mqtt interface providing similar functionality as pavucontrol

[janvda]

The goal is to provide an mqtt interface that allows to do and see the same things as pavucontrol.

This includes the following features:

1. Regarding input devices (audio capture devices)
   1. List input devices
   2. Specify active one
   3. Specify volume
   4. mute
   5. show current volume real-time
2. Regarding output devices (playback devices) The same as for the input devices
3. Regarding playback
4. Regarding recording
5. Regarding configuration

[janvda]

Some interesting projects to start of:

• C-API: https://freedesktop.org/software/pulseaudio/doxygen/index.html

• python

  • https://pypi.org/project/pulsemixer/
  • https://pypi.org/project/pulsectl/ => chosen library
  • https://menno.io/posts/pulseaudio_monitoring/ (audio level monitoring)
• node.js
  • https://github.com/mscdex/paclient => blocking issue: mscdex/paclient#1
  • https://www.npmjs.com/package/pulseaudio-client

[janvda]

I have tried to use the node.js library https://github.com/mscdex/paclient but due to following issue https://github.com/mscdex/paclient/issues/1 this is currently not an option.

[janvda]

I have upgraded Host OS version to balenaOS 2.43.0+rev1 and this resolved the problem.

See following output

root@ba7c427:/# aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
  Subdevices: 7/7
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 IEC958/HDMI [bcm2835 IEC958/HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 0: ALSA [bcm2835 ALSA], device 2: bcm2835 IEC958/HDMI1 [bcm2835 IEC958/HDMI1]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Device [USB2.0 Device], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
root@ba7c427:/#