Наложение текста на предварительный просмотр веб-камеры с помощью directshow

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Привет
Как вы накладываете изображения/текст на предварительный просмотр веб-камеры?

Предварительный просмотр кода:

    Enum PlayState
        init
        stopped
        paused
        running
    End Enum
 
    Dim currentState As PlayState = PlayState.stopped
 
    Dim d As Integer = Convert.ToInt32("0X8000", 16)
    Dim WM_GRAPHNOTIFY As Integer = d + 1
    Dim videoWindow As IVideoWindow = Nothing
    Dim mediaControl As IMediaControl = Nothing
    Dim mediaEventEx As IMediaEventEx = Nothing
    Dim graphBuilder As IGraphBuilder = Nothing
    Dim captureGraphBuilder As ICaptureGraphBuilder2 = Nothing
    Dim rot As DsROTEntry = Nothing
 
Private Sub startPreview()
 
        Dim sourceFilter As IBaseFilter = Nothing
 
        graphBuilder = CType(New FilterGraph, IGraphBuilder)
        captureGraphBuilder = CType(New CaptureGraphBuilder2, ICaptureGraphBuilder2)
        mediaControl = CType(graphBuilder, IMediaControl)
        videoWindow = CType(graphBuilder, IVideoWindow)
        mediaEventEx = CType(graphBuilder, IMediaEventEx)
        mediaEventEx.SetNotifyWindow(Me.Handle, WM_GRAPHNOTIFY, IntPtr.Zero)
        captureGraphBuilder.SetFiltergraph(graphBuilder)
        sampGrabber = CType(New SampleGrabber, ISampleGrabber)
        baseGrabFlt = CType(sampGrabber, IBaseFilter)
 
        Dim classEnum As IEnumMoniker = Nothing
        Dim moniker As IMoniker() = New IMoniker(0) {}
        Dim source As Object = Nothing
        Dim devEnum As ICreateDevEnum = CType(New CreateDevEnum, ICreateDevEnum)
        devEnum.CreateClassEnumerator(FilterCategory.VideoInputDevice, classEnum, 0)
        Marshal.ReleaseComObject(devEnum)
 
        If classEnum Is Nothing Then Throw New ApplicationException("No camera detected")
 
        If classEnum.Next(moniker.Length, moniker, IntPtr.Zero) = 0 Then
            moniker(0).BindToObject(Nothing, Nothing, GetType(IBaseFilter).GUID, source)
        Else
            Throw New ApplicationException("Detected camera is inaccessible")
        End If
 
        Marshal.ReleaseComObject(moniker(0))
        Marshal.ReleaseComObject(classEnum)
 
        sourceFilter = CType(source, IBaseFilter)
 
        graphBuilder.AddFilter(sourceFilter, "Video Capture")
        captureGraphBuilder.RenderStream(PinCategory.Preview, MediaType.Video, sourceFilter, Nothing, Nothing)
        Marshal.ReleaseComObject(sourceFilter)
 
        videoWindow.put_Owner(CAM1.Handle)
        videoWindow.put_WindowStyle(WindowStyle.Child Or WindowStyle.ClipChildren)
        videoWindow.SetWindowPosition(0, 0, CAM1.Width, CAM1.Height)
        videoWindow.put_Visible(OABool.True)
 
        rot = New DsROTEntry(graphBuilder)
        mediaControl.Run()
        currentState = PlayState.running
 
    End Sub

Что я уже пробовал:

Глядя на несколько форумов, весь код написан на C++

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