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