Mac VM (guest) + Linux (host) + BlackHole = route audio to Linux

[avently]

Hello. Thank you for your hard work.
I'm trying to play audio from Mac (running in Qemu virtual machine) by using virtual output audio channel made by BlackHole. The VM is running from Linux host. The idea is to route that virtual audio channel to local Linux host. Guest Mac is accessible via network from host so I can setup SSH connection with port forwarding if needed.

For now when I run shairport-sync with default config I don't see an option to share sound to host via Airplay menu on Mac (top right corner in menu). However I see that there is an option to do it from Music app on Mac but it fails to connect to the host when I choose the host name in that Music app.

I don't have any firewalls so everything should just work if I'm able to preperly setup both sides (guest and host).

Can you suggest me a configuration that will achive the idea?

[mikebrady]

Thanks for this interesting question. There are many unknowns in it, so I think the approach would be to check each piece separately as much as possible.

If you set Shairport Sync's log_verbosity to 1 and enable the gathering of statistics, you should be able to see if it is receiving and attempting to play audio.

VMs typically don't do real-time timing very well, and this may be stopping synchronisation from working and thus causing the output to remain silent. To avoid this, it might we worth using a backend that doesn't attempt to do active synchronisation, so a backend like the stdout or the unix pipe backend might be preferable to the alsa backend.

The "Discovery" apps on Mac and iOS should help to see if Shairport Sync is correctly advertised and visible in Bonjour on the network, as will avahi-browse on the Linux device.