// Y range is 16 ~ 235, PbPr range is -112 ~ 112
float X = 1/15.9375;
Y = Y-X;
Y = Y * 255/219;
if(Y <= 0) Y = 0;
if(Y >= 1) Y = 1;
Pb = Pb * 128/112;
Pr = Pr * 128/112;
float R = Y+2*Pr*(1-Kr);;
float G = Y - (2*Kb*(1-Kb)/(1-Kb-Kr)) * Pb
- (2*Kr*(1-Kr)/(1-Kb-Kr)) * Pr;
float B = Y+2*Pb*(1-Kb);