getid3_ogg::ParseOggPageHeader(): array|false

530	public function ParseOggPageHeader() {531		// http://xiph.org/ogg/vorbis/doc/framing.html532		$oggheader = array();533		$oggheader['page_start_offset'] = $this->ftell(); // where we started from in the file534 535		$filedata = $this->fread($this->getid3->fread_buffer_size());536		$filedataoffset = 0;537		while (substr($filedata, $filedataoffset++, 4) != 'OggS') {538			if (($this->ftell() - $oggheader['page_start_offset']) >= $this->getid3->fread_buffer_size()) {539				// should be found before here540				return false;541			}542			if (($filedataoffset + 28) > strlen($filedata)) {543				if ($this->feof() || (($filedata .= $this->fread($this->getid3->fread_buffer_size())) === '')) {544					// get some more data, unless eof, in which case fail545					return false;546				}547			}548		}549		$filedataoffset += strlen('OggS') - 1; // page, delimited by 'OggS'550 551		$oggheader['stream_structver']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));552		$filedataoffset += 1;553		$oggheader['flags_raw']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));554		$filedataoffset += 1;555		$oggheader['flags']['fresh']    = (bool) ($oggheader['flags_raw'] & 0x01); // fresh packet556		$oggheader['flags']['bos']      = (bool) ($oggheader['flags_raw'] & 0x02); // first page of logical bitstream (bos)557		$oggheader['flags']['eos']      = (bool) ($oggheader['flags_raw'] & 0x04); // last page of logical bitstream (eos)558 559		$oggheader['pcm_abs_position']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 8));560		$filedataoffset += 8;561		$oggheader['stream_serialno']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));562		$filedataoffset += 4;563		$oggheader['page_seqno']        = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));564		$filedataoffset += 4;565		$oggheader['page_checksum']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));566		$filedataoffset += 4;567		$oggheader['page_segments']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));568		$filedataoffset += 1;569		$oggheader['page_length'] = 0;570		for ($i = 0; $i < $oggheader['page_segments']; $i++) {571			$oggheader['segment_table'][$i] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));572			$filedataoffset += 1;573			$oggheader['page_length'] += $oggheader['segment_table'][$i];574		}575		$oggheader['header_end_offset'] = $oggheader['page_start_offset'] + $filedataoffset;576		$oggheader['page_end_offset']   = $oggheader['header_end_offset'] + $oggheader['page_length'];577		$this->fseek($oggheader['header_end_offset']);578 579		return $oggheader;580	}