// uniform vec2 PREFIX(tc_scale);
// uniform float PREFIX(round_fac), PREFIX(inv_round_fac);
+// See footer.frag for details about this if statement.
+#ifndef YCBCR_ALSO_OUTPUT_RGBA
+#define YCBCR_ALSO_OUTPUT_RGBA 0
+#endif
+
#if YCBCR_ALSO_OUTPUT_RGBA
// There are two values to dither; otherwise, exactly the same as the algorithm below