Fix WSL Audio Output on Windows 10

Version, Version and Version

This is the updated version, I use Windows 10 21H2 when writing the draft.

Windows: Version 22H2 (OS Build 25182.1000)
WSL: 2 (WSLg)
Distro: Devuan Testing
Windows PulseAudio: 1.1 (2011-10-25), installed via Chocolatey
Libpulse0: 15.0+dfsg1-4+b1
Cmus: 2.10.0-2
Windows Terminal: 1.14.2282.0

Intro

Today I wanted to enjoy my Memories Off OST collection on cmus on Debian on WSL 2 on Windows 10. As I did not upgrade to Windows 11 due to privacy and stability concerns, I could not use built-in GUI app feature for WSL.

I started the journey to fix broken audio output in WSL.

Get the Malody Working

Before I start, please be aware that each step is on Windows/WSL or you’ll get confused.

1. Download PulseAudio for Windows

On Windows:

The guide I followed used a third party built for X2Go (Remote Desktop client). I chose to use the good old Chocolatey anyway. The package uses the preview binary provided by freedesktop.org. Just run choco install pulseaudio -y in an elevated PowerShell window.

2. Configure PulseAudio for Windows

On Windows:

First we need to find the installation directory of PulseAudio for Windows.

$ Get-Command pulseaudio.exe
CommandType     Name                                               Version    Source
-----------     ----                                               -------    ------
Application     pulseaudio.exe                                     1.0.0.0    C:\ProgramData\chocolatey\bin\pulseaudio.exe

Create a file called config.pa in the folder we got above. In this case, C: \ProgramData\chocolatey\bin.

Open the file and add following lines and save the file:

load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1;172.16.0.0/12
load-module module-esound-protocol-tcp auth-ip-acl=127.0.0.1;172.16.0.0/12
load-module module-waveout sink_name=output source_name=input record=0

Explanation:

We allow connections from 127.0.0.1 (local IP address) and 172.16.0.0/12 (default IP range, i.e. 172.16.0.0 - 172.31.255.255) for WSL2.
To stream the audio to external devices, change the first line to load-module module-native-protocol-tcp auth-anonymous=1 to allow anonymous connections. It’s better not to change it for better security.
record=0 disable the microphone. Change it to record=1 if you need that.

3. Run PulseAudio (Freely)

The guide I followed uses NSSM to install PulseAudio as a Windows service, but I did not like that.

Head to the installation folder and create a shortcut, copy it to a folder in $PATH and rename it to pa.

Under the “Shortcut” section of Properties:

Target: C:\ProgramData\chocolatey\bin\pulseaudio.exe -F C:\ProgramData\chocolatey\bin\config.pa --exit-idle-time=-1
Start in: C:\ProgramData\chocolatey\bin
Run: Minimized
In the “Advanced” tab, enable the “Run as administrator” option.

Explanation:

-F tells PulseAudio to run the specified script on program startup.
--exit-idle-time=-1 disables the option to terminate the daemon after a number of seconds of inactivity.

Now when we want to start PulseAudio server on Windows, just press Win + R, type pa, hit enter and go.

4. Configure PulseAudio in WSL

On WSL:

libpulse0 should be installed by default but just make sure by running sudo apt install libpulse0.

Edit shell config file using the favored editor. In this case, vim ~/.zshrc, paste the following to somewhere:

# Enable audio output (PulseAudio) on WSL 2
# Get the IP Address of the Windows 10 Host and use it in Environment.
# Internal WSL IP
export HOST_IP="$(ip route |awk '/^default/{print $3}')"
export PULSE_SERVER="tcp:$HOST_IP"
# Enable this only if I wanna use GUI
#export DISPLAY="$HOST_IP:0.0"

Note:

Uncomment the last line to enable audio support for graphical applications.
If you are on WSL 2.0.0 and above, and using mirrored networking mode, change export PULSE_SERVER="tcp:$HOST_IP" to export PULSE_SERVER="tcp:127.0.0.1".

Restart your default shell. In this case, exec zsh.

5. Configure Cmus in WSL

Edit ~/.config/cmus/rc(create it if it doesn’t exist) and add set output_plugin=pulse to get its sound output to work on Windows.

It can be done within cmus by running :set output_plugin=pulse and :save if you wish to do so.

Cmus may arise an error when starting:

cmus: Error: an error occured while initializing MPRIS: No medium found. MPRIS will be disabled.

This can be ignored by running :set mpris=false in cmus from this issue .

6. Enjoy

On Windows: Win + R ->pa
On WSL: cmus

Don’t forget to allow the PulseAudio server to bypass the firewall. It should only need local network access in most cases.

I don’t know why, but certain songs can cause cmus to jam, and WSL just halt with CPU burning and fun taking off. tmux kill-server did not solve the issue. I had to use wsl --shutdown in PowerShell to stop that.

I did not experience it for a long time so chances are WSL team fixed it already.