voku / portable-utf8

          if ($c2 >= "\x80" && $c2 <= "\xBF") { // yeah, almost sure it's UTF8 already

            $buf .= $c1 . $c2;

            $i++;

          } else { // not valid UTF8 - convert it

            $cc1tmp = ord($c1) / 64;

            $cc1 = self::chr_and_parse_int($cc1tmp) | "\xC0";

            $cc2 = ($c1 & "\x3F") | "\x80";

            $buf .= $cc1 . $cc2;

          }

        } elseif ($c1 >= "\xE0" && $c1 <= "\xEF") { // looks like 3 bytes UTF8

          if ($c2 >= "\x80" && $c2 <= "\xBF" && $c3 >= "\x80" && $c3 <= "\xBF") { // yeah, almost sure it's UTF8 already

            $buf .= $c1 . $c2 . $c3;

            $i += 2;

          } else { // not valid UTF8 - convert it

            $cc1tmp = ord($c1) / 64;

            $cc1 = self::chr_and_parse_int($cc1tmp) | "\xC0";

            $cc2 = ($c1 & "\x3F") | "\x80";

            $buf .= $cc1 . $cc2;

          }

        } elseif ($c1 >= "\xF0" && $c1 <= "\xF7") { // looks like 4 bytes UTF8

          if ($c2 >= "\x80" && $c2 <= "\xBF" && $c3 >= "\x80" && $c3 <= "\xBF" && $c4 >= "\x80" && $c4 <= "\xBF") { // yeah, almost sure it's UTF8 already

            $buf .= $c1 . $c2 . $c3 . $c4;

            $i += 3;

          } else { // not valid UTF8 - convert it

            $cc1tmp = ord($c1) / 64;

            $cc1 = self::chr_and_parse_int($cc1tmp) | "\xC0";

            $cc2 = ($c1 & "\x3F") | "\x80";

            $buf .= $cc1 . $cc2;

          }

        } else { // doesn't look like UTF8, but should be converted

          $cc1tmp = ord($c1) / 64;

            $buf .= $cc1 . $cc2;

          }

        } else { // doesn't look like UTF8, but should be converted

          $cc1tmp = ord($c1) / 64;

          $cc1 = self::chr_and_parse_int($cc1tmp) | "\xC0";

          $cc2 = ($c1 & "\x3F") | "\x80";

          $buf .= $cc1 . $cc2;

        }

      } elseif (($c1 & "\xC0") === "\x80") { // needs conversion

        $ordC1 = ord($c1);

        if (isset(self::$WIN1252_TO_UTF8[$ordC1])) { // found in Windows-1252 special cases

          $buf .= self::$WIN1252_TO_UTF8[$ordC1];

        } else {

          $cc1 = self::chr_and_parse_int($ordC1 / 64) | "\xC0";

          $cc2 = ($c1 & "\x3F") | "\x80";

          $buf .= $cc1 . $cc2;

        }

      } else { // it doesn't need conversion

        $buf .= $c1;