PulseAudio

From openSUSE

PulseAudio is a networked sound server that allows software mixing of audio. See the PulseAudio website for more details.

It provides:

• Software mixing of multiple audio streams, bypassing any restrictions the hardware has.
• Network transparency, allowing an application to play back or record audio on a different machine than the one it is running on.
• Sound API abstraction, alleviating the need for multiple backends in applications to handle the wide diversity of sound systems out there.
• Generic hardware abstraction, giving the possibility of doing things like individual volumes per application.

PulseAudio comes with many plugin modules. All audio from/to clients and audio interfaces goes through modules. PulseAudio clients can send audio to "sinks" and receive audio from "sources". A client can be GStreamer, xinelib, MPlayer or any other audio application. Only the device drivers/audio interfaces can be either sources or sinks (they are often hardware in- and out-puts).

Configuration

PulseAudio is used in openSUSE 11.0 for GNOME installations, it is not used in non-GNOME installs. This makes it a source of problems given the wide range of sound systems/applications being used in multimedia applications. That's why if you are having issues with PulseAudio, before reporting them to our Bugzilla, make sure you read this article about the perfect PulseAudio setup. It contains information about making all available sound systems use PulseAudio for the actual sound playing.

Issues

5.1 Sound

There were issues getting 5.1 sound working out of the box, see bug 381686 for more information. Many people have a surround card, but have speakers for just two channels, so PulseAudio can't really default to a surround setup. To enable all the channels, edit /etc/pulse/daemon.conf: uncomment the default-sample-channels line (i.e. remove the semicolon from the beginning of the line) and set the value to 6 if you have a 5.1 setup, or 8 if you have 7.1 setup etc. Or even easier, you can run paprefs and set the speaker setup via the paprefs GUI.

Glitches in audio playback

Edit /etc/pulse/daemon.conf: uncomment the default-fragments and default-fragment-size-msec, and change values from the default 4 and 25 to 16 and 21.

Please report back in bug 381686if this works or not for you.

Returning to esound

Remove all pulseaudio* packages and install esound.

See Also

• Development page on PulseAudio Integration into openSUSE 11.0
• PulseAudio website