Developer Guide

Mixxx Developer Guide

The purpose of this guide is to give you, our intrepid contributor, an overview of the Mixxx codebase. Mixxx is a big project with millions of lines of code so it can be daunting at first. If you know how to get around then it really isn't that big and scary.

This guide is a work in progress. If you have any questions, join the Mixxx Zulip chat to get live help from developers

Prerequisites

First, get the code of Mixxx using Git.

To understand this guide, you should have a working experience with a systems language like C, C++, or Java. You should be able to get by with trial and error even if you don't know these. It will help significantly if you have some experience with the Qt Framework which Mixxx uses extensively.

We also highly recommend that you use a C++ IDE rather than a text editor. Mixxx is a huge project spread across hundreds of source code files. IDEs index the entire code tree and allow you to jump from where a function is used to its definition, even if that is in another file (which it often is). Without this powerful tool, you will spend a lot of time simply finding the code you're looking for instead of understanding what it is doing. We have guides for setting up several IDEs to work on Mixxx, but feel free to use whatever IDE you prefer.

Please check out the Learning resources page to learn about the basics and underlying concepts

Core Infrastructure

These are the fundamental building blocks used almost everywhere in Mixxx. You should skim these first so that you aren't confused when you see them in other sections.

• Control System (ControlObjects)
• Config System (ConfigObject, ConfigKey)

Major Subsystems

• Startup
• Library
• Shoutcast
• Mixing Engine
• Deck/Sampler Processing
• Effects Framework
• SoundManager (OS audio interface)
• SoundSource (per-format audio decoding)
• Analysers (beat detection, key detection, waveform analysis, replaygain, etc.)
• Vinyl Control
• Controllers (MIDI, HID, etc.)
• Keyboard Control
• Preferences Dialogs
• Waveforms
• Skins
• GUI Widgets (non-skin)