HDMI audio output pi 5

[bjh]

Is HDMI audio supported on a headless raspberry pi 5 running RoonBridge? I cannot get audio to work even though system audio, and other audio applications (Plexamp) do work. Roon does show the device as an endpoint but says “too many errors” when I try to play to it.

HDMI audio not working on headless Raspberry Pi 5 with Roon (ref#9HNHUE)

What best describes your playback issue? · Music doesn't start when I press "Play" What type of Zone is affected by this problem? · *Network Zones* are affected. Is the affected network Zone connected with Ethernet or WiFi? · WiFi Does the issue affect all file formats? · The issue affects *multiple/all* file formats. Does the issue happen with local library music, streaming service music, or both? · *Only local library *music is affected. Where is your local content stored? · On the sam…

[Erik_Squires]

I just found the fix to this. Look inside /var/roon/RAATServer/Settings. You’ll find a JSON file for each HDMI device. It will look like this:

{“unique_id”: “617c2b7a-8bf6-18d6-0243-1e918a7e673c”, “external_config”: {}, “output”: {“name”: “vc4-hdmi-1”, “type”: “alsa”, “device”: “hw:CARD=vc4hdmi1,DEV=0”, “dsd_mode”: “none”}, “volume”: {“type”: “alsa”, “device”: “hw:CARD=vc4hdmi1,DEV=0”}}

There are 2 places where it says “hw:CARD=vc4hdmi…” replace the “hw” at the beginning of the string with “hdmi” . Here’s my final version:

{“unique_id”: “617c2b7a-8bf6-18d6-0243-1e918a7e673c”, “external_config”: {}, “output”: {“name”: “vc4-hdmi-1”, “type”: “alsa”, “device”: “hdmi:CARD=vc4hdmi1,DEV=0”, “dsd_mode”: “none”}, “volume”: {“type”: “alsa”, “device”: “hdmi:CARD=vc4hdmi1,DEV=0”}}

Also worth noting that when you get it working the Pi 5 has 32 bit audio posssible, which the pi 4 seemed to only get to 16.

The problem is caused by hw:CARD being a raw device, which does NOT talk PCM, but the RAATServer wants to talk PCM, which is why the virtual ALSA device, hdmi:CARD, works.

Eseentially for whatever reason RAATServer is enumerating the raw devices for HDMI when it should be using the ALSA devices instead. I would definitely call this an intallation bug.