makes a minimum phase version of the input audio

minphase.py

import numpy as np
import soundfile as sf
import os
import tkinter as tk
from tkinter import filedialog
from scipy.fft import fft, ifft, next_fast_len


def minipassMethod(ir):
	ir = np.asarray(ir, dtype=np.float64)
	N = len(ir)
	L = next_fast_len(16 * N)  # zero pad to efficient length, anything above 2*N pretty much. the bigger, the less artifacts you get

	# should probably actually find a better purer way of doing this, im unsure if its possible to actually get a perfect minimized phase at all but im hoping somewhere out there in the vast realm of signal processing that there is some sure-fire way of actually minning the phase completely without any artifacts or ringing or reflections or whateverhaveyou within a reasonable time complexity and memory complexity hopefully at most nlogn on both (math crack pipe dream honestly)
	# god i really don't know what im doing

	print("fft")
	spectrum = fft(ir, n=L) # fft of padded signal
	mag = np.abs(spectrum)
	mag = np.maximum(mag, np.finfo(np.float64).tiny)

	print("cep")
	cepstrum = ifft(np.log(mag)).real # i think its important to remember that numpy does the natural log. i keep forgetting this over time lmaooaoa

	print("min")
	minphaseCep = np.zeros_like(cepstrum)
	minphaseCep[0] = cepstrum[0]

  # this odd even check will pretty much always be even unless you decide change that at the definition of L
	if L % 2 == 0:
		minphaseCep[1:L // 2] = 2 * cepstrum[1:L // 2]
		minphaseCep[L // 2] = cepstrum[L // 2]  # no nyquist change
	else:
		minphaseCep[1:(L + 1) // 2] = 2 * cepstrum[1:(L + 1) // 2]

	print("recon")
	minphaseSpectrum = np.exp(fft(minphaseCep))
	minphaseIR = ifft(minphaseSpectrum).real[:N]

	return minphaseIR


def processAudio(input, out):
	data, sr = sf.read(input, always_2d=True)
	minphaseSignal = np.stack([minipassMethod(ch) for ch in data.T], axis=1)
	sf.write(out, minphaseSignal, sr, subtype='FLOAT')


if __name__ == "__main__":
	root = tk.Tk()
	root.withdraw()
	filePath = filedialog.askopenfilename(filetypes=[("Audio files", "*.wav *.flac *.aiff *.ogg *.mp3 *.m4a *.opus")])
	if filePath:
		dirName, baseName = os.path.split(filePath)
		baseName = os.path.splitext(baseName)[0]
		outName = f"minphase {baseName}.wav"
		outPath = os.path.join(dirName, outName)
		processAudio(filePath, outPath)
		print(f"minphase@: {outPath}")