Native pipewire support on Linux

[f1ori]

Hi,
is there native pipewire support on Linux planed or anybody working on this? With Fedora 34, the first Linux distribution makes pipewire the default. Pipewire would make configuration much easier, because it handles most audio use cases and doesn't need a special setup like jack.

[hoffie]

I think I remember that the Flatpak builds required pipewire support and it seemed to work, but I haven't tried myself yet. Maybe you can find the relevant code, scripts or configs by looking in the issues/discussions and/or on Flathub (?). I also assume that this made use of some compatibility (?) mode from pipewire.

So, without knowing any details about pipewire, but assuming that it is a new set of APIs, I'm pretty sure that there is no native support yet and I haven't seen any open issues or PRs about it either.

Have you tried using Jamulus with pipewire?

[hoffie]

I think anything which helps to make Jamulus work out of the box would be good.

I can't judge what exactly native pipewire supports would mean, but I would assume that something similar to the current jack implementation would be needed. Maybe someone else from @jamulussoftware/maindevelopers can comment on whether this would be acceptable.
Personally I think it is.

[jujudusud]

@f1ori did you go any further?

[jujudusud]

I think anything which helps to make Jamulus work out of the box would be good.

I can't judge what exactly native pipewire supports would mean, but I would assume that something similar to the current jack implementation would be needed. Maybe someone else from @jamulussoftware/maindevelopers can comment on whether this would be acceptable. Personally I think it is.

@hoffie , one thing to make Jamulus fully usable with PipeWire would be the implementation of runtime buffer size change.
There is a todo in the code about this. I actually read documentations to understand how to add this fonctionnality to Jamulus. Don't know for now how to do this in C++.

[jujudusud]

@jamulussoftware/maindevelopers Anything to say about adding runtime buffer size change on Linux?

[ann0see]

If you succeed go for it. But the audio functionality is quite hard to get right from my experience.

[jujudusud]

I think that pipewire comes to replace pulse audio which lives with Alsa by relying on the apulse library. Jack remains usable even in the presence of pipewire. As long as pipewire will not be at the level of Jack in terms of low audio latency and synchronization of the streams (jack transport) I think that it is not the place to go.
On the other hand, even if it is very convenient and powerful, Qjackctl is not the only way to change JACK settings.
It is also possible to do this from the command line.

[Beiri22]

But isn't pipewire intended to replace pulse and jack?

[jujudusud]

Pipewire is made to replace JACK + PulseAudio + Gstreamer.

[jujudusud]

And recently -> ffado

[jujudusud]

For information :
I installed 'PipeWire' + 'pipewire-jack' + 'Jamulus'.
I added 'Patchance' to set the buffer size and to route audio.
It works fine.

[jujudusud]

I'm bringing this thread up again to talk about my experience with PipeWire and Jamulus and a linux machine.

First of all, with a few settings, it works.

I'm using archlinux as operating system, ALSA + PipeWire for the sound server. PipeWire is providing JACK with pipewire-jack.
PipeWire version: 0.3.77
My kernel version: Linux 6.4.11 SMP PREEMPT_DYNAMIC x86_64 GNU/Linux

In order to have the best results in term of sound quality and lowest latency, I have to force the samplerate to 48 kHz and the buffer size to 128. I'm doing that with PipeControl.
If I don't apply these settings, I get an exploding delay and poorer sound quality.
Without settings applied: Ping 18 ms, Delay 95 ms, Jitter green. Some artifacts.
With settings applied: Ping 17 ms, Delay 53 ms, jitter green. Nearly no artifacts.

Just to let you know.

[pljones]

It might be worth writing this up as a KB entry.

[jujudusud]

Certainly.
What I'd like to know before writing this kind of "reference" document is whether there is a solution for launching software with the right samplerate and buffer size simply with a command line in a PipeWire setup instead of "bricking" the entire system.

[jujudusud]

Using :
PIPEWIRE_LATENCY=128/48000 jamulus
to lunch the application.
A good way to force Jamulus to use the right samplerate and buffer size.
There is another way, using PipeWire's Jack rules but, for now, I don't know how.

If anyone knows anything ... :-)

[jujudusud]

The best solution for now seems to be : https://gitlab.freedesktop.org/pipewire/pipewire/-/wikis/Guide-JACK

pw-metadata -n settings 0 clock.force-rate 48000
pw-metadata -n settings 0 clock.force-quantum 128

[jujudusud]

Now that the PipeWire 1.0.0 is out and many Linux distros Comes with it as default, what is the plan to document this new use case?

[ann0see]

I don't have much experience with pipewire yet. But if it's becoming default, it should (must) be documented

[jujudusud]

Thanks ann0see.
I opened an issue : number 979 of jamulus website here
I have to document that part. We should go to into this issue and the future PR to talk about the "how to document".
I have some ideas. I will explain as soon as possible what I'm thinking about that.

[jujudusud]

Done,

Please see PR of jamulus website number 980 : here