PulseAudio Tames the Linux Audio Zoo, Part 2: Page 2

PulseAudio has a collection of good user-space utilities:

• Device Chooser
• Volume Control
• Volume Meter
• Manager
• Preferences

If your distribution has not messed with the package names, installing pulseaudio gets you the core sound server, and pavucontrol, pavumeter, paman, padevchooser, and paprefs are the user-space applications. Your distribution may also install Avahi/Zeroconf because PulseAudio uses it to auto-detect other audio servers on your network, and it should also install libasound2-plugins for ALSA compatibility.

After installation, run a simple command-line test:

$  pulseaudio --version

W: main.c: WARNING: called SUID root, but not in group 'pulse-rt'.
pulseaudio 0.9.6

pulse-rt stands for "pulse real-time", and you need to be a member of the pulse-rt group to get rid of this warning. The easy and safe way is to edit the /etc/group file directly:

pulse-rt:x:125:carla

Anytime you change your group memberships you have to log out and then log back in to activate the changes, so do that next. After logging back in, check your group membership:

$ groups
carla adm dialout floppy audio dip video plugdev fuse lpadmin admin pulse-rt

It isn't strictly necessary to do this, but enabling realtime priority means better audio quality.

We still need ALSA compatibility, so add these lines to /etc/asound.conf:

pcm.pulse {type pulse}
ctl.pulse {type pulse}

Now find yourself a nice WAV file to play and give it a whirl:

$  aplay -D pulse music/1st-set.wav
*** PULSEAUDIO: Unable to connect: Connection refused
aplay: main:545: audio open error: Connection refused

Oops. A quick ps ax|grep pulse reveals that the PulseAudio daemon isn't even running. Another symptom of this is when you open the graphical Pulse Audio Manager, you see something like Figure 1 with a "connection refused" message. So what to do?