Getting Pulseaudio and alsa to share one sound card

[Richard Reina]

I have a Raspberry Pi 3b with a Hifiberry Amp4/DAC hat runs Moode Audio OS.

If I pick Pulse as they audio device in LedFx and play a sound file with aplay
sound_file.wav my leds react to the music.

The problem is that after aplay has finished playing the sound file if I
then go try to use Moode audio player Moode audio won't play music and
gives me the following error:

MPD error Failed to open "ALSA Default" (alsa); Failed to open ALSA device
"_audioout": Device or resource busy

This persists until I stop Ledfx. Is there a way I can switch back and
forth between aplay and Moode Audio player without having to stop and start
Ledfx? I am not looking to get LedFx working with Moode I only want
reactive lights when I play a song with aplay.

$ aplay -l

**** List of PLAYBACK Hardware Devices ****

card 0: sndrpihifiberry [snd_rpi_hifiberry_dacplus], device 0: HiFiBerry
DAC+ HiFi pcm512x-hifi-0 [HiFiBerry DAC+ HiFi pcm512x-hifi-0]

Subdevices: 0/1

Subdevice #0: subdevice #0

$ amixer
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 65536
  Mono:
  Front Left: Playback 65536 [100%] [on]
  Front Right: Playback 65536 [100%] [on]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch cswitch-joined
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 65536
  Front Left: Capture 65536 [100%] [on]
  Front Right: Capture 65536 [100%] [on]
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/pulseaudio-discuss/attachments/20240507/1f252226/attachment.htm>