FILETIMEtoUNIXtime example

$thisfile_asf_filepropertiesobject['offset']             = $NextObjectOffset + $offset;
                    $thisfile_asf_filepropertiesobject['objectid']           = $NextObjectGUID;
                    $thisfile_asf_filepropertiesobject['objectid_guid']      = $NextObjectGUIDtext;
                    $thisfile_asf_filepropertiesobject['objectsize']         = $NextObjectSize;
                    $thisfile_asf_filepropertiesobject['fileid']             = substr($ASFHeaderData, $offset, 16);
                    $offset += 16;
                    $thisfile_asf_filepropertiesobject['fileid_guid']        = $this->BytestringToGUID($thisfile_asf_filepropertiesobject['fileid']);
                    $thisfile_asf_filepropertiesobject['filesize']           = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 8));
                    $offset += 8;
                    $thisfile_asf_filepropertiesobject['creation_date']      = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 8));
                    $thisfile_asf_filepropertiesobject['creation_date_unix'] = $this->FILETIMEtoUNIXtime($thisfile_asf_filepropertiesobject['creation_date']);
                    $offset += 8;
                    $thisfile_asf_filepropertiesobject['data_packets']       = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 8));
                    $offset += 8;
                    $thisfile_asf_filepropertiesobject['play_duration']      = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 8));
                    $offset += 8;
                    $thisfile_asf_filepropertiesobject['send_duration']      = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 8));
                    $offset += 8;
                    $thisfile_asf_filepropertiesobject['preroll']            = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 8));
                    $offset += 8;
                    $thisfile_asf_filepropertiesobject['flags_raw']          = getid3_lib::LittleEndian2Int(substr($ASFHeaderData, $offset, 4));
                    $offset += 4;