C#

------------ FrameGrabber ----------------

  static object m_obj = new object()
  Bitmap CurrentBitmap = null;

   // setting the member variable......... this is accessed in MainForm
   public Bitmap CurrentFrame
   {
       get
       {
           Bitmap bmp = null;
           try
           {
               lock (m_obj)
               {
                   if (CurrentBitmap != null)
                       bmp = new Bitmap(CurrentBitmap);
               }
           }
           catch (Exception ex)
           {
       MessageBox.Show(ex.Message);
           }
           return bmp;
       }
   }

 // whenever an event is raised with new image - i set the CurrentBitmap
  private void OnNewFrame(Frame frm)
  {
       Bitmap current_bitmap = new Bitmap(frm.Image);

       lock (m_obj)
       {
           if (current_bitmap != null)
           {
               if (DateTime.Now.Subtract(LastFrameSendTime).TotalMilliseconds >= FrameDelay)
               {
                   LastFrameSendTime = DateTime.Now;
                   CurrentBitmap = new Bitmap(current_bitmap);
               }
           }
       }
  }

------------ MainForm ----------------

                   bool isplaying = objFrameGrabber.Player.IsPlaying;
                   while ((isplaying))
                   {
                       Bitmap current_frame = objFrameGrabber.CurrentFrame;
                       while ((current_frame == null)
                       {
                           System.Threading.Thread.Sleep(10);
                           current_frame = objFrameGrabber.CurrentFrame;
                       }

                       // AND HERE COMES THE EXCEPTION

                       picLiveVideo.Image = current_frame;
                   }

public class DSS
{
  // implement functionality, methods, etc. including:
  public ITSF TSF { get; private set; }
}
public interface ITSF
{
  string Prop1 { get; set; }
  // etc.
}

[ComVisible(false)]
public class DSS
{
  // implement functionality, methods, etc. including:
  public ITSF TSF { get; private set; }
}
[Guid("...")]
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
public interface ITSF
{
  string Prop1 { get; set; }
  // etc.
}

[Guid("...")]
[ClassInterface(ClassInterfaceType.None)]
public class DSScom : DSS, IDSS
{
  // implement functionality, methods, etc. including:
  public ITSF TSF { get; private set; }
}
[Guid("...")]
[InterfaceType(ComInterfaceType.InterfaceIsIDispatch)]
public interface IDSS
{
  ITSF TSF { get; }
  // etc.
  // Different methods from the DSS class
}