[3318] | 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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