Getting hdmi signal of a camera to TCP/IP network and read on computer
I think that the best way to go is to use a mixer like the BlackMagic ATEM-series. I am working in a film-studio and have worked mainly with the ATEM Television Studio HD Mixer, which has all the capabilities you would want.
Mixers like these have SDI/BNC and HDMI inputs and are capable of mixing and converting each signal, using lower-thirds, live-keying (if you want to use a webcam with greenscreen) and much more. Yes, they are expensive, but if you're serious about this I would highly recommend it. You will have a better signal than through Wifi streaming or wireless transmissions...