Color correction for YUV-overlay (Xv) ?

[niemayer]

While the nvidia drivers provide a color correction feature for the "ordinary" X11 display, it seems there is no such feature for the YUV overlay (used by the Xv extension). There is that "hue"-slider in nvidia-control, but that's not really the same - I want to adjust some "colorfulness" of certain grey levels where the "hue"-slider won't help me.

Is this a hardware limitation or is there just no fancy interface?

I'm quite willing to hack a little if that is required to modify the LUTs for the DAC in overlay mode...