   Can I set backbuffer larger than screen for capturing video?
  I need to capture video from my Direct 3D application. I set windowed mode and backbuffer according to size of AVI video. For example 1280x960. But my screen is only 1024x768. Is it correct? It works on my PC, but I'm afraid some video card may prohibit setting of backbuffer size larger than screen size in windowed mode.   
  The back buffer needs to be the same size as the display. But you can create a larger render target and use it independent from the screen resolution.   ;  But it's not a fullscreen mode. Backbuffer can be any according size of window.   