getid3_mp3

22class getid3_mp3 extends getid3_handler23{24	/**25	 * Forces getID3() to scan the file byte-by-byte and log all the valid audio frame headers - extremely slow,26	 * unrecommended, but may provide data from otherwise-unusable files.27	 *28	 * @var bool29	 */30	public $allow_bruteforce = false;31 32	/**33	 * number of frames to scan to determine if MPEG-audio sequence is valid34	 * Lower this number to 5-20 for faster scanning35	 * Increase this number to 50+ for most accurate detection of valid VBR/CBR mpeg-audio streams36	 *37	 * @var int38	 */39	public $mp3_valid_check_frames = 50;40 41	/**42	 * @return bool43	 */44	public function Analyze() {45		$info = &$this->getid3->info;46 47		$initialOffset = $info['avdataoffset'];48 49		if (!$this->getOnlyMPEGaudioInfo($info['avdataoffset'])) {50			if ($this->allow_bruteforce) {51				$this->error('Rescanning file in BruteForce mode');52				$this->getOnlyMPEGaudioInfoBruteForce();53			}54		}55 56 57		if (isset($info['mpeg']['audio']['bitrate_mode'])) {58			$info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);59		}60 61		$CurrentDataLAMEversionString = null;62		if (((isset($info['id3v2']['headerlength']) && ($info['avdataoffset'] > $info['id3v2']['headerlength'])) || (!isset($info['id3v2']) && ($info['avdataoffset'] > 0) && ($info['avdataoffset'] != $initialOffset)))) {63 64			$synchoffsetwarning = 'Unknown data before synch ';65			if (isset($info['id3v2']['headerlength'])) {66				$synchoffsetwarning .= '(ID3v2 header ends at '.$info['id3v2']['headerlength'].', then '.($info['avdataoffset'] - $info['id3v2']['headerlength']).' bytes garbage, ';67			} elseif ($initialOffset > 0) {68				$synchoffsetwarning .= '(should be at '.$initialOffset.', ';69			} else {70				$synchoffsetwarning .= '(should be at beginning of file, ';71			}72			$synchoffsetwarning .= 'synch detected at '.$info['avdataoffset'].')';73			if (isset($info['audio']['bitrate_mode']) && ($info['audio']['bitrate_mode'] == 'cbr')) {74 75				if (!empty($info['id3v2']['headerlength']) && (($info['avdataoffset'] - $info['id3v2']['headerlength']) == $info['mpeg']['audio']['framelength'])) {76 77					$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90-3.92) DLL in CBR mode.';78					$info['audio']['codec'] = 'LAME';79					$CurrentDataLAMEversionString = 'LAME3.';80 81				} elseif (empty($info['id3v2']['headerlength']) && ($info['avdataoffset'] == $info['mpeg']['audio']['framelength'])) {82 83					$synchoffsetwarning .= '. This is a known problem with some versions of LAME (3.90 - 3.92) DLL in CBR mode.';84					$info['audio']['codec'] = 'LAME';85					$CurrentDataLAMEversionString = 'LAME3.';86 87				}88 89			}90			$this->warning($synchoffsetwarning);91 92		}93 94		if (isset($info['mpeg']['audio']['LAME'])) {95			$info['audio']['codec'] = 'LAME';96			if (!empty($info['mpeg']['audio']['LAME']['long_version'])) {97				$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['long_version'], "\x00");98			} elseif (!empty($info['mpeg']['audio']['LAME']['short_version'])) {99				$info['audio']['encoder'] = rtrim($info['mpeg']['audio']['LAME']['short_version'], "\x00");100			}101		}