Have you ever wondered how WirePlumber, PipeWire's default session manager, can be customized to tune PipeWire on your embedded Linux system for a particular use case? Recently, we had the opportunity to work with a customer who needed to do exactly that. Knowing that people are often confused about this configuration process, I wrote an article that explains it in detail, based on my experience from this project.

WirePlumber’s configuration is organized around components and profiles. Components represent the individual modules and scripts that provide specific functionality. Each component is described with attributes such as its name, type, and the features it provides. Components can also declare dependencies using requires (mandatory dependencies) and wants (optional dependencies), allowing for a flexible and modular loading process where components are only loaded if they are needed.

Profiles, on the other hand, define which components are loaded for a particular use case. Each profile has a name and can specify which component features are required, disabled, or left optional. Profiles can also inherit from other profiles, making it easy to build on existing configurations and avoid duplication. This structure allows users to tailor WirePlumber’s behavior to their specific needs by enabling or disabling features as appropriate for their environment.

When building custom configurations, it is good common practice to drop in configuration fragment files, which allow you to override specific parts of the default upstream configuration. Among other things, you can override profiles and change which components they load or which other profiles they inherit from. This was the approach taken in our customer's project where we modified the default main profile, avoiding the need to change the systemd unit to load a custom profile.

Features unnecessary for the customer's use case, such as video capture and MIDI device monitors, were explicitly disabled. This streamlined the system to focus solely on audio functionality, while still allowing some video-related features like screen sharing to work. Additionally, we disabled modules and scripts related to state management, Flatpak and Snap access rules, and various other desktop-oriented features. This careful selection and disabling of features resulted in a minimal, clean configuration, optimized for the specific requirements of this embedded Linux environment.

If you are interested in more details, you can read the full article here.

Should you need assistance navigating PipeWire's and WirePlumber's customization options further, contact us to learn how exactly they can be tailored to your product's needs.