How to transmit video broadcast from multiple sources to multiple monitors in random order?

Question

Video broadcast

Given: several sources of video broadcasts over IP (IP1, IP2, IP3).
Required: display the image on 4 monitors (M1, M2, M3, M4) in random order.
As an example:
On M1, M2 output IP2.
Display IP3 on M3.
On M4 output IP1.
Standard KVM is not suitable for such forwarding. Virtualization will slow down.
As an option - to put on each monitor on a nettop?
Any other suggestions?