Lib.rs

A Simple Noise Gate for Rust

---

Noise Gate

A simple Noise Gate algorithm written for Rust for handling of streaming audio from CPAL. Noise Gates are extremely useful for cleaning up muddy audio streams: breathing noises, page turns, microphone knocks, keyboard clatter, HVAC hum, fan noises, room reverb, and so forth to help remove unwanted sounds from your stream. While a noise gate won't completely eliminate background noise, it can help make your audio stream sounds much cleaner.

Usage

This crate is intended to be used with raw audio streams from CPAL or the like.

1. Add the crate to your project

cargo add audio-gate

2. Create the Noise Gate outside of your main stream (preferrably your input stream) with the desired parameters.

let mut gate = NoiseGate::new(
    -36.0, // Open Threshold
    -54.0, // Close Treshold
    48000.0, // Sample Rate
    2, // Channels
    150.0, // Release Rate
    25.0, // Attack Rate
    150.0 // Hold time
);

3. Process each frame of audio with the gate to remove unwanted sound. The following example is from CPAL

let stream = match device.build_input_stream(
    &config,
    move |data: &[f32], _: &cpal::InputCallbackInfo| {
        let gated_data = gate.process_frame(&data);
        for &sample in gated_data.as_slice() {
            producer.push(sample).unwrap_or({});
        }
    },
    move |err| {},
    None
) {
    Ok(stream) => stream,
    Err(e) => {
        return Err(anyhow!("{}", e.to_string()));
    }
};

Hear the difference

A feedback example is provided in the examples directory so that you can hear the difference a noise gate might apply to your audio stream.

To hear your current input with the noise gate applied run the example:

cargo run --example feedback -- --with-gate

To hear your audio with it not applied run the example without the flag:

cargo run --example feedback

License

This application is licensed under the BSD 3 Clause License