www/plugins-dist/medias/lib/getid3/module.audio.lpac.php

   1 <?php
   2
   3 /////////////////////////////////////////////////////////////////
   4 /// getID3() by James Heinrich <info@getid3.org>               //
   5 //  available at https://github.com/JamesHeinrich/getID3       //
   6 //            or https://www.getid3.org                        //
   7 //            or http://getid3.sourceforge.net                 //
   8 //  see readme.txt for more details                            //
   9 /////////////////////////////////////////////////////////////////
  10 //                                                             //
  11 // module.audio.lpac.php                                       //
  12 // module for analyzing LPAC Audio files                       //
  13 // dependencies: module.audio-video.riff.php                   //
  14 //                                                            ///
  15 /////////////////////////////////////////////////////////////////
  16
  17 getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true);
  18
  19 class getid3_lpac extends getid3_handler
  20 {
  21         /**
  22          * @return bool
  23          */
  24         public function Analyze() {
  25                 $info = &$this->getid3->info;
  26
  27                 $this->fseek($info['avdataoffset']);
  28                 $LPACheader = $this->fread(14);
  29                 $StreamMarker = substr($LPACheader, 0, 4);
  30                 if ($StreamMarker != 'LPAC') {
  31                         $this->error('Expected "LPAC" at offset '.$info['avdataoffset'].', found "'.$StreamMarker.'"');
  32                         return false;
  33                 }
  34                 $info['avdataoffset'] += 14;
  35
  36                 $info['fileformat']            = 'lpac';
  37                 $info['audio']['dataformat']   = 'lpac';
  38                 $info['audio']['lossless']     = true;
  39                 $info['audio']['bitrate_mode'] = 'vbr';
  40
  41                 $info['lpac']['file_version'] = getid3_lib::BigEndian2Int(substr($LPACheader,  4, 1));
  42                 $flags['audio_type']                  = getid3_lib::BigEndian2Int(substr($LPACheader,  5, 1));
  43                 $info['lpac']['total_samples']= getid3_lib::BigEndian2Int(substr($LPACheader,  6, 4));
  44                 $flags['parameters']                  = getid3_lib::BigEndian2Int(substr($LPACheader, 10, 4));
  45
  46                 $info['lpac']['flags']['is_wave'] = (bool) ($flags['audio_type'] & 0x40);
  47                 $info['lpac']['flags']['stereo']  = (bool) ($flags['audio_type'] & 0x04);
  48                 $info['lpac']['flags']['24_bit']  = (bool) ($flags['audio_type'] & 0x02);
  49                 $info['lpac']['flags']['16_bit']  = (bool) ($flags['audio_type'] & 0x01);
  50
  51                 if ($info['lpac']['flags']['24_bit'] && $info['lpac']['flags']['16_bit']) {
  52                         $this->warning('24-bit and 16-bit flags cannot both be set');
  53                 }
  54
  55                 $info['lpac']['flags']['fast_compress']             =  (bool) ($flags['parameters'] & 0x40000000);
  56                 $info['lpac']['flags']['random_access']             =  (bool) ($flags['parameters'] & 0x08000000);
  57                 $info['lpac']['block_length']                       = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256;
  58                 $info['lpac']['flags']['adaptive_prediction_order'] =  (bool) ($flags['parameters'] & 0x00800000);
  59                 $info['lpac']['flags']['adaptive_quantization']     =  (bool) ($flags['parameters'] & 0x00400000);
  60                 $info['lpac']['flags']['joint_stereo']              =  (bool) ($flags['parameters'] & 0x00040000);
  61                 $info['lpac']['quantization']                       =         ($flags['parameters'] & 0x00001F00) >> 8;
  62                 $info['lpac']['max_prediction_order']               =         ($flags['parameters'] & 0x0000003F);
  63
  64                 if ($info['lpac']['flags']['fast_compress'] && ($info['lpac']['max_prediction_order'] != 3)) {
  65                         $this->warning('max_prediction_order expected to be "3" if fast_compress is true, actual value is "'.$info['lpac']['max_prediction_order'].'"');
  66                 }
  67                 switch ($info['lpac']['file_version']) {
  68                         case 6:
  69                                 if ($info['lpac']['flags']['adaptive_quantization']) {
  70                                         $this->warning('adaptive_quantization expected to be false in LPAC file stucture v6, actually true');
  71                                 }
  72                                 if ($info['lpac']['quantization'] != 20) {
  73                                         $this->warning('Quantization expected to be 20 in LPAC file stucture v6, actually '.$info['lpac']['flags']['Q']);
  74                                 }
  75                                 break;
  76
  77                         default:
  78                                 //$this->warning('This version of getID3() ['.$this->getid3->version().'] only supports LPAC file format version 6, this file is version '.$info['lpac']['file_version'].' - please report to info@getid3.org');
  79                                 break;
  80                 }
  81
  82                 $getid3_temp = new getID3();
  83                 $getid3_temp->openfile($this->getid3->filename);
  84                 $getid3_temp->info = $info;
  85                 $getid3_riff = new getid3_riff($getid3_temp);
  86                 $getid3_riff->Analyze();
  87                 $info['avdataoffset']                = $getid3_temp->info['avdataoffset'];
  88                 $info['riff']                        = $getid3_temp->info['riff'];
  89                 $info['error']                       = $getid3_temp->info['error'];
  90                 $info['warning']                     = $getid3_temp->info['warning'];
  91                 $info['lpac']['comments']['comment'] = $getid3_temp->info['comments'];
  92                 $info['audio']['sample_rate']        = $getid3_temp->info['audio']['sample_rate'];
  93                 unset($getid3_temp, $getid3_riff);
  94
  95                 $info['audio']['channels']    = ($info['lpac']['flags']['stereo'] ? 2 : 1);
  96
  97                 if ($info['lpac']['flags']['24_bit']) {
  98                         $info['audio']['bits_per_sample'] = $info['riff']['audio'][0]['bits_per_sample'];
  99                 } elseif ($info['lpac']['flags']['16_bit']) {
 100                         $info['audio']['bits_per_sample'] = 16;
 101                 } else {
 102                         $info['audio']['bits_per_sample'] = 8;
 103                 }
 104
 105                 if ($info['lpac']['flags']['fast_compress']) {
 106                          // fast
 107                         $info['audio']['encoder_options'] = '-1';
 108                 } else {
 109                         switch ($info['lpac']['max_prediction_order']) {
 110                                 case 20: // simple
 111                                         $info['audio']['encoder_options'] = '-2';
 112                                         break;
 113                                 case 30: // medium
 114                                         $info['audio']['encoder_options'] = '-3';
 115                                         break;
 116                                 case 40: // high
 117                                         $info['audio']['encoder_options'] = '-4';
 118                                         break;
 119                                 case 60: // extrahigh
 120                                         $info['audio']['encoder_options'] = '-5';
 121                                         break;
 122                         }
 123                 }
 124
 125                 $info['playtime_seconds'] = $info['lpac']['total_samples'] / $info['audio']['sample_rate'];
 126                 $info['audio']['bitrate'] = (($info['avdataend'] - $info['avdataoffset']) * 8) / $info['playtime_seconds'];
 127
 128                 return true;
 129         }
 130
 131 }