Configuring and
Troubleshooting Sound in Debian Linux
How to get sound working in Debian
The sound system has low level drivers (ALSA) and daemonds above
them that figure out which program should get access first.
Today things are in transition to using alsa and jack for really
quality sound without the problems of the past.
What to install
alsa-base ALSA driver configuration files
alsa-modules ALSA driver modulesalsa-oss
ALSA OSS-compatibility libraryalsa-source
ALSA driver sourcesalsa-utils
ALSA utilities
alsamixergui graphical soundcard mixer for ALSA soundcard driver
alsaplayer PCM player designed for ALSA
alsaplayer-com PCM player designed for ALSA (common files)
alsaplayer-gtk PCM player designed for ALSA (GTK version)
alsaplayer-jack PCM player designed for ALSA (jack output
module)
alsaplayer-oss PCM player designed for ALSA (OSS output module)
snd-gtk-alsa Sound file editor (GTK+ user interface)
vlc-plugin-alsa ALSA audio output plugin for VLC
alsaplayer-jack PCM player designed for ALSA (jack output
module)
jack Rip and encode CDs with one command
jackd JACK Audio Connection Kit (server and example clients)
What to configure
run
#lspci | grep audio
This should tell you what audio card you have
Get module-assistant and run it and select the audio card from
the list (you can fix an error here by running dpkg-reconfigure
alsa-source)
Stick the followign in .bash_profile
richard -d alsa &
>> this fails to work all the time right now - let me know if
you get Jack working well under KDE (3.2 right now)
Testing
run
#alsaconf
Then run
#alsactl store
then run
#speaker-test
In KDE (3.2 for now) set sound system to use ALSA (Advanced
Linux Sound architecture)
ALSA Configuration in Debian
ALSA, the Advanced Linux Sound Architecture, is both a project
and a body of software. The project was started because the OSS
architecture is technically weak in some respects, and the free
variant of OSS (see OSSFree) lacks some drivers available only
in the commercial variant. For several years the ALSA software
was developed separately from Linux. The drivers were added to
the Linux codebase during the 2.5 development series and became
the standard sound driver system in Linux 2.6.
ALSA is not just a set of sound drivers; it is also a library
with an extensible API that gives applications access to the
latest features of sound cards (e.g., multiple sound channels,
Dolby [AC3], etc.). ALSA provides efficient support for many
applications (e.g., XMMS), is fully modularized, is
wiki:Self:SMP and thread-safe.
Applications written for OSS can be made to work with ALSA by
means of either userspace emulation (using the aoss program
loader) or kernelspace emulation (the snd-*-oss drivers).
However, you cannot use both ALSA and OSS drivers at the same
time.
N.B. ALSA driver names always start with snd- .
Required Packages
libasound2
libasound2-doc
alsa-base
alsa-utils
alsa-oss
alsamixergui
Loading modules
Recent alsa-base packages are designed to "just" work with
hotplug and discover. The alsa-base package does not load
modules; instead, hotplug or discover detects the sound hardware
and loads the right ALSA modules and then alsa-base takes care
of setting usable mixer levels.
You can also run alsaconf. This program uses a different method
of detecting hardware and if it thinks it has figured out what
module is needed, it generates a /etc/modutils/sound or /etc/modprobe.d/sound
file (depending on whether you are running Linux 2.4 or 2.6,
respectively). With the latter file in place, the module in
question will be loaded when the "snd" module is loaded. It
suffices then to load the snd module in order to load the driver
module for your specific hardware. To make use of this module
loading mechanism you probably need to add "snd" to
/etc/modules.
You can also try to detect and configure your sound card
manually.
If you have a PCI soundcard, do an 'lspci -v' to list all
available pci devices. The list will most probably include a
reference to a multimedia audio device: that is your SoundCard.
If you use a ISA PNP card, utilize the command pnpdump
For a USB card, use hotplug.
You could now have a look at the ALSA soundcard matrix to find
out which driver name can be used for the chipset you found.
ALSA and OSS
If your system is already configured to load OSS drivers for
your sound card then look at your current module loader
configuration files. There will be entries for the OSS modules
which will give you clues about which chipsets your sound cards
have. Don't forget to disable these entries before reconfiguring
things to load ALSA modules.
If you don't unload all OSS modules then ALSA modules will not
be able to initialise (or work properly) because the OSS driver
will be futzing with the sound hardware that the ALSA driver
needs to control. If you see a message about "sound card not
detected" and you are sure you have the right ALSA driver, the
presence of an OSS module could be the reason.
Test
Test the driver, using aplay, mplay or xmms for example
To test midi, you can use aplaymidi.
Sharing a card among multiple processes
It is often desirable to be able to share a sound card among
several processes running at the same time. This requires the
ability to mix the sound outputs of those processes into a
single stream.
If your cheap sound card doesn't support hardware mixing try the
dmix plugin. This has been set up automatically since libasound2
version 1.0.10-2; in prior versions, look at /usr/share/doc/libasound2/examples/asound.conf_dmix
to see how to enable DMIX in /etc/asound.conf (for all users) or
~.asoundrc (for your user).
Troubleshooting
To see what indexes have been assigned to cards, run:
cat /proc/asound/cards
The first card that ALSA finds is usually given index 0 and thus
is usually the 'default' sound card. If you are unlucky then the
first sound card found is one that it not suitable for playing
system sounds. There are two ways to fix this problem.
1. Force the cards to load in a different order. I chose this
route, and added the following to my /etc/modprobe.d/sound:
options snd-trident index=0
options snd-usb-audio index=1
This forces my Trident card to be the default (card 0) and my
USB microphone to be card 1.
2. Change the default card by editing /etc/asound.conf or ~/.asoundrc
Version
Look at /proc/asound/version.
Common Sound Problems in Debian with
Solutions
Want to enable sound on Debian? Have two
sound cards to make things worse?
This is the most trickiest part and irritating job on linux. The
Debian packages are completely broken and go by this manual
method.
Alsa is one place where you can find drivers for most of the
chipsets and you can first see if your audio chip has a driver
available here. Then download the alsa-drivers, alsa-libs,
alsa-utils and do a ./configure and make install them, the same
sequence
You can put the below lines in your /etc/modutils/alsa file. I
have an Analog Devices 1885 and a SoundBlaster PCI 16 on my
system. I would like to use the SB-PCI 16 by default.
alias char-major-116 snd
alias char-major-14 soundcore
alias snd-card-0 snd-card-ens1371
alias sound-slot-0 snd-card-0
alias sound-service-0-0 snd-mixer-oss
alias sound-service-0-1 snd-seq-oss
alias sound-service-0-3 snd-pcm-oss
alias sound-service-0-8 snd-seq-oss
alias sound-service-0-12 snd-pcm-oss
alias snd-card-1
alias sound-slot-1 snd-card-1
alias sound-service-1-0 snd-mixer-oss
alias sound-service-1-1 snd-seq-oss
alias sound-service-1-3 snd-pcm-oss
alias sound-service-1-8 snd-seq-oss
alias sound-service-1-12 snd-pcm-oss
options snd snd_major=116 snd_cards_limit=2 snd_device_mode=0660
snd_device_gid=29 snd_device_uid=0
options snd-card-ens1371 snd_index=0 snd_id=CARD_0
Do /etc/init.d/alsasound start. If needed, do a modprobe of
snd-mixer-oss, snd-pcm-oss, snd-seq-oss.
If you do a 'cat /proc/asound/sndstat', you should see something
like,
Sound Driver:3.8.1a-980706 (ALSA v0.9.0beta10 emulation code)
Kernel: Linux debian 2.4.16 #24 SMP Fri Mar 1 23:48:20 CST 2002
i686
Config options: 0
Installed drivers:
Type 10: ALSA emulation
Card config:
Ensoniq AudioPCI ES1371 at 0xcf00, irq 11
Audio devices:
1: ES1371 DAC2/ADC (DUPLEX)
Synth devices: NOT ENABLED IN CONFIG
Midi devices:
1: ES1371
Timers:
7: system timer
Mixers:
1: mixer10
Congratulations, you are all done with the sound now. Just do a
alsa mixer and set the sound levels by using arrow keys and "M"
for mute/unmute.
Sound works wells as 'root', but not as
user
I don't know why don't these things be taken care of
automatically by alsa, but you need to do this - if having a
problem.
# chmod o=+rw /dev/mixer*
# chmod o=+rw /dev/dsp*
Or you can add the specific users (who need to play sound on the
system) into the group 'audio' using 'usermod'
Why does my volume become 'muted' on every
boot?
Append these lines to your /etc/rc.d/rc.local or /etc/init.d/alsasound
/usr/bin/amixer set Master 50 unmute >/dev/null 2>&1
/usr/bin/amixer set PCM 50 unmute >/dev/null 2>&1
/dev/null /usr/bin/amixer set CD 50 unmute >/dev/null 2>&1
Have a proper working sound configuration,
but don't hear any gnome sounds?
Give suid permission to the 'esd' binary and start 'esound' as a
daemon process. Check if you are present in the group 'audio' on
your system. If you still don't hear any gnome sounds, start the
'esd' binary as 'esd &' and try out! After starting Gnome, if
you don't see any output for "ps aux | grep esd", enter these
lines in /etc/esound/esd.conf
[esd]
auto_spawn=1
spawn_options=-terminate -nobeeps -as 5
spawn_wait_ms=100
and the below lines in ~/.gnome/sound/system
[settings]
start_esd=true
event_sounds=true
