getid3_flac

25class getid3_flac extends getid3_handler26{27	const syncword = 'fLaC';28 29	/**30	 * @return bool31	 */32	public function Analyze() {33		$info = &$this->getid3->info;34 35		$this->fseek($info['avdataoffset']);36		$StreamMarker = $this->fread(4);37		if ($StreamMarker != self::syncword) {38			return $this->error('Expecting "'.getid3_lib::PrintHexBytes(self::syncword).'" at offset '.$info['avdataoffset'].', found "'.getid3_lib::PrintHexBytes($StreamMarker).'"');39		}40		$info['fileformat']            = 'flac';41		$info['audio']['dataformat']   = 'flac';42		$info['audio']['bitrate_mode'] = 'vbr';43		$info['audio']['lossless']     = true;44 45		// parse flac container46		return $this->parseMETAdata();47	}48 49	/**50	 * @return bool51	 */52	public function parseMETAdata() {53		$info = &$this->getid3->info;54		do {55			$BlockOffset   = $this->ftell();56			$BlockHeader   = $this->fread(4);57			$LBFBT         = getid3_lib::BigEndian2Int(substr($BlockHeader, 0, 1));  // LBFBT = LastBlockFlag + BlockType58			$LastBlockFlag = (bool) ($LBFBT & 0x80);59			$BlockType     =        ($LBFBT & 0x7F);60			$BlockLength   = getid3_lib::BigEndian2Int(substr($BlockHeader, 1, 3));61			$BlockTypeText = self::metaBlockTypeLookup($BlockType);62 63			if (($BlockOffset + 4 + $BlockLength) > $info['avdataend']) {64				$this->warning('METADATA_BLOCK_HEADER.BLOCK_TYPE ('.$BlockTypeText.') at offset '.$BlockOffset.' extends beyond end of file');65				break;66			}67			if ($BlockLength < 1) {68				if ($BlockTypeText != 'reserved') {69					// probably supposed to be zero-length70					$this->warning('METADATA_BLOCK_HEADER.BLOCK_LENGTH ('.$BlockTypeText.') at offset '.$BlockOffset.' is zero bytes');71					continue;72				}73				$this->error('METADATA_BLOCK_HEADER.BLOCK_LENGTH ('.$BlockLength.') at offset '.$BlockOffset.' is invalid');74				break;75			}76 77			$info['flac'][$BlockTypeText]['raw'] = array();78			$BlockTypeText_raw = &$info['flac'][$BlockTypeText]['raw'];79 80			$BlockTypeText_raw['offset']          = $BlockOffset;81			$BlockTypeText_raw['last_meta_block'] = $LastBlockFlag;82			$BlockTypeText_raw['block_type']      = $BlockType;83			$BlockTypeText_raw['block_type_text'] = $BlockTypeText;84			$BlockTypeText_raw['block_length']    = $BlockLength;85			if ($BlockTypeText_raw['block_type'] != 0x06) { // do not read attachment data automatically86				$BlockTypeText_raw['block_data']  = $this->fread($BlockLength);87			}88 89			switch ($BlockTypeText) {90				case 'STREAMINFO':     // 0x0091					if (!$this->parseSTREAMINFO($BlockTypeText_raw['block_data'])) {92						return false;93					}94					break;95 96				case 'PADDING':        // 0x0197					unset($info['flac']['PADDING']); // ignore98					break;99 100				case 'APPLICATION':    // 0x02101					if (!$this->parseAPPLICATION($BlockTypeText_raw['block_data'])) {102						return false;103					}104					break;