[host] added format converter class

host/Shaders/BGRAtoNV12.hlsl

@@ -0,0 +1,26 @@
+Texture2D    texTexture;
+SamplerState texSampler;
+
+struct VS
+{
+  float4 pos : SV_Position;
+  float2 tex : TEXCOORD;
+};
+
+float4 RGBtoYUV(float4 rgba)
+{
+  float4 yuva;
+  yuva.r = rgba.r * 0.2126 + 0.7152 * rgba.g + 0.0722 * rgba.b;
+  yuva.g = (rgba.b - yuva.r) / 1.8556;
+  yuva.b = (rgba.r - yuva.r) / 1.5748;
+  yuva.a = rgba.a;
+  yuva.gb += 0.5;
+  return yuva;
+}
+
+float4 main(VS input) : SV_TARGET
+{
+  const float4 rgba = texTexture.Sample(texSampler, input.tex);
+  const float4 yuva = RGBtoYUV(rgba);
+  return yuva;
+}

host/Shaders/Vertex.hlsl

@@ -0,0 +1,16 @@
+struct VS
+{
+  float4 pos : POSITION;
+  float2 tex : TEXCOORD; 
+};
+
+struct PS
+{
+  float4 pos : SV_Position;
+  float2 tex : TEXCOORD;
+};
+
+PS main(VS input)
+{
+  return input;
+}