Compositing (viewing background scene)

I wish to composit an object on top of some footage. I have already done the camera matching in icarus. In blender the object is built but the animation is yet to be built. The 'background footage is an avi. Is it possible to have this show in the 3d work window and change frames as i do as i build the animation?

ok maybe i should say, i read previous posts on this subject and i know how to display a particluar frame of a movie at render. What i would like is to be able to see that movie update itself within the 3d window. I am creating the animation that sits on top of the video and the movement of the 3d object is related to an object moving in the video.


video tut down bottom.

Hopefully someone else will this useful

Definitely. Thank you.
Helped me a ton