Open source & licensing
Cue2 application
Cue2 application code is released under the MIT License. See the LICENSE file in the source repository.
You are free to use, modify, and redistribute Cue2 under the terms of that license. The software is provided as-is, without warranty.
Copyright © 2025–2026 Samuel Moxham.
FFmpeg
Cue2 loads FFmpeg shared libraries dynamically at runtime for decode and related media work. Bundled FFmpeg binaries are distributed under LGPLv2.1 or later.
Implications for distributors and packagers:
- Dynamic linking is the intended LGPL-compliant pattern used by Cue2.
- Corresponding FFmpeg source for the bundled library versions is provided via project documentation and/or GitHub Releases as described in the repository.
- Patent and codec considerations for certain formats remain the responsibility of whoever redistributes or deploys those codecs.
The LGPLv2.1 text ships in the application LICENSES folder. The RtMidi license is LICENSES/RtMidi.txt.
MIDI
Cue2 uses RtMidi 6.0 (MIT-style, Gary P. Scavone) for MIDI device input and output. Platform natives are loaded at runtime the same way FFmpeg natives are:
| Platform | File |
|---|---|
| Windows (x64 and arm64) | rtmidi.dll |
| macOS (arm64) | librtmidi.dylib |
| Linux (x64 and arm64) | librtmidi.so |
Linux builds are ALSA-only and need system libasound.so.2 (libasound2 / libasound2t64 on Debian/Ubuntu). JACK is not required.
Project: github.com/thestk/rtmidi
OSC
Cue2 uses Rug.Osc (MIT) for OSC send and receive.
Project: bitbucket.org/rugcode/rug.osc
Other dependencies
| Dependency | Role | License |
|---|---|---|
| Godot Engine | Application runtime | MIT |
| SDL3 / SDL3-CS | Audio device I/O | zlib |
| FFmpeg (native libraries) | Media decode | LGPLv2.1+ |
| FFmpeg.AutoGen | C# bindings for FFmpeg | MIT |
| RtMidi | MIDI device input and output | MIT-style |
| Rug.Osc | OSC send and receive | MIT |
Attribution for these libraries appears in the in-app About dialog (Help → About Cue2). Always check that dialog and the LICENSES folder for the build you ship — versions can move between releases.