I'm trying to connect PureData with LMMS... watched this video:

But it doesn't work for me. After I click on ALSA (like the guy in the video) I get this error:
"ALSA output error (snd_pcm_open): Device or resource busy"

I found this forum topic: http://puredata.hurleur.com/sujet-1396-alsa-issues

but running pd with "-alsa -alsaadd default" added does not solve the problem for me...

My specs:
Ubuntu up to date
PureData 0.43.4

Things have probably changed since that 2008 forum post. By now most Linux systems run Pulseaudio by default and Pd seems to be the only application not to work with Pulseaudio, but requiring an alsa device for itself. In order to play Pd together with other apps, everything must be routed through Jack. Pulseaudio can be routed through Jack too. There is a pd-dev list thread on this topic, starting here:

http://www.mail-archive.com/pd-dev@iem.at/msg12160.html

The cool thing about this routing is: you can eventually send audio from any app to Pd and vice versa, including those apps which are not Jackified. I got this working on Xubuntu. But not on Kubuntu, unfortunately! Still have to find out why.

Katja

I'm stuck here... I only understand around 40% of what these devs are talking about... Installed jack and trying to route everything through jack... but than in pd I don't have "jack" under "Media"...

Hi,

If you don't have "jack" under "Media", it probably means that Pd was compiled without Jack support. With "PureData 0.43.4", do you mean vanilla Pd? I'm using Pd-extended 0.44.0 from the nightly builds, and it does have Jack support. Vanilla Pd (0.45.0 is the latest) can be compiled with Jack support too, I could find out how if you need it. Sorry that it all sounds so complicated. Linux audio is confusing. But if you get things working it seems more flexible than other OS.

Katja

No I'm also using pd-extended.. how do I build it with jack support?

I guess you didn't compile Pd-extended yourself (because I would expect you have 0.44 in that case)? Correct me if I'm wrong.

Pd-extended binary builds (from puredata.info and the nightly builds) have Jack support by default, to my knowledge. If you have a binary build installed and it doesn't show 'jack' in the media menu, something else may be wrong, which I cannot understand right away.

What do you use, self-built or precompiled binary? (If it's the binary it makes no sense to compile your own, too much work for probably no improvement).

Katja

I spend one sleepless night a while ago installing all the dependencies. I can compile it with no problem. The reason for that is that ubuntu ppa didn't work that night.. today I see it's working...

So I installed it from ppa right now...

Great! Now I have jack in media... how do I set this up?

OK cool. Don't know if LMMS has Jack support but in that case it could be simple: first start Jack and then the 'clients' LMMS and Pd-extended. But it may not be simple if Pulseaudio is in the game too. What I have done, is to prevent Pulseaudio from autospawning so that I can turn it on or off at will (various ways to do this are described online). I installed pulseaudio-module-jack. Now, pulseaudio can be an autoconnected Jack client just like Pd and others. So first make sure that Pulseaudio, Pd or other ALSA clients are not running, and start jack via qjackctl. Then start Pd, and on command line, start pulseaudio. In the qjackctl connections graph Pd and pulseaudio should both appear automatically. That is, if you have jackd2 installed and not the older jackd1 (important). You can change the connections routings to your liking. Pulseaudio can thus be considered a submixer of Jack, mixing all the non-jackified applications. This is how I mix the video editor together with Pd, but I can also send the video editor's signal to Pd by changing the routing of Pulseaudio in Jack. Sometimes I accidentally try to start jack when there's already an ALSA client running (Pd in most cases), and this will confuse Jack. I get a D-BUS error, which won't go away till I manually kill the process jackdbus. This can be done from the task manager or with command htop.

The above doesn't sound very user-friendly, does it? And I did not get it working on Kubuntu. Soon as Pd is started, all other signal-streaming apps just freeze. It works fine on my Xubuntu though. So I'm eager to know how it works for you on Ubuntu.

Katja

ok. so this are the steps I have to make:

1. make sure that pulseaudio is not running (not sure how.. i guess "pulseaudio -k" kills it)
2. start qjackctl
3. click start
4. start pd-extended
5. start pulseaudio

Last step fails i think:

E: [pulseaudio] pid.c: Daemon already running.
E: [pulseaudio] main.c: pa_pid_file_create() failed.

In qjackctl Connections under "Audio" pd_extended_0 and PulseAudio JACK Sink are added. But from here I'm lost. I'm actually giving up on lmms and trying out ardour. Will report the progress.

I actually got it working with ardour.

Steps:
1. Start jack and ardour
2. Create Session and add new track for pd
3. Start pd with -jack option
4. Select Jack under Media
5. Go to qjackctl -> Connections and connect pd outputs on the left with the ardour's "pd" entry on the right.
6. This way I can record pd output in Ardour. Which is actually what I need.

Thanks for help and your patience with me... you were awesome!

1. make sure that pulseaudio is not running (not sure how.. i guess "pulseaudio -k" kills it)

It takes just one more step to include Pulseaudio in the game too. Pulseaudio can be killed, yes, but it autospawns within one second or so. Therefore it is possibly muted by command pasuspender, issued by one of the other apps. You need to prevent autospawning of Pulseaudio so you can control it's start and stop moment, which matters for any Jack client. It is a matter of putting 'autospawn=no' in a Pulseaudio config file. It can be somewhere in /etc butI have it in ~/.pulse/client.conf (create if it's not yet there). The exact text is:

autospawn=no
daemon-binary=/bin/true

I cant't remember where I found this info but it works. Pulseaudio isn't autostarted and I can start it at will by issuing command 'pulseaudio', and stop it with ctl+c. It's also possible to start with 'pulseaudio --start' and stop with 'pulseaudio --kill' if you want to return the command to do other things in that terminal window. But I find it useful to see possible error messages from Pulseaudio.

Pulseaudio messes up my alsamixer settings frequently!. I have an ALSA mixer in the panel, it's called xfce4-mixer. When Pulseaudio is started, I get pavucontrol in the panel too so I have two mixers. Sometimes, Pulseaudio just disables xfce4-mixer's master channel, or it sets mic input to max so I get extreme distortion. That's why I dislike Pulseaudio, and I want it to start only when it's really indispensible (that is, when non-Jackified apps must be mixed with Jackified apps).

Katja

Sorry to necro this thread, but I finally found out how to run PureData under Pulseaudio (which otherwise results with "ALSA output error (snd_pcm_open): Device or resource busy").

First of all, run:

pd -alsa -listdev

PD will start, and in the message window you'll see:

audio input devices:
1. HDA Intel PCH (hardware)
2. HDA Intel PCH (plug-in)
audio output devices:
1. HDA Intel PCH (hardware)
2. HDA Intel PCH (plug-in)
API number 1

no midi input devices found
no midi output devices found

... or something similar.

Now, let's add the pulse ALSA device, and run -listdev again:

pd -alsa -alsaadd pulse -listdev

The output is now:

audio input devices:
1. HDA Intel PCH (hardware)
2. HDA Intel PCH (plug-in)
3. pulse
audio output devices:
1. HDA Intel PCH (hardware)
2. HDA Intel PCH (plug-in)
3. pulse
API number 1

no midi input devices found
no midi output devices found

Notice, how from the original two ALSA devices, now we got three - where the third one is pulse!

Now, the only thing we want to do, is that at startup (so, via the command line), we set pd to run in ALSA mode, we add the pulse ALSA device, and then we choose the third (3) device (which is to say, pulse) as the audio output device - and the command line argument for that in pd is -audiooutdev:

pd -alsa -alsaadd pulse -audiooutdev 3 ~/Desktop/mypatch.pd

Yup, now when you enable DSP, the patch mypatch.pd should play through Pulseaudio, which means it will play (and mix) with other applications that may be playing sound at the time! You can confirm that the correct output device has been selected from the command line, if you open Media/Audio Settings... once pd starts:

As the screenshot shows, now "Output device 1" is set to "pulse", which is what we needed.

Hope this helps someone!

EDIT: I had also done changes to /etc/pulse/default.pa as per https://wiki.archlinux.org/index.php/PulseAudio#ALSA.2Fdmix_without_grabbing_hardware_device beforehand, not sure whether that makes a difference or not (in any case, trying to add dmix as a PD device and playing through it, doesn't work on my Ubuntu 14.04)