No, this isn't a thing with JRiver. It's not even really a thing outside of the professional realm.
Video over IP at high fidelity is somewhat impractical still. However, audio over IP is very doable.
I transport all my audio over IP. A PC in a rack renders video (directly connected via 100ft fiber optic active HDMI 2.1) to the theater display, and the audio is sent out over IP (so just cat5) to a tiny fanless system located in my audio rack, which then feeds D/A to get audio out. This also means that my main workstation can similarly send it's audio over IP to either the main surround rig, or a headphone endpoint simultaneously.
If you have no need for that sort of flexibility or are working with a receiver, I highly recommend just running a decent active fiber optic HDMI and calling it a day.
Addendum: Yes, you can transport video over IP no problem, but you're using JRiver to get the best video quality possible, that means that compression or chroma subsampling applied is going to remove many of the benefits of using JRiver. Video is very high bitrate, audio, audio is easy. You can sling around 64-128 channels no problem.