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c#directshowdirectshow.net

facing issue of "Parameter is not valid" inside BufferCB


I am creating desktop recording (screen recording) application using Directshow.NET and C#. I am almost done, application is able to record desktop screen. To paint mouse pointer in recording video I have implemented BufferCB from SampleGrabber and with the help of my another post Fliped cursor icon on desktop recording using directshow i am able to paint mouse pointer in correct orientation

Here is my code of BufferCB :

[System.Security.Permissions.SecurityPermission(
System.Security.Permissions.SecurityAction.LinkDemand, Flags =
System.Security.Permissions.SecurityPermissionFlag.UnmanagedCode)] 
int ISampleGrabberCB.BufferCB(double SampleTime, IntPtr pBuffer, int BufferLen)
{
    if (!wait)
    {
        wait = true;
        Rectangle imageBounds = new Rectangle(0, 0, m_videoWidth, m_videoHeight);
        Bitmap bitmap = new Bitmap(m_videoWidth, m_videoHeight, System.Drawing.Imaging.PixelFormat.Format24bppRgb);
        System.Drawing.Imaging.BitmapData bitmapData = bitmap.LockBits(imageBounds, System.Drawing.Imaging.ImageLockMode.ReadWrite, bitmap.PixelFormat);
        IntPtr ptr = bitmapData.Scan0;
        bitmap.UnlockBits(bitmapData);
        CopyMemory(ptr, pBuffer, (uint)BufferLen);
        bitmap.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipY);
        using (Graphics g = Graphics.FromImage(bitmap))
        {
            CURSORINFO cursorInfo;
            cursorInfo.cbSize = Marshal.SizeOf(typeof(CURSORINFO));

            if (GetCursorInfo(out cursorInfo) && cursorInfo.flags == CURSOR_SHOWING)
            {                        
                IntPtr iconPointer = CopyIcon(cursorInfo.hCursor);
                ICONINFO iconInfo;
                int iconX, iconY;
                if (GetIconInfo(iconPointer, out iconInfo))
                {
                    // calculate the correct position of the cursor
                    iconX = cursorInfo.ptScreenPos.x - ((int)iconInfo.xHotspot);
                    iconY = cursorInfo.ptScreenPos.y - ((int)iconInfo.yHotspot);

                    //GETTING ARGUMENTEXCEPTION AT BELOW LINE                                
                    IntPtr hdc = g.GetHdc();
                    DrawIcon(hdc, iconX, iconY, cursorInfo.hCursor);                                
                    g.ReleaseHdc(hdc);                                
                }                        
            }
            g.DrawImage(companylogo, m_videoWidth - 100 , 20);
        }
        bitmap.RotateFlip(System.Drawing.RotateFlipType.RotateNoneFlipY);
        bitmapData = bitmap.LockBits(imageBounds, System.Drawing.Imaging.ImageLockMode.ReadWrite, bitmap.PixelFormat);
        ptr = bitmapData.Scan0;
        bitmap.UnlockBits(bitmapData);                
        CopyMemory(pBuffer, ptr, (uint)BufferLen);
        bitmap.Dispose();
        wait = false;
    }
    return 0;
}

Mouse pointer is getting paint on video but after some time of recording I am getting ArgumentException "Parameter is not valid." at line of code IntPtr hdc = g.GetHdc();

Can anyone help me put to solve this?

StackTrace:
at System.Drawing.Graphics.GetHdc()


Solution

  • Look at the answer in this question. They discuss the same error message.