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.mpc.php                                                 |

    18 // | Module for analyzing Musepack/MPEG+ Audio files                      |

    19 // | dependencies: NONE                                                   |

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

    21 //

    22 // $Id: module.audio.mpc.php,v 1.3 2006/11/02 10:48:01 ah Exp $

    23 

    24         

    25         

    26 class getid3_mpc extends getid3_handler

    27 {

    28 

    29     public function Analyze() {

    30 

    31         $getid3 = $this->getid3;

    32         

    33         // http://www.uni-jena.de/~pfk/mpp/sv8/header.html

    34 

    35         $getid3->info['fileformat']            = 'mpc';

    36         $getid3->info['audio']['dataformat']   = 'mpc';

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

    38         $getid3->info['audio']['channels']     = 2;  // the format appears to be hardcoded for stereo only

    39         $getid3->info['audio']['lossless']     = false;

    40         

    41         $getid3->info['mpc']['header'] = array ();

    42         $info_mpc_header = &$getid3->info['mpc']['header'];

    43         $info_mpc_header['size'] = 28;

    44         $info_mpc_header['raw']['preamble'] = 'MP+';    // Magic bytes

    45         

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

    47         $mpc_header_data = fread($getid3->fp, 28);

    48         

    49         $stream_version_byte = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 3, 1));

    50         $info_mpc_header['stream_major_version'] = ($stream_version_byte & 0x0F);

    51         $info_mpc_header['stream_minor_version'] = ($stream_version_byte & 0xF0) >> 4;

    52         if ($info_mpc_header['stream_major_version'] != 7) {

    53             throw new getid3_exception('Only Musepack SV7 supported');

    54         }

    55             

    56         $info_mpc_header['frame_count'] = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 4, 4));

    57         

    58         $info_mpc_header['raw']['title_peak']      = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 12, 2));

    59         $info_mpc_header['raw']['title_gain']      = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 14, 2), true);

    60         $info_mpc_header['raw']['album_peak']      = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 16, 2));

    61         $info_mpc_header['raw']['album_gain']      = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 18, 2), true);

    62         

    63         $info_mpc_header['raw']['not_sure_what']   = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 24, 3));

    64         $info_mpc_header['raw']['encoder_version'] = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 27, 1));

    65         

    66         $flags_dword1                              = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 8, 4));

    67         $flags_dword2                              = getid3_lib::LittleEndian2Int(substr($mpc_header_data, 20, 4));

    68         

    69         $info_mpc_header['intensity_stereo']   = (bool)(($flags_dword1 & 0x80000000) >> 31);

    70         $info_mpc_header['mid_side_stereo']    = (bool)(($flags_dword1 & 0x40000000) >> 30);

    71         $info_mpc_header['max_subband']        =         ($flags_dword1 & 0x3F000000) >> 24;

    72         $info_mpc_header['raw']['profile']     =         ($flags_dword1 & 0x00F00000) >> 20;

    73         $info_mpc_header['begin_loud']         = (bool)(($flags_dword1 & 0x00080000) >> 19);

    74         $info_mpc_header['end_loud']           = (bool)(($flags_dword1 & 0x00040000) >> 18);

    75         $info_mpc_header['raw']['sample_rate'] =         ($flags_dword1 & 0x00030000) >> 16;

    76         $info_mpc_header['max_level']          =         ($flags_dword1 & 0x0000FFFF);

    77         

    78         $info_mpc_header['true_gapless']       = (bool)(($flags_dword2 & 0x80000000) >> 31);

    79         $info_mpc_header['last_frame_length']  =         ($flags_dword2 & 0x7FF00000) >> 20;

    80         

    81         $info_mpc_header['profile']            = getid3_mpc::MPCprofileNameLookup($info_mpc_header['raw']['profile']);

    82         $info_mpc_header['sample_rate']        = getid3_mpc::MPCfrequencyLookup($info_mpc_header['raw']['sample_rate']);

    83         $getid3->info['audio']['sample_rate']  = $info_mpc_header['sample_rate'];

    84         $info_mpc_header['samples']            = ((($info_mpc_header['frame_count'] - 1) * 1152) + $info_mpc_header['last_frame_length']) * $getid3->info['audio']['channels'];

    85 

    86         $getid3->info['playtime_seconds'] = ($info_mpc_header['samples'] / $getid3->info['audio']['channels']) / $getid3->info['audio']['sample_rate'];

    87 

    88         $getid3->info['avdataoffset'] += $info_mpc_header['size'];

    89         

    90         $getid3->info['audio']['bitrate'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['playtime_seconds'];

    91 

    92         $info_mpc_header['title_peak']    = $info_mpc_header['raw']['title_peak'];

    93         $info_mpc_header['title_peak_db'] = getid3_mpc::MPCpeakDBLookup($info_mpc_header['title_peak']);

    94         if ($info_mpc_header['raw']['title_gain'] < 0) {

    95             $info_mpc_header['title_gain_db'] = (float)(32768 + $info_mpc_header['raw']['title_gain']) / -100;

    96         } 

    97         else {

    98             $info_mpc_header['title_gain_db'] = (float)$info_mpc_header['raw']['title_gain'] / 100;

    99         }

   100 

   101         $info_mpc_header['album_peak']    = $info_mpc_header['raw']['album_peak'];

   102         $info_mpc_header['album_peak_db'] = getid3_mpc::MPCpeakDBLookup($info_mpc_header['album_peak']);

   103         if ($info_mpc_header['raw']['album_gain'] < 0) {

   104             $info_mpc_header['album_gain_db'] = (float)(32768 + $info_mpc_header['raw']['album_gain']) / -100;

   105         } 

   106         else {

   107             $info_mpc_header['album_gain_db'] = (float)$info_mpc_header['raw']['album_gain'] / 100;;

   108         }

   109         $info_mpc_header['encoder_version'] = getid3_mpc::MPCencoderVersionLookup($info_mpc_header['raw']['encoder_version']);

   110 

   111         $getid3->info['replay_gain']['track']['adjustment'] = $info_mpc_header['title_gain_db'];

   112         $getid3->info['replay_gain']['album']['adjustment'] = $info_mpc_header['album_gain_db'];

   113 

   114         if ($info_mpc_header['title_peak'] > 0) {

   115             $getid3->info['replay_gain']['track']['peak'] = $info_mpc_header['title_peak'];

   116         } 

   117         elseif (round($info_mpc_header['max_level'] * 1.18) > 0) {

   118             $getid3->info['replay_gain']['track']['peak'] = (int)(round($info_mpc_header['max_level'] * 1.18)); // why? I don't know - see mppdec.c

   119         }

   120         if ($info_mpc_header['album_peak'] > 0) {

   121             $getid3->info['replay_gain']['album']['peak'] = $info_mpc_header['album_peak'];

   122         }

   123 

   124         $getid3->info['audio']['encoder']         = $info_mpc_header['encoder_version'];

   125         $getid3->info['audio']['encoder_options'] = $info_mpc_header['profile'];

   126         

   127         return true;

   128     }

   129 

   130 

   131 

   132     public static function MPCprofileNameLookup($profileid) {

   133         

   134         static $lookup = array (

   135             0  => 'no profile',

   136             1  => 'Experimental',

   137             2  => 'unused',

   138             3  => 'unused',

   139             4  => 'unused',

   140             5  => 'below Telephone (q = 0.0)',

   141             6  => 'below Telephone (q = 1.0)',

   142             7  => 'Telephone (q = 2.0)',

   143             8  => 'Thumb (q = 3.0)',

   144             9  => 'Radio (q = 4.0)',

   145             10 => 'Standard (q = 5.0)',

   146             11 => 'Extreme (q = 6.0)',

   147             12 => 'Insane (q = 7.0)',

   148             13 => 'BrainDead (q = 8.0)',

   149             14 => 'above BrainDead (q = 9.0)',

   150             15 => 'above BrainDead (q = 10.0)'

   151         );

   152         return (isset($lookup[$profileid]) ? $lookup[$profileid] : 'invalid');

   153     }

   154 

   155 

   156 

   157     public static function MPCfrequencyLookup($frequencyid) {

   158         

   159         static $lookup = array (

   160             0 => 44100,

   161             1 => 48000,

   162             2 => 37800,

   163             3 => 32000

   164         );

   165         return (isset($lookup[$frequencyid]) ? $lookup[$frequencyid] : 'invalid');

   166     }

   167 

   168 

   169 

   170     public static function MPCpeakDBLookup($int_value) {

   171         

   172         if ($int_value > 0) {

   173             return ((log10($int_value) / log10(2)) - 15) * 6;

   174         }

   175         return false;

   176     }

   177 

   178 

   179 

   180     public static function MPCencoderVersionLookup($encoder_version) {

   181     

   182         //Encoder version * 100  (106 = 1.06)

   183         //EncoderVersion % 10 == 0        Release (1.0)

   184         //EncoderVersion %  2 == 0        Beta (1.06)

   185         //EncoderVersion %  2 == 1        Alpha (1.05a...z)

   186 

   187         if ($encoder_version == 0) {

   188             // very old version, not known exactly which

   189             return 'Buschmann v1.7.0-v1.7.9 or Klemm v0.90-v1.05';

   190         }

   191 

   192         if (($encoder_version % 10) == 0) {

   193 

   194             // release version

   195             return number_format($encoder_version / 100, 2);

   196 

   197         } elseif (($encoder_version % 2) == 0) {

   198 

   199             // beta version

   200             return number_format($encoder_version / 100, 2).' beta';

   201 

   202         }

   203 

   204         // alpha version

   205         return number_format($encoder_version / 100, 2).' alpha';

   206     }

   207 

   208 }

   209 

   210 

   211 ?>
author	Robert McIntyre <rlm@mit.edu>
date	Mon, 11 Jul 2011 03:06:13 -0400
parents	3f6b44aa6b35
children