Google Analog mux, for example 74HC4051. Use a Pic and muxes to switch things as you want. Maybe 4051 is not the best for you in this case because of fairly high ON resistance but the idea is the same. Use the control pins to select input and the signal is connected to the output pin. 4053 is a dual mux and will make it really easy to connect video and audio if you see a need for it.