Linux - Toggle PipeWire Audio Output

Most modern Linux desktop systems use PipeWire for managing audio streams. WirePlumber is a session manager for PipeWire.

On my Debian system, I sometimes listen to audio through my headphones (plugged into the 1/8-inch jack in my monitor), and sometimes through a set of small speakers (plugged into a USB DAC). I need a simple way to switch back and forth between USB and HDMI output without opening a GUI or running several shell commands. This small Bash script is what I came up with. I just run it, and it toggles audio output between the 2 devices. I assigned a keyboard shortcut (F12) in Gnome, so I can run it by pressing a key.

This script uses the WirePlumber Control CLI (wpctl) to achieve this. To set it up, you need to know the ID for the 2 audio sinks you want to switch between.

To find them, run:

wpctl status

Look for the Sinks section in the output. You should see a section like this:

 ├─ Sinks:
 │      35. PCM2704C stereo audio DAC Digital Stereo (IEC958) [vol: 0.65]
 │  *   57. Radeon High Definition Audio Controller [Rembrandt/Strix] Digital Stereo (HDMI) [vol: 0.51]

In my case, the ID’s are 35 and 37. I set these as values for HEADPHONE_SINK and SPEAKER_SINK in my script. The rest of the logic sets the default sink to whichever one is not currently in use and moves the currently playing stream to it:

#!/usr/bin/env bash
#
# Toggle PipeWire audio output device/sink
#
# - uses WirePlumber to switch audio output between HDMI (headphones) and
#   USB DAC (speakers)

HEADPHONE_SINK=35 # HDMI
SPEAKER_SINK=57 # USB DAC

current_sink=$(wpctl status | awk '
    /\*/ {
        match($0, /[0-9]+\./)
        if (RSTART) { print substr($0,RSTART,RLENGTH); exit }
    }
' | tr -d '.')

if [ "${current_sink}" = "${HEADPHONE_SINK}" ]; then
    new_sink="${SPEAKER_SINK}"
else
    new_sink="${HEADPHONE_SINK}"
fi

wpctl set-default "${new_sink}"

# move currently playing audio streams to the new sink
wpctl status | awk '
    /Streams:/ {in_streams=1}
    /Video/ {in_streams=0}
    in_streams && /^[[:space:]]*[0-9]+\.\s+output/ {
        match($0, /[0-9]+\./)
        if (RSTART) print substr($0,RSTART,RLENGTH)
    }
' | tr -d '.' | xargs -r -I{} wpctl set {} "${new_sink}"

echo "switched audio output to sink ${new_sink}"

Now I can toggle my audio output between headphones and speakers by pressing a key that runs this script!