RUSTLIBFILT

A python library, written in Rust, for the design and implentation of digital audio filters

how to use rustlibfilt:

1. install or update rust from https://forge.rust-lang.org/infra/other-installation-methods.html

2. install maturin with cargo

   cargo install maturin

3. create virtual env (follow conda example) and install dependecies

   conda create -n rpy pyhton=3.11
   conda activate rpy

4. clone the repo and compile

   git clone --depth 1 
   ./rustlibfilt
   pip install -r requirements.txt
   make

5. you can import rustlibfilt in python and use it

   # import section
   from rustlibfilt import Biquad
   import librosa as lb
   import soundfile as sf
   
   # main scripts
   
   PATH = "./audio_files/vox.wav"
   SIG, SR = lb.load(PATH, sr=None)
   
   # main function
   def main() -> None:
       bq = Biquad(fs=SR)
       coeffs = bq.design_filter(mode="peq", fc=300, q=0.5, dbgain=-12)
       
       # for sample in x:
       #     y = bq.bfilt_sample(sample=sample, coeffs=coeffs)
       
       filtered_frame = bq.filt_frame(frame=SIG, coeffs=coeffs)
       bq.clear_delayed_samples_cache()
       sf.write("filtered.wav", data=filtered_frame, samplerate=SR, subtype="PCM_16")
       
   
   # [MAIN PROGRAM]: if the module is being run as the main program, it calls the "main()" function
   if __name__ == "__main__":
       main()

   Alternatively, you can import Rustlibfilt from rustlibfilt so that you have auto-completion for functions and their respective documentation.

   # import section
   from rustlibfilt import Rustlibfilt
   import numpy as np
   import soundfile as sf
   
   # main scripts
   SR = 44100
   NOISE = np.random.uniform(-1, 1, SR)
   N = len(NOISE)
   
   # main function
   def main() -> None:
       bq = Rustlibfilt(fs=SR, family="biquad", mode="lp")
       bq.design_filter(fc=500, q=2)
       print(bq.coeffs)
       
       buffer = int(0.0034 * SR / 2)
       cb = Rustlibfilt(fs=SR, family="harmonic", mode="combi", buffer_lenght=buffer)
       cb.design_filter(t60=.7)
       print(1/0.0034)
       
       y = np.zeros(N)
       for i in range(N):
           y[i] = bq.filt_sample(sample=NOISE[i])
       
       bq.clear_delayed_samples_cache()
       y = bq.filt_frame(frame=NOISE)
       
       y = cb.filt_frame(frame=NOISE)
   
       sf.write("filtered_test.wav", data=y, samplerate=SR, subtype="PCM_16")
   
   
   # [MAIN PROGRAM]: if the module is being run as the main program, it calls the "main()" function
   if __name__ == "__main__":
       main()

Version 0.1.1

1. Alternatively, now you can import Rustlibfilt from rustlibfilt so that you have auto-completion for functions and their respective documentation.

   from rustlibfilt import Rustlibfilt

   read the doc from

   print(help(Rustlibfilt))

2. add new filter types:
   Zavalishin:

   • OnePoleZeroDelay
   • NaiveOnePole
   • TrapIntOnePole
   • StateVariable

   Butter:

   • Lp
   • Hp
   • Bp
   • Notch

3. now you can specify the order of the filter (only for onepole, narrow and butter)

Version 0.1.0

Filter types:
Biquad:

• Lp
• Hp
• Bp0dB
• Bpsg
• Notch
• Ap
• Peq
• LpShelf
• HpShelf

Reverb:

• CombFIR
• CombIIR
• LowPassFeedbackCombFilterIIR
• Allpass
• LowPassFeedbackAllpassFilterIIR

One Pole:

• Lp
• Hp

DcBlock:

• DcBlockJulius

Narrow:

• Bp
• Notch

TwoZeroTwoPole:

• Bp
• Notch

References

• V. Zavalishin, The Art of VA Filter Design, 2018
• Audio EQ Cookbook by Robert Bristow-Johnson, https://www.musicdsp.org/en/latest/Filters/197-rbj-audio-eq-cookbook.html
• https://www.musicdsp.org/en/latest/Filters/index.html
• https://www.dspguide.com/ch19.htm
• BQD filter design equation, AN2874 Applications note, STMicroelectronics, 2009
• D. Horvath; Z. Cervenanska: J. Kotianova, Digital implementation of Butterworth first-order filter type IIR