[raron]

> You won't be able to source any kind of protocol translation chip

I think many of those chips are simple off-the-shelf parts. Probably you would need special licenses only to decode HDCP.

If you have an FPGA, you could even create valid Ethernet frames and send the data / video stream over any standard switch / media converter as long as you have enough bandwidth and no packet loss. (10G would be enough for FullHD and 25G for 4K if you make it a bit smarter and can strip the blanking interval.)