Pack MV

shaders/cBlockMatching.fx

@@ -95,7 +95,7 @@ namespace cBlockMatching
         float2 InvTexSize = fwidth(Input.Tex0);
 
         float2 Vectors = tex2Dlod(SampleOFlowTex, float4(Input.Tex0.xy, 0.0, _MipBias)).xy;
-        Vectors = DecodeVectors(Vectors, InvTexSize);
+        Vectors = UnnormalizeMotionVectors(UnpackMotionVectors(Vectors), InvTexSize);
 
         float3 NVectors = normalize(float3(Vectors, 1.0));
         NVectors = saturate((NVectors * 0.5) + 0.5);

shaders/cMotionBlur.fx

@@ -138,7 +138,7 @@ namespace cMotionBlur
         float2 ScreenSize = float2(BUFFER_WIDTH, BUFFER_HEIGHT);
         float2 ScreenCoord = Input.Tex0.xy;
 
-        float2 Velocity = tex2Dlod(SampleTempTex2b, float4(Input.Tex0.xy, 0.0, _MipBias)).xy;
+        float2 Velocity = UnpackMotionVectors(tex2Dlod(SampleTempTex2b, float4(Input.Tex0.xy, 0.0, _MipBias)).xy);
 
         float2 ScaledVelocity = Velocity * _Scale;
         ScaledVelocity = (_FrameRateScaling) ? ScaledVelocity / FrameTimeRatio : ScaledVelocity;

shaders/cOpticalFlow.fx

@@ -100,7 +100,7 @@ namespace cOpticalFlow
         float2 VelocityCoord;
         VelocityCoord.x = Origin.x * PixelSize.x;
         VelocityCoord.y = 1.0 - (Origin.y * PixelSize.y);
-        Output.Velocity = tex2Dlod(SampleTempTex2b, float4(VelocityCoord, 0.0, _MipBias)).xy / PixelSize;
+        Output.Velocity = UnpackMotionVectors(tex2Dlod(SampleTempTex2b, float4(VelocityCoord, 0.0, _MipBias)).xy) / PixelSize;
         Output.Velocity.y *= -1.0;
 
         // Scale velocity
@@ -208,7 +208,7 @@ namespace cOpticalFlow
     float4 PS_Shading(VS2PS_Quad Input) : SV_TARGET0
     {
         float2 Vectors = tex2Dlod(SampleTempTex2b, float4(Input.Tex0.xy, 0.0, _MipBias)).xy;
-        Vectors = DecodeVectors(Vectors, fwidth(Input.Tex0));
+        Vectors = UnnormalizeMotionVectors(UnpackMotionVectors(Vectors), fwidth(Input.Tex0));
         Vectors.y *= -1.0;
         float Magnitude = length(float3(Vectors, 1.0));
 

shaders/kDatamosh.fx

@@ -203,7 +203,7 @@ namespace kDatamosh
         Random.z = RandUV(Tex.yx - Time.xx);
 
         // Normalized screen space -> Pixel coordinates
-        MV = DecodeVectors(MV * _Scale, TexSize);
+        MV = UnnormalizeMotionVectors(MV * _Scale, TexSize);
 
         // Small random displacement (diffusion)
         MV += (Random.xy - 0.5)  * _Diffusion;
@@ -218,7 +218,7 @@ namespace kDatamosh
         float3 Random = 0.0;
 
         // Motion vectors
-        float2 MV = tex2Dlod(SampleFilteredFlowTex, float4(Input.Tex0, 0.0, _MipBias)).xy;
+        float2 MV = UnpackMotionVectors(tex2Dlod(SampleFilteredFlowTex, float4(Input.Tex0, 0.0, _MipBias)).xy);
 
         // Get motion blocks
         MV = GetMVBlocks(MV, Input.Tex0, Random);
@@ -257,7 +257,7 @@ namespace kDatamosh
         float3 Random = 0.0;
 
         // Motion vectors
-        float2 MV = tex2Dlod(SampleFilteredFlowTex, float4(Input.Tex0, 0.0, _MipBias)).xy;
+        float2 MV = UnpackMotionVectors(tex2Dlod(SampleFilteredFlowTex, float4(Input.Tex0, 0.0, _MipBias)).xy);
 
         // Get motion blocks
         MV = GetMVBlocks(MV, Input.Tex0, Random);
@@ -266,7 +266,7 @@ namespace kDatamosh
         float RandomMotion = RandUV(Input.Tex0 + length(MV));
 
         // Pixel coordinates -> Normalized screen space
-        MV = EncodeVectors(MV, TexSize);
+        MV = NormalizeMotionVectors(MV, TexSize);
 
         // Color from the original image
         float4 Source = tex2D(CShade_SampleColorTex, Input.Tex0);

shaders/shared/cVideoProcessing.fxh

@@ -8,14 +8,46 @@
         [Functions]
     */
 
+    float GetHalfMax()
+    {
+        // Get the Half format distribution of bits
+        // Sign Exponent Significand  
+        // 0    00000    000000000
+        const int SignBit = 0;
+        const int ExponentBits = 5;
+        const int SignificandBits = 10;
+
+        const int Bias = -15;
+
+        const int Exponent = 1 << ExponentBits;
+        const int Significand = 1 << SignificandBits;
+
+        const float MaxExponent = (Exponent - (1 << 1)) + Bias;
+        const float MaxSignificand = 1.0 + float((Significand - 1.0) / Significand);
+
+        return pow(-1, SignBit) * exp2(MaxExponent) * MaxSignificand;
+    }
+
+	// [-Half, Half] -> [-1.0, 1.0]
+    float2 UnpackMotionVectors(float2 Half2)
+    {
+    	return clamp(Half2 / GetHalfMax(), -1.0, 1.0);
+    }
+
+	// [-1.0, 1.0] -> [-Half, Half]
+    float2 PackMotionVectors(float2 Half2)
+    {
+    	return Half2 * GetHalfMax();
+    }
+
     // [-1.0, 1.0] -> [Width, Height]
-    float2 DecodeVectors(float2 Vectors, float2 ImageSize)
+    float2 UnnormalizeMotionVectors(float2 Vectors, float2 ImageSize)
     {
         return Vectors / abs(ImageSize);
     }
 
     // [Width, Height] -> [-1.0, 1.0]
-    float2 EncodeVectors(float2 Vectors, float2 ImageSize)
+    float2 NormalizeMotionVectors(float2 Vectors, float2 ImageSize)
     {
         return clamp(Vectors * abs(ImageSize), -1.0, 1.0);
     }
@@ -50,17 +82,20 @@
         // Get required data to calculate main texel data
         const float Pi2 = acos(-1.0) * 2.0;
 
+		// Unpack and upscale vectors
+		Vectors = UnpackMotionVectors(Vectors);
+
         // Calculate main texel data (TexelSize, TexelLOD)
         WarpTex = float4(MainTex, MainTex + Vectors);
 
         // Get gradient information
         float4 TexIx = ddx(WarpTex);
         float4 TexIy = ddy(WarpTex);
         float2 PixelSize = abs(TexIx.xy) + abs(TexIy.xy);
-
-        // Un-normalize data for processing
-        WarpTex *= (1.0 / abs(PixelSize.xyxy));
-        Vectors = DecodeVectors(Vectors, PixelSize);
+        
+        // Upscale
+        WarpTex.xy = UnnormalizeMotionVectors(WarpTex.xy, PixelSize);
+        WarpTex.zw = UnnormalizeMotionVectors(WarpTex.zw, PixelSize);
 
         [loop] for(int i = 1; i < 4; ++i)
         {
@@ -114,7 +149,8 @@
         float2 Flow = (D == 0.0) ? 0.0 : mul(B, A);
 
         // Propagate and encode vectors
-        return EncodeVectors(Vectors + Flow, PixelSize);
+        Vectors = UnnormalizeMotionVectors(Vectors, PixelSize) + Flow;
+        return PackMotionVectors(NormalizeMotionVectors(Vectors, PixelSize));
     }
 
     /*
@@ -222,7 +258,7 @@
 
         // Un-normalize data for processing
         B.Tex *= (1.0 / B.PixelSize.xyxy);
-        Vectors = DecodeVectors(Vectors, B.PixelSize);
+        Vectors = UnpackMotionVectors(Vectors);
 
         // Pre-calculate template
         float2 Template[4];
@@ -231,6 +267,6 @@
         // Calculate three-step search
         // Propagate and encode vectors
         Vectors += SearchArea(SampleImage, B, Template);
-        return EncodeVectors(Vectors, B.PixelSize);
+        return PackMotionVectors(Vectors);
     }
 #endif