🔇 Background Muter

A lightweight, ultra-efficient Windows application written in Rust that automatically mutes applications running in the background. Never be interrupted by unexpected sounds from background apps again!

✨ Features

• Automatic Background Muting: Instantly mutes any application that loses focus
• Smart Detection: Automatically detects all applications producing audio
• Exclusion List: Add apps to a whitelist so they continue playing in the background
• System Tray Integration: Runs silently in your system tray
• Ultra-Low Resource Usage: ~0% CPU, ~3MB RAM, no GPU/VRAM usage
• Persistent Settings: Your preferences are saved between sessions (edit config.json)
• Native Windows: Pure Win32 implementation - no heavy GUI frameworks
• Fast Response: Sub-500ms response time to focus changes

📊 Resource Usage

Metric	Value
CPU Usage	~0% (idle)
RAM (Private)	~3 MB
RAM (Working Set)	~15 MB
GPU/VRAM	0 MB
Binary Size	~800 KB

🚀 Installation

Prerequisites

• Windows 10 or later
• Rust 1.75 or later

Building from Source

# Clone the repository
git clone https://github.com/username/rust-bg-muter.git
cd rust-bg-muter

# Build in release mode (recommended)
cargo build --release

# The executable will be at target/release/bg-muter.exe

Running

# Run directly with cargo
cargo run --release

# Or run the executable
./target/release/bg-muter.exe

🎯 Usage

Basic Usage

1. Launch the application - It will appear in your system tray
2. Left-click the tray icon to open the menu
3. Toggle muting from the tray menu
4. View settings to see current configuration

Configuration

Settings are stored in a JSON file at:

• %APPDATA%\rust-bg-muter\config.json

Edit this file to configure:

• excluded_apps: List of apps to never mute (e.g., ["spotify.exe", "discord.exe"])
• poll_interval_ms: How often to check for changes (default: 500ms)
• start_minimized: Start hidden in tray (default: false)
• start_with_windows: Auto-start with Windows (default: false)

Example config:

{
  "excluded_apps": ["spotify.exe", "discord.exe", "vlc.exe"],
  "muting_enabled": true,
  "poll_interval_ms": 500,
  "start_minimized": true,
  "start_with_windows": true
}

System Tray

• Left-click: Open the context menu
• Right-click: Open the context menu
  • Toggle muting on/off
  • View settings
  • Exit the application

⚙️ Configuration

🏗️ Architecture

The application is built with a lightweight, modular architecture:

src/
├── main.rs       # Application entry point and tray loop
├── lib.rs        # Library exports
├── audio.rs      # Windows Audio Session API (WASAPI) integration
├── config.rs     # Configuration management and persistence
├── muter.rs      # Core muting logic and engine
├── process.rs    # Process detection and foreground tracking
├── startup.rs    # Windows startup registry integration
└── tray.rs       # System tray integration (native Win32)

Key Technologies

• tray-icon: Lightweight system tray
• windows-rs: Windows API bindings
• WASAPI: Windows Audio Session API for audio control
• Native Win32: Message pump and dialogs (no heavy GUI frameworks)

Design Principles

1. Minimal Dependencies: No eframe/egui/tokio - pure Win32 tray app
2. Event-Driven: Uses MsgWaitForMultipleObjectsEx for efficient waiting
3. Lazy Refresh: Audio sessions only refreshed every 2s or on foreground change
4. Zero GPU: No OpenGL/DirectX - all rendering via OS

🔧 Development

Project Structure

rust-bg-muter/
├── Cargo.toml      # Dependencies and metadata
├── build.rs        # Build script for Windows resources
├── assets/         # Icon files
├── src/            # Source code
│   └── ...
└── README.md       # This file

Building for Development

# Debug build (faster compilation)
cargo build

# Run with logging
RUST_LOG=debug cargo run

# Run tests
cargo test

Code Quality

# Format code
cargo fmt

# Run clippy lints
cargo clippy -- -D warnings

# Check for issues
cargo check

📝 License

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

🙏 Acknowledgments

• The Rust community for excellent crates
• Microsoft for the Windows Audio Session API
• The tray-icon project for lightweight tray integration

📬 Support

If you encounter any issues or have questions:

1. Check the Issues page
2. Open a new issue with detailed information about your problem

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Made with ❤️ and Rust