I haven't seen USB-C adapters (though they are bound to exist). The USB-A to Ethernet adapters I've seen usually have come in pairs as you convert USB to Ethernet, transport over Ethernet, then at PC use another adapter to convert back to USB for connection to computer. If converting from USB to Ethernet on a LAN, then getting that signal/data/ {video stream in your case} would typically depend on proprietary software from the company providing the physical adapter to connect to ethernet data and convert back into something PC could use