player.WhenFrame = THISBACK(OnFrame);            // OnFrame user function to be called every time there is a new video frame
...
void OnFrame(SDLSurface &surface) {                // SDLSurface is a new class to handle SDL painting. surface includes the video frame bitmap
    ImageDraw iw(100, 40);                        // Sample U++ paint
    iw.DrawEllipse(0, 0, 100, 40, Green());
    iw.DrawText(35, 10, "U++", Arial(18).Bold(), Black()); 
    
    surface.Lock();    
    surface.DrawImage(iw, 20, 20, Black());        // Copy the drawn U++ to SDL
    surface.DrawLine(0, 0, surface.GetWidth(), surface.GetHeight(), White());    // Directly draw other things
    surface.Unlock();
}