My Raspberry Pi (Pi 1 model B) is connected to a 5.1 analog sound system through an USB sound card (Asus Xonar U7).
I added a bluetooth dongle and bluealsa to the Pi to turn it into an audio device, so other devices such as Android and iOS phones / tablets can stream music to it. I used this guide to set it all up: https://gist.github.com/mill1000/74c7473ee3b4a5b13f6325e9994ff84c
This is working fine for music, which is usually stereo, but now I also want the Pi to act as a 5.1 audio device for the PC on which I watch TV and stream video.
The PC (Windows 10 Home) can see the bluetooth-enabled Raspberry Pi, but thinks it's a stereo headset. What would I have to change on the Raspberry Pi to make it advertize itself as a 5.1 capable audio device over bluetooth?
I tried different bluetooth device classes that the Pi advertizes, but that didn't change anything about the fact that Windows thinks it's only stereo.
The Pi definitely is able to output 6-channel audio to the sound system; I successfully set up stereo to 5.1 upmix via /etc/asound.conf, but in the end that's not what I want because I would lose the surround effect.
The 5.1 audio from TV / Netflix on the PC should go over bluetooth to the Pi and from there to the speakers, without being mixed up or down in-between. Is that possible?