When we, as the Sooloos team, were acquired by Meridian back in 2008, we proposed this exact product. We called it “the input device” – for example, take your record player’s analog output and route it around your home, and zone group it, etc… basically take telephony (point to point wires) and network it (packetize + route). As you can see, that project went nowhere because we never could get our acquirers to move on such weird hardware.
With Roon, it makes even more sense. There is a realtime nature to the audio, but we have that already with internet radio streaming.
I’ll bring it up with @brian and we can probably get it added to the roadmap now… it’d be pretty sweet to use a USB input on a RPi or Cubox to pull this off.
There is also the solution of a virtual sound card… but I’ve never seen it done right. Devialet’s AIR is a perfect example of what a disaster that solution can be.