@@ -1238,7 +1238,7 @@ lutrgb="r=negval:g=negval:b=negval"
lutyuv="y=negval:u=negval:v=negval"
# negate luminance
-lutyuv=negval
+lutyuv=y=negval
# remove chroma components, turns the video into a graytone image
lutyuv="u=128:v=128"
Stefano Sabatini