Dummy sound card volume

[jflatt]

I have a receiver that doesn't have an on-screen display. The receiver is also tucked away in a nook behind the TV, so when I change the volume, I can only tell if its changing by listening. I currently have myth configured with external volume, and I have a Pulse-Eight USB HDMI CEC dongle. What I'd like to do is use MythTV's on-screen volume to show. Would it be possible to create a dummy soundcard module, tie MythTV internal volume control to the dummy soundcard, and sync the volumes to my AVR via CEC commands? Anybody have some scripts that would already handle this?