home | list info | list archive | date index | thread index

[OCLUG-Tech] Re: [UPDATE] Sound problems with FC4 + ALSA + bttv ??

Hi;

I've learnt a lot about ALSA since I first wrote this post.  I hope by
updating it I can get some help.

"My level of sound knowledge is pre-newbie. Never played with sound
adjustments before and only own one cd recording. But ...

1) My main specific problem is that I can't get some apps to use PCM."

Other problems include: 
2) Most times my event sounds have scratchy backgrounds.  E.g. the 
system-config-soundcard test is audible but very distorted on the 
right hand speaker.
3) Some programs like audacity can't find the sound card while others 
like Helix can.
4) I get different responses depending whether I am user bill, su (root) 
or in the root user account.

"tvtimes keeps reverting to line-in
Audacity gives error: "There was an error initializing the audio i/o
layer. ..."
Every time I logon, PCM gets muted in my mixer gui.
On 'line-in' my speakers hiss and squawk and the event sounds are
terrible but I have no background noise problems when 'line-in' is muted
and PCM is open.
CD's play fine.
My tvtimes configuration file /etc/tvtime/tvtime.xml is set to <option
name="MixerDevice" value="/dev/mixer:pcm"/>

gstreamer-properties gui (Multimedia Systems Selector) test gives me the
following:

With PCM on and 'line-in ' muted:
Output ALSA pipeline alsasink = good clear sound.
Input ALSA pipeline alsasrc = no sound (crashes gui)

With PCM muted and 'line-in ' on:
Output ALSA pipeline alsasink = sound + hissing background.
Input ALSA pipeline alsasrc = no sound (crashes gui)

permissions on /dev/dsp /dev/audio /dev/mixer all crw------- 

dmesg says at the audio portion of startup bttv is being installed.  

I have just clean installed Fedora Core 4 . Under FC3 I didn't have a
memorable sound problem, but, then I wasn't looking.  Fedora Core 4 is
supposed to have ALSA as part of the Kernal.  

I am using P4 on a Intel 82850 motherboard, Ensoniq 5889 AudioPCI sound
card and an
ATI TV Wonder tuner. Also listed is Brooktree Bt878 video capture and
Bt878 audio capture.

I ran lsmod | grep ^snd and got the following:
snd_ens1371 31649 1
snd_rawmidi 30305 1 snd_ens1371
snd_ac97_codec 75961 1 snd_ens1371
snd_seq_dummy 3653 0
snd_seq_oss 37057 0
snd_seq_midi_event 9153 1 snd_seq_oss
snd_seq 62289 5 snd_seq_dummy,snd_seq_oss,snd_seq_midi_event
snd_seq_device 8781 4 snd_rawmidi,snd_seq_dummy,snd_seq_oss,snd_seq
snd_pcm_oss 51185 0
snd_mixer_oss 17857 1 snd_pcm_oss
snd_pcm 100169 3 snd_ens1371,snd_ac97_codec,snd_pcm_oss
snd_timer 33605 2 snd_seq,snd_pcm
snd 57157 12
snd_ens1371,snd_rawmidi,snd_ac97_codec,snd_seq_oss ,snd_seq,snd_seq_device,snd_pcm_oss,snd_mixer_oss, snd_pcm,snd_timer
snd_page_alloc 9669 1 snd_pcm

plus; soundcore 10913 1 snd

plus;
bt878 10457 0
tuner 27121 0
bttv 161393 1 bt878
video_buf 23749 1 bttv
i2c_algo_bit 9289 1 bttv
v4l2_common 5825 1 bttv
btcx_risc 4937 1 bttv
tveeprom 13017 1 bttv
videodev 9537 1 bttv"

fuser /dev/dsp /dev/audio returns nothing.
fuser /dev/mixer returns - /dev/mixer	19079

"I have moved my sound and TV cards to new slots and securely reset all
my speaker leads.  My Windows XP setup works perfectly with the
following settings:

WindowsXP
Vol Control:  40%
Wave: 40%
SW Synth: 95%
Line-in: Mute
CD Audio: 50%"

*note Synth devices in linux*
/proc/asound/oss/sndstat shows

Sound Driver:3.8.1a-980706 (ALSA v1.0.9rc2 emulation code)
Kernel: Linux CASE 2.6.12-1.1398_FC4 #1 Fri Jul 15 00:52:32 EDT 2005 i686
Config options: 0

Installed drivers: 
Type 10: ALSA emulation

Card config: 
Ensoniq AudioPCI ENS1371 at 0xdf00, irq 11

Audio devices:
0: ES1371 DAC2/ADC (DUPLEX)

Synth devices: NOT ENABLED IN CONFIG

Midi devices:
0: ES1371

Timers:
7: system timer

Mixers:
0: SigmaTel STAC9721,23

"I have played around with my mixer settings so often I no longer
remember the original installed settings. I am flumexed.

I have googled for four weeks now. TLDP How To's seem out of date. 
ALSA site has material that was published in 1999 and is largely 
irrelevant to my problems.  No where is there a clean simple explanation 
of what the various mixer choices are for or what the various modules do. 
So besides an answer to the specific question above. Where can I get 
started leaning about using (really basic) sound?"

As user I still get event sounds after I have muted everything in
alsamixer - volume control.  Even stranger, if I go to /usr/share/sounds
in File Browser and just focus the cursor (i.e. don't click) on a *.wav
event file I get the sound in spite of everything being muted and the
files being owned by root (other is set to r).

As root user I don't get sounds being played on focus, but I do get
sound through Helix even though everything is muted.

In both cases the sound has background distortion, which is the main
problem I am trying to solve.

Is it possible that something is somehow getting loaded before ALSA and
taking over the sound system before ALSA has a chance to take control??

I have spent a week following through the PAM permissions for sound (it was about time I 
learnt PAM).  Everything seems to be in order.  However, any fixes I do find (eg. At the 
RH bugzilla site or the ALSA site) keep getting changed back at login. And I can't find 
what program is doing that.

Regards Bill