PulseAudio

Hardware - Sound

Introduction

PulseAudio, previously known as Polypaudio, is a sound server for POSIX and WIN32. It is a replacement for ESoundDaemon.

Here are some features of PulseAudio:

* High quality software mixing of multiple audio streams with support for more than one entrance(source) and exit(sink). * Can be used to combine multiple sound cards into one (with frequency rate). * Large set of supported client libraries. Applications that use ESD, ALSA, oss, libao and GStreamer, are supported without the need to any changes to them. Modules for PulseAudio is available for xmms and mplayer. * Low latency, and a very accurate measurement delay time for recording and playback. Ability to fully synchronize multiple playback streams. * Network transparency: the application can play or record audio on a computer other than the one on which they run. * Extensible architecture with modules for jackd, multicast-rtp, lirc and avahi, among others.

Installing PulseAudio

Since at least squeeze, installing pulseaudio through apt in this way should result in a pulseaudio system that "just works". Pulseaudio becomes the default when the pacakge is installed. Everything (including flash) will use it.

This can be checked by with [b]pavucontrol[/b] (in the pavucontrol package). If the sound is registering in the vu vumetre of that program, then it is being routed through the pulse system.

Surround sound system

Many people have a multi-channel sound cards, but use the speakers for the two channels. PulseAudio has no default settings for surround sound support. To enable all channels, edit the file / etc / pulse / daemon.conf: uncomment default-sample-channels (ie remove the semicolon at the beginning of the line) and set it to 6 if you System 5.1 or 8, if your system is 7.1.

# Default default-sample-channels = 2 # To 5.1 default-sample-channels = 6 # To 7.1 default-sample-channels = 8 After making the changes, restart Pulseaudio.

Solving Problems

The lack of playback devices or audio capture

If we update or some time later Pulseaudio stopped correctly determine the input / output devices and sources, try to clear the configuration files pulseaudio. To do this, delete the folder: ~ /. Pulse, ~ /. Pulse-cookie and / tmp/.esd- *. Forcibly end the process pulseaudio command:

# Killall -9 pulseaudio Then run:

$ Pulseaudio - start If that does not work well and remove the / etc / pulse and reinstall PulseAudio.

Wheezing and audio interruptions

If a low-power machine having wheezing, in / etc / pulse / daemon.conf list the following:

high-priority = no nice-level = -1 realtime-scheduling = yes realtime-priority = 5 flat-volumes = no resample-method = speex-float-1 default-sample-rate = 48000 Interrupting play in Amarok when running Skype Comment out or remove the line in the / etc / pulse / default.pa

load-module module-cork-music-on-phone Excessive CPU usage and distortion Add a line to / etc / pulse / default.pa

load-module module-udev-detect tsched = 0 Sound level is low or low sound Add a line to / etc / pulse / daemon.conf:

flat-volumes = no Various problems with Skype and Wine Add or uncomment the line in / etc / pulse / daemon.conf

default-fragments = 25 default-fragment-size-msec = 25

Wheezing and audio interruptions If a low-power machine having wheezing, in / etc / pulse / daemon.conf list the following:

high-priority = no nice-level = -1 realtime-scheduling = yes realtime-priority = 5 flat-volumes = no resample-method = speex-float-1 default-sample-rate = 48000

Interrupting play in Amarok when running Skype

Comment out or remove the line in the / etc / pulse / default.pa

load-module module-cork-music-on-phone

Excessive CPU usage and distortion

Add a line to / etc / pulse / default.pa

load-module module-udev-detect tsched = 0

Sound level is low or low sound

Add a line to / etc / pulse / daemon.conf:

Various problems with Skype and Wine

Add or uncomment the line in / etc / pulse / daemon.conf

default-fragments = 25 default-fragment-size-msec = 25

Advanced

Install from source

Seems as though there ought to be some general instructions for building things from source in Debian, but I couldn't find them when editing this.

Download

from here:

http://www.freedesktop.org/wiki/Software/PulseAudio/Download/

Configure

???

Build

make

Install

Put it somewhere. Make some links so programs can find it.

http://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/User/PerfectSetup/


CategoryHardware