$ perl -e '$f="\xff\x01\x67";print $f' | od -t x1
0000000 ff 01 67
0000003

$ perl -e '$f="\xff\x01\x67";use Encode; $f=encode("utf8", decode("iso-8859-1",$f));print $f' | od -t x1
0000000 c3 bf 01 67
0000004