🎵 Note Naga MIDI Editor 🎵

A simple, feature-rich MIDI editor with advanced audio processing capabilities

Work in progress

Features • Screenshots • Installation • Usage • Architecture • Todo • Contributing

---

📖 Overview

Note Naga is a professional MIDI editor built with C++ and Qt, featuring a custom real-time audio engine. It provides comprehensive tools for MIDI composition, editing, mixing, and audio processing with an intuitive graphical interface.

✨ Features

🎹 MIDI Editing

• Piano Roll Editor - Visual note editing with grid snapping and multiple selection
• Multi-track Support - Unlimited MIDI tracks with individual routing
• Advanced Note Manipulation:
  • ✂️ Quantize notes to grid
  • 🎲 Humanize timing and velocity
  • 🎼 Transpose notes
  • 📊 Velocity editing and scaling
  • ⏱️ Duration editing and scaling
  • 🎵 Legato and Staccato modes
  • 🔄 Invert and retrograde transformations
  • 🧹 Delete overlapping notes
  • ⏰ Scale timing
• Flexible Grid System - Multiple resolution options (whole, half, quarter, eighth, etc.)
• Follow Modes - Center, left-side, step-by-step, and none
• Loop Playback - Seamless loop support for composition workflow

🎚️ Mixing & Routing

• Track Mixer - Per-track volume, pan, mute, and solo controls
• Visual Volume Meters - Real-time multi-channel volume visualization
• Instrument Assignment - Support for FluidSynth (SoundFont) and external MIDI devices
• Flexible Routing - Connect tracks to different synthesizers and DSP chains

🎛️ Audio Processing (DSP Engine)

The engine includes 18 professional DSP effects:

Effect	Description
🔊 Gain	Volume control with dB scaling
🎚️ Pan	Stereo positioning
⚡ Compressor	Dynamic range compression
🚫 Limiter	Peak limiting protection
🌊 Noise Gate	Automatic noise reduction
🎚️ Single EQ	Parametric equalizer (single band)
📊 Multi EQ	Multi-band equalizer
🎸 Filter	Low-pass, high-pass, band-pass filters
🌌 Reverb	Room and hall reverb effects
⏱️ Delay	Echo and delay effects
🎵 Chorus	Thickening and doubling
🌀 Flanger	Jet-like modulation
🎭 Phaser	Phase-shifting modulation
🔥 Saturator	Harmonic saturation and warmth
⚡ Exciter	High-frequency enhancement
🎪 Tremolo	Amplitude modulation
📡 Stereo Imager	Stereo width control
🎲 Bitcrusher	Lo-fi digital distortion

📊 Audio Analysis

• Spectrum Analyzer - Real-time frequency spectrum visualization
• Volume Indicators - LED-style volume meters with peak detection

🎬 Media Export

• Video Export - Export MIDI performance as video with visual piano roll
• MIDI Export - Save projects as standard MIDI files (coming soon)
• Customizable Video Settings - Resolution, FPS, codec options
• Real-time Preview - Preview video output before export

🎼 Synthesizers

• FluidSynth Integration - High-quality SoundFont-based synthesis
• External MIDI Support - Route to hardware synthesizers
• Multi-instance Support - Multiple synthesizer instances per project

🎨 User Interface

• Modern Dark Theme - Eye-friendly dark color scheme
• Flexible Dock System - Customizable workspace layout
• Keyboard Shortcuts - Efficient workflow with hotkeys
• Responsive Design - Smooth interaction and real-time updates

📸 Screenshots

Main Editor Interface

Audio Export Interface

Video export example: https://youtu.be/78l0hsS38Ow

🏗️ Architecture

Note Naga is built on a modular architecture separating the GUI from the audio engine:

Project Structure

NoteNaga/
├── src/                    # GUI application
│   ├── gui/               # Main window and UI components
│   │   ├── components/    # Reusable UI widgets
│   │   ├── dialogs/       # Dialog windows
│   │   ├── dock_system/   # Custom dock system
│   │   ├── editor/        # Piano roll editor
│   │   └── widgets/       # Track list, mixer, DSP widgets
│   ├── media_export/      # Video/audio export functionality
│   └── main.cpp           # Application entry point
│
└── note_naga_engine/      # Audio engine library
    ├── core/              # Core types and project data
    ├── dsp/               # DSP effect blocks
    ├── io/                # MIDI file I/O
    ├── module/            # Engine modules (mixer, playback, etc.)
    └── synth/             # Synthesizer implementations

Engine Architecture

The audio engine features a multi-threaded architecture:

1. Playback Worker - Reads MIDI sequences and sends note events to mixer
2. Mixer - Routes notes to appropriate synthesizers and processes audio
3. DSP Engine - Applies effect chains to audio streams
4. Audio Worker - Manages audio output callback and buffer management
5. Spectrum Analyzer - Real-time frequency analysis

Data Flow

MIDI File → Project Data → Playback Worker → Mixer → Synthesizers
                                                  ↓
                                            DSP Engine → Audio Output

🛠️ Installation

Prerequisites

• CMake 3.16 or higher
• Qt 5 or 6 (Widgets, Concurrent, Svg)
• OpenCV (for video export)
• FluidSynth (for SoundFont synthesis)
• C++17 compatible compiler

Build Instructions

Clone the repository

git clone https://github.com/0xMartin/NoteNagaCPlusPlus.git
cd NoteNagaCPlusPlus

Build with Qt support (GUI + Engine)

cmake -S . -B build
make -C build -j8

Build engine only (no Qt dependencies)

cd note_naga_engine
cmake -S . -B build -DQT_DEACTIVATED=ON
make -C build -j8

Run the application

./build/NoteNaga.app/Contents/MacOS/NoteNaga  # macOS
./build/NoteNaga                               # Linux
./build/NoteNaga.exe                           # Windows

🚀 Usage

Basic Workflow

1. Load MIDI File: File → Open to load an existing MIDI file
2. Edit Notes: Click and drag in the piano roll to create/modify notes
3. Configure Instruments: Assign SoundFonts to tracks in the mixer
4. Apply Effects: Add DSP blocks to tracks or master output
5. Playback: Use transport controls to play and navigate
6. Export: File → Export Video to render performance

Keyboard Shortcuts

Shortcut	Action
Space	Play/Pause
Home	Go to start
End	Go to end
Ctrl+O	Open MIDI file
Ctrl+E	Export video
Ctrl+Q	Quit application

MIDI Utilities

Access advanced MIDI editing tools from the Edit menu:

• Quantize - Snap notes to grid
• Humanize - Add natural timing variations
• Transpose - Shift pitch up/down
• Velocity Tools - Set or scale note velocities
• Duration Tools - Adjust note lengths
• Articulation - Apply legato or staccato

📋 Todo

🔴 High Priority (v1.0)

• 🐛 Fix: Newly added notes not playing during playback
• 💾 MIDI Export: Save projects as standard MIDI files
• 💾 Project Save/Load: Complete project persistence
• 📁 Project Explorer: Dialog for new/open/recent projects

🟡 UI/UX Improvements

• 🎨 Section-based Layout: Split app into dedicated sections
  • MIDI Editor: Track list + Piano roll + Mixer
  • DSP Editor: DSP blocks + Volume indicator + Spectrum analyzer + Track preview
  • Export: Media export dialog
• 🖱️ Context Menus: Right-click menus for all major components
• 📊 Velocity Editor: Visual velocity editing panel
• ✏️ Enhanced Note Editing: Better manipulation and selection tools
• 🎯 Apply to Selection: MIDI utilities work on selected notes only (or all if none selected)

🟢 Advanced Features

• 🎹 MIDI Input: Record notes from external MIDI devices
• ↩️ Undo/Redo: History system for all edit operations
• 🔌 Plugin Support: VST/AU plugin integration
• 🎛️ Automation: Automate mixer and effect parameters over time
• 📝 Notation View: Traditional music notation display
• 🎨 Custom Themes: User-configurable color schemes
• 🎵 Audio Import: Mix audio tracks with MIDI

⚙️ Technical Improvements

• 🧪 Unit Tests: Comprehensive test coverage for engine
• 📚 Documentation: Complete API documentation
• 🔧 Performance: Optimize DSP processing for large projects
• 🌐 Localization: Multi-language support
• 📦 Package Manager: Simplified installation process

📊 Project Data Structure

Current project stores:

1. MIDI data (sequences, tracks, notes)
2. Mixer configuration (routing entries)
3. DSP block data (effects and parameters)

🤝 Contributing

Contributions are welcome! Please feel free to submit pull requests or open issues for bugs and feature requests.

Development Setup

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Coding Guidelines

• Follow C++17 standards
• Use Qt conventions for GUI code
• Keep engine code Qt-independent (can be built with -DQT_DEACTIVATED=ON)
• Add comments for complex algorithms
• Test changes thoroughly before submitting

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

👨‍💻 Author

Martin Krčma (0xMartin)

• GitHub: @0xMartin
• Repository: NoteNagaCPlusPlus

🙏 Acknowledgments

• Qt Framework - Cross-platform GUI toolkit
• FluidSynth - Software synthesizer
• OpenCV - Computer vision and video processing library
• CMake - Build system generator

📚 Additional Resources

• Qt Documentation
• FluidSynth Documentation
• MIDI Specification

---

Made with ❤️ by 0xMartin

⭐ Star this repo if you find it useful!