[kde-linux] Re: sound problem

[Duncan]

James posted on Wed, 08 Jun 2011 00:08:14 -0400 as excerpted:

> I have KDE-4.6.3.
> When I have 2 tabs in Dolphin and try to close the window, I get a
> warning sound.
> Test for all output devices listed under Computer/System Settings/Phonon
> don't produce sound.
> default - the audio playback service default does not work. Falling back
> to default HDA NVidia #1 HDA NVidia
> 
> Amarok sometimes works and sometimes doesn't.
> Dragon player is also sometimes.
> Vlc never works.
> 
> There used to be a command line wrapper for aRts, is there one for
> Phonon?
> 
> Audacity says "No devices found" when I try to set the output playback
> device in the preferences.
> 
> kscd says "the audio playback service default does not work. Falling
> back to default".
> 
> Does Phonon use udev?

I'm not sure quite how the logic of the thing works (udev or what), but 
it's worth noting that there's several possible phonon backends.  Many 
people have had much better luck changing it to something other than what 
they were using originally.  FWIW, I was using phonon-xine and switched to 
phonon-vlc and the phonon issues I was having disappeared.

Also, phonon-xine is I believe deprecated now, and they're encouraging 
people and distributions to switch to something else. With 4.6, phonon-
gstreamer became the default backend for kde upstream, but that doesn't 
necessarily mean that's the distribution default. But I had problems with 
gstreamer years ago and haven't had it installed at all for years, so 
tried phonon-vlc first, and it cured the phonon problems I was having. =:^)

So try switching to either phonon-vlc or phonon-gstreamer (or try both and 
see if one works, if you're still on phonon-xine and the first one doesn't 
work), and see if that helps.

But you already mentioned that vlc was having problems too, so phonon-vlc 
may well not help either.  What's interesting here, however, is that vlc 
itself is not a kde app.  If it's having problems too, then it's quite 
possible simply switching backends won't help, as it seems the problem is 
lower down in the stack.

If you have pulse-audio enabled, that's another layer that could be 
causing problems.  (FWIW, I won't install it here on Gentoo, as another 
layer to cause potential problems is NOT my idea of fun, but some 
distributions don't give you much choice in that regard.)

Or it could be alsa itself, or your hardware.  In particular, various 
laptop hardware has issues with the sound hardware being too eager to 
power-save, with alsa mistaking the power-saving mode for disabled/turned-
off/entirely-disappeared.

I *DO* know that the kernel alsa hda driver is still under active 
development (I regularly run direct upstream Linux git tree testing 
kernels), in that they're constantly tweaking it in each new kernel, 
adding support for newer model hardware, tweaking this or that bit that's 
still broken on the last couple of generations (tho older hda hardware 
tends to be more stable), etc.  Thus, it could very well be that you'll 
have better luck with a newer, or possibly older, kernel, too.  But of 
course if you don't build your own kernels, your choices of distro kernels 
are often somewhat limited, and unless you have the time and motivation to 
learn how to build your own, you may simply have to wait for a newer one 
and hope that fixes the problem.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman