Pulseaudio

This page contains dedicated information about Pulseaudio. See Linux audio page for more general information (might also include some general info on Pulseaudio).

References

• Pulseaudio under the hood

Commands

pactl

pactl list                 # View devices (including bluetooth headsets...)

• pactl can also be used to run the config commands from e.g. Template:~/.pulse/default.pa directly. For instance:

pactl load-module module-native-protocol-tcp listen=192.168.1.10 # Use the local IP address
pactl load-module module-zeroconf-publish

Pulseaudio with systemd

On recent Ubuntu / Debian version, Pulseaudio is started by systemd.

• Unit file is at /etc/systemd/user/default.target.wants/pulseaudio.service.

This file starts pulseaudio in non-daemon mode.

• To get pulseaudio log, do something like journalctl | grep pulseaudio.

• To restart pulseaudio, simply kill it. For instance:

pulseaudio -k

✐	Configuring pulseaudio to log in a file does not work very well. Better use systemd journal.

How-To

PulseAudio across network with Avahi / auto-discovery

This configuration is very useful to send sound to another network device (for instance, if you have one headset but multiple computers) [1].

First install pulseaudio-module-zeroconf on both server and client:

sudo apt install pulseaudio-module-zeroconf

In the server computer (the one that will play the sound), add to ~/.pulse/default.pa:

.include /etc/pulse/default.pa

load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1
load-module module-zeroconf-publish

In the client computer (the one that will send the sound), add to ~/.pulse/default.pa:

.include /etc/pulse/default.pa

load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1
load-module module-zeroconf-discover

On the server, we must open the TCP port 4713 in the firewall.

By default, Pulseaudio is configured to use cookie authentication, except for the address excluded by auth-ip-acl (this can be sequence of address, see online documentation). The easiest is to copy the cookie from the server to the client:

cd ~/.config/pulse
scp server:.pulse/cookie .

Finally, restart pulseaudio on both computers:

pulseaudio -k

Fix [puseaudio] module-tunnel.c

Failed to authenticate

• Make sure that there is no other cookie file in user home.
• In particular, there are two separate directories: ~/.pulse and ~/.config/pulse. The cookie is taken from 2nd directory, whereas the configuration is read from the first folder.
• The easiest is to symlink the 2nd folder to first one:

rm -rf ~/.config/pulse
ln -sf ../.pulse ~/.config/pulse
pulseaudio -k

PulseAudio in multi-user (relay)

The solution is to have all users have their own PulseAudio server, but all of these relay to one server (typically the one of current active user, see [2]).

For each potential active user, edit file ~/.pulse/default.pa:

.include /etc/pulse/default.pa

load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1

For all users that needs to relay to active user, edit file ~/.pulse/client.conf:

default-server = 127.0.0.1

Active user might also need to run:

xhost +

PulseAudio in multi-user (system mode)

Main article: [3] (see also [4])

CAUTION — PulseAudio developers seriously recommend against this (see [5])

The solution here is to run pulseaudio as a system-wide daemon. For this:

• Enable system start. For 12.04, edit /etc/default/pulseaudio:

PULSEAUDIO_SYSTEM_START=1

For 12.10, edit /etc/init/pulseaudio.conf:

start on runlevel [2345]

• Edit /etc/pulse/daemon.conf — See man pulse-daemon.conf for more information.

daemonize = yes
local-server-type = system

• Edit /etc/pulse/client.conf (this is actually not really necessary

autospawn = no

We also need to add users to the pulse-access group.

sudo usermod -a -G pulse-access <username>

Troubleshooting

Get verbose log

• Edit /etc/systemd/user/default.target.wants/pulseaudio.service:

-ExecStart=/usr/bin/pulseaudio --daemonize=no
+ExecStart=/usr/bin/pulseaudio --daemonize=no -v

Get the log with

sudo journalctl -b | grep pulse

Clean up config

Cleaning up the user config may solve issues (like not working speaker):

• remove all files in .pulse and .config/pulse, except possibly client.conf, cookie and default.pa.

General

Troubleshooting PulseAudio:

paplay /usr/share/sounds/alsa/Front_Center.wav           # Try to play using PulseAudio

Choppy sound in flash video

Reference askubuntu.

• Simply kill and restart pulseaudio:

pulseaudio -k
pusseaudio -D       # To restart it - not needed if pulse runs in daemon mode

Understanding / Troubleshooting PulseAudio

• Only active user has access to /dev/snd/* devices. Access is granted by ConsoleKit when user logs in [6]. Access control can be seen with

getfacl /dev/snd/*

• To restart PulseAudio [7]

pulseaudio --check && echo running       # Check if any pulseaudio is running
pulseaudio -k                            # ... if so, kill it
pulseaudio -D                            # and start it again (optional is auto-spawn is enabled)