Re: [Alsa-user] SoundBlaster Live, recording (fwd)

[Takashi I. <ti...@su...>]

At Wed, 10 Jul 2002 09:03:31 +0200 (MEST),
Dominik Szczerba wrote:
> 
> Hi
> 
> I see a discussion on soundblaster live so I try again:
> 
> I saw below quoted pieces of informations on your FAQs:
> 
> --------------------
> 
> >>  However, the resulting WAV file doesn't contain any sound.
> >
> > From alsa-driver/doc/SB-Live-mixer.txt:
> > name='AC97 Capture Volume',index=0
> > This control is used to attenuate samples for left and right front ADC
> > PCM slots
> >
> > and you have:
> >        control.16 {
> >                comment.access 'read write'
> >                comment.type INTEGER
> >                comment.range '0 - 100'
> >                iface MIXER
> >                name 'AC97 Capture Volume'
> >                value.0 0
> >                value.1 0
> >        }
> 
> ------------------------
> 
> Would you please explain me what you are talking about? I seem to have
> exactly the same problem (with line-in, I havent tried microphone yet).
> It worked *ONCE*, played back recorded wav, then didnt want to record
> anymore.
> 
> What files are you taling about?

the file above is taken from /etc/asound.state.
this file is generated by alsactl utility program, and contains all
current mixer/control status of the card(s).

to get this file, run "alsactl store" as root.
you can save as a different file via -f option.  see help or man page.

the file is a general text file.  you can read and edit it.
after changing it, you can restore it via "alsactl restore".

> What is .asoundrc?

this is a different file.
this defines your own configuration of pcm, control, etc.
confusingly there is another file, /etc/asound.conf, which is similar
with ~/.asoundrc file but defined as global, not for a user.

> What is this long "control" file you are quoting? (it looks a bit like
> output of amixer, but mine produces another kind of list.)

the output of amixer is an "interpreted" version of control status.
there is no exactly "mixer" api on alsa.  there is only "control"
api.  the mixers belong to controls.

anyway, amixer tries to compose some control elements as one mixer
item.  for example, "AC97 playback switch" and "AC97 playback volume"
will be combined as one mixer element "AC97".
what you'll see on the output of amixer is the list of these combined
elements, such like "AC97".  on the other hand, /etc/asound contains
the control elements, i.e. such like "AC97 playback volume".


now, backing again to your problem.
i guess you didn't adjust "AC97 Capture Volume".  this is the volume
to be routed from AC97 to FX8010 engine.
there are several ways to change them. the easiest one is to use
alsamixer program.  run alsamixer, and look for "AC97 Capture" item,
and increase the value.

there is also "Capture" volume.  this is the capture volume adjusted
inside AC97 chip.  you need to adjust this value as you like.

in addition to them, you need to choose a correct capture source,
i.e. Line.  (choose it by space key).
btw, the "Line" volume has nothing to do with capture volume.  it's a
playback volume.


Takashi