Can I establish "automatic" connections in Pipewire?

m_square · 2021-08-21 09:48:53

Hello there!
First of all I am sorry for the vague title, I am fishing somewhat in the dark myself. But please let me explain...

I got pipewire setup successfully. All my clients are working, low latency for recording in a DAW is there and helvum lets me connect nodes to my hearts content.
What I don't understand is how to either save said connections between nodes or establish some kind of matching rules for nodes.

Let me give you an example:
I'd like to be able to EQ my media streams from the web. Therefore I want Firefox to output into a calf/carla rack and that should output to the soundcard.
I dabbled a bit in pw-cli and can see the potential in using create-link. But that wants <node-id> <port-id>. Those ids are changing every time a node is created. For instance a Firefox node is created and destroyed depending on whether it's playing audio or not. Is there a solution to use the property application.name to establish links? I guess, then I could come up with a script to start everything.

I am totally dumbstruck with this, any pointers will be greatly appreciated.

Greetings,
Markus

d_fajardo · 2021-08-21 10:57:25

This sounds pretty much like inter-process communication. You can take a look at D-Bus if it could help. This is my wild guess.

m_square · 2021-08-21 11:17:22

Hi @d_fajardo thanks for your reply,
but no, not really. I'm talking about the "virtual cables" in pipewire. Just like in Jack where you can route the signal between clients. There is even a GUI for that ( helvum). I just want to somehow save where I plugged the different clients within the chain.

d_fajardo · 2021-08-21 11:25:51

Thanks for clarifying. I didn't mention I don't use Pipewire that's why it was a wild guess, but I do all my routing via JACK when I need to. Then I just let Pulseaudio without interference for the usual.

Maniaxx · 2021-08-22 09:52:45

I used to use Jack Matchmaker with auto-connect disabled in pipewire.
The problem with that is that you have to define every program/node. Any unknown one will be unconnected. That's not optimal.

These days i use an ALSA loopback device (snd-aloop) and define it as default device. This loopback device can be placed freely in the audio graph in Carla/Catia/qjackctl etc.

I do the saving/creation of the graph with Carla only. I'm not sure if it can be done with Pipewire (maybe with the session manager or wireplumber, i don't know).

Last edited by Maniaxx (2021-08-22 09:57:28)

m_square · 2021-08-22 15:54:35

Hey @Maniaxx,
thanks for the suggestion. That sounds promising.
I'll look into it in the next few days when there is some time.

Arch Linux

#1 2021-08-21 09:48:53

Can I establish "automatic" connections in Pipewire?

#2 2021-08-21 10:57:25

Re: Can I establish "automatic" connections in Pipewire?

#3 2021-08-21 11:17:22

Re: Can I establish "automatic" connections in Pipewire?

#4 2021-08-21 11:25:51

Re: Can I establish "automatic" connections in Pipewire?

#5 2021-08-22 09:52:45

Re: Can I establish "automatic" connections in Pipewire?

#6 2021-08-22 15:54:35

Re: Can I establish "automatic" connections in Pipewire?

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