[pulseaudio-discuss] PulseAudio questions

Lennart Poettering lennart at poettering.net
Mon Sep 3 10:26:53 PDT 2007

On Tue, 28.08.07 13:39, Nikita V. Youshchenko (yoush at cs.msu.su) wrote:

> > It is very difficult to debug this from here. I think the workaround
> > in PA would be far from trivial.
> I'm willing to help debugging. What should I do/check/etc ?

Please send me a (full) gdb backtrace when the assert is hit. And also
send me a full "strace -f" up to the same point. Both things together
should help me further quite a bit.

> > > 4. Is there any audio mixer application that may run within KDE's
> > > panel, and control audio volume in this configuration.
> > > KDE's kmix talks to ALSA directly. I was able to fool it by writing in
> > > alsa configuration file that ctl 'hw' is 'type pulse', and it even
> > > worked. But real 'hw' device has parameters, so my hack resulted in
> > > kmix recognized 32 mixers :).
> >
> > 32 mixers? How come? Please explain?
> nikita at desktopvm:~> cat /tmp/xxx
> ctl.hw {
>     type pulse;
> }
> pcm.default {
>     type pulse
> }
> ctl.default {
>     type pulse
> }
> nikita at desktopvm:~> ALSA_CONFIG_PATH=/tmp/xxx kmix --nofork
> And see how many mixer it finds. Oh, there are not 32, only 20 :)
> Looks like kmix tries to open different ALSA mixers, and with such a config 
> all those are opened successfully and forwarded to pulseaudio.

Hmm. This looks like serious misuse of the ALSA API from the kmix
people. Please report this to them.

If I understood correctly they make up devcie names and try if they
work? That'd be silly...

> > > Maybe it is possible to set up things such that 'hw' only with
> > > particular parameters is 'type pulse', and with all other parameters
> > > it is non-existent?  Or just use another mixer app which is more
> > > pulseaudio-friendly (but still runs in KDE panel!)
> >
> > I am sorry. I have no experience with KDE. Presumably you can use the
> > combination of padevchooser and pavucontrol.
> The question was more about ALSA than about KDE.
> Probably I may write something in the alsa configuration file that ctl hw 
> only with particular parameters will be forwarded to pulse, and all others 
> will be reported as non-existent.

The proper place to fix this seems to pe KDE for me. I'll add dirty
workarounds to PA only if nothing else works. But KDE is free
software, so please give them a ping!


Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net         ICQ# 11060553
http://0pointer.net/lennart/           GnuPG 0x1A015CC4

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