Re: [gentoo-user] Pure Data (Pd) can't access ALSA device

[Lasse Pouru]

I don't (and won't) use PulseAudio and haven't set up dmix or anything
like it. The weird thing is the simultaneous audio works with every
other program I use (Qutebrowser, mpd, Audacity etc.) -- it's only Pd
that gives the error.

I already use JACK when recording but it would be more convenient for me
to use ALSA when I'm just quickly trying out stuff. (I've set up JACK to
use an audio interface I don't have plugged in most of the time.)

- Lasse

Daniel Sonck <daniel@×××××.nl> writes:

> This sounds pretty normal to me. ALSA isn't really suited for simultaneous
> audio access. In general with ALSA you have only one program that can use
> audio at a time, or you use the mixer module from ALSA. I assume a program
> running on the background has claimed ALSA already for certain reasons.
>
> If you run PulseAudio (which is pretty standard on a regular desktop), this
> one will be the cullprit. Usually the jack tools are smart enough to suspend
> pulseaudio. You can in fact run puredata through the pasuspend script which
> suspends pulseaudio so ALSA is free again.
>
> What I recommend (which you already tried) is using JACK. JACK will take
> ownership of your ALSA device, and gives you a capable routing system allowing
> you to hook up more than just PureData to your audio card. Optionally routing
> it to other software. In addition, it's possible to compile pulseaudio with
> jack support which means you can in fact have regular (non-audio) apps work
> together with jack, which is what I sometimes use: Set up my audio studio
> setup, while still having pulseaudio around for stuff like browsers and video
> players. If I suddenly have a creative spark, I have my studio ready to play
> with. When I'm done, browsers still work with sound
>
> Daniel
>
> On vrijdag 22 september 2017 18:23:10 CEST Lasse Pouru wrote:
>> I can't get Pure Data to work with ALSA. It detects my sound card, but
>> whenever I try to turn on the audio I get the error:
>>
>> ALSA output error (snd_pcm_open): Device or resource busy.
>>
>> I've tried both using the ebuild from the audio-overlay and compiling
>> from the source on the Pd website, both behave the same. I've read that
>> Pd deals with ALSA differently than most other programs, but haven't
>> found an explanation how. I did get it to work with JACK.
>>
>> - Lasse