-enum MovitPixelFormat { FORMAT_RGB, FORMAT_RGBA, FORMAT_BGR, FORMAT_BGRA, FORMAT_GRAYSCALE };
+// Note: Movit's internal processing formats do not have enough
+// accuracy to support 12-bit input, so if you want to use Rec. 2020,
+// you should probably stick to 10-bit, or accept somewhat reduced
+// accuracy for 12-bit. Input depths above 8 bits are also generally
+// less tested.
+//
+// We also only support “conventional non-constant luminance” for Rec. 2020,
+// where Y' is derived from R'G'B' instead of RGB, since this is the same
+// system as used in Rec. 601 and 709.