Pipewire

Pipewire is the new sound system on Linux, meant to replace Pulseaudio.

Links

• PipeWire - Debian Wiki.
• PipeWire - ArchLinux
• PipeWire on HackerNews
• PipeWire repo - GitLab

• PipeWire issue trackers
• PipeWire Module: Protocol Pulse, Config PulseAudio, Migrate PulseAudio.

• Pipewire docs.
• WirePlumber - documentation

References

Configuration files:

• /usr/share/pipewire
• /usr/share/wireplumber

Commands

# View status
systemctl --user status pipewire

# Use PipeWire instead of JACK
pw-jack SOMEAPP

# PipeWire process viewer (quantum usage...)
pw-top

# Setup sinks, sources, audio devices
pw-link
qjackctl         # Graphical tool, leveraging on JACK
qpwgraph         # Alternative, pipewire native

# Get settings
pw-metadata -n settings

# Set settings
pw-metadata -n settings 0 clock.rate 48000
pw-metadata -n settings 0 clock.allowed-rates '[ 48000, 96000, 44100 ]'

# Command line
pw-cli
> info all

Configuration

• Package configuration files are located in /usr/share/pipewire and /usr/share/wireplumber.
• To change them, copy and edit them in /etc/pipewire (system-wide) or ~/.config/pipewire (local changes).

pipewire-pulse.conf

• A single section can also be updated through a file in /etc/pipewire/pipewire-pulse.conf.d/ or ~/.config/pipewire/pipewire-pulse.conf.d/

cat /usr/share/pipewire/pipewire-pulse.conf
# # PulseAudio config file for PipeWire version "0.3.50" #
# #
# # Copy and edit this file in /etc/pipewire for system-wide changes
# # or in ~/.config/pipewire for local changes.
# #
# # It is also possible to place a file with an updated section in
# #  for system-wide changes or in
# # ~/.config/pipewire/pipewire-pulse.conf.d/ for local changes.

• One can see current module configuration with pactl:

pactl list modules      # See active modules and their config

Troubleshooting

Setting and keeping bluetooth profile for headset

We want to use the profile sbc sbc_xq for our BT headset Sony WH-1000XM3.

Set the profile manually - profile should be persistent on reboot / reconnect.

• In principe WirePlumber should remember the last selected profile.
• See [1]

# See available profile and device id with 'pactl list'
pactl set-card-profile bluez_card.38_18_4C_4B_6A_3A a2dp-sink-sbc_xq

Configure profile

• When using pipewire-media-session, the default profile could be selected in bluez-monitor.conf, but this file no longer exists with WirePlumber.
• (UPDATE - Archlinux - Pipewire) Edit /etc/wireplumber/bluetooth.lua.d/51-bluez-config.lua (or ~/.config/wireplumber/bluetooth.lua.d/51-bluez-config.lua):

bluez_monitor.properties = {
  ["bluez5.enable-sbc-xq"] = true,
  ["bluez5.enable-msbc"] = true,
  ["bluez5.codecs"] = "[sbc sbc_xq]",
}

Crackling / Stuttering audio

This applies in a VM. Not sure these apply when PipeWire is run on the host.

• https://superuser.com/questions/1646216/fedora-34-vmware-workstation-vm-upgraded-from-fedora-33-has-audio-crackling
• https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/469

Note that recent PipeWire already supports different auto-config if running in a vm [2].

Enable multi-user / network audio

References

• https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Network
• Multi-user audio sharing with PipeWire - archlinux forum
• PipeWire issue 847
• Sharing unix socket between multiple users

An advanced config that allows to share the unix socket, for even lower latency. Use case was specifically for streaming audio coming from a VM!

Currently PipeWire support sharing through network using Pulse, but auth-anonymous is always turned on (auth-ip-acl not implemented).

• (pipewire 0.3.50+) On the main user, create file ~/.config/pipewire/pipewire-pulse.conf.d/multi-user-zeroconf.conf

# This config file is a refinement of config file /usr/share/pipewire/pipewire-pulse.conf.

# We listen to network socket to enable multi-user / network playback.
# LIMITATION: The laptop speaker is advertised by zeroconf, but playback fails. Playback through BT headset is ok though.
# LIMITATION: auth-ip-acl might not work
# LIMITATION: We listen to ipv4 0.0.0.0 only, and use firewall to further restrict access to private network only.
context.exec = [
    { path = "pactl"        args = "load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1 listen=0.0.0.0" }
    { path = "pactl"        args = "load-module module-zeroconf-publish" }
]

# # Below, an alternative way for multi-user / network (however we still need zeroconf above)
# # Note that this method doesn't load the native-protocol-tcp module
# pulse.properties = {
#     # the addresses this server listens on
#     server.address = [
#         "unix:native"
#         "tcp:4713"                         # IPv4 and IPv6 on all addresses
#         # "tcp:127.0.0.1:4713"               # IPv4 on a single address
#         #
#         #{ address = "tcp:4713"             # address
#         #  max-clients = 64                 # maximum number of clients
#         #  listen-backlog = 32              # backlog in the server listen queue
#         #  client.access = "restricted"     # permissions for clients
#         #}
#     ]
#     # vm.overrides = {
#     #     pulse.min.quantum = 1024/48000      # 22ms
#     # }
# }

Note: we CANNOT edit pipewire-pulse.conf or any system-level file (like in /etc/pipewire/pipewire-pulse.d) because the TCP socket would already be used, and service would fail to load.

Now, restart pipewire-pulse, and check it works:

# We must restart the SOCKET (this also restart the SERVICE)
systemctl --user restart pipewire-pulse.socket
PULSE_SERVER=tcp:127.0.0.1:4713 pactl info
PULSE_SERVER=unix:/run/user/1000/pulse/native pactl info

• On the secondary user:

# We can either export this variable
export PULSE_SERVER=127.0.0.1            # OR ...
export PULSE_SERVER=tcp:127.0.0.1:4713
PULSE_SERVER=127.0.0.1 pactl info

Or we can edit ~/.pulse/client.conf like we did with PulseAudio:

default-server = 127.0.0.1

Note: make sure the port is allowed in the firewall as well.

• On the remote client, use the module PipeWire Module: Pulse Tunnel:

# ################# NOT TESTED #############################
context.modules = [
{   name = libpipewire-module-pulse-tunnel
    args = {
        tunnel.mode = playback
        # Set the remote address to tunnel to
        pulse.server.address = "tcp:192.168.1.126"
        #audio.rate=<sample rate>
        #audio.channels=<number of channels>
        #audio.position=<channel map>
        #node.target=<remote target node>
        stream.props = {
            # extra sink properties
        }
    }
}
]

We can also use the PipeWire Module: Zeroconf Discover, that will automatically create sinks/sources to/from remote PulseAudio servers.

context.modules = [
{   name = libpipewire-module-zeroconf-discover
    args = { }
}
]

VMWare VM

• We cannot get audio to work on VMWare VM, under user vbox, although same user can play audio file with eg mplayer.
• Instead we share the pipewire unix socket, as explained here.
• Pipewire unix socket for main user is located at /run/user/1000/pipewire-0:

ss -lpn | grep pipewire-0
# u_str LISTEN 0  4096  /run/user/1000/pipewire-0 26175  * 0  users:(("pipewire",pid=2207,fd=3),("systemd",pid=2190,fd=32))

• We must share this socket with user vbox, but keeping some access control.
• We create a folder /mnt/pipewire, with access for group audio, and we add user vbox to that group.

sudo mkdir /mnt/pipewire
sudo chgrp audio /mnt/pipewire
sudo chmod 750 /mnt/pipewire
sudo gpasswd -a vbox audio

• We add a binding mount point in fstab, that can be mounted by user (option user):

# Pipewire audio sharing (for user vbox). This requires:
#   sudo mkdir /mnt/pipewire
#   sudo chgrp audio /mnt/pipewire
#   sudo chmod 750 /mnt/pipewire
#   sudo gpasswd -a vbox audio
/run/user/1000/pipewire-0 /mnt/pipewire/pipewire-0 none bind,rw,user,noauto 0 0

• We add systemd override to pipewire.socket, to mount/umount that point automatically.

systemctl edit --user pipewire.socket # or edit file '~/.config/systemd/user/pipewire.socket.d/override.conf'
# [Socket]
# ExecStartPost=/bin/mount /mnt/pipewire/pipewire-0
# ExecStopPre=/bin/umount /mnt/pipewire/pipewire-0

• As user vbox, simply add to ~vbox/.profile:

export PIPEWIRE_RUNTIME_DIR=/mnt/pipewire