Soundly Audio Editor

A fast, lightweight audio editor built with Rust and Python, featuring real-time waveform visualization and support for multiple audio formats.

Features

• Multi-format support: Import and export WAV, FLAC, and MP3 files
• Real-time waveform visualization: Zoom in to individual samples or zoom out to see hours of audio
• Region-based editing: Select and delete audio regions with visual feedback
• Playback controls: Play, pause, repeat, and navigate through audio
• High-quality export: Configurable compression for FLAC (0-8) and bitrate for MP3 (128-320 kbps)
• Pure Rust FLAC encoder: Custom implementation based on RFC 9639
• Multi-track support: View, playback, and export multiple tracks, differentiated by color

Building

Prerequisites

• Python 3.8 or higher
• Rust toolchain (install from rustup.rs or via package manager)
• PyQt6 and NumPy (installed automatically by maturin)

Build Steps

1. Clone the repository:

git clone https://github.com/ajcm474/soundly
cd soundly

2. Build and install using maturin:

pip install maturin
maturin develop --release

Or build a wheel for distribution:

maturin build --release
pip install target/wheels/soundly-*.whl

Running

After building, run the application:

python python/main.py

Usage

Importing Audio

• File → Import → Audio File... to import WAV, FLAC, or MP3 files
• Supported sample rates: 8 kHz to 192 kHz
• Supported channel configurations: Mono and Stereo

Playback

• Space: Toggle play/pause
• Play button: Start or resume playback
• Pause button: Pause playback
• ⏮ Rewind: Stop and return to beginning
• Skip ⏭: Jump to the end
• 🔁 Repeat: Toggle repeat mode for continuous playback

Editing

• Click and drag: Select a region of audio
• Delete/Backspace: Remove the selected region
• The playback cursor shows the current position

Zooming

• Ctrl/Cmd + Plus: Zoom in (can zoom down to individual samples)
• Ctrl/Cmd + Minus: Zoom out
• Mouse wheel: Zoom in/out centered on mouse position
• Auto-scrolling follows playback when zoomed in

Exporting

• File → Export → WAV...: Export as uncompressed WAV
• File → Export → FLAC...: Export with configurable compression (0=fastest, 8=best compression)
• File → Export → MP3...: Export with configurable bitrate (128-320 kbps)
• Exports the selected region if one exists, otherwise exports the entire file

Current Limitations

• Undo/Redo: Not yet implemented - edits are permanent
• Effects: No audio effects or filters currently available
• Selection precision: Minimum selection size is 1ms
• FLAC encoder: Custom implementation supports compression levels 0-8 but may be less efficient
• Memory usage: Entire audio file is loaded into memory (not suitable for very large files >1GB)
• Sample rate conversion: Not supported - export uses the same sample rate as the source
• Bit depth: Internal processing uses 32-bit float; export is 16-bit for all formats

Keyboard Shortcuts

• Space: Toggle play/pause
• Delete/Backspace: Delete selected region
• Ctrl/Cmd + =: Zoom in
• Ctrl/Cmd + -: Zoom out
• Ctrl/Cmd + Q: Quit application

Architecture

The project uses a hybrid architecture:

• Rust core (src/): Audio decoding, encoding, playback engine, and DSP operations
• Python GUI (python/): PyQt6-based user interface and visualization
• PyO3 bindings: Zero-copy data transfer between Rust and Python

This design provides native performance for audio operations while maintaining a flexible, easy-to-modify GUI.

License

This project is released under the Apache 2.0 License. See LICENSE for details.