mambax7 /
xoopseditors
| Total Complexity | 53 |
| Total Lines | 444 |
| Duplicated Lines | 0 % |
| Changes | 1 | ||
| Bugs | 0 | Features | 0 |
Complex classes like getid3_ac3 often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use getid3_ac3, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 24 | class getid3_ac3 extends getid3_handler |
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| 25 | { |
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| 26 | |||
| 27 | public function Analyze() |
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| 28 | { |
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| 29 | $getid3 = $this->getid3; |
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| 30 | |||
| 31 | // http://www.atsc.org/standards/a_52a.pdf |
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| 32 | |||
| 33 | $getid3->info['fileformat'] = 'ac3'; |
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| 34 | $getid3->info['audio']['dataformat'] = 'ac3'; |
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| 35 | $getid3->info['audio']['bitrate_mode'] = 'cbr'; |
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| 36 | $getid3->info['audio']['lossless'] = false; |
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| 37 | |||
| 38 | $getid3->info['ac3']['raw']['bsi'] = []; |
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| 39 | $info_ac3 = &$getid3->info['ac3']; |
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| 40 | $info_ac3_raw = &$info_ac3['raw']; |
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| 41 | $info_ac3_raw_bsi = &$info_ac3_raw['bsi']; |
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| 42 | |||
| 43 | // An AC-3 serial coded audio bit stream is made up of a sequence of synchronization frames |
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| 44 | // Each synchronization frame contains 6 coded audio blocks (AB), each of which represent 256 |
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| 45 | // new audio samples per channel. A synchronization information (SI) header at the beginning |
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| 46 | // of each frame contains information needed to acquire and maintain synchronization. A |
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| 47 | // bit stream information (BSI) header follows SI, and contains parameters describing the coded |
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| 48 | // audio service. The coded audio blocks may be followed by an auxiliary data (Aux) field. At the |
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| 49 | // end of each frame is an error check field that includes a CRC word for error detection. An |
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| 50 | // additional CRC word is located in the SI header, the use of which, by a decoder, is optional. |
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| 51 | // |
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| 52 | // syncinfo() | bsi() | AB0 | AB1 | AB2 | AB3 | AB4 | AB5 | Aux | CRC |
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| 53 | |||
| 54 | $this->fseek($getid3->info['avdataoffset'], SEEK_SET); |
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| 55 | $ac3_header['syncinfo'] = $this->fread(5); |
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|
Comprehensibility
Best Practice
introduced
by
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| 56 | $info_ac3_raw['synchinfo']['synchword'] = substr($ac3_header['syncinfo'], 0, 2); |
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| 57 | |||
| 58 | if ("\x0B\x77" != $info_ac3_raw['synchinfo']['synchword']) { |
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| 59 | throw new getid3_exception('Expecting "\x0B\x77" at offset ' . $getid3->info['avdataoffset'] . ', found \x' . strtoupper(dechex($ac3_header['syncinfo']{0})) . '\x' . strtoupper(dechex($ac3_header['syncinfo']{1})) . ' instead'); |
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| 60 | } |
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| 61 | |||
| 62 | // syncinfo() { |
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| 63 | // syncword 16 |
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| 64 | // crc1 16 |
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| 65 | // fscod 2 |
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| 66 | // frmsizecod 6 |
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| 67 | // } /* end of syncinfo */ |
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| 68 | |||
| 69 | $info_ac3_raw['synchinfo']['crc1'] = getid3_lib::LittleEndian2Int(substr($ac3_header['syncinfo'], 2, 2)); |
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| 70 | $ac3_synchinfo_fscod_frmsizecod = getid3_lib::LittleEndian2Int(substr($ac3_header['syncinfo'], 4, 1)); |
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| 71 | $info_ac3_raw['synchinfo']['fscod'] = ($ac3_synchinfo_fscod_frmsizecod & 0xC0) >> 6; |
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| 72 | $info_ac3_raw['synchinfo']['frmsizecod'] = ($ac3_synchinfo_fscod_frmsizecod & 0x3F); |
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| 73 | |||
| 74 | $info_ac3['sample_rate'] = getid3_ac3::AC3sampleRateCodeLookup($info_ac3_raw['synchinfo']['fscod']); |
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| 75 | if ($info_ac3_raw['synchinfo']['fscod'] <= 3) { |
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| 76 | $getid3->info['audio']['sample_rate'] = $info_ac3['sample_rate']; |
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| 77 | } |
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| 78 | |||
| 79 | $info_ac3['frame_length'] = getid3_ac3::AC3frameSizeLookup($info_ac3_raw['synchinfo']['frmsizecod'], $info_ac3_raw['synchinfo']['fscod']); |
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| 80 | $info_ac3['bitrate'] = getid3_ac3::AC3bitrateLookup($info_ac3_raw['synchinfo']['frmsizecod']); |
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| 81 | $getid3->info['audio']['bitrate'] = $info_ac3['bitrate']; |
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| 82 | |||
| 83 | $ac3_header['bsi'] = getid3_lib::BigEndian2Bin($this->fread(15)); |
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| 84 | |||
| 85 | $info_ac3_raw_bsi['bsid'] = bindec(substr($ac3_header['bsi'], 0, 5)); |
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| 86 | if ($info_ac3_raw_bsi['bsid'] > 8) { |
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| 87 | // Decoders which can decode version 8 will thus be able to decode version numbers less than 8. |
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| 88 | // If this standard is extended by the addition of additional elements or features, a value of bsid greater than 8 will be used. |
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| 89 | // Decoders built to this version of the standard will not be able to decode versions with bsid greater than 8. |
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| 90 | throw new getid3_exception('Bit stream identification is version ' . $info_ac3_raw_bsi['bsid'] . ', but getID3() only understands up to version 8'); |
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| 91 | } |
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| 92 | |||
| 93 | $info_ac3_raw_bsi['bsmod'] = bindec(substr($ac3_header['bsi'], 5, 3)); |
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| 94 | $info_ac3_raw_bsi['acmod'] = bindec(substr($ac3_header['bsi'], 8, 3)); |
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| 95 | |||
| 96 | $info_ac3['service_type'] = getid3_ac3::AC3serviceTypeLookup($info_ac3_raw_bsi['bsmod'], $info_ac3_raw_bsi['acmod']); |
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| 97 | $ac3_coding_mode = getid3_ac3::AC3audioCodingModeLookup($info_ac3_raw_bsi['acmod']); |
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| 98 | foreach ($ac3_coding_mode as $key => $value) { |
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| 99 | $info_ac3[$key] = $value; |
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| 100 | } |
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| 101 | switch ($info_ac3_raw_bsi['acmod']) { |
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| 102 | case 0: |
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| 103 | case 1: |
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| 104 | $getid3->info['audio']['channelmode'] = 'mono'; |
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| 105 | break; |
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| 106 | case 3: |
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| 107 | case 4: |
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| 108 | $getid3->info['audio']['channelmode'] = 'stereo'; |
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| 109 | break; |
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| 110 | default: |
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| 111 | $getid3->info['audio']['channelmode'] = 'surround'; |
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| 112 | break; |
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| 113 | } |
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| 114 | $getid3->info['audio']['channels'] = $info_ac3['num_channels']; |
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| 115 | |||
| 116 | $offset = 11; |
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| 117 | |||
| 118 | if ($info_ac3_raw_bsi['acmod'] & 0x01) { |
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| 119 | // If the lsb of acmod is a 1, center channel is in use and cmixlev follows in the bit stream. |
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| 120 | $info_ac3_raw_bsi['cmixlev'] = bindec(substr($ac3_header['bsi'], $offset, 2)); |
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| 121 | $info_ac3['center_mix_level'] = getid3_ac3::AC3centerMixLevelLookup($info_ac3_raw_bsi['cmixlev']); |
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| 122 | $offset += 2; |
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| 123 | } |
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| 124 | |||
| 125 | if ($info_ac3_raw_bsi['acmod'] & 0x04) { |
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| 126 | // If the msb of acmod is a 1, surround channels are in use and surmixlev follows in the bit stream. |
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| 127 | $info_ac3_raw_bsi['surmixlev'] = bindec(substr($ac3_header['bsi'], $offset, 2)); |
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| 128 | $info_ac3['surround_mix_level'] = getid3_ac3::AC3surroundMixLevelLookup($info_ac3_raw_bsi['surmixlev']); |
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| 129 | $offset += 2; |
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| 130 | } |
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| 131 | |||
| 132 | if (0x02 == $info_ac3_raw_bsi['acmod']) { |
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| 133 | // When operating in the two channel mode, this 2-bit code indicates whether or not the program has been encoded in Dolby Surround. |
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| 134 | $info_ac3_raw_bsi['dsurmod'] = bindec(substr($ac3_header['bsi'], $offset, 2)); |
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| 135 | $info_ac3['dolby_surround_mode'] = getid3_ac3::AC3dolbySurroundModeLookup($info_ac3_raw_bsi['dsurmod']); |
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| 136 | $offset += 2; |
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| 137 | } |
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| 138 | |||
| 139 | $info_ac3_raw_bsi['lfeon'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 140 | $info_ac3['lfe_enabled'] = $info_ac3_raw_bsi['lfeon']; |
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| 141 | if ($info_ac3_raw_bsi['lfeon']) { |
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| 142 | $getid3->info['audio']['channels'] .= '.1'; |
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| 143 | } |
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| 144 | |||
| 145 | $info_ac3['channels_enabled'] = getid3_ac3::AC3channelsEnabledLookup($info_ac3_raw_bsi['acmod'], $info_ac3_raw_bsi['lfeon']); |
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| 146 | |||
| 147 | // This indicates how far the average dialogue level is below digital 100 percent. Valid values are 1�31. |
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| 148 | // The value of 0 is reserved. The values of 1 to 31 are interpreted as -1 dB to -31 dB with respect to digital 100 percent. |
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| 149 | $info_ac3_raw_bsi['dialnorm'] = bindec(substr($ac3_header['bsi'], $offset, 5)); |
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| 150 | $offset += 5; |
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| 151 | $info_ac3['dialogue_normalization'] = '-' . $info_ac3_raw_bsi['dialnorm'] . 'dB'; |
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| 152 | |||
| 153 | $info_ac3_raw_bsi['compre_flag'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 154 | if ($info_ac3_raw_bsi['compre_flag']) { |
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| 155 | $info_ac3_raw_bsi['compr'] = bindec(substr($ac3_header['bsi'], $offset, 8)); |
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| 156 | $offset += 8; |
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| 157 | |||
| 158 | $info_ac3['heavy_compression'] = getid3_ac3::AC3heavyCompression($info_ac3_raw_bsi['compr']); |
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| 159 | } |
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| 160 | |||
| 161 | $info_ac3_raw_bsi['langcode_flag'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 162 | if ($info_ac3_raw_bsi['langcode_flag']) { |
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| 163 | $info_ac3_raw_bsi['langcod'] = bindec(substr($ac3_header['bsi'], $offset, 8)); |
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| 164 | $offset += 8; |
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| 165 | } |
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| 166 | |||
| 167 | $info_ac3_raw_bsi['audprodie'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 168 | if ($info_ac3_raw_bsi['audprodie']) { |
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| 169 | $info_ac3_raw_bsi['mixlevel'] = bindec(substr($ac3_header['bsi'], $offset, 5)); |
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| 170 | $offset += 5; |
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| 171 | |||
| 172 | $info_ac3_raw_bsi['roomtyp'] = bindec(substr($ac3_header['bsi'], $offset, 2)); |
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| 173 | $offset += 2; |
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| 174 | |||
| 175 | $info_ac3['mixing_level'] = (80 + $info_ac3_raw_bsi['mixlevel']) . 'dB'; |
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| 176 | $info_ac3['room_type'] = getid3_ac3::AC3roomTypeLookup($info_ac3_raw_bsi['roomtyp']); |
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| 177 | } |
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| 178 | |||
| 179 | if (0x00 == $info_ac3_raw_bsi['acmod']) { |
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| 180 | // If acmod is 0, then two completely independent program channels (dual mono) |
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| 181 | // are encoded into the bit stream, and are referenced as Ch1, Ch2. In this case, |
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| 182 | // a number of additional items are present in BSI or audblk to fully describe Ch2. |
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| 183 | |||
| 184 | // This indicates how far the average dialogue level is below digital 100 percent. Valid values are 1�31. |
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| 185 | // The value of 0 is reserved. The values of 1 to 31 are interpreted as -1 dB to -31 dB with respect to digital 100 percent. |
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| 186 | $info_ac3_raw_bsi['dialnorm2'] = bindec(substr($ac3_header['bsi'], $offset, 5)); |
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| 187 | $offset += 5; |
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| 188 | |||
| 189 | $info_ac3['dialogue_normalization2'] = '-' . $info_ac3_raw_bsi['dialnorm2'] . 'dB'; |
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| 190 | |||
| 191 | $info_ac3_raw_bsi['compre_flag2'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 192 | if ($info_ac3_raw_bsi['compre_flag2']) { |
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| 193 | $info_ac3_raw_bsi['compr2'] = bindec(substr($ac3_header['bsi'], $offset, 8)); |
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| 194 | $offset += 8; |
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| 195 | |||
| 196 | $info_ac3['heavy_compression2'] = getid3_ac3::AC3heavyCompression($info_ac3_raw_bsi['compr2']); |
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| 197 | } |
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| 198 | |||
| 199 | $info_ac3_raw_bsi['langcode_flag2'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 200 | if ($info_ac3_raw_bsi['langcode_flag2']) { |
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| 201 | $info_ac3_raw_bsi['langcod2'] = bindec(substr($ac3_header['bsi'], $offset, 8)); |
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| 202 | $offset += 8; |
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| 203 | } |
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| 204 | |||
| 205 | $info_ac3_raw_bsi['audprodie2'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 206 | if ($info_ac3_raw_bsi['audprodie2']) { |
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| 207 | $info_ac3_raw_bsi['mixlevel2'] = bindec(substr($ac3_header['bsi'], $offset, 5)); |
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| 208 | $offset += 5; |
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| 209 | |||
| 210 | $info_ac3_raw_bsi['roomtyp2'] = bindec(substr($ac3_header['bsi'], $offset, 2)); |
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| 211 | $offset += 2; |
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| 212 | |||
| 213 | $info_ac3['mixing_level2'] = (80 + $info_ac3_raw_bsi['mixlevel2']) . 'dB'; |
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| 214 | $info_ac3['room_type2'] = getid3_ac3::AC3roomTypeLookup($info_ac3_raw_bsi['roomtyp2']); |
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| 215 | } |
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| 216 | } |
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| 217 | |||
| 218 | $info_ac3_raw_bsi['copyright'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 219 | |||
| 220 | $info_ac3_raw_bsi['original'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 221 | |||
| 222 | $info_ac3_raw_bsi['timecode1_flag'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 223 | if ($info_ac3_raw_bsi['timecode1_flag']) { |
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| 224 | $info_ac3_raw_bsi['timecode1'] = bindec(substr($ac3_header['bsi'], $offset, 14)); |
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| 225 | $offset += 14; |
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| 226 | } |
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| 227 | |||
| 228 | $info_ac3_raw_bsi['timecode2_flag'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 229 | if ($info_ac3_raw_bsi['timecode2_flag']) { |
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| 230 | $info_ac3_raw_bsi['timecode2'] = bindec(substr($ac3_header['bsi'], $offset, 14)); |
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| 231 | $offset += 14; |
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| 232 | } |
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| 233 | |||
| 234 | $info_ac3_raw_bsi['addbsi_flag'] = '1' == $ac3_header['bsi']{$offset++}; |
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| 235 | if ($info_ac3_raw_bsi['addbsi_flag']) { |
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| 236 | $info_ac3_raw_bsi['addbsi_length'] = bindec(substr($ac3_header['bsi'], $offset, 6)); |
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| 237 | $offset += 6; |
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| 238 | |||
| 239 | $ac3_header['bsi'] .= getid3_lib::BigEndian2Bin($this->fread($info_ac3_raw_bsi['addbsi_length'])); |
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| 240 | |||
| 241 | $info_ac3_raw_bsi['addbsi_data'] = substr($ac3_header['bsi'], 119, $info_ac3_raw_bsi['addbsi_length'] * 8); |
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| 242 | } |
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| 243 | |||
| 244 | return true; |
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| 245 | } |
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| 246 | |||
| 247 | public static function AC3sampleRateCodeLookup($fscod) |
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| 248 | { |
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| 249 | static $lookup = [ |
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| 250 | 0 => 48000, |
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| 251 | 1 => 44100, |
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| 252 | 2 => 32000, |
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| 253 | 3 => 'reserved' // If the reserved code is indicated, the decoder should not attempt to decode audio and should mute. |
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| 254 | ]; |
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| 255 | return (isset($lookup[$fscod]) ? $lookup[$fscod] : false); |
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| 256 | } |
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| 257 | |||
| 258 | public static function AC3serviceTypeLookup($bsmod, $acmod) |
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| 259 | { |
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| 260 | static $lookup = [ |
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| 261 | 0 => 'main audio service: complete main (CM)', |
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| 262 | 1 => 'main audio service: music and effects (ME)', |
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| 263 | 2 => 'associated service: visually impaired (VI)', |
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| 264 | 3 => 'associated service: hearing impaired (HI)', |
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| 265 | 4 => 'associated service: dialogue (D)', |
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| 266 | 5 => 'associated service: commentary (C)', |
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| 267 | 6 => 'associated service: emergency (E)', |
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| 268 | 7 => 'main audio service: karaoke' |
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| 269 | ]; |
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| 270 | |||
| 271 | if (7 == $bsmod && 1 == $acmod) { |
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| 272 | return 'associated service: voice over (VO)'; |
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| 273 | } |
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| 274 | |||
| 275 | return (isset($lookup[$bsmod]) ? $lookup[$bsmod] : false); |
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| 276 | } |
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| 277 | |||
| 278 | public static function AC3audioCodingModeLookup($acmod) |
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| 279 | { |
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| 280 | // array (channel configuration, # channels (not incl LFE), channel order) |
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| 281 | static $lookup = [ |
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| 282 | 0 => ['channel_config' => '1+1', 'num_channels' => 2, 'channel_order' => 'Ch1,Ch2'], |
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| 283 | 1 => ['channel_config' => '1/0', 'num_channels' => 1, 'channel_order' => 'C'], |
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| 284 | 2 => ['channel_config' => '2/0', 'num_channels' => 2, 'channel_order' => 'L,R'], |
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| 285 | 3 => ['channel_config' => '3/0', 'num_channels' => 3, 'channel_order' => 'L,C,R'], |
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| 286 | 4 => ['channel_config' => '2/1', 'num_channels' => 3, 'channel_order' => 'L,R,S'], |
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| 287 | 5 => ['channel_config' => '3/1', 'num_channels' => 4, 'channel_order' => 'L,C,R,S'], |
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| 288 | 6 => ['channel_config' => '2/2', 'num_channels' => 4, 'channel_order' => 'L,R,SL,SR'], |
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| 289 | 7 => ['channel_config' => '3/2', 'num_channels' => 5, 'channel_order' => 'L,C,R,SL,SR'] |
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| 290 | ]; |
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| 291 | return (isset($lookup[$acmod]) ? $lookup[$acmod] : false); |
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| 292 | } |
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| 293 | |||
| 294 | public static function AC3centerMixLevelLookup($cmixlev) |
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| 295 | { |
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| 296 | static $lookup; |
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| 297 | if (!@$lookup) { |
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| 298 | $lookup = [ |
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| 299 | 0 => pow(2, -3.0 / 6), // 0.707 (�3.0 dB) |
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| 300 | 1 => pow(2, -4.5 / 6), // 0.595 (�4.5 dB) |
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| 301 | 2 => pow(2, -6.0 / 6), // 0.500 (�6.0 dB) |
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| 302 | 3 => 'reserved' |
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| 303 | ]; |
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| 304 | } |
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| 305 | return (isset($lookup[$cmixlev]) ? $lookup[$cmixlev] : false); |
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| 306 | } |
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| 307 | |||
| 308 | public static function AC3surroundMixLevelLookup($surmixlev) |
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| 309 | { |
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| 310 | static $lookup; |
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| 311 | if (!@$lookup) { |
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| 312 | $lookup = [ |
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| 313 | 0 => pow(2, -3.0 / 6), |
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| 314 | 1 => pow(2, -6.0 / 6), |
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| 315 | 2 => 0, |
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| 316 | 3 => 'reserved' |
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| 317 | ]; |
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| 318 | } |
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| 319 | return (isset($lookup[$surmixlev]) ? $lookup[$surmixlev] : false); |
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| 320 | } |
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| 321 | |||
| 322 | public static function AC3dolbySurroundModeLookup($dsurmod) |
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| 323 | { |
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| 324 | static $lookup = [ |
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| 325 | 0 => 'not indicated', |
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| 326 | 1 => 'Not Dolby Surround encoded', |
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| 327 | 2 => 'Dolby Surround encoded', |
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| 328 | 3 => 'reserved' |
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| 329 | ]; |
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| 330 | return (isset($lookup[$dsurmod]) ? $lookup[$dsurmod] : false); |
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| 331 | } |
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| 332 | |||
| 333 | public static function AC3channelsEnabledLookup($acmod, $lfeon) |
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| 334 | { |
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| 335 | return [ |
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| 336 | 'ch1' => 0 == $acmod, |
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| 337 | 'ch2' => 0 == $acmod, |
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| 338 | 'left' => $acmod > 1, |
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| 339 | 'right' => $acmod > 1, |
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| 340 | 'center' => (bool)($acmod & 0x01), |
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| 341 | 'surround_mono' => 4 == $acmod || 5 == $acmod, |
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| 342 | 'surround_left' => 6 == $acmod || 7 == $acmod, |
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| 343 | 'surround_right' => 6 == $acmod || 7 == $acmod, |
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| 344 | 'lfe' => $lfeon |
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| 345 | ]; |
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| 346 | } |
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| 347 | |||
| 348 | public static function AC3heavyCompression($compre) |
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| 349 | { |
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| 350 | // The first four bits indicate gain changes in 6.02dB increments which can be |
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| 351 | // implemented with an arithmetic shift operation. The following four bits |
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| 352 | // indicate linear gain changes, and require a 5-bit multiply. |
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| 353 | // We will represent the two 4-bit fields of compr as follows: |
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| 354 | // X0 X1 X2 X3 . Y4 Y5 Y6 Y7 |
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| 355 | // The meaning of the X values is most simply described by considering X to represent a 4-bit |
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| 356 | // signed integer with values from �8 to +7. The gain indicated by X is then (X + 1) * 6.02 dB. The |
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| 357 | // following table shows this in detail. |
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| 358 | |||
| 359 | // Meaning of 4 msb of compr |
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| 360 | // 7 +48.16 dB |
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| 361 | // 6 +42.14 dB |
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| 362 | // 5 +36.12 dB |
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| 363 | // 4 +30.10 dB |
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| 364 | // 3 +24.08 dB |
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| 365 | // 2 +18.06 dB |
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| 366 | // 1 +12.04 dB |
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| 367 | // 0 +6.02 dB |
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| 368 | // -1 0 dB |
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| 369 | // -2 �6.02 dB |
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| 370 | // -3 �12.04 dB |
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| 371 | // -4 �18.06 dB |
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| 372 | // -5 �24.08 dB |
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| 373 | // -6 �30.10 dB |
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| 374 | // -7 �36.12 dB |
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| 375 | // -8 �42.14 dB |
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| 376 | |||
| 377 | $fourbit = str_pad(decbin(($compre & 0xF0) >> 4), 4, '0', STR_PAD_LEFT); |
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| 378 | if ('1' == $fourbit{0}) { |
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| 379 | $log_gain = -8 + bindec(substr($fourbit, 1)); |
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| 380 | } else { |
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| 381 | $log_gain = bindec(substr($fourbit, 1)); |
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| 382 | } |
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| 383 | $log_gain = ($log_gain + 1) * (20 * log10(2)); |
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| 384 | |||
| 385 | // The value of Y is a linear representation of a gain change of up to �6 dB. Y is considered to |
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| 386 | // be an unsigned fractional integer, with a leading value of 1, or: 0.1 Y4 Y5 Y6 Y7 (base 2). Y can |
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| 387 | // represent values between 0.111112 (or 31/32) and 0.100002 (or 1/2). Thus, Y can represent gain |
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| 388 | // changes from �0.28 dB to �6.02 dB. |
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| 389 | |||
| 390 | $lin_gain = (16 + ($compre & 0x0F)) / 32; |
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| 391 | |||
| 392 | // The combination of X and Y values allows compr to indicate gain changes from |
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| 393 | // 48.16 � 0.28 = +47.89 dB, to |
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| 394 | // �42.14 � 6.02 = �48.16 dB. |
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| 395 | |||
| 396 | return $log_gain - $lin_gain; |
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| 397 | } |
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| 398 | |||
| 399 | public static function AC3roomTypeLookup($roomtyp) |
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| 408 | } |
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| 409 | |||
| 410 | public static function AC3frameSizeLookup($frmsizecod, $fscod) |
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| 441 | } |
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| 442 | |||
| 443 | public static function AC3bitrateLookup($frmsizecod) |
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| 444 | { |
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| 445 | static $lookup = [ |
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| 446 | 0 => 32000, |
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| 468 | } |
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| 469 | |||
| 470 | } |
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| 471 | |||
| 472 | |||
| 473 |
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