Some of the best apps are those that specialize in a single task. With Patchfield, a new open-source audio library for Android, you can create highly focused audio apps (such as synthesizers and effects) and then combine their capabilities by connecting them to one another in a virtual patch bay. Inspired by JACK, the JACK Audio Connection Kit, Patchfield provides a simple, callback-driven API for implementing audio modules, a flexible API for managing the signal processing graph, and support for inter-app audio routing. Patchfield is the 20% project of Peter Brinkmann, an engineer on the speech infrastructure team.

Running as a remote service, Patchfield allows audio developers to create interoperable apps that focus on a single task each, such as synthesis or effects or recording. The output of one app can be connected to the input of another, for a combinatorial explosion of possibilities. Running locally within a single app, Patchfield provides a powerful way of organizing the audio components of an app. The implementation resides entirely in user space and works on many stock consumer devices, such as Nexus 7 and 10.

Patchfield is available at GitHub, under the the Apache 2.0 License. The repository includes the core library as well as a number of sample projects that illustrate how to use Patchfield. Happy hacking!

DevBytes video: http://www.youtube.com/watch?v=LTisevoxm64

By Peter Brinkmann, Speech Infrastructure team