J-Delay

JACK Audio Input Latency Compensator
By Marco Herglotz

J-Delay is a lightweight, persistent latency compensation tool designed for the JACK Audio Connection Kit. It solves synchronization issues in hybrid setups (Software + Hardware) by allowing precise millisecond delay adjustments for input channels.

Specially optimized for Windows to prevent "Pipe Busy" errors.

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Features

• 🎛 Precision Delay: Adjust delay from 0.00 to 1000.00 ms via Slider or Text Input.
• 🔗 Stereo Linking: Link faders for odd/even channel pairs.
• 🔄 Dynamic Channels: Add/Remove channels on the fly (up to 128+).
• 💾 Auto-Save & Presets: Remembers your settings and offers 8 Preset Slots.
• 🛡 Persistent Connection: Keeps the JACK client alive in the background to prevent Windows named pipe errors.
• 🚦 Smart Status: Visual feedback for connection status (Ready/Running/Error).

Installation

Prerequisites

• Python 3 (Make sure to check "Add to PATH" during installation).
• JACK Audio Connection Kit (e.g., QJackCtl).

Quick Start (Windows)

1. Download the repository.
2. Double-click run_j_delay.bat.
3. The script will automatically install required dependencies (JACK-Client, numpy) and launch the GUI.

Manual Start (Linux/macOS)

pip install JACK-Client numpy
python J-Delay.py

Usage

1. Start JACK (QJackCtl).
2. Launch J-Delay.
3. Click ACTIVATE to register ports in the graph.
4. Connect your audio source to j_delay:in_X and j_delay:out_X to your destination.
5. Adjust the sliders until your audio is synchronized.

Configuration

Settings (Channel count, Names, Delays) are automatically saved to J-Delay.ini.

Custom Channel Names: Enable the "Edit Names" checkbox in the header, then double-click a channel label to rename it (e.g., "Kick Drum").

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

This project is licensed under the GNU General Public License v3.0.