YUV decoder. http://www.loopsketch.com/blog/?p=350

YUV.hlsl

Texture2D diffuseTexture;
SamplerState diffuseTextureSampler;

struct VS_IN
{
    float4 Position: POSITION;
    float4 Color: COLOR;
    float2 Tex: TEXCOORD0;
};

struct VS_OUT
{
    float4 Position: SV_POSITION;
    float4 Color: COLOR;
    float2 Tex: TEXCOORD0;
};

typedef VS_OUT PS_IN;

cbuffer cb0
{
	row_major matrix ModelMatrix;
}
cbuffer cb1
{
	row_major matrix ViewMatrix;
}
cbuffer cb2
{
	row_major matrix ProjectionMatrix;
};

VS_OUT vsMain(VS_IN input)
{
    VS_OUT Output;
	Output.Position = input.Position;
	Output.Color = input.Color;
    Output.Tex = input.Tex;
    return Output;    
}

float4 getYuvEven(float2 tex)
{
	float Y = diffuseTexture.Sample(diffuseTextureSampler
		, float2(tex.x, tex.y * 2 / 3)).r;
	float U = diffuseTexture.Sample(diffuseTextureSampler
		, float2(tex.x / 2, (4 + tex.y) / 6)).r - 0.5;
	float V = diffuseTexture.Sample(diffuseTextureSampler
		, float2(tex.x / 2, (5 + tex.y) / 6)).r - 0.5;
	return float4(Y, U, V, 1);
}

float4 getYuvOdd(float2 tex)
{
	//return float4(0, 0, 0, 0);

	float Y = diffuseTexture.Sample(diffuseTextureSampler
		, float2(tex.x, tex.y * 2 / 3)).r;
	float U = diffuseTexture.Sample(diffuseTextureSampler
		, float2((1+tex.x) / 2, (4 + tex.y) / 6)).r - 0.5;
	float V = diffuseTexture.Sample(diffuseTextureSampler
		, float2((1+tex.x) / 2, (5 + tex.y) / 6)).r - 0.5;
	return float4(Y, U, V, 1);
}

float4 psMain(PS_IN input) : SV_TARGET
{
	uint w, h;
	diffuseTexture.GetDimensions(w, h);
	uint2 P = input.Tex * uint2(w, h);

	float4 yuv = P.y % 2 == 0 ? getYuvEven(input.Tex) : getYuvOdd(input.Tex);

	const float4x4 YUVMatrix = {
		1,  0,        1.402,   0,
		1, -0.34414, -0.71414, 0,
		1,  1.772,    0,       0,
		1,  1,        1,       1 };
	return (mul(YUVMatrix, yuv) - 0.0627f) * 1.164f;
}