diff options
Diffstat (limited to 'getid3/module.audio.lpac.php')
| -rw-r--r-- | getid3/module.audio.lpac.php | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/getid3/module.audio.lpac.php b/getid3/module.audio.lpac.php new file mode 100644 index 0000000..3c04492 --- /dev/null +++ b/getid3/module.audio.lpac.php @@ -0,0 +1,126 @@ +<?php +///////////////////////////////////////////////////////////////// +/// getID3() by James Heinrich <info@getid3.org> // +// available at http://getid3.sourceforge.net // +// or http://www.getid3.org // +///////////////////////////////////////////////////////////////// +// See readme.txt for more details // +///////////////////////////////////////////////////////////////// +// // +// module.audio.lpac.php // +// module for analyzing LPAC Audio files // +// dependencies: module.audio-video.riff.php // +// /// +///////////////////////////////////////////////////////////////// + +getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true); + +class getid3_lpac +{ + + function getid3_lpac(&$fd, &$ThisFileInfo) { + + fseek($fd, $ThisFileInfo['avdataoffset'], SEEK_SET); + $LPACheader = fread($fd, 14); + if (substr($LPACheader, 0, 4) != 'LPAC') { + $ThisFileInfo['error'][] = 'Expected "LPAC" at offset '.$ThisFileInfo['avdataoffset'].', found "'.$StreamMarker.'"'; + return false; + } + $ThisFileInfo['avdataoffset'] += 14; + + $ThisFileInfo['fileformat'] = 'lpac'; + $ThisFileInfo['audio']['dataformat'] = 'lpac'; + $ThisFileInfo['audio']['lossless'] = true; + $ThisFileInfo['audio']['bitrate_mode'] = 'vbr'; + + $ThisFileInfo['lpac']['file_version'] = getid3_lib::BigEndian2Int(substr($LPACheader, 4, 1)); + $flags['audio_type'] = getid3_lib::BigEndian2Int(substr($LPACheader, 5, 1)); + $ThisFileInfo['lpac']['total_samples']= getid3_lib::BigEndian2Int(substr($LPACheader, 6, 4)); + $flags['parameters'] = getid3_lib::BigEndian2Int(substr($LPACheader, 10, 4)); + + $ThisFileInfo['lpac']['flags']['is_wave'] = (bool) ($flags['audio_type'] & 0x40); + $ThisFileInfo['lpac']['flags']['stereo'] = (bool) ($flags['audio_type'] & 0x04); + $ThisFileInfo['lpac']['flags']['24_bit'] = (bool) ($flags['audio_type'] & 0x02); + $ThisFileInfo['lpac']['flags']['16_bit'] = (bool) ($flags['audio_type'] & 0x01); + + if ($ThisFileInfo['lpac']['flags']['24_bit'] && $ThisFileInfo['lpac']['flags']['16_bit']) { + $ThisFileInfo['warning'][] = '24-bit and 16-bit flags cannot both be set'; + } + + $ThisFileInfo['lpac']['flags']['fast_compress'] = (bool) ($flags['parameters'] & 0x40000000); + $ThisFileInfo['lpac']['flags']['random_access'] = (bool) ($flags['parameters'] & 0x08000000); + $ThisFileInfo['lpac']['block_length'] = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256; + $ThisFileInfo['lpac']['flags']['adaptive_prediction_order'] = (bool) ($flags['parameters'] & 0x00800000); + $ThisFileInfo['lpac']['flags']['adaptive_quantization'] = (bool) ($flags['parameters'] & 0x00400000); + $ThisFileInfo['lpac']['flags']['joint_stereo'] = (bool) ($flags['parameters'] & 0x00040000); + $ThisFileInfo['lpac']['quantization'] = ($flags['parameters'] & 0x00001F00) >> 8; + $ThisFileInfo['lpac']['max_prediction_order'] = ($flags['parameters'] & 0x0000003F); + + if ($ThisFileInfo['lpac']['flags']['fast_compress'] && ($ThisFileInfo['lpac']['max_prediction_order'] != 3)) { + $ThisFileInfo['warning'][] = 'max_prediction_order expected to be "3" if fast_compress is true, actual value is "'.$ThisFileInfo['lpac']['max_prediction_order'].'"'; + } + switch ($ThisFileInfo['lpac']['file_version']) { + case 6: + if ($ThisFileInfo['lpac']['flags']['adaptive_quantization']) { + $ThisFileInfo['warning'][] = 'adaptive_quantization expected to be false in LPAC file stucture v6, actually true'; + } + if ($ThisFileInfo['lpac']['quantization'] != 20) { + $ThisFileInfo['warning'][] = 'Quantization expected to be 20 in LPAC file stucture v6, actually '.$ThisFileInfo['lpac']['flags']['Q']; + } + break; + + default: + //$ThisFileInfo['warning'][] = 'This version of getID3() only supports LPAC file format version 6, this file is version '.$ThisFileInfo['lpac']['file_version'].' - please report to info@getid3.org'; + break; + } + + $dummy = $ThisFileInfo; + $riff = new getid3_riff($fd, $dummy); + unset($riff); + $ThisFileInfo['avdataoffset'] = $dummy['avdataoffset']; + $ThisFileInfo['riff'] = $dummy['riff']; + $ThisFileInfo['error'] = $dummy['error']; + $ThisFileInfo['warning'] = $dummy['warning']; + $ThisFileInfo['lpac']['comments']['comment'] = $dummy['comments']; + $ThisFileInfo['audio']['sample_rate'] = $dummy['audio']['sample_rate']; + + $ThisFileInfo['audio']['channels'] = ($ThisFileInfo['lpac']['flags']['stereo'] ? 2 : 1); + + if ($ThisFileInfo['lpac']['flags']['24_bit']) { + $ThisFileInfo['audio']['bits_per_sample'] = $ThisFileInfo['riff']['audio'][0]['bits_per_sample']; + } elseif ($ThisFileInfo['lpac']['flags']['16_bit']) { + $ThisFileInfo['audio']['bits_per_sample'] = 16; + } else { + $ThisFileInfo['audio']['bits_per_sample'] = 8; + } + + if ($ThisFileInfo['lpac']['flags']['fast_compress']) { + // fast + $ThisFileInfo['audio']['encoder_options'] = '-1'; + } else { + switch ($ThisFileInfo['lpac']['max_prediction_order']) { + case 20: // simple + $ThisFileInfo['audio']['encoder_options'] = '-2'; + break; + case 30: // medium + $ThisFileInfo['audio']['encoder_options'] = '-3'; + break; + case 40: // high + $ThisFileInfo['audio']['encoder_options'] = '-4'; + break; + case 60: // extrahigh + $ThisFileInfo['audio']['encoder_options'] = '-5'; + break; + } + } + + $ThisFileInfo['playtime_seconds'] = $ThisFileInfo['lpac']['total_samples'] / $ThisFileInfo['audio']['sample_rate']; + $ThisFileInfo['audio']['bitrate'] = (($ThisFileInfo['avdataend'] - $ThisFileInfo['avdataoffset']) * 8) / $ThisFileInfo['playtime_seconds']; + + return true; + } + +} + + +?>
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