getid3_ogg::ParseOggPageHeader

	/**
	 * @return array|false
	 */
	public function ParseOggPageHeader() {
		// http://xiph.org/ogg/vorbis/doc/framing.html
		$oggheader['page_start_offset'] = $this->ftell(); // where we started from in the file

		$filedata = $this->fread($this->getid3->fread_buffer_size());
		$filedataoffset = 0;
		while ((substr($filedata, $filedataoffset++, 4) != 'OggS')) {
			if (($this->ftell() - $oggheader['page_start_offset']) >= $this->getid3->fread_buffer_size()) {
				// should be found before here
				return false;
			}
			if ((($filedataoffset + 28) > strlen($filedata)) || (strlen($filedata) < 28)) {
				if ($this->feof() || (($filedata .= $this->fread($this->getid3->fread_buffer_size())) === '')) {
					// get some more data, unless eof, in which case fail
					return false;
				}
			}
		}
		$filedataoffset += strlen('OggS') - 1; // page, delimited by 'OggS'

		$oggheader['stream_structver']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
		$filedataoffset += 1;
		$oggheader['flags_raw']         = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
		$filedataoffset += 1;
		$oggheader['flags']['fresh']    = (bool) ($oggheader['flags_raw'] & 0x01); // fresh packet
		$oggheader['flags']['bos']      = (bool) ($oggheader['flags_raw'] & 0x02); // first page of logical bitstream (bos)
		$oggheader['flags']['eos']      = (bool) ($oggheader['flags_raw'] & 0x04); // last page of logical bitstream (eos)

		$oggheader['pcm_abs_position']  = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 8));
		$filedataoffset += 8;
		$oggheader['stream_serialno']   = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
		$filedataoffset += 4;
		$oggheader['page_seqno']        = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
		$filedataoffset += 4;
		$oggheader['page_checksum']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 4));
		$filedataoffset += 4;
		$oggheader['page_segments']     = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
		$filedataoffset += 1;
		$oggheader['page_length'] = 0;
		for ($i = 0; $i < $oggheader['page_segments']; $i++) {
			$oggheader['segment_table'][$i] = getid3_lib::LittleEndian2Int(substr($filedata, $filedataoffset, 1));
			$filedataoffset += 1;
			$oggheader['page_length'] += $oggheader['segment_table'][$i];
		}
		$oggheader['header_end_offset'] = $oggheader['page_start_offset'] + $filedataoffset;
		$oggheader['page_end_offset']   = $oggheader['header_end_offset'] + $oggheader['page_length'];
		$this->fseek($oggheader['header_end_offset']);