Virtual mic in Pipewire

Support Sound
1

Hi there.
I use Iriun Webcam to make short videos to support my classes.
Until a few months ago I used PulseAudio as default sound server. So, to get audio input I used to run:

pacmd load-module module-alsa-source source_properties=device.description=Iriun device=hw:Loopback,0,0

Nevertheless, Manjaro switched for Pipewire.
I trying to get the Loopback interface to capture sound from my Phone as I did before.
After some research, I found a way to identify the capture device with aplay:

aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  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
  Subdevice #7: subdevice #7
card 0: Loopback [Loopback], device 1: Loopback PCM [Loopback PCM]
  Subdevices: 8/8
  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
  Subdevice #7: subdevice #7
card 1: SB [HDA ATI SB], device 0: ALC889 Analog [ALC889 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: SB [HDA ATI SB], device 1: ALC889 Digital [ALC889 Digital]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 3: HDMI 0 [LEN S24e-03]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 7: HDMI 1 [2369M]
  Subdevices: 0/1
  Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 8: HDMI 2 [HDMI 2]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 9: HDMI 3 [HDMI 3]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

And after that I used arecord to identify the correct ID.
I’ve confirmed it is in the “hw:0,0”.

So I’ve looked up into a way to get the sound of the Mic and found the pipewire.conf file.
I put these lines in pipewire.conf in my user config folder:

context.objects = [
    {   factory = adapter
        args = {
            factory.name     = api.alsa.pcm.source
            node.name        = "iriun-mic"
            node.description = "Iriun"
            media.class      = "Audio/Source/Virtual"
            api.alsa.path    = "hw:Loopback,0,0"
            audio.format    = "S32LE"
            audio.rate       = 48000
            audio.channels   = 2
            audio.position  = "FL,FR"
        }
    }
]

Then

systemctl restart --user pipewire

But no sound was captured ever.
I’ve also tried some changes in these lines (mono/stereo, bitrate, format etc.) but none of these changes produced any effect.

Mic has no sound.

Am I missing something?

Thanks in advance.

2

Manjaro switched for Pipewire.

Manjaro users can use metapackages manjaro-pipewire or manjaro-pulse to switch between audio servers

trying to get the Loopback interface to capture sound from my Phone as I did before

PulseAudio pacmd commands do not work with pipewire-pulse replacement
But many pactl commands do work

Migrate PulseAudio · Wiki · PipeWire / pipewire · GitLab

modules

pipewire-pulse has support for some pulseaudio modules. They can be loaded and unloaded in the same way as is done on PulseAudio:

This command should work to load module-alsa-source in pipewire-pulse

pactl load-module module-alsa-source source_properties=device.description=Iriun device=hw:Loopback,0,0
3

Hi.
Thanks for the support.
When I run the command I get

Failure: Unknown error code

Unfortunately I don’t know how to provide more information about this.

Edit:

I found the documentation about module-alsa-source and then I removed the “source-properties=devicedescription” fragment.
In the Gnome settings the Loopback on 0,0 was visible as an option, but again with no sound.
A few moments after that, all the inputs were gone.

4

See PipeWire Wiki for how to use pw-loopback command for virtual devices