Decklink Alpha channel

Hi,

I would like to understand how complex it is to output semi-transparent graphic and text to a decklink card to be overlaid by a downstream keyer? I have many year of coding experience with many languages but no experience in directshow.

For ex. will this code output a semi transparent Hello text that could be overlay by a downstream keyer or it's a lot more complex than that?

Code: Select all

   void DrawStringPointF( PaintEventArgs^ e )
   {
      String^ drawString = "Hello";

      System::Drawing::Font^ drawFont = gcnew System::Drawing::Font( "Arial",16 );

      Color customColor = Color::FromArgb( 50, Color::Gray );
      SolidBrush^ shadowBrush = gcnew SolidBrush( customColor );

      PointF drawPoint = PointF(150.0F,150.0F);

      e->Graphics->DrawString( drawString, drawFont, shadowBrush, drawPoint );
   }

Thanks,