getid3_riff::ParseRIFF( int $startoffset, int $maxoffset ): array|false

1592	public function ParseRIFF($startoffset, $maxoffset) {1593		$info = &$this->getid3->info;1594 1595		$RIFFchunk = array();1596		$FoundAllChunksWeNeed = false;1597		$LISTchunkParent = null;1598		$LISTchunkMaxOffset = null;1599		$AC3syncwordBytes = pack('n', getid3_ac3::syncword); // 0x0B77 -> "\x0B\x77"1600 1601		try {1602			$this->fseek($startoffset);1603			$maxoffset = min($maxoffset, $info['avdataend']);1604			while ($this->ftell() < $maxoffset) {1605				$chunknamesize = $this->fread(8);1606				//$chunkname =                          substr($chunknamesize, 0, 4);1607				$chunkname = str_replace("\x00", '_', substr($chunknamesize, 0, 4));  // note: chunk names of 4 null bytes do appear to be legal (has been observed inside INFO and PRMI chunks, for example), but makes traversing array keys more difficult1608				$chunksize =  $this->EitherEndian2Int(substr($chunknamesize, 4, 4));1609				//if (strlen(trim($chunkname, "\x00")) < 4) {1610				if (strlen($chunkname) < 4) {1611					$this->error('Expecting chunk name at offset '.($this->ftell() - 8).' but found nothing. Aborting RIFF parsing.');1612					break;1613				}1614				if ($chunksize == 0) {1615					if ($chunkname == 'JUNK') {1616						// this is allowed1617					} elseif ($chunkname == 'data') {1618						// https://github.com/JamesHeinrich/getID3/issues/4681619						// may occur in streaming files where the data size is unknown1620						$chunksize = $info['avdataend'] - $this->ftell();1621						$this->warning('RIFF.data size field is empty, assuming the correct value is filesize-offset ('.$chunksize.')');1622					} else {1623						$this->warning('Chunk ('.$chunkname.') size at offset '.($this->ftell() - 4).' is zero. Aborting RIFF parsing.');1624						break;1625					}1626				}1627				if (($chunksize % 2) != 0) {1628					// all structures are packed on word boundaries1629					$chunksize++;1630				}1631 1632				switch ($chunkname) {1633					case 'LIST':1634						$listname = $this->fread(4);1635						if (preg_match('#^(movi|rec )$#i', $listname)) {1636							$RIFFchunk[$listname]['offset'] = $this->ftell() - 4;1637							$RIFFchunk[$listname]['size']   = $chunksize;1638 1639							if (!$FoundAllChunksWeNeed) {1640								$WhereWeWere      = $this->ftell();1641								$AudioChunkHeader = $this->fread(12);1642								$AudioChunkStreamNum  =                              substr($AudioChunkHeader, 0, 2);1643								$AudioChunkStreamType =                              substr($AudioChunkHeader, 2, 2);1644								$AudioChunkSize       = getid3_lib::LittleEndian2Int(substr($AudioChunkHeader, 4, 4));1645 1646								if ($AudioChunkStreamType == 'wb') {1647									$FirstFourBytes = substr($AudioChunkHeader, 8, 4);1648									if (preg_match('/^\xFF[\xE2-\xE7\xF2-\xF7\xFA-\xFF][\x00-\xEB]/s', $FirstFourBytes)) {1649										// MP31650										if (getid3_mp3::MPEGaudioHeaderBytesValid($FirstFourBytes)) {1651											$getid3_temp = new getID3();1652											$getid3_temp->openfile($this->getid3->filename, $this->getid3->info['filesize'], $this->getid3->fp);1653											$getid3_temp->info['avdataoffset'] = $this->ftell() - 4;1654											$getid3_temp->info['avdataend']    = $this->ftell() + $AudioChunkSize;1655											$getid3_mp3 = new getid3_mp3($getid3_temp, __CLASS__);1656											$getid3_mp3->getOnlyMPEGaudioInfo($getid3_temp->info['avdataoffset'], false);1657											if (isset($getid3_temp->info['mpeg']['audio'])) {1658												$info['mpeg']['audio']         = $getid3_temp->info['mpeg']['audio'];1659												$info['audio']                 = $getid3_temp->info['audio'];1660												$info['audio']['dataformat']   = 'mp'.$info['mpeg']['audio']['layer'];1661												$info['audio']['sample_rate']  = $info['mpeg']['audio']['sample_rate'];1662												$info['audio']['channels']     = $info['mpeg']['audio']['channels'];1663												$info['audio']['bitrate']      = $info['mpeg']['audio']['bitrate'];1664												$info['audio']['bitrate_mode'] = strtolower($info['mpeg']['audio']['bitrate_mode']);1665												//$info['bitrate']               = $info['audio']['bitrate'];1666											}1667											unset($getid3_temp, $getid3_mp3);1668										}1669 1670									} elseif (strpos($FirstFourBytes, $AC3syncwordBytes) === 0) {1671										// AC3