Hi, Using delphi I am trying to render a directshow clip using a callback function. For ages nothing worked until I realised glDrawPixels does not force opengl to render the pixels. I then saved the frame in a temporary buffer and called refresh. In the Opengl draw method I used glDrawPixels to draw the frame from the temporary buffer. This works fine but how can I avoid the copy. Is there a way to force opengl to render without forcing a paint.