How to swap audio channels? (FL, FR) - Fedora Linux 41

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1

Hi all.

I’am having trouble to swap audio channels in Fedora 41.
Following instruction leading to an error message due to changes on how config files are handled in wireplumber > v0.4.

wireplumber version:

Compiled with libwireplumber 0.5.8
Linked with libwireplumber 0.5.8

followed instructions:
→

error message

wireplumber: Old configuration file detected: /home/salzi/.config/wireplumber/main.lua.d/99-swap-channels.lua
Feb 23 00:55:26 salzi-pc wireplumber[12523]: wireplumber: Lua configuration files are NOT supported in WirePlumber 0.5. You need to port them to the new format if you want to use them.
                                             -> See https://pipewire.pages.freedesktop.org/wireplumber/daemon/configuration/migration.html

As for informations on following site, i changed config and path to
→
https://pipewire.pages.freedesktop.org/wireplumber/daemon/configuration/migration.html

path
→ .config/wireplumber/wireplumber.conf.d/51-swap-channels.conf

config

monitor.alsa.rules = [
  {
    matches = [
      {
        node.name = "alsa_output.usb-Generic_USB_Audio-00.HiFi__Speaker__sink"
      }
    ]
    actions = {
      update-props = {
        audio.position = "FR,FL"
      }
    }
  }
]

here my wpctl inspect output:

id 45, type PipeWire:Interface:Node
    alsa.card = "0"
    alsa.card_name = "USB Audio"
    alsa.class = "generic"
    alsa.components = "USB0b05:1a52"
    alsa.device = "0"
    alsa.driver_name = "snd_usb_audio"
    alsa.id = "USB Audio"
    alsa.long_card_name = "Generic USB Audio at usb-0000:0b:00.0-6, high speed"
    alsa.mixer_device = "_ucm0005.hw:Audio"
    alsa.mixer_name = "USB Mixer"
    alsa.name = "USB Audio"
    alsa.resolution_bits = "16"
    alsa.subclass = "generic-mix"
    alsa.subdevice = "0"
    alsa.subdevice_name = "subdevice #0"
    alsa.sync.id = "00000000:00000000:00000000:00000000"
    api.alsa.card.longname = "Generic USB Audio at usb-0000:0b:00.0-6, high speed"
    api.alsa.card.name = "USB Audio"
    api.alsa.headroom = "256"
    api.alsa.open.ucm = "true"
    api.alsa.path = "hw:Audio"
    api.alsa.pcm.card = "0"
    api.alsa.pcm.stream = "playback"
    api.alsa.period-num = "128"
    api.alsa.period-size = "256"
    audio.channels = "2"
    audio.position = "FL,FR"
    card.profile.device = "12"
  * client.id = "49"
    clock.quantum-limit = "8192"
    device.api = "alsa"
    device.class = "sound"
  * device.id = "35"
    device.profile.description = "Speakers"
    device.profile.name = "HiFi: Speaker: sink"
    device.routes = "1"
  * factory.id = "19"
    factory.name = "api.alsa.pcm.sink"
    library.name = "audioconvert/libspa-audioconvert"
  * media.class = "Audio/Sink"
  * node.description = "USB Audio Speakers"
    node.driver = "true"
    node.loop.name = "data-loop.0"
    node.max-latency = "16384/48000"
  * node.name = "alsa_output.usb-Generic_USB_Audio-00.HiFi__Speaker__sink"
  * node.nick = "USB Audio"
    node.pause-on-idle = "false"
  * object.path = "alsa:acp:Audio:12:playback"
  * object.serial = "79"
    port.group = "playback"
  * priority.driver = "1000"
  * priority.session = "1000"

I also tried different combinations of contend in that config file.

  • device.name, node.name, alsa.card_name…
    Changing the node.description for exampe works for me with this method.

I restarted the services with following command after every change
→
systemctl --user restart wireplumber pipewire pipewire-pulse

i cant get it working

2

Current workaround for me:

pactl load-module module-remap-sink sink_name=Hippeldibippeldi master=1 channels=2 master_channel_map=front-left,front-right channel_map=front-right,front-left set-default-sink Hippeldibippeldi

Meybe i put this in a start script and be done with it.
But it bugs me not being able to solve this via config file.