MFShader Plugin

Since version 2.5 of the Video SDK, you can apply a custom video transformation with an HLSL pixel shader. The functionality is provided by the MFShader plugin.

The plugin requires GPU pipeline mode. Enable it before creating the SDK objects that will process frames:

var factory = new MFFactoryClass();
factory.PropsSet("gpu_pipeline", "true");

The shader must be an HLSL pixel shader with PS as the entry point. The shader source is assigned with the shader property:

m_objShader.PropsSet("shader", shaderString);

To check whether the shader was compiled and initialized, read shader_state:

m_objShader.PropsGet("shader_state", out string state);

Possible states are:

• not_inited
• failed
• inited
• failed_to_render

If the shader is not valid, the plugin returns an error state. The plugin is not a shader debugger, so validate syntax separately with a Direct3D/HLSL tool such as https://www.shadertoy.com/ or with D3DCompile. Shadertoy can be useful for ideas, but its examples are GLSL and must be converted to HLSL manually.

Shader initialization can cause a short one-time drop because the shader is compiled. Depending on the system, this usually takes around 10-30 ms.

MFormats Usage

In MFormats, process an MFFrame directly with IMFProcess.ProcessFrame. Optional UI parameters can be passed as frame side data named shader_data.

byte[] shaderData = BuildConstantBuffer();
IntPtr dataPtr = Marshal.AllocHGlobal(shaderData.Length);
try
{
    Marshal.Copy(shaderData, 0, dataPtr, shaderData.Length);
    frame.MFDataSet("shader_data", shaderData.Length, dataPtr.ToInt64());

    MFFrame processedFrame;
    int framesRest;
    ((IMFProcess)m_objShader).ProcessFrame(frame, out processedFrame, out framesRest, "");
}
finally
{
    Marshal.FreeHGlobal(dataPtr);
}

MPlatform Usage

In MPlatform, add MFShader to the object graph like other plugins. For a file source, the graph can be:

var source = new MFileClass();
var preview = new MPreviewClass();
var shader = new MFShaderClass();

shader.PropsSet("shader", shaderString);
source.PluginsAdd(shader, 0);

preview.ObjectStart(source);
preview.PreviewWindowSet("", previewPanel.Handle.ToInt64());
preview.PreviewEnable("", 1, 1);

If the shader uses tunable constants, add a lightweight plugin before MFShader that writes the current constant buffer to each frame as shader_data, then add MFShader after it:

source.PluginsAdd(shaderDataPlugin, 0);
source.PluginsAdd(shader, 0);

The WPF MPlatform sample included with this article uses this pattern: MFile -> ShaderDataPlugin -> MFShader -> MPreview/MRenderer.

Shader Parameters

A common approach is to declare a constant buffer in HLSL and pack UI values into float4 slots:

cbuffer ShaderParams : register(b0)
{
    float4 p0;
    float4 p1;
};

float4 PS(PS_INPUT input) : SV_Target
{
    float amount = p0.x;
    return inputTexture.Sample(inputSampler, input.Tex) * amount;
}

The sample shader library stores each effect in a separate *.shader.json file next to its HLSL file. The JSON describes the effect, its category, and the UI controls that map to constant-buffer slots.

Shader Library Overview

The expanded WPF samples include a reusable shaders folder with 62 JSON/HLSL effects. Each shader can be loaded by the sample, applied to the video, and tuned from the UI without changing the application code.

The library covers common broadcast and streaming workflows such as color correction, keying, scaling, deinterlacing, overlays, crop/aspect work, monitoring aids, denoise/repair, HDR/SDR tone mapping, and stylized effects. The complete catalog below lists every included shader and its live controls.

Complete Shader Catalog

The shaders folder contains one JSON/HLSL pair for each effect below. The JSON file stores the shader name, category, description, HLSL file name, and the UI parameters that the samples expose for live tuning.

Preview GIFs are small documentation previews generated from synthetic source material. They show the intended visual direction of each effect; exact output depends on the source video, GPU pipeline, shader parameters, and host graph.

Preview	Shader	Category	Purpose	Live controls
	Analog Signal Interference	Retro / Analog	Smooth RF-style wave distortion, line noise, desaturation, and color drift.	Wave Displacement, Line Noise, Speed, Desaturation
	Anamorphic De-Squeeze Preview	Camera Assist	Preview horizontal de-squeeze for anamorphic camera feeds with optional crop dimming.	Squeeze Factor, Zoom, Outside Dim
	Banding Reducer / Fine Dither	Video Repair	Adds subtle animated grain and micro-dither to reduce visible gradients and banding.	Strength, Animate, Luma Only
	Bilateral Denoise	Production Core	Edge-preserving spatial denoise for noisy camera feeds, compressed sources, and low-light material.	Strength, Range Sigma, Spatial Sigma, Radius, Detail Restore
	Bloom / Glow	Finishing	Highlight bloom for glamour camera looks, neon overlays, and bright UI/game sources.	Threshold, Intensity, Radius, Saturation
	Box Blur	Blur / Detail	Single-pass blur useful for background softening and quick privacy masks.	Radius, Mix
	Broadcast Safe Limiter	QC / Compliance	Softly clamps RGB and luma toward common video-safe levels for fast confidence checks.	Black Level, White Level, Softness, Mix
	Cartoon / Cel Shade	Stylize	Posterized lighting with dark edge lines for comic and toon looks.	Tone Levels, Edge Strength, Edge Threshold, Saturation
	Channel Inspector	QC / Monitoring	Diagnostic channel viewer for red, green, blue, alpha, luma, or saturation.	Mode, False Color
	Chroma Bleed Reducer	Video Repair	Reduces horizontal chroma bleed by smoothing color difference while preserving luma detail.	Radius, Amount
	Chroma Key Matte Preview	Keying / QC	Visualizes a green-screen key matte and optional spill suppression for setup checks.	Key Red, Key Green, Key Blue, Threshold, Softness, Spill Suppress, Matte View
	Clipping Warning	QC / Monitoring	Flashes underexposed and clipped highlights for fast signal checks.	Black Clip, White Clip, Opacity, Flash
	Color Bars / Ramp Generator	Delivery Looks	Generates SMPTE-like color bars and grayscale ramp over the current frame for output path checks.	Mix, Show Ramp
	Color Corrector	Camera / Program	Primary color controls for quick camera matching, playback normalization, and program feed trims.	Exposure, Contrast, Saturation, Gamma, Lift, Gain
	Color Space / Range Converter	Production Core	RGB matrix and legal/full range conversion for Rec.601, Rec.709, and Rec.2020 style program normalization.	Input Standard, Output Standard, Input Range, Output Range, Clamp Output, Mix
	Crop / Aspect Guides	Graphics / Layout	Shows common social and broadcast crop guides: 16:9, 9:16, 1:1, 4:5, or custom aspect.	Target Aspect, Line Width, Outside Dim, Line Opacity
	Crop / Pad / Aspect Transform	Production Core	Actual crop, scale-to-aspect, and padding transform for fitting source pictures into delivery frames.	Crop Left, Crop Right, Crop Top, Crop Bottom, Target Aspect, Zoom, Pad Opacity, Show Bounds, Pad Red, Pad Green, Pad Blue
	CRT Monitor	Retro / Analog	CRT-style curvature, scanlines, phosphor mask, vignette, and mild highlight bloom.	Curvature, Scanlines, Phosphor Mask, Vignette, Glow
	Deinterlace Line Blend	Video Repair	Simple line-blend deinterlace preview for interlaced or combed source material.	Blend, Field Parity, Show Processed Lines
	Digital Glitch	Retro / Analog	Block displacement, RGB drift, and random corruption inspired by OBS glitch filters.	Amount, Block Height, Speed, Color Drift
	Directional Blur	Blur / Detail	Linear motion-style blur in any direction.	Distance, Angle, Mix
	Drop Shadow	Graphics / Layout	Offset dark shadow based on alpha or luma. Works best on keyed/graphic sources, but can stylize full-frame video too.	Offset X, Offset Y, Softness, Opacity
	Dual Zebra Exposure	Camera Assist	Two zebra overlays for skin/gray reference and highlight clipping at the same time.	Low Threshold, High Threshold, Opacity, Stripe Size
	Duotone	Stylize	Maps luma between two colors for branded or editorial looks.	Shadow Red, Shadow Green, Shadow Blue, Highlight Red, Highlight Green, Highlight Blue, Mix
	Edge-Adaptive Deinterlace	Production Core	Directional interpolation deinterlace for combed/interlaced sources, preserving edges better than line blend.	Strength, Field Parity, Edge Bias, Show Processed Lines
	Edge Outline / Stroke	Graphics / Layout	Creates an outline from alpha or image edges; useful for keyed people, overlays, and stylized video.	Edge Threshold, Width, Red, Green, Blue, Opacity
	External Overlay Composite	Production Core	Generic second-texture overlay compositor for pipelines that bind an overlay source to texture register t1.	Opacity, Blend Mode, Black Key, Key Softness, Center X, Center Y, Scale X, Scale Y
	False Color Exposure	Camera Assist	Maps luma to false-color exposure bands for fast broadcast/camera checks.	Black Clip, Gray Point, White Clip, Mix
	Focus Peaking	Camera Assist	Highlights high-frequency detail for focus checks on camera feeds.	Threshold, Intensity, Width, Mono Preview
	Halftone	Stylize	Comic-print dot screen driven by image luminance.	Cell Size, Contrast, Color Mode
	HDR-to-SDR Tone Map Preview	Delivery Looks	Simple tone-map preview for high dynamic range or overbright sources displayed in SDR.	Exposure, Shoulder, Saturation, Mix
	Hot Pixel Suppressor	Video Repair	Suppresses isolated bright or dark pixels using a local neighborhood median approximation.	Threshold, Amount
	Improved Chroma Keyer	Keying / QC	Green/blue keyer with similarity, smoothness, edge soften, despill, and matte preview.	Key Red, Key Green, Key Blue, Similarity, Smoothness, Despill, Edge Soften, Matte View
	Lanczos Scale Preview	Production Core	High-quality resampling preview for scale/crop decisions using a tunable Lanczos-style filter.	Scale X, Scale Y, Center X, Center Y, Filter Lobes, Compare Split, Show Bounds, Mix
	Lens Distortion	Creative / Utility	A tunable barrel or pincushion warp based on the original custom shader sample idea.	Power, Zoom, Center X, Center Y
	Letterbox / Pillarbox Matte	Graphics / Layout	Adds clean aspect-ratio mattes for framing checks, previews, or program-style outputs.	Target Aspect, Opacity, Feather, Matte Red, Matte Green, Matte Blue
	Lower-Third Spotlight	Streaming Production	Dims the background while preserving a configurable lower-third or title area.	Top, Bottom, Dim Amount, Feather
	Luma Waveform Overlay	QC / Monitoring	Approximate luma waveform overlay for quick exposure distribution checks.	Overlay Height, Opacity, Sample Density, Background Dim
	Luminance Key	Keying / QC	Creates alpha from brightness for overlays, light leaks, footage masks, and source compositing workflows.	Low Cut, High Cut, Invert, Matte View
	LUT-Style Color Grade	Camera / Program	Single-shader film grade inspired by OBS color/LUT workflows: contrast curve, teal-orange balance, fade, and grain.	Contrast, Teal / Orange, Fade, Grain
	Median Despeckle	Production Core	Median-style spot cleanup for salt-and-pepper noise, sensor speckles, and isolated compression hits.	Threshold, Mix, Always Filter, Show Mask
	Ordered Dither	Stylize	Bayer-style ordered dithering for retro computer, newspaper, and banding-control looks.	Levels, Strength, Monochrome
	Pixelate / Mosaic	Blur / Detail	Fast square mosaic pixelation for privacy, stylized transitions, or low-res looks.	Block Size, Mix
	Posterize	Stylize	Reduces color levels for poster, comic, and low-bandwidth looks.	Levels, Gamma, Mix
	Privacy Region Mosaic	Streaming Production	Pixelates a configurable rectangular region for privacy, passwords, scoreboards, or sensitive feeds.	Center X, Center Y, Width, Height, Block Size, Feather
	RGB Parade Overlay	QC / Monitoring	Approximate RGB parade overlay for channel balance and clipping checks.	Overlay Height, Opacity, Sample Density, Background Dim
	RGB Split / Chromatic Aberration	Optics	Manual or radial channel separation for lens errors, impact hits, and glitch looks.	Amount, Radial, Angle
	Rounded Corners / Mask	Graphics / Layout	Rounds frame corners with optional border and background fill.	Radius, Feather, Border Width, Border Opacity
	Rule of Thirds / Center Cross	Camera Assist	Composition overlay with rule-of-thirds grid, center cross, and optional horizon line.	Grid Opacity, Center Opacity, Line Width, Horizon Line
	Safe Area Guides	Graphics / Layout	Draws action-safe and title-safe overlays for graphics placement and playout checks.	Action Safe, Title Safe, Line Width, Outside Dim, Line Opacity
	Safe Gamut Warning	QC / Monitoring	Highlights RGB/luma values outside configurable legal broadcast bounds.	Low Limit, High Limit, Opacity, Show Legal Only
	Scanlines	Retro / Analog	Animated horizontal scanlines with tunable period, speed, and brightness floor.	Period, Intensity, Speed, Brightness Floor
	Selective Color	Camera / Program	Keeps a chosen hue in color while desaturating the rest, or boosts only the selected hue.	Target Hue, Hue Width, Outside Saturation, Inside Boost
	Sharpen / Detail	Finishing	A lightweight unsharp mask for soft feeds, archive material, and confidence previews.	Amount, Radius, Highlight Protect, Mix
	Skin Tone Assist	Camera Assist	Highlights likely skin-tone hue/luma regions for camera matching and quick white-balance checks.	Target Hue, Hue Width, Opacity, Dim Others
	Thermal / Night Vision	Stylize	Switchable thermal palette and green night-vision look with animated noise.	Thermal Mode, Gain, Noise, Vignette
	Vectorscope Overlay	QC / Monitoring	Approximate vectorscope overlay for hue/saturation distribution checks.	Scope Size, Opacity, Sample Grid, Background Dim
	VHS / Bad TV	Retro / Analog	Tape jitter, chroma offset, head-switching noise, scanline shimmer, and desaturation.	Frame Jitter, Chroma Shift, Noise, Head Switch, Desaturate
	Vignette Focus	Creative	Subtle edge falloff for interviews, studio inserts, and screen content that needs center emphasis.	Strength, Radius, Softness, Center Lift
	White Balance Trim	Camera / Program	Temperature and tint correction for matching camera feeds or fixing mixed lighting in playback.	Temperature, Tint, Vibrance, Preserve Luma
	Zebra Exposure	Camera Assist	Overlays diagonal highlight stripes above a luma threshold for exposure checks.	Threshold, Stripe Size, Opacity, Rolloff
	Zoom Blur	Blur / Detail	Radial zoom blur for impact effects, transitions, and stylized highlights.	Strength, Center X, Center Y, Mix

Some shaders are diagnostic or preview-oriented. For example, the waveform, RGB parade, and vectorscope shaders are useful for visual checks in the sample, but they are not a replacement for engineering-grade measurement scopes. The External Overlay Composite shader expects an additional overlay texture bound to t1; the sample UI loads and tunes the shader, but does not currently provide a second media source to that texture register.

Samples

The original MFormats SDK sample is installed here:

c:\Program Files (x86)\Medialooks\MFormats SDK\Samples\C#\Sample Custom Shader\

The expanded WPF samples in this package are:

• MFormatsShaderLibrary - explicit frame processing sample.
• MPlatformShaderLibrary - plugin object-graph sample.
• shaders - reusable JSON/HLSL shader library.