Getting a video input as a full screen background

Hi Guys

I am trying to use Unreal as a TV production AR renderer, a bit like VizRT but better.

I have succeded in getting a live video feed mapped onto a surface but what I really need to do is have the live video act as a full frame background so that I can then put the virtual assets in front.

I have tried to find a way of a HUD widget behind everything else but cannot get that to work and my efforts with getting billboards to follow the camera dont really work and seem a bit of a cludge.

Am I missing something obvious, can you help.

Many thanks


Can you tell me how you got the live video input into Unreal? I have a matrox card that is feeding the video.