hi,
i have alsa,esd,arts and nas installed .
the permissions on /dev/dsp are

crw-rw---- 1 root audio 14, 3 Apr 29 11:28 /dev/dsp

and on /dev/snd are

crw-rw---- 1 root audio 116, 0 Apr 29 11:28 controlC0
crw-rw---- 1 root audio 116, 24 Apr 29 11:28 pcmC0D0c
crw-rw---- 1 root audio 116, 16 Apr 29 11:28 pcmC0D0p
crw-rw---- 1 root audio 116, 1 Apr 29 11:28 seq
crw-rw---- 1 root audio 116, 33 Apr 29 11:28 timer

my user is added as a user to the "audio" group.

however if i try to open a audio file (as non-root)with xmms i get:

ALSA lib confmisc.c:670snd_func_card_driver) cannot find card '0'
ALSA lib conf.c:3500_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:391snd_func_concat) error evaluating strings
ALSA lib conf.c:3500_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1070snd_func_refer) error evaluating name
ALSA lib conf.c:3500_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:3968snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2143snd_pcm_open_noupdate) Unknown PCM default

** WARNING **: alsa_setup(): Failed to open pcm device (default): No such device


with mplayer(as non-root):

Checking audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
AF_pre: 44100Hz/2ch/s16le
[AO OSS] audio_setup: Can't open audio device /dev/dsp: Permission denied
alsa-init: no soundcards found: Success
[AO ARTS] Connected to sound server.
[AO ARTS] Stream opened.
[AO ARTS] buffer size: 20480
[AO ARTS] buffer size: 2048
AO: [arts] 44100Hz 2ch s16le (2 bps)
Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...

playing audio works if i do "sudo xmms" or "sudo mplayer"
the relevant line is /etc/group is:
audio:x:11:<my-user-name>

i indeed do not have read permissions over /dev/dsp:
cat /dev/dsp
cat: /dev/dsp: Permission denied

in kde's sound control,if i try setting audio device to alsa,i get no sound.there is no sound with arts either.with esd i get a error message "could no start sound server".only nas works.but audio is very choppy.this is the problem in amarok too.
the audio grup has rw permissions over /dev/dsp,and my user is a member of that group.so why is permission being denied?

Welcome to LQ!

What distro are you using? Please put this in your profile, it makes it easier for us to help you.

Does sound work as root?

Try adding global read and write permissions to /dev/dsp and see what happens.

--Ian

hi,
my distro is linuxfromscratch

yes,sound works as root.(sudo mplayer and sudo xmms works)


after changing permisions of /dev/dsp to rwx for all,sound work in mplayer(both for movies and songs.).relevant part of Mplayer's console output for movie file is:

Checking audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
AF_pre: 44100Hz/2ch/s16le
AO: [oss] 44100Hz 2ch s16le (2 bps)
Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
Starting playback...

and similarly for songs too.

However xmms still does'nt work.Console output is:

** WARNING **: alsa_get_mixer(): Attaching to mixer hw:0 failed: No such device
ALSA lib confmisc.c:670snd_func_card_driver) cannot find card '0'
ALSA lib conf.c:3500_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:391snd_func_concat) error evaluating strings
ALSA lib conf.c:3500_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1070snd_func_refer) error evaluating name
ALSA lib conf.c:3500_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:3968snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2143snd_pcm_open_noupdate) Unknown PCM default

** WARNING **: alsa_setup(): Failed to open pcm device (default): No such device


sudo xmms works.
Also,just after i changed /dev/dsp permisions to 777,KDE's sound center crashed with a SIGSEGV signal.


All this was in KDE.I have xfce installed too.In XFCE,i get the following result id /dev/dsp permision is 660(root-read/write group-read/write).
xmms does'nt give sound(same error as in kde above)
xine-ui does'nt play sound
mplayer plays sound both for songs and movie files.mplayer's console output for movie file is:

Checking audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
AF_pre: 44100Hz/2ch/s16le
[AO OSS] audio_setup: Can't open audio device /dev/dsp: Permission denied
alsa-init: no soundcards found: Success
[AO ARTS] can't connect to aRts soundserver
ALSA lib confmisc.c:670-(snd_func_card_driver) cannot find card '0'
ALSA lib conf.c:3500-(_snd_config_evaluate) function snd_func_card_driver returned error: No such device
ALSA lib confmisc.c:391-(snd_func_concat) error evaluating strings
ALSA lib conf.c:3500-(_snd_config_evaluate) function snd_func_concat returned error: No such device
ALSA lib confmisc.c:1070-(snd_func_refer) error evaluating name
ALSA lib conf.c:3500-(_snd_config_evaluate) function snd_func_refer returned error: No such device
ALSA lib conf.c:3968-(snd_config_expand) Evaluate error: No such device
ALSA lib pcm.c:2143-(snd_pcm_open_noupdate) Unknown PCM default
[AO ESD] esd_open_sound failed: Connection refused
AO: [nas] 44100Hz 2ch s16le (2 bps)
Building audio filter chain for 44100Hz/2ch/s16le -> 44100Hz/2ch/s16le...
Starting playback...


With /dev/dsp permission as 777:
xmms still does'nt work(exactly same error message)
mplayer works fine
xine-ui works fine.

I must mention that xmms's ouptu plugin is set as ALSA.

ps:Some strange html behavior.":" when enclosed in italics is printed as a smiley in replies.

Change the permissions for:
/dev/mixer
/dev/snd/timer
/dev/snd/controlC0
/dev/snd/pcmC0D0c
/dev/snd/pcmC0D0p

thanks!!
i changed /dev/mixer and everything under /dev/snd to 777.Now even sound under alsa in kde works great.