Feature Request: Per-Application Audio Sink Routing (Independent of Default Output)

[Thayuno]

Select Topic Area

Feature Request

Body

Feature Request: Per-Application Audio Sink Routing

Description

The current audio sink implementation is limited because it is hard-coded to capture the system's default output. To function, it forces the entire system's default output into the sink.

This creates a significant usability issue: if I want to share only one specific application's audio (e.g., Nucleus Co-op) with a remote client while keeping my other activities private, I have to do the opposite of what is intuitive. Since the client "hears" everything on the default device, I am forced to manually redirect every other running application to my headphones.

The Problem: It is counterintuitive and far more labor-intensive to redirect every application I don't want to share than to simply select the ones I do.

Proposed Change: Per-Application Audio Sinking

I propose implementing audio sinking on a per-application basis. For example:

• Desktop Mode: The client continues to capture the default output as it does now.
• Virtual Desktop/Specific Applications: The sinks a dedicated device (e.g., Steam Streaming Speakers), without changing the system's global default output.

This would allow for routing specific programs to a virtual output automatically or manually without affecting the rest of the system's audio routing.

Use Case & Motivation

I often play co-op games with friends or let them play remotely while I study or watch YouTube videos. I want to prevent our audio streams from mixing.

Current suboptimal workaround:

1. Set the Steam Streaming sink as the Global Default Output.
2. Manually move every other application (Browser, Music, System Sounds) to my physical headphones.
3. Every new program opened must also be manually redirected to avoid being heard by the client.

Desired Workflow:

1. Keep my headphones as the System Default Output.
2. Simply route the Game/Program to the streaming sink.
3. The rest of the system audio remains untouched, private, and local.

Technical Summary

By allowing the sink to be configured per application, the software can create a dedicated monitor for virtual audio that only captures intended streams. This leaves the "Default" device exclusively for the local user, eliminating the need for complex manual re-routing.

[ReenigneArcher]

LizardByte/roadmap#31

[NIICKTCHUNS]

Would be nice to have an option to select specific applications to remove their audio from being captured on Linux, this is already possible with an plugin to OBS, it works extremely well, it should be able to do, look at this https://github.com/dimtpap/obs-pipewire-audio-capture

This project uses PipeWire to do the audio capture, as far as I know, sunshine uses PulseAudio which is an old solution, but I don't really know if this is possible to do with Pulse. But what really matters is the feature anyway