Example shaders

shaders/waveform-overlay/shader.json

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+{
+  "id": "waveform-overlay",
+  "name": "Waveform Overlay",
+  "description": "Draws a lightweight luma waveform overlay along the bottom of the video.",
+  "category": "Utility",
+  "entryPoint": "shadeVideo",
+  "parameters": [
+    {
+      "id": "overlayHeight",
+      "label": "Overlay Height",
+      "type": "float",
+      "default": 0.32,
+      "min": 0.1,
+      "max": 1.0,
+      "step": 0.01
+    },
+    {
+      "id": "waveformOpacity",
+      "label": "Waveform Opacity",
+      "type": "float",
+      "default": 0.8,
+      "min": 0.0,
+      "max": 1.0,
+      "step": 0.01
+    },
+    {
+      "id": "backgroundOpacity",
+      "label": "Background",
+      "type": "float",
+      "default": 0.35,
+      "min": 0.0,
+      "max": 1.0,
+      "step": 0.01
+    },
+    {
+      "id": "lineThickness",
+      "label": "Line Thickness",
+      "type": "float",
+      "default": 2.0,
+      "min": 0.5,
+      "max": 10.0,
+      "step": 0.1
+    },
+    {
+      "id": "waveformColor",
+      "label": "Waveform Color",
+      "type": "color",
+      "default": [0.2, 1.0, 0.65, 1.0]
+    }
+  ]
+}

shaders/waveform-overlay/shader.slang

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+float4 shadeVideo(ShaderContext context)
+{
+	float4 color = context.sourceColor;
+	float height = saturate(overlayHeight);
+	float overlayStart = 1.0 - height;
+	if (context.uv.y < overlayStart)
+		return color;
+
+	float2 scopeUv = float2(context.uv.x, (context.uv.y - overlayStart) / max(height, 0.001));
+	float luma = dot(sampleVideo(float2(context.uv.x, 0.5)).rgb, float3(0.2126, 0.7152, 0.0722));
+	float targetY = 1.0 - saturate(luma);
+	float pixelThickness = max(lineThickness, 0.5) / max(context.outputResolution.y * height, 1.0);
+	float wave = 1.0 - smoothstep(pixelThickness, pixelThickness * 2.5, abs(scopeUv.y - targetY));
+
+	float grid = 0.0;
+	grid = max(grid, 1.0 - smoothstep(0.002, 0.006, abs(scopeUv.y - 0.25)));
+	grid = max(grid, 1.0 - smoothstep(0.002, 0.006, abs(scopeUv.y - 0.50)));
+	grid = max(grid, 1.0 - smoothstep(0.002, 0.006, abs(scopeUv.y - 0.75)));
+
+	float3 bg = lerp(color.rgb, float3(0.0, 0.0, 0.0), saturate(backgroundOpacity));
+	float3 withGrid = lerp(bg, float3(0.16, 0.22, 0.28), grid * 0.5);
+	float3 scoped = lerp(withGrid, waveformColor.rgb, wave * saturate(waveformOpacity) * waveformColor.a);
+	return float4(scoped, color.a);
+}