Difference between revisions of "PulseAudio"

Revision as of 05:58, 6 May 2013

PulseAudio is the default sound server that serves as a proxy to sound applications using existing kernel sound components like ALSA or OSS. Since ALSA is included in Arch Linux by default so the most common deployment scenarios include PulseAudio with ALSA.

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Installation

• Required PKG: pulseaudio
• Optional GTK GUIs: paprefs and pavucontrol
• Optional volume control via mapped keyboard keys: pulseaudio_ctl^AUR
• Optional console mixer: ponymix-git^AUR and pamixer-git^AUR
• Optional system tray icon: pasystray-git^AUR
• Optional KDE plasma applet: kdemultimedia-kmix and kdeplasma-applets-veromix^AUR

Running

In the unlikely event that pulseaudio is not automatically called upon entering X, it can can be started with:

$ pulseaudio --start

PulseAudio can be stopped with:

$ pulseaudio -k

Equalizer

Newer pulseaudio versions have an intergrated 10-band equalizer system. In order to use the equalizer do the following:

Load equalizer sink module

$ pactl load-module module-equalizer-sink

Install and run the gui frontend

# pacman -S --needed python2-pyqt

$ qpaeq

Load equalizer module on every boot

Edit the file /etc/pulse/default.pa with your favorite editor and append the following lines:

### Load the integrated pulseaudio equalizer module
load-module module-equalizer-sink

Backend Configuration

ALSA

• Recommended PKG: pulseaudio-alsa
• Optional PKGs: lib32-libpulse and lib32-alsa-plugins

For the applications that do not support PulseAudio and support ALSA it is recommended to install the PulseAudio plugin for ALSA. This package also contains the necessary /etc/asound.conf for configuring ALSA to use PulseAudio.

To prevent applications from using ALSA's OSS emulation and bypassing Pulseaudio (thereby preventing other applications from playing sound), make sure the module snd_pcm_oss is not being loaded at boot. If it is currently loaded (lsmod|grep oss), disable it by executing:

# rmmod snd_pcm_oss

ALSA/dmix without grabbing hardware device

You may want to use ALSA directly in most of your applications and to be able to use other applications, which constantly require PulseAudio at the same time. The following steps allow you to make PulseAudio use dmix instead of grabbing ALSA hardware device.

• Remove package pulseaudio-alsa, which provides compatibility layer between ALSA applications and PulseAudio. After this your ALSA apps will use ALSA directly without being hooked by Pulse.

$ sudo pacman -R pulseaudio-alsa

• Edit /etc/pulse/default.pa.

Find and uncomment lines which load backend drivers. Add device parameters as follows. Then find and comment lines which load autodetect modules.

load-module module-alsa-sink device=dmix
load-module module-alsa-source device=dsnoop
# load-module module-udev-detect
# load-module module-detect

• Optional: If you use kdemultimedia-kmix you may want to control ALSA volume instead of PulseAudio volume:

$ echo export KMIX_PULSEAUDIO_DISABLE=1 > ~/.kde4/env/kmix_disable_pulse.sh
$ chmod +x ~/.kde4/env/kmix_disable_pulse.sh

• Now, reboot your computer and try running alsa and pulseaudio applications at the same time. They both should produce sound simultaneously.

Use pavucontrol to control PulseAudio volume if needed.

OSS

There are multiple ways of making OSS-only programs play to PulseAudio:

ossp

Start ossp with:

# systemctl start osspd

padsp wrapper (part of PulseAudio)

Programs using OSS can work with PulseAudio by starting it with padsp:

$ padsp OSSprogram

A few examples:

$ padsp aumix
$ padsp sox foo.wav -t ossdsp /dev/dsp

You can also add a custom wrapper script like this:

/usr/local/bin/OSSProgram

#!/bin/sh
exec padsp /usr/bin/OSSprogram "$@"

Make sure /usr/local/bin comes before /usr/bin in your PATH.

GStreamer

To make GStreamer use PulseAudio, you need to install gst-plugins-good or gstreamer0.10-good-plugins.

OpenAL

/etc/openal/alsoft.conf

drivers=pulse,alsa

libao

Edit the libao configuration file:

/etc/libao.conf

default_driver=pulse

Be sure to remove the dev=default option of the alsa driver or adjust it to specify a specific Pulse sink name or number. Alternatively, note that you could keep the libao standard of outputting to the alsa driver and its default device if you install pulseaudio-alsa since the ALSA default device then is PulseAudio.

ESD

PulseAudio is a drop-in replacement for the enlightened sound daemon (ESD). While PulseAudio is running, ESD clients should be able to output to it without configuration.

Desktop Environments

General X11

Check to see if PulseAudio is running:

$ ps aux | grep pulse
facade   1794  0.0  0.0 360464  6532 ?        S<l  15:33   0:00 /usr/bin/pulseaudio --start
facade   1827  0.0  0.0  68888  2608 ?        S    15:33   0:00 /usr/lib/pulse/gconf-helper

If Pulseaudio is not running and users are using X, the following will start PulseAudio with the needed the X11 plugins manually:

$ start-pulseaudio-x11

If you are not running Gnome, KDE or XFCE and your ~/.xinitrc does not source the scripts in /etc/X11/xinit/xinitrc.d (such as is done in the example file /etc/skel/.xinitrc) then you can launch PulseAudio on boot with:

~/.xinitrc

/usr/bin/start-pulseaudio-x11

GNOME

As of GNOME 3, GNOME fully integrates with PulseAudio and no extra configuration is needed.

KDE 3

PulseAudio is not a drop-in replacement for aRts. Users of KDE 3 cannot use PulseAudio. However note, recent versions of PulseAudio may have eliminated the prohibition:

See: http://www.pulseaudio.org/wiki/PerfectSetup KDE 3 uses the artsd sound server by default. However, artsd itself can be configured to use an Esound backend. Edit kcmartsrc (either in /etc/kde or /usr/share/config for global configuration or .kde/share/config to configure only one user) like this:

[Arts]
Arguments=\s-F 10 -S 4096 -a esd -n -s 1 -m artsmessage -c drkonqi -l 3 -f
NetworkTransparent=true
SuspendTime=1

KDE Plasma Workspaces and Qt4

PulseAudio, it will be used by KDE/Qt4 applications. For more information see the KDE page in the PulseAudio wiki.

PulseAudio support has been merged into KMix, the default KDE sound mixer.

If the phonon-gstreamer backend is used for Phonon, GStreamer should also be configured to use PulseAudio by installing gstreamer0.10-good-plugins.

One useful tidbit from that page is to add load-module module-device-manager to /etc/pulse/default.pa.

Additionally, the kdeplasma-applets-veromix^AUR is available in the AUR as a KDE alternative to KMix or pavucontrol.

Xfce

Applications running under Xfce can take advantage of PulseAudio. To manage PulseAudio settings you can use pavucontrol.

Applications

Audacious

Audacious natively supports PulseAudio. In order to use it, set Audacious Preferences -> Audio -> Current output plugin to 'PulseAudio Output Plugin'.

Java/OpenJDK 6

Create a wrapper for the java executable using padsp as seen on the Java sound with Pulseaudio page.

Music Player Daemon (MPD)

configure MPD to use PulseAudio. See also MPD/Tips_and_Tricks#MPD_.26_PulseAudio.

MPlayer

MPlayer natively supports PulseAudio output with the "-ao pulse" option. It can also be configured to default to PulseAudio output, in ~/.mplayer/config for per-user, or /etc/mplayer/mplayer.conf for system-wide:

/etc/mplayer/mplayer.conf

ao=pulse

Skype (x86_64 only)

Install lib32-libpulse, otherwise the following error will occur when trying to initiate a call: "Problem with Audio Playback".

Troubleshooting

No sound after install

Muted audio device

If one experiences no audio output via any means while using ALSA, attempt to unmute the sound card. To do this, launch alsamixer and make sure each column has a green 00 under it (this can be toggled by pressing Template:Keypress):

$ alsamixer -c 0

Bad configuration files

If after starting pulseaudio, the system outputs no sound, it may be necessary to delete the contents of ~/.pulse. Pulseaudio will automatically create new configuration files on its next start.

Flash Content

Since Adobe Flash does not directly support PulseAudio the recommended way is to configure ALSA to use the virtual PulseAudio soundcard.

Alternatively you may try out libflashsupport-pulse^AUR from the AUR.

No cards

If PulseAudio starts, run pacmd list. If no cards are reported, make sure that the ALSA devices are not in use:

$ fuser -v /dev/snd/*
$ fuser -v /dev/dsp

Make sure any applications using the pcm or dsp files are shut down before restarting PulseAudio.

The only device shown is "dummy output"

This may be caused by different reasons, one of them being the .asoundrc file in $HOME is taking precedence over the systemwide /etc/asound.conf.

The user file is modified also by the tool asoundconf or by its graphical variant asoundconf-gtk (the latter is named "Default sound card" in the menu) as soon as it runs. Prevent the effects of .asoundrc altogether by commenting the last line like this:

.asoundrc

# </home/<yourusername>/.asoundrc.asoundconf>

Maybe some program is monopolizing the audio device:

# fuser -v /dev/snd/*

                     USER       PID  ACCESS COMMAND
/dev/snd/controlC0:  root        931 F....  timidity
                     bob        1195 F....  panel-6-mixer
/dev/snd/controlC1:  bob        1195 F....  panel-6-mixer
                     bob        1215 F....  pulseaudio
/dev/snd/pcmC0D0p:   root        931 F...m  timidity
/dev/snd/seq:        root        931 F....  timidity
/dev/snd/timer:      root        931 f....  timidity

That means timidity blocks pulseaudio from accessing the audio devices. Just killing timidity will make the sound work again.

Another reason is FluidSynth conclicting with pulseaudio as discussed in this thread. The solution is to remove FluidSynth:

# pacman -Rnsc fluidsynth

KDE4

It may be that another output device set as preferred in phonon. Make sure that every setting reflects the preferred output device at the top, and check the playback streams tab in kmix to make sure that applications are using the device for output.

Failed to create sink input: sink is suspended

If you do not have any output sound and receive dozens of errors related to a suspended sink in your journalctl -b log, then backup first and then delete your user-specific pulse folders:

$ rm -r ~/.pulse ~/.pulse-cookie

Bluetooth headset replay problems

Some user report huge delays or even no sound when the bluetooth connection does not send any data. This is due to an idle-suspend-module that puts the related sinks/sources automatically into suspend. As this can cause problems with headset, the responsible module can be deactivated.

$ cp /etc/pulse/default.pa ~/.pulse/default.pa

~/.pulse/default.pa

; load-module module-suspend-on-idle

$ pulseaudio -k && pulseaudio --start

More information

Automatically switch to Bluetooth or USB headset

Add the following:

/etc/pulse/default.pa

# automatically switch to newly-connected devices
load-module module-switch-on-connect

Pulse overwrites ALSA settings

Pulseaudio usually overwrites the ALSA settings- for example set with alsamixer- at start up, even when the alsa daemon is loaded. Since there seems to be no other way to restrict this behaviour, a workaround is to restore the alsa settings again after pulseaudio had started. Add the following command to .xinitrc or .bash_profile or any other autostart file:

restore_alsa() {
 while [ -z "`pidof pulseaudio`" ]; do
  sleep 0.5
 done
 alsactl -f /var/lib/alsa/asound.state restore 
}
restore_alsa &

Prevent Pulse from restarting after being killed

Sometimes you may wish to temporarily disable Pulse. In order to do so you will have to prevent Pulse from restarting after being killed.

$ echo autospawn=no > ~/.pulse/client.conf

Daemon startup failed

Try resetting PulseAudio:

$ rm -rf /tmp/pulse* ~/.pulse*
$ pulseaudio -k
$ pulseaudio --start

If there is no server running but pulseaudio fails to start with an error message "User-configured server at ... refusing to start/autospawn", the issue may be with PulseAudio settings from a previous login. Check to see if there are any stale properties attached to the X11 root window with pax11publish -d, and if there are, remove them with pax11publish -r before trying to start the server. This manual cleanup is always required when using LXDM because it does not restart the X server on logout; see LXDM#PulseAudio.

inotify issue

If this doesn't work, run the following:

$ pulseaudio -vvvv

If you see an error that looks like this:

E: [pulseaudio] module-udev-detect.c: You apparently ran out of inotify watches, probably because Tracker/Beagle took them all away. I wished people would do their homework first and fix inotify before using it for watching whole directory trees which is something the current inotify is certainly not useful for. Please make sure to drop the Tracker/Beagle guys a line complaining about their broken use of inotify.

Then you have run out of inotify watches.

This can quickly be resolved by running:

$ echo 100000 > /proc/sys/fs/inotify/max_user_watches

To have it permanently changed, add to /etc/sysctl.conf

# Increase inotify max watchs per user
fs.inotify.max_user_watches = 100000

padevchooser

If one cannot launch the PulseAudio Device Chooser, first (re)start the Avahi daemon as follows:

# systemctl restart avahi-daemon

Glitches, skips or crackling

The newer implementation of PulseAudio sound server uses a timer-based audio scheduling instead of the traditional interrupt-driven approach.

Timer-based scheduling may expose issues in some ALSA drivers. On the other hand, other drivers might be glitchy without it on, so check to see what works on your system.

To turn timer-based scheduling off add tsched=0 in /etc/pulse/default.pa:

/etc/pulse/default.pa

load-module module-udev-detect tsched=0

Then restart the PulseAudio server:

$ pulseaudio -k
$ pulseaudio --start

Do the reverse to enable timer-based scheduling, if not already enabled by default.

Please report any such cards to PulseAudio Broken Sound Driver page

Setting the default fragment number and buffer size in Pulseaudio

More Information

Finding out your audio device parameters (1/4)

To find your sound card buffering settings:

$ echo autospawn = no >> ~/.pulse/client.conf
$ pulseaudio -k
$ LANG=C timeout --foreground -k 10 -s kill 10 pulseaudio -vvvv 2>&1 | grep device.buffering -B 10
$ sed -i '$d' ~/.pulse/client.conf

For each sound card detected by Pulseaudio, you will see output similar to this:

I: [pulseaudio] source.c:     alsa.long_card_name = "HDA Intel at 0xfa200000 irq 46"
I: [pulseaudio] source.c:     alsa.driver_name = "snd_hda_intel"
I: [pulseaudio] source.c:     device.bus_path = "pci-0000:00:1b.0"
I: [pulseaudio] source.c:     sysfs.path = "/devices/pci0000:00/0000:00:1b.0/sound/card0"
I: [pulseaudio] source.c:     device.bus = "pci"
I: [pulseaudio] source.c:     device.vendor.id = "8086"
I: [pulseaudio] source.c:     device.vendor.name = "Intel Corporation"
I: [pulseaudio] source.c:     device.product.name = "82801I (ICH9 Family) HD Audio Controller"
I: [pulseaudio] source.c:     device.form_factor = "internal"
I: [pulseaudio] source.c:     device.string = "front:0"
I: [pulseaudio] source.c:     device.buffering.buffer_size = "768000"
I: [pulseaudio] source.c:     device.buffering.fragment_size = "384000"

Take note the buffer_size and fragment_size values for the relevant sound card.

Calculate your fragment size in msecs and number of fragments (2/4)

Pulseaudio's default sampling rate and bit depth are set to 44100Hz @ 16 bits.

With this configuration, the bit rate we need is 44100*16 = 44100 is disabled and needs to be changed to 96000:

# sed 's/; default-sample-rate = 44100/default-sample-rate = 96000/g' -i /etc/pulse/daemon.conf

Restart pulseaudio to apply the new settings (4/5)

$ pulseaudio -k
$ pulseaudio --start

Finally check by recording and playing it back (5/5)

Let us record some voice using mic for say 10 seconds. Make sure the mic is not muted and all

$ arecord -f cd -d 10 test-mic.wav

After 10 seconds, let us play the recording...

$ aplay test-mic.wav

Now hopefully, there is no static noise in microphone recording anymore.

My Bluetooth device is paired but does not play any sound

See the article in Bluetooth section

Starting from PulseAudio 2.99 and bluez 4.101 you should avoid using Socket interface. Do NOT use:

/etc/bluetooth/audio.conf

[General]
Enable=Socket

If you face problems with A2DP and PA 2.99 make sure you have sbc library:

# pacman -S sbc 

Subwoofer stops working after end of every song

Known issue: https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/494099

To fix this, must edit: /etc/pulse/daemon.conf and enable enable-lfe-remixing :

/etc/pulse/daemon.conf

enable-lfe-remixing = yes

Pulseaudio uses wrong microphone

If Pulseaudio uses the wrong microphone, and changing the Input Device with Pavucontrol did not help, take a look at alsamixer. It seems that Pavucontrol does not always set the input source correctly.

$ alsamixer

Press Template:Keypress and choose your sound card, e.g. HDA Intel. Now press Template:Keypress to display all items. Try to find the item: Input Source. With the up/down arrow keys you are able to change the input source.

Now try if the correct microphone is used for recording.

Choppy Sound with Analog Surround Sound Setup

The low-frequency effects (LFE) channel is not remixed per default. To enable it the following needs to be set in /etc/pulse/daemon.conf :

/etc/pulse/daemon.conf

enable-lfe-remixing = yes

No sound below a volume cutoff

Known issue (won't fix): https://bugs.launchpad.net/ubuntu/+source/pulseaudio/+bug/223133

If sound doesn't play when Pulseaudio's volume is set below a certain level, try ignore_dB=1 in /etc/pulse/default.pa:

/etc/pulse/default.pa

load-module module-udev-detect ignore_dB=1

However, be aware that it may cause another bug preventing pulseaudio to unmute speakers when headphones or other audio devices are unplugged

Low volume for internal mic

If you experience low volume on internal notebook microphone, try setting:

/etc/pulse/default.pa

set-source-volume 1 300000

External links

• http://www.pulseaudio.org/wiki/PerfectSetup - A good guide to make your configuration perfect
• http://www.alsa-project.org/main/index.php/Asoundrc - Alsa wiki on .asoundrc
• http://www.pulseaudio.org/ - PulseAudio official site
• http://www.pulseaudio.org/wiki/FAQ - PulseAudio FAQ