I'm designing a Raspberry Pi -based LED visualization wall that can, for example, display the frequency spectrum of the sound output of another computer. The logical choice would be to use PulseAudio for monitoring the audio over LAN.
There's a problem, though. I can easily play audio from one computer to another and also record a remote mic input, so there's nothing wrong with my basic setup, but for some reason I fail to record the monitor source that should provide a mix of all audio played on the remote computer. I can even see the remote monitor source on the input list of PulseAudio Volume Control (pavucontrol), but all I get is silence when it's selected for recording. Locally the monitor source works OK. The sink is a HDMI output with regular stereo PCM, not AC3/DTS passthrough.
Am I missing something essential here? Is network access to monitor sources prevented for some reason?
If there's a solution to this, I'd be happy to see a CLI alternative too, as that's what I'll primarily need for my project.
I've used up all my Google-fu with no success, but I'd be surprised if nobody has done this before.
Update: Added output of pacmd list-sources | grep name:
as requested. Tunneled items are listed twice because of IPv6, but that's not a problem.
name: <alsa_output.pci-0000_00_1b.0.analog-stereo.monitor>
name: <alsa_input.pci-0000_00_1b.0.analog-stereo>
name: <tunnel.mediacenter.local.alsa_input.pci-0000_00_14.2.analog-stereo>
name: <tunnel.mediacenter.local.alsa_input.pci-0000_00_14.2.analog-stereo.2>
name: <tunnel.mediacenter.local.alsa_output.pci-0000_01_00.1.hdmi-stereo.monitor>
name: <tunnel.mediacenter.local.alsa_output.pci-0000_00_14.2.iec958-stereo.monitor>
name: <tunnel.mediacenter.local.alsa_output.pci-0000_01_00.1.hdmi-stereo.2.monitor>
name: <tunnel.mediacenter.local.alsa_output.pci-0000_00_14.2.iec958-stereo.2.monitor>
pacmd list-sources | grep name:
, so we get a better idea which devices are attached.