BT.709 to BT.601.hlsl

sampler s0;
float2 c0;

float4 main(float2 tex : TEXCOORD0) : COLOR
{
	float4 si = tex2D(s0, tex);
	float3 s1 = si.rgb;
	s1 = float3(dot(float3(.2126, .7152, .0722), s1), dot(float3(-.1063/.9278, -.3576/.9278, .5), s1), dot(float3(.5, -.3576/.7874, -.0361/.7874), s1));
	return float3(s1.x+1.402*s1.z, dot(s1, float3(1, -.202008/.587, -.419198/.587)), s1.x+1.772*s1.y).rgbb;
}