updates

shaders/greenscreen-key/shader.slang

@@ -50,12 +50,17 @@ float rawAlphaAt(float2 uv, ShaderContext context)
 	return saturate(alpha);
 }
 
-float refinedAlphaAt(float2 uv, ShaderContext context)
+float matteAlphaAt(float2 uv)
+{
+	return saturate(sampleVideo(saturate(uv)).a);
+}
+
+float refinedAlphaFromMatte(float2 uv, ShaderContext context)
 {
 	float2 pixel = 1.0 / max(context.outputResolution, float2(1.0, 1.0));
 	float blur = max(matteBlur, 0.0);
 	float aaRadius = max(blur, 0.65);
-	float centerAlpha = rawAlphaAt(uv, context);
+	float centerAlpha = matteAlphaAt(uv);
 	float alpha = centerAlpha * 0.30;
 
 	if (aaRadius > 0.0001)
@@ -64,51 +69,51 @@ float refinedAlphaAt(float2 uv, ShaderContext context)
 		float2 halfRadius = radius * 0.5;
 		float alphaMin = centerAlpha;
 		float alphaMax = centerAlpha;
-		float sampleAlpha = rawAlphaAt(uv + float2(halfRadius.x, 0.0), context);
+		float sampleAlpha = matteAlphaAt(uv + float2(halfRadius.x, 0.0));
 		alpha += sampleAlpha * 0.065;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv - float2(halfRadius.x, 0.0), context);
+		sampleAlpha = matteAlphaAt(uv - float2(halfRadius.x, 0.0));
 		alpha += sampleAlpha * 0.065;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv + float2(0.0, halfRadius.y), context);
+		sampleAlpha = matteAlphaAt(uv + float2(0.0, halfRadius.y));
 		alpha += sampleAlpha * 0.065;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv - float2(0.0, halfRadius.y), context);
+		sampleAlpha = matteAlphaAt(uv - float2(0.0, halfRadius.y));
 		alpha += sampleAlpha * 0.065;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv + float2(radius.x, 0.0), context);
+		sampleAlpha = matteAlphaAt(uv + float2(radius.x, 0.0));
 		alpha += sampleAlpha * 0.06;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv - float2(radius.x, 0.0), context);
+		sampleAlpha = matteAlphaAt(uv - float2(radius.x, 0.0));
 		alpha += sampleAlpha * 0.06;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv + float2(0.0, radius.y), context);
+		sampleAlpha = matteAlphaAt(uv + float2(0.0, radius.y));
 		alpha += sampleAlpha * 0.06;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv - float2(0.0, radius.y), context);
+		sampleAlpha = matteAlphaAt(uv - float2(0.0, radius.y));
 		alpha += sampleAlpha * 0.06;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv + radius, context);
+		sampleAlpha = matteAlphaAt(uv + radius);
 		alpha += sampleAlpha * 0.05;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv - radius, context);
+		sampleAlpha = matteAlphaAt(uv - radius);
 		alpha += sampleAlpha * 0.05;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv + float2(radius.x, -radius.y), context);
+		sampleAlpha = matteAlphaAt(uv + float2(radius.x, -radius.y));
 		alpha += sampleAlpha * 0.05;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
-		sampleAlpha = rawAlphaAt(uv + float2(-radius.x, radius.y), context);
+		sampleAlpha = matteAlphaAt(uv + float2(-radius.x, radius.y));
 		alpha += sampleAlpha * 0.05;
 		alphaMin = min(alphaMin, sampleAlpha);
 		alphaMax = max(alphaMax, sampleAlpha);
@@ -118,7 +123,7 @@ float refinedAlphaAt(float2 uv, ShaderContext context)
 	}
 	else
 	{
-		alpha = rawAlphaAt(uv, context);
+		alpha = centerAlpha;
 	}
 
 	alpha = saturate((alpha - clipBlack) / max(clipWhite - clipBlack, 0.0001));
@@ -147,17 +152,43 @@ float3 despillColor(float3 color, float alpha)
 	return saturate(neutralized);
 }
 
-float4 shadeVideo(ShaderContext context)
+float cropMaskAt(float2 uv, ShaderContext context)
+{
+	float2 feather = 1.0 / max(context.outputResolution, float2(1.0, 1.0));
+	float left = smoothstep(saturate(cropLeft), saturate(cropLeft) + feather.x, uv.x);
+	float right = 1.0 - smoothstep(1.0 - saturate(cropRight) - feather.x, 1.0 - saturate(cropRight), uv.x);
+	float top = smoothstep(saturate(cropTop), saturate(cropTop) + feather.y, uv.y);
+	float bottom = 1.0 - smoothstep(1.0 - saturate(cropBottom) - feather.y, 1.0 - saturate(cropBottom), uv.y);
+	return saturate(left * right * top * bottom);
+}
+
+float4 buildRawMatte(ShaderContext context)
 {
 	float4 src = context.sourceColor;
 	float3 color = saturate(src.rgb);
-	float alpha = refinedAlphaAt(context.uv, context);
+	float alpha = rawAlphaAt(context.uv, context);
+	return float4(color, alpha);
+}
+
+float4 refineMatte(ShaderContext context)
+{
+	float4 raw = sampleVideo(context.uv);
+	float alpha = refinedAlphaFromMatte(context.uv, context);
+	return float4(saturate(raw.rgb), alpha);
+}
+
+float4 applyKey(ShaderContext context)
+{
+	float4 keyed = sampleVideo(context.uv);
+	float3 color = saturate(keyed.rgb);
+	float alpha = saturate(keyed.a);
 	float spill = spillAmountForColor(color);
 	float3 despilled = despillColor(color, alpha);
+	float cropMask = cropMaskAt(context.uv, context);
+	alpha *= cropMask;
 
 	float edgeAmount = saturate(1.0 - abs(alpha * 2.0 - 1.0));
 	despilled = lerp(despilled, despilled * saturate(edgeColor.rgb), edgeAmount * saturate(edgeRecover));
-	alpha = saturate(lerp(alpha, rawAlphaAt(context.uv, context), edgeAmount * saturate(edgeRecover) * 0.35));
 
 	if (viewMode == 1)
 		return float4(alpha, alpha, alpha, 1.0);
@@ -167,10 +198,15 @@ float4 shadeVideo(ShaderContext context)
 		return float4(despilled, 1.0);
 	if (viewMode == 4)
 	{
-		float rawAlpha = rawAlphaAt(context.uv, context);
+		float rawAlpha = rawAlphaAt(context.uv, context) * cropMask;
 		return float4(rawAlpha, alpha, spill, 1.0);
 	}
 
 	float3 premultiplied = saturate(despilled) * alpha;
 	return float4(premultiplied, alpha);
 }
+
+float4 shadeVideo(ShaderContext context)
+{
+	return applyKey(context);
+}