1 | <?php |
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2 | // +----------------------------------------------------------------------+ |
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3 | // | PHP version 5 | |
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4 | // +----------------------------------------------------------------------+ |
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5 | // | Copyright (c) 2002-2006 James Heinrich, Allan Hansen | |
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6 | // +----------------------------------------------------------------------+ |
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7 | // | This source file is subject to version 2 of the GPL license, | |
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8 | // | that is bundled with this package in the file license.txt and is | |
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9 | // | available through the world-wide-web at the following url: | |
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10 | // | http://www.gnu.org/copyleft/gpl.html | |
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11 | // +----------------------------------------------------------------------+ |
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12 | // | getID3() - http://getid3.sourceforge.net or http://www.getid3.org | |
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13 | // +----------------------------------------------------------------------+ |
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14 | // | Authors: James Heinrich <infoØgetid3*org> | |
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15 | // | Allan Hansen <ahØartemis*dk> | |
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16 | // +----------------------------------------------------------------------+ |
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17 | // | module.audio.lpac.php | |
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18 | // | Module for analyzing LPAC Audio files | |
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19 | // | dependencies: module.audio-video.riff.php | |
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20 | // +----------------------------------------------------------------------+ |
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21 | // |
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22 | // $Id: module.audio.lpac.php 3318 2009-05-20 21:54:10Z vdigital $ |
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23 | |
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24 | |
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25 | |
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26 | class getid3_lpac extends getid3_handler |
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27 | { |
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28 | |
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29 | public function Analyze() { |
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30 | |
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31 | $getid3 = $this->getid3; |
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32 | |
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33 | $getid3->include_module('audio-video.riff'); |
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34 | |
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35 | // Magic bytes - 'LPAC' |
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36 | |
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37 | fseek($getid3->fp, $getid3->info['avdataoffset'], SEEK_SET); |
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38 | $lpac_header = fread($getid3->fp, 14); |
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39 | |
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40 | $getid3->info['avdataoffset'] += 14; |
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41 | |
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42 | $getid3->info['lpac'] = array (); |
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43 | $info_lpac = &$getid3->info['lpac']; |
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44 | |
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45 | $getid3->info['fileformat'] = 'lpac'; |
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46 | $getid3->info['audio']['dataformat'] = 'lpac'; |
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47 | $getid3->info['audio']['lossless'] = true; |
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48 | $getid3->info['audio']['bitrate_mode'] = 'vbr'; |
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49 | |
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50 | $info_lpac['file_version'] = getid3_lib::BigEndian2Int($lpac_header{4}); |
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51 | $flags['audio_type'] = getid3_lib::BigEndian2Int($lpac_header{5}); |
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52 | $info_lpac['total_samples'] = getid3_lib::BigEndian2Int(substr($lpac_header, 6, 4)); |
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53 | $flags['parameters'] = getid3_lib::BigEndian2Int(substr($lpac_header, 10, 4)); |
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54 | |
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55 | $info_lpac['flags']['is_wave'] = (bool)($flags['audio_type'] & 0x40); |
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56 | $info_lpac['flags']['stereo'] = (bool)($flags['audio_type'] & 0x04); |
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57 | $info_lpac['flags']['24_bit'] = (bool)($flags['audio_type'] & 0x02); |
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58 | $info_lpac['flags']['16_bit'] = (bool)($flags['audio_type'] & 0x01); |
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59 | |
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60 | if ($info_lpac['flags']['24_bit'] && $info_lpac['flags']['16_bit']) { |
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61 | $getid3->warning('24-bit and 16-bit flags cannot both be set'); |
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62 | } |
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63 | |
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64 | $info_lpac['flags']['fast_compress'] = (bool)($flags['parameters'] & 0x40000000); |
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65 | $info_lpac['flags']['random_access'] = (bool)($flags['parameters'] & 0x08000000); |
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66 | $info_lpac['block_length'] = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256; |
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67 | $info_lpac['flags']['adaptive_prediction_order'] = (bool)($flags['parameters'] & 0x00800000); |
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68 | $info_lpac['flags']['adaptive_quantization'] = (bool)($flags['parameters'] & 0x00400000); |
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69 | $info_lpac['flags']['joint_stereo'] = (bool)($flags['parameters'] & 0x00040000); |
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70 | $info_lpac['quantization'] = ($flags['parameters'] & 0x00001F00) >> 8; |
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71 | $info_lpac['max_prediction_order'] = ($flags['parameters'] & 0x0000003F); |
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72 | |
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73 | if ($info_lpac['flags']['fast_compress'] && ($info_lpac['max_prediction_order'] != 3)) { |
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74 | $getid3->warning('max_prediction_order expected to be "3" if fast_compress is true, actual value is "'.$info_lpac['max_prediction_order'].'"'); |
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75 | } |
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76 | |
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77 | switch ($info_lpac['file_version']) { |
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78 | |
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79 | case 6: |
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80 | if ($info_lpac['flags']['adaptive_quantization']) { |
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81 | $getid3->warning('adaptive_quantization expected to be false in LPAC file stucture v6, actually true'); |
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82 | } |
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83 | if ($info_lpac['quantization'] != 20) { |
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84 | $getid3->warning('Quantization expected to be 20 in LPAC file stucture v6, actually '.$info_lpac['flags']['Q']); |
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85 | } |
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86 | break; |
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87 | |
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88 | |
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89 | default: |
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90 | //$getid3->warning('This version of getID3() only supports LPAC file format version 6, this file is version '.$info_lpac['file_version'].' - please report to info@getid3.org'); |
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91 | break; |
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92 | } |
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93 | |
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94 | // Clone getid3 - messing with something - better safe than sorry |
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95 | $clone = clone $getid3; |
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96 | |
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97 | // Analyze clone by fp |
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98 | $riff = new getid3_riff($clone); |
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99 | $riff->Analyze(); |
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100 | |
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101 | // Import from clone and destroy |
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102 | $getid3->info['avdataoffset'] = $clone->info['avdataoffset']; |
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103 | $getid3->info['riff'] = $clone->info['riff']; |
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104 | //$info_lpac['comments']['comment'] = $clone->info['comments']; |
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105 | $getid3->info['audio']['sample_rate'] = $clone->info['audio']['sample_rate']; |
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106 | $getid3->warnings($clone->warnings()); |
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107 | unset($clone); |
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108 | |
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109 | $getid3->info['audio']['channels'] = ($info_lpac['flags']['stereo'] ? 2 : 1); |
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110 | |
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111 | if ($info_lpac['flags']['24_bit']) { |
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112 | $getid3->info['audio']['bits_per_sample'] = $getid3->info['riff']['audio'][0]['bits_per_sample']; |
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113 | } elseif ($info_lpac['flags']['16_bit']) { |
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114 | $getid3->info['audio']['bits_per_sample'] = 16; |
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115 | } else { |
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116 | $getid3->info['audio']['bits_per_sample'] = 8; |
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117 | } |
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118 | |
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119 | if ($info_lpac['flags']['fast_compress']) { |
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120 | // fast |
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121 | $getid3->info['audio']['encoder_options'] = '-1'; |
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122 | } else { |
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123 | switch ($info_lpac['max_prediction_order']) { |
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124 | case 20: // simple |
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125 | $getid3->info['audio']['encoder_options'] = '-2'; |
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126 | break; |
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127 | case 30: // medium |
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128 | $getid3->info['audio']['encoder_options'] = '-3'; |
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129 | break; |
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130 | case 40: // high |
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131 | $getid3->info['audio']['encoder_options'] = '-4'; |
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132 | break; |
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133 | case 60: // extrahigh |
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134 | $getid3->info['audio']['encoder_options'] = '-5'; |
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135 | break; |
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136 | } |
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137 | } |
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138 | |
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139 | $getid3->info['playtime_seconds'] = $info_lpac['total_samples'] / $getid3->info['audio']['sample_rate']; |
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140 | $getid3->info['audio']['bitrate'] = (($getid3->info['avdataend'] - $getid3->info['avdataoffset']) * 8) / $getid3->info['playtime_seconds']; |
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141 | |
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142 | return true; |
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143 | } |
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144 | |
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145 | } |
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146 | |
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147 | |
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148 | ?> |
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