Mercurial > judyates

     1 <?php

     2 // +----------------------------------------------------------------------+

     3 // | PHP version 5                                                        |

     4 // +----------------------------------------------------------------------+

     5 // | Copyright (c) 2002-2006 James Heinrich, Allan Hansen                 |

     6 // +----------------------------------------------------------------------+

     7 // | This source file is subject to version 2 of the GPL license,         |

     8 // | that is bundled with this package in the file license.txt and is     |

     9 // | available through the world-wide-web at the following url:           |

    10 // | http://www.gnu.org/copyleft/gpl.html                                 |

    11 // +----------------------------------------------------------------------+

    12 // | getID3() - http://getid3.sourceforge.net or http://www.getid3.org    |

    13 // +----------------------------------------------------------------------+

    14 // | Authors: James Heinrich <infoØgetid3*org>                            |

    15 // |          Allan Hansen <ahØartemis*dk>                                |

    16 // +----------------------------------------------------------------------+

    17 // | module.audio.rkau.php                                                |

    18 // | Module for analyzing RKAU Audio files                                |

    19 // | dependencies: NONE                                                   |

    20 // +----------------------------------------------------------------------+

    21 //

    22 // $Id: module.audio.rkau.php,v 1.2 2006/11/02 10:48:01 ah Exp $

    23 

    24         

    25         

    26 class getid3_rkau extends getid3_handler

    27 {

    28 

    29     public function Analyze() {

    30 

    31         $getid3 = $this->getid3;

    32         

    33         fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET);

    34         $rkau_header = fread($getid3->fp, 20);

    35         

    36         // Magic bytes 'RKA'

    37             

    38         $getid3->info['fileformat']            = 'rkau';

    39         $getid3->info['audio']['dataformat']   = 'rkau';

    40         $getid3->info['audio']['bitrate_mode'] = 'vbr';

    41         

    42         // Shortcut

    43         $getid3->info['rkau'] = array ();

    44         $info_rkau            = &$getid3->info['rkau'];

    45         

    46         $info_rkau['raw']['version']   = getid3_lib::LittleEndian2Int(substr($rkau_header, 3, 1));

    47         $info_rkau['version']          = '1.'.str_pad($info_rkau['raw']['version'] & 0x0F, 2, '0', STR_PAD_LEFT);

    48         if (($info_rkau['version'] > 1.07) || ($info_rkau['version'] < 1.06)) {

    49             throw new getid3_exception('This version of getID3() can only parse RKAU files v1.06 and 1.07 (this file is v'.$info_rkau['version'].')');

    50         }

    51 

    52         getid3_lib::ReadSequence('LittleEndian2Int', $info_rkau, $rkau_header,  4,

    53             array (

    54                 'source_bytes'     => 4,

    55                 'sample_rate'      => 4,

    56                 'channels'         => 1,

    57                 'bits_per_sample'  => 1

    58             )

    59         );

    60 

    61         $info_rkau['raw']['quality']   = getid3_lib::LittleEndian2Int(substr($rkau_header, 14, 1));

    62         

    63         $quality =  $info_rkau['raw']['quality'] & 0x0F;

    64 

    65         $info_rkau['lossless']          = (($quality == 0) ? true : false);

    66         $info_rkau['compression_level'] = (($info_rkau['raw']['quality'] & 0xF0) >> 4) + 1;

    67         if (!$info_rkau['lossless']) {

    68             $info_rkau['quality_setting'] = $quality;

    69         }

    70         

    71         $info_rkau['raw']['flags']            = getid3_lib::LittleEndian2Int(substr($rkau_header, 15, 1));

    72         $info_rkau['flags']['joint_stereo']   = (bool)(!($info_rkau['raw']['flags'] & 0x01));

    73         $info_rkau['flags']['streaming']      =  (bool) ($info_rkau['raw']['flags'] & 0x02);

    74         $info_rkau['flags']['vrq_lossy_mode'] =  (bool) ($info_rkau['raw']['flags'] & 0x04);

    75 

    76         if ($info_rkau['flags']['streaming']) {

    77             $getid3->info['avdataoffset'] += 20;

    78             $info_rkau['compressed_bytes']  = getid3_lib::LittleEndian2Int(substr($rkau_header, 16, 4));

    79         } 

    80         else {

    81             $getid3->info['avdataoffset'] += 16;

    82             $info_rkau['compressed_bytes'] = $getid3->info['avdataend'] - $getid3->info['avdataoffset'] - 1;

    83         }

    84         // Note: compressed_bytes does not always equal what appears to be the actual number of compressed bytes,

    85         // sometimes it's more, sometimes less. No idea why(?)

    86 

    87         $getid3->info['audio']['lossless']        = $info_rkau['lossless'];

    88         $getid3->info['audio']['channels']        = $info_rkau['channels'];

    89         $getid3->info['audio']['bits_per_sample'] = $info_rkau['bits_per_sample'];

    90         $getid3->info['audio']['sample_rate']     = $info_rkau['sample_rate'];

    91 

    92         $getid3->info['playtime_seconds']         = $info_rkau['source_bytes'] / ($info_rkau['sample_rate'] * $info_rkau['channels'] * ($info_rkau['bits_per_sample'] / 8));

    93         $getid3->info['audio']['bitrate']         = ($info_rkau['compressed_bytes'] * 8) / $getid3->info['playtime_seconds'];

    94 

    95         return true;

    96 

    97     }

    98 

    99 }

   100 

   101 ?>
author	Robert McIntyre <rlm@mit.edu>
date	Tue, 22 Jun 2010 13:41:04 -0400
parents	3f6b44aa6b35
children