Allow 4-character extensions

encode.pl

@@ -109,7 +109,7 @@ if ($title) {
 if (!defined($out_file) || length($out_file) < 1) {
 	$out_file = $in_file;
 } else {
-	my ($force_format) = $out_file =~ /\.(\w{2,3})$/;
+	my ($force_format) = $out_file =~ /\.(\w{2,4})$/;
 	if (lc($force_format) eq 'mkv') {
 		$FORMAT = 'mkv';
 	}