Pipewire

Handy link (thanks archetech on #lfs-support): ​https://wiki.gentoo.org/wiki/PipeWire
It has some indications for SysV (OpenRC startup).

Wireplumber

Currently Pipewire is only used as a build dependency in the book. To make it really useful, we need to install a session manager. Wireplumber is the recommended session manager.

Wireplumber can be downloaded at ​https://gitlab.freedesktop.org/pipewire/wireplumber/-/releases.

Required: Glib and Pipewire

Recommended: Lua

Optional dependencies: doxygen, lxml, and gobject-introspection (needed for g-i data), sphinx, and breathe (external, docs)

meson setup --prefix=/usr --buildtype=release -Dsystem-lua=true
ninja 
ninja test
sudo ninja install

Pipewire itself must be built with wireplumber support, so use the option

-Dsession-managers=/usr/bin/wireplumber

before building wireplumber (the session manager need not be present when building pipewire).

With Wireplumber we can run Pipewire daemon with:

• On systemd:

  sudo systemctl --global enable pipewire
  systemctl --user start pipewire
  

• On SysV (solution by Douglas Reno, adapted from Alpine linux):
  As root:

  cat >/usr/bin/pipewire-launcher.sh <<EOF
  #!/bin/sh
  exec /usr/bin/pipewire &
  sleep 1
  exec /usr/bin/wireplumber &
  EOF
  chmod +x /usr/bin/pipewire-launcher.sh
  cat >/etc/xdg/autostart/pipewire.desktop <<EOF
  [Desktop Entry]
  Version=1.0
  Name=Pipewire
  Comment=Starts the Pipewire daemons
  Exec=/usr/bin/pipewire-launcher.sh
  Terminal=false
  Type=Application
  EOF
  

  then restart the graphical session.

The screen recorder built in GNOME shell should work now.

Replace Pulseaudio

With Wireplumber, Pipewire can function as a drop-in replacement of Pulseaudio.

sudo systemctl --global enable pipewire-pulse.socket
sudo systemctl --global disable pulseaudio

Then logout and login again.

Use Pipewire for ALSA-based applications

If Pipewire is running, it will occupy the sound card device and an ALSA-based application cannot use the card at the same time. To work around the issue, tell alsa-lib to use a virtual device provided by Pipewire:

sudo install -vdm755 /etc/alsa/conf.d
sudo ln -sfvr /usr/share/alsa/alsa.conf.d/99-pipewire-default.conf /etc/alsa/conf.d

Bluetooth LDAC support

Install ldacBT before building Pipewire. The link to ldacBT is available on the book page. Installation process of ldacBT:

mkdir build; cd build
cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=/usr
make
# no test suite available
sudo make install