Help needed. Start & stop ingame video with changing textures

The project is just one room. A presentation for an event.

My problem:
I have 5 screens in the room. At the start of the game, simple textures with logos should be visible on the screens. When a key is pressed, the same video should start on all five screens. The video runs in a loop, but should be able to be stopped at any time and the original textures should reappear.

Any help would be very appreciated.

tia,
urig