x264: don't parse preset-related options as params

encoder/x264/x264.go

@@ -93,6 +93,9 @@ func NewEncoder(w io.Writer, stream *y4m.Stream, settings map[string]any) (*Enco
 	}
 
 	for k, v := range settings {
+		if k == "profile" || k == "preset" || k == "tune" {
+			continue
+		}
 		if err := func() error {
 			var strVal *C.char
 			if val, ok := v.(string); ok {