Guitar RackCraft

A real-time guitar effects processor for Android. Hosts 120+ LV2 audio plugins in a chainable rack interface with low-latency audio via Oboe and native plugin UIs rendered through a custom X11/EGL emulation layer.

Features

• Chain multiple LV2 plugins with drag-and-drop reordering
• Real-time audio processing with low-latency Oboe I/O
• Native X11 plugin UIs rendered on Android via custom X11 server + EGL
• Neural amp modeling (NAM, AIDA-X)
• WAV file playback through the effects chain
• Audio recording (raw input + processed output)
• Preset save/restore

Requirements

• Android 8.0+ (API 26), arm64-v8a
• JDK 17
• Android SDK (API 35, NDK 27.2.12479018, CMake 3.22.1)
• System packages: ninja-build meson python3 python3-mako pkg-config autoconf automake libtool gettext patch cmake flex bison ocaml ocamlbuild ocaml-findlib libnum-ocaml-dev

Build

# Initialize submodules
git submodule update --init --recursive

# Build native libraries
./build.sh

# Build and install debug APK
./run.sh debug

# Build release APK + AAB
./run.sh release

# Build Play Store AAB with asset packs
./run.sh playstore

Build flavors

Flavor	Description
full	All plugins bundled in a single APK
playstore	Plugins split into asset packs (gxplugins, neural, brummer) for Play Store delivery

Architecture

• Kotlin/Compose - Android UI layer
• C++17 - Audio engine, LV2 host, X11 server
• Oboe - Low-latency audio I/O
• lilv - LV2 plugin loading and management
• Cairo/Mesa - 2D/3D rendering for plugin UIs
• X11 emulation - Custom minimal X11 server bridging native plugin UIs to Android surfaces

See 3rd_party/README.md for the full list of dependencies.

License

GPLv3 - see LICENSE.