NickeManarin/ScreenToGif · error · Exception

DirectShow SampleGrabber not installed/registered!

Error message

DirectShow SampleGrabber not installed/registered!

What it means

CaptureWebcam.CreateGraph needs the DirectShow SampleGrabber COM filter. It calls Type.GetTypeFromCLSID(Uuid.Clsid.SampleGrabber); if that returns null (the COM class is not registered), it throws. The SampleGrabber lives in qedit.dll and is part of the legacy DirectShow runtime.

Source

Thrown at ScreenToGif/Webcam/DirectX/CaptureWebcam.cs:260

        {
            //Make a new filter graph.
            GraphBuilder = (ExtendStreaming.IGraphBuilder)Activator.CreateInstance(Type.GetTypeFromCLSID(Uuid.Clsid.FilterGraph, true));

            //Get the Capture Graph Builder.
            var clsid = Uuid.Clsid.CaptureGraphBuilder2;
            var riid = typeof(ExtendStreaming.ICaptureGraphBuilder2).GUID;
            CaptureGraphBuilder = (ExtendStreaming.ICaptureGraphBuilder2)Activator.CreateInstance(Type.GetTypeFromCLSID(clsid, true));

            //Link the CaptureGraphBuilder to the filter graph
            var hr = CaptureGraphBuilder.SetFiltergraph(GraphBuilder);

            if (hr < 0)
                Marshal.ThrowExceptionForHR(hr);

            var comType = Type.GetTypeFromCLSID(Uuid.Clsid.SampleGrabber);

            if (comType == null)
                throw new Exception("DirectShow SampleGrabber not installed/registered!");

            var comObj = Activator.CreateInstance(comType);
            SampGrabber = (EditStreaming.ISampleGrabber)comObj; comObj = null;

            _baseGrabFlt = (CoreStreaming.IBaseFilter) SampGrabber;

            var media = new CoreStreaming.AmMediaType();

            //Get the video device and add it to the filter graph
            if (VideoDevice != null)
            {
                VideoDeviceFilter = (CoreStreaming.IBaseFilter)Marshal.BindToMoniker(VideoDevice.MonikerString);

                hr = GraphBuilder.AddFilter(VideoDeviceFilter, "Video Capture Device");

                if (hr < 0)
                    Marshal.ThrowExceptionForHR(hr);

View on GitHub (pinned to a4d0a67c21)

Solutions

1. Install the Media Feature Pack (N/KN editions) or enable the Desktop Experience / Media Foundation feature on Server.
2. Re-register qedit.dll: run `regsvr32 %SystemRoot%\System32\qedit.dll` from an elevated prompt.
3. Run `sfc /scannow` to restore missing system binaries.
4. If webcam capture is optional, disable the webcam feature until the runtime is repaired.

Example fix

// before
var comType = Type.GetTypeFromCLSID(Uuid.Clsid.SampleGrabber);
if (comType == null)
    throw new Exception("DirectShow SampleGrabber not installed/registered!");

// after
var comType = Type.GetTypeFromCLSID(Uuid.Clsid.SampleGrabber);
if (comType == null)
    throw new Exception("DirectShow SampleGrabber not installed/registered. Install the Media Feature Pack (N editions) or run: regsvr32 %SystemRoot%\\System32\\qedit.dll");

var comType = Type.GetTypeFromCLSID(Uuid.Clsid.SampleGrabber);
if (comType == null)
    // surface a user message: install Media Feature Pack or run regsvr32 qedit.dll
return comType != null;

static bool IsSampleGrabberRegistered => Type.GetTypeFromCLSID(Uuid.Clsid.SampleGrabber) != null;

try { CreateGraph(); }
catch (Exception ex) when (ex.Message.Contains("SampleGrabber"))
{ /* instruct user to install Media Feature Pack / register qedit.dll */ }

When it happens

Trigger: Selecting a webcam device when qedit.dll (which registers the SampleGrabber CLSID) is missing or unregistered on the machine.

Common situations: Windows N / KN editions without the Media Feature Pack; Windows Server without Desktop Experience / Media Foundation; qedit.dll removed or unregistered by a cleanup tool; older qedit.dll never registered on a stripped Windows image.

Related errors

• Windows 8 or newer is required for capturing the screen usin

AI-assisted analysis of NickeManarin/ScreenToGif@a4d0a67c21 (2026-08-13). Data as JSON: /api/errors/cd76c2239e556a88. Report an issue: GitHub.