name : module.audio.lpac.php <?php ///////////////////////////////////////////////////////////////// /// getID3() by James Heinrich <info@getid3.org> // // available at https://github.com/JamesHeinrich/getID3 // // or https://www.getid3.org // // or http://getid3.sourceforge.net // // see readme.txt for more details // ///////////////////////////////////////////////////////////////// // // // module.audio.lpac.php // // module for analyzing LPAC Audio files // // dependencies: module.audio-video.riff.php // // /// ///////////////////////////////////////////////////////////////// if (!defined('GETID3_INCLUDEPATH')) { // prevent path-exposing attacks that access modules directly on public webservers exit; } getid3_lib::IncludeDependency(GETID3_INCLUDEPATH.'module.audio-video.riff.php', __FILE__, true); class getid3_lpac extends getid3_handler { /** * @return bool */ public function Analyze() { $info = &$this->getid3->info; $this->fseek($info['avdataoffset']); $LPACheader = $this->fread(14); $StreamMarker = substr($LPACheader, 0, 4); if ($StreamMarker != 'LPAC') { $this->error('Expected "LPAC" at offset '.$info['avdataoffset'].', found "'.$StreamMarker.'"'); return false; } $flags = array(); $info['avdataoffset'] += 14; $info['fileformat'] = 'lpac'; $info['audio']['dataformat'] = 'lpac'; $info['audio']['lossless'] = true; $info['audio']['bitrate_mode'] = 'vbr'; $info['lpac']['file_version'] = getid3_lib::BigEndian2Int(substr($LPACheader, 4, 1)); $flags['audio_type'] = getid3_lib::BigEndian2Int(substr($LPACheader, 5, 1)); $info['lpac']['total_samples']= getid3_lib::BigEndian2Int(substr($LPACheader, 6, 4)); $flags['parameters'] = getid3_lib::BigEndian2Int(substr($LPACheader, 10, 4)); $info['lpac']['flags']['is_wave'] = (bool) ($flags['audio_type'] & 0x40); $info['lpac']['flags']['stereo'] = (bool) ($flags['audio_type'] & 0x04); $info['lpac']['flags']['24_bit'] = (bool) ($flags['audio_type'] & 0x02); $info['lpac']['flags']['16_bit'] = (bool) ($flags['audio_type'] & 0x01); if ($info['lpac']['flags']['24_bit'] && $info['lpac']['flags']['16_bit']) { $this->warning('24-bit and 16-bit flags cannot both be set'); } $info['lpac']['flags']['fast_compress'] = (bool) ($flags['parameters'] & 0x40000000); $info['lpac']['flags']['random_access'] = (bool) ($flags['parameters'] & 0x08000000); $info['lpac']['block_length'] = pow(2, (($flags['parameters'] & 0x07000000) >> 24)) * 256; $info['lpac']['flags']['adaptive_prediction_order'] = (bool) ($flags['parameters'] & 0x00800000); $info['lpac']['flags']['adaptive_quantization'] = (bool) ($flags['parameters'] & 0x00400000); $info['lpac']['flags']['joint_stereo'] = (bool) ($flags['parameters'] & 0x00040000); $info['lpac']['quantization'] = ($flags['parameters'] & 0x00001F00) >> 8; $info['lpac']['max_prediction_order'] = ($flags['parameters'] & 0x0000003F); if ($info['lpac']['flags']['fast_compress'] && ($info['lpac']['max_prediction_order'] != 3)) { $this->warning('max_prediction_order expected to be "3" if fast_compress is true, actual value is "'.$info['lpac']['max_prediction_order'].'"'); } switch ($info['lpac']['file_version']) { case 6: if ($info['lpac']['flags']['adaptive_quantization']) { $this->warning('adaptive_quantization expected to be false in LPAC file stucture v6, actually true'); } if ($info['lpac']['quantization'] != 20) { $this->warning('Quantization expected to be 20 in LPAC file stucture v6, actually '.$info['lpac']['flags']['Q']); } break; default: //$this->warning('This version of getID3() ['.$this->getid3->version().'] only supports LPAC file format version 6, this file is version '.$info['lpac']['file_version'].' - please report to info@getid3.org'); break; } $getid3_temp = new getID3(); $getid3_temp->openfile($this->getid3->filename, $this->getid3->info['filesize'], $this->getid3->fp); $getid3_temp->info = $info; $getid3_riff = new getid3_riff($getid3_temp); $getid3_riff->Analyze(); $info['avdataoffset'] = $getid3_temp->info['avdataoffset']; $info['riff'] = $getid3_temp->info['riff']; $info['error'] = $getid3_temp->info['error']; $info['warning'] = $getid3_temp->info['warning']; $info['lpac']['comments']['comment'] = $getid3_temp->info['comments']; $info['audio']['sample_rate'] = $getid3_temp->info['audio']['sample_rate']; unset($getid3_temp, $getid3_riff); $info['audio']['channels'] = ($info['lpac']['flags']['stereo'] ? 2 : 1); if ($info['lpac']['flags']['24_bit']) { $info['audio']['bits_per_sample'] = $info['riff']['audio'][0]['bits_per_sample']; } elseif ($info['lpac']['flags']['16_bit']) { $info['audio']['bits_per_sample'] = 16; } else { $info['audio']['bits_per_sample'] = 8; } if ($info['lpac']['flags']['fast_compress']) { // fast $info['audio']['encoder_options'] = '-1'; } else { switch ($info['lpac']['max_prediction_order']) { case 20: // simple $info['audio']['encoder_options'] = '-2'; break; case 30: // medium $info['audio']['encoder_options'] = '-3'; break; case 40: // high $info['audio']['encoder_options'] = '-4'; break; case 60: // extrahigh $info['audio']['encoder_options'] = '-5'; break; } } $info['playtime_seconds'] = getid3_lib::SafeDiv($info['lpac']['total_samples'], $info['audio']['sample_rate']); $info['audio']['bitrate'] = getid3_lib::SafeDiv(($info['avdataend'] - $info['avdataoffset']) * 8, $info['playtime_seconds']); return true; } }