Getting Pulseaudio and alsa to share one sound card

Georg Chini georg at chini.tk
Tue May 7 19:59:51 UTC 2024


Hi,

mh, looks like you have a problem then. Pulseaudio exclusively opens the 
sound devices, so
if the player cannot be configured to use the alsa default device, it 
will not work. You could
try using dmix (https://wiki.archlinux.org/title/PulseAudio chapter 
5.1.3, just used Google,
did not check the content)

The only other option left is to start the player with pasuspender, but 
then again ledfx won't
work while the player is active.

Regards
                Georg

On 07.05.24 21:50, Richard Reina wrote:
> $ aplay -L
> null
>     Discard all samples (playback) or generate zero samples (capture)
> default
>     Playback/recording through the PulseAudio sound server
> lavrate
>     Rate Converter Plugin Using Libav/FFmpeg Library
> samplerate
>     Rate Converter Plugin Using Samplerate Library
> speexrate
>     Rate Converter Plugin Using Speex Resampler
> jack
>     JACK Audio Connection Kit
> oss
>     Open Sound System
> pulse
>     PulseAudio Sound Server
> upmix
>     Plugin for channel upmix (4,6,8)
> vdownmix
>     Plugin for channel downmix (stereo) with a simple spacialization
> _audioout
> _audioout__
> alsaequal
> plug_alsaequal
> btstream
> camilladsp
> crossfeed
> plug_bs2b
> eqfa12p
> plug_eqfa12p
> invpolarity
> trx_send
> hw:CARD=sndrpihifiberry,DEV=0
>     snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
>     Direct hardware device without any conversions
> plughw:CARD=sndrpihifiberry,DEV=0
>     snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
>     Hardware device with all software conversions
> sysdefault:CARD=sndrpihifiberry
>     snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
>     Default Audio Device
> dmix:CARD=sndrpihifiberry,DEV=0
>     snd_rpi_hifiberry_dacplus, HiFiBerry DAC+ HiFi pcm512x-hifi-0
>     Direct sample mixing device
> usbstream:CARD=sndrpihifiberry
>     snd_rpi_hifiberry_dacplus
>     USB Stream Output
>
> El mar, 7 may 2024 a las 14:44, Georg Chini (<georg at chini.tk>) escribió:
>
>     Hi,
>
>     so what's the output of aplay -L?
>
>     Regards
>                    Georg
>
>     On 07.05.24 21:12, Richard Reina wrote:
>>     Hello Georg, Thank you for the reply. Yes Moode accesses alsa
>>     directly and unfortunately there is no option for making it use
>>     pulse.
>>
>>     El mar, 7 may 2024 a las 13:33, Georg Chini (<georg at chini.tk>)
>>     escribió:
>>
>>         Hello,
>>
>>         maybe you don't have the alsa config for pulseaudio. Normally
>>         aplay -L
>>         shows that the default device points to pulse:
>>
>>         null
>>             Discard all samples (playback) or generate zero samples
>>         (capture)
>>         default
>>             Playback/recording through the PulseAudio sound server
>>
>>         ...
>>
>>         pulse
>>             PulseAudio Sound Server
>>
>>         ...
>>
>>         I guess the Moode audio player tries to access the ALSA
>>         device directly
>>         and fails because the device is already in use by pulseaudio.
>>         There might
>>         also be a configuration option in the player to make it use
>>         pulse.
>>
>>         Regards
>>                       Georg
>>
>>         On 07.05.24 18:34, Richard Reina wrote:
>>>         Yes it's a requirement. Setting the audio device to pulse in
>>>         Ledfx is the only way it will work.
>>>
>>>         El mar, 7 may 2024 a las 11:21, Mark Gaiser
>>>         (<markg85 at gmail.com>) escribió:
>>>
>>>             Have you tried changing your device in ledfx to pulse?
>>>             https://ledfx.readthedocs.io/en/latest/directing_audio.html
>>>
>>>             Again no idea if this works, I don't know nor use ledfx
>>>             :) Just trying to help out.
>>>
>>>             On Tue, May 7, 2024 at 6:14 PM Richard Reina
>>>             <gatorreina at gmail.com> wrote:
>>>
>>>                 Hi Mark,
>>>
>>>                 Thank you for the reply.  paplay also works but
>>>                 there's no change. It's not the playing of the song
>>>                 that locks up the device and causes Moode audio not
>>>                 to be able to use it, it's the starting of ledfx.
>>>                 Once I do systemctl start ledfx the moode audio
>>>                 player can no longer use the output device
>>>                 regardless if I play a sound file with aplay, paplay
>>>                 or don't play a sound file at all. Moode audio can't
>>>                 use the device until I do systemctl stop ledfx.
>>>
>>>                 El mar, 7 may 2024 a las 10:48, Mark Gaiser
>>>                 (<markg85 at gmail.com>) escribió:
>>>
>>>                     Can you use paplay instead?
>>>                     That is the pulseaudio aplay drop-in replacement.
>>>                     I'm guessing you won't have "device or resource
>>>                     busy" errors when using paplay.
>>>
>>>                     I did not test this! But do let us know if it
>>>                     works for you :)
>>>
>>>                     On Tue, May 7, 2024 at 3:24 PM Richard Reina
>>>                     <gatorreina at gmail.com> wrote:
>>>
>>>                         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]
>>>
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