Rust: no_std digital low pass filter library

This is a no_std Rust library for simple digital low pass filters. You can use it for example to get the low frequencies from a song.

I'm not an expert on digital signal processing. Code contributions are highly welcome! :)

Difference to biquad

⚠ TL;DR: Prefer crate biquad and use this crate only for educational purposes.
This crate provides a basic and simple to understand, first order lowpass filter. The biquad crate offers second order filters, with higher accuracy. Due to my testing, a lowpass filter with biquad has the same computational costs as my crate, but offers a better resolution for actually cutting of signals above the cut-off frequency while the preserved signal will be less attenuated, compared to my filter implementation. For production, please use biquad.

How to use

use lowpass_filter::lowpass_filter;

/// Minimal example how to use this crate/how to apply low pass filter.
fn main() {
    // read this from MP3 for example
    let mut mono_audio_data = [0.0, 1.0, -5.0, 1551.0, 141.0, 24.0];
    // mutates the input buffer
    lowpass_filter(&mut mono_audio_data, 44100.0, 120.0);
}

Visual Examples

1: Original Waveform of a short sample

1: Lowpassed Waveform

2: Original Waveform of a song

2: Lowpassed Waveform

2: 3x Lowpassed Waveform