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

```rust use lowpassfilter::lowpassfilter;

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