I have successfully set up a 3 device multi-room audio setup.
My living room is connected through HDMI to our TV, which is then forwarded to our soundbar using ARC.
And this works! Awesome, whenever I want to extend the multi-room synced sound to the living room, I just connect to the PI4 BalenaSound HDMI source on my TV and get sound.
However, I am a bit finnicky about still images on a TV (to avoid etc burnins). Is there a way I can change this image to something else? (Like a black image, in hopes of my OLED to turn of the pixels).
Or dont transmit video, but transmit audio?