ALSA, JACK and PulseAudio... what a mess

[T3STY]

As I was looking for a replacement for Nero Wave Editor I found and installed ardour (graphical audio editor), then I run it and ... it gives me and error about not finding the JACK audio server. I search and get information about JACK and I find out that it is a full audio server capable of driving application's audio from/to the real sound card, by using ALSA as a backend.
Since I read it can drive very low latency audio from apps to ALSA, I thought I could totally replace PulseAudio with JACK. Can that be done? Is it safe? The information on the website is not really clear about that so I hope you can tell me more. Also, if JACK drives low latency audio, why wasn't it integrated as audio server in any Linux distribution (including Fedora, obviously)?

[DBelton]

Pulseaudio is supposed to give control to jack when jack is running. You can configure pulseaudio to route it's input/output through jack if you want, but then you need to run jack all of the time.

Edit:

You may want to look at the Fedora guides on Jack.

http://docs.fedoraproject.org/en-US/...sing_JACK.html

And specifically the one pertaining to pulseaudio and jack running together

http://docs.fedoraproject.org/en-US/...with_JACK.html

[assen]

Hi,

If low latency is your goal, no use to concatenate pulse to jack - only use jack.

Why isn't jack default for Linux? Well, very few apps support it natively; or maybe very few apps support it because it was never pushed into a mainstream distro - like RH did with Poettering's monster (PA) many years ago.

WWell,

[DBelton]

I totally agree with you, assen, but as you say, it's hard to get rid of pulseaudio and use jack totally, even though that would really be the best.

I also totally agree that Poettering created a monster with pulseaudio, same as he is doing with systemd.

[Fenrin]

I am not using pulseaudio under Fedora 18 currently. Gnome 3 requires it, but actually it works without it just fine.

removing it without removing gnome 3 is for example possible via:

rpm -e --nodeps pulseaudio

I am using OSSv4 instead of Alsa. If you want to give OSSv4 a try, there are two options to install. Either install the proprietary licensed rpm or install the GPL licensed version from here: http://www.4front-tech.com/developer...es/stable/gpl/

[T3STY]

Thank you for the replies guys!
I was looking to remove PulseAudio too because skype through PulseAudio outputs scratchy audio (most of it is noise) and I'm unable to use the microphone. Then, since I'd need JACK for ardour I thought I could simply use it alone without PulseAudio.
About OSSv4, I never tried to remove ALSA, not even in virtual, so I'm pretty sure I'd break most of the system. I'll make a virtual machine for testing then I'll try it... in the meanwhile, do you know of any good guide for replacing ALSA with OSS?

[Fenrin]

no good OSSv4 specific guides for Fedora I dont know. For Arch LInux is here a wiki post about OSS: https://wiki.archlinux.org/index.php/Open_Sound_System

before you install it, you must have kernel-header, kernel-devel, binutils and other packages (perhaps already installed) have installed.

For applications which use OpenAL you have to edit this file: /etc/openal/alsoft.conf
in the line where it says driver= there should be only oss.

I read that mumble could have issues with OSSv4 for example. About Skype I don't know. For me the sound in Firefox is not working (in Opera and Epiphany, gnome-mplayer it works).

After it is installed you should reboot. If you have installed gtk2-devel before installation, you can use ossxmix as soundmixer. The commands soundon, soundoff, osstest can be used to see if it is working.

[Fenrin]

just got OSSv4 on a Debian Wheezy based linux working, the things I had to do:

su
apt-get install automake binutils DKMS libgtk2.0-dev oss-compat
apt-get remove alsa
exit

the headers of the kernel has to be installed as well.

then download the latest GPL licensed *.tar.bz2 archive here. Extract it, navigate into its folder and then:

mkdir ./BUILD
cd ./BUILD
../configure
make
su -c 'make install'

the sound in gnome-mplayer doesn't work out of the box. I remember I had to do the same under Fedora with gnome-mplayer. Below preferences→mplayer→additional parameters should be -ao oss. Then sound in gnome-mplayer works. The sound in Iceweasel (Debians Firefox like browser) works as well.

Under Fedora alsa has not to be uninstalled - it has too many dependencies there.

[dknation]

Just install qjackctl (it's in the repos) if not already installed, and run it.
From there you can adjust your jack-settings and then start Jack.
Jack will put PA aside while running and PA will start again when you stop Jack.
It's been a while since I used Ardour now, but I think there is an option to let Ardour start Jack for you when you open Ardour,
so you don't have to remember to start Jack before Ardour all the time.
Maybe you'll have to stop Jack manually, in order to get PA running again.

I have had a setup once with no PA, only using Alsa and also Jack when it was needed.
I was using Fluxbox at the moment.
Actually I don't think PA is such a bad idea.
Alsa cannot handle audiostreams at different bit rates simultaneosly.
PA can do that.
It might not be of any importance for some, but if you listen to some audiofiles, want to hear system sounds and whatever more it might be, PA is the answer.
Also, Spotify depends on PA, if you are planning to use that.

EDIT: Oops! Sorry for the bump. I didn't see it was a month ago.