No audio output for FPP 10.0 Beta 3 w/Pipewire Simple #2811

FPP v10.0-beta3 on a Kulp K128D-B with Beagle Bone Black

Describe the bug and Steps to reproduce:

1. Flash an SD card with FPP 10.0 Beta 3
2. After booting up FPP, connect to the web UI, set no FPP and OS password, set the host name to FPPtesting, set the local time zone, and accept all other default settings.
3. In FPP, navigate to Help > System Health Check. Confirm all checks show green with no issues.
4. In FPP, navigate to Content Setup > File Manager, then select the Audio tab.
5. Upload an mp3 music file.
6. Connect headphones to the 3.5 mm on-board stereo plug on the K128D-B cape.
7. Reboot FPP
8. In FPP, navigate to Status Control > Status Page, set the volume to 100, and select the uploaded mp3 file and play it.
9. No audio is output.

In a related test of audio over FM transmission:

1. In FPP, navigate to Content Setup > Plugin Manager, and select the Audio category.
2. Install the Si4713/Vast V-FMT212R plugin.
3. Navigate to Input/Output Setup > Vast V-FMT212.
4. Set the following settings:

Connection: I2C
Reset GPIO: P8-29 (GPIO: 1/23)
enable volume hack: yes
Frequency: 90.5 FM
Power: 115 db microvolts
Preemphassis: 75 us
Antenna tuning capacitor: 0
audio limiter: off
audio compression: off
audio compression threshold: -15
audio gain: 16
RDS: enabled

5. Connect headphones to the 3.5 mm stereo plug on the Vast V-FMT212 expansion board.
6. Reboot FPP
7. In FPP, navigate to Status Control > Status Page, set the volume to 100, and select the uploaded mp3 file and play it.
8. No audio is output via the 3.5 mm stereo plug or via FM transmission.

Expected behavior:
In FPP v9.5.3-13-g0c739f63d, the same settings documented above with the same testing methodology produce the expected audio output to the 3.5 mm stereo plugs on both the K128D-B main board and the Vast V-FMT212 expansion board. The expected audio is also heard via FM transmission.

Additional context:
It may be related that when rebooting FPP 10.0 Beta 3 for the first time before testing the K128D-B's onboard 3.5 mm stereo plug for audio, the Help > System Health Check page reported this error:

PipeWire Audio: not running
The PipeWire audio stack needs attention. Restarting the audio services will bounce PipeWire and reconnect the media pipeline.

The System Health Check page offered a 'Restart Audio Services' button in the error message described above, but each attempt to restart it via this button caused the error to re-appear after an FPP restart. A reboot of FPP seemed to clear this error, even though no audio was output via either of the 3.5 mm stereo plugs or via FM transmission following the reboot.

Additional Attachments

• The health-check-page.png screen shot attached to this issue shows the PipeWire Audio error on the System Health Check page.
• The fpp-audio-video-settings.png screen shot attached to this issue shows all of the FPP audio/video settings in effect at the time of the tests. With the change to PipeWire Audio in FPP 10.0, it may not be applicable, but in FPP 9.5.x, the 'Audio Output Mixer Device' used to be set to 'PCM' by default. However, in 10.0, this field no longer contains any value to select.