 1, + 'block_type' => 7, + 'length' => 24 + ) + ); + if ($blockHeader['block_type'] != 4) { + throw new OggException("Stream Undecodable", OGG_ERROR_UNDECODABLE); + } + + $this->_decodeBareCommentsHeader(); + } +} +?> |