index.py

from pydub import AudioSegment
from os import listdir
import numpy as np
import math

song_dir = "songs"
attenuate_db = 0
accentuate_db = 2


def bass_line_freq(track):
    sample_track = list(track)

    # c-value
    est_mean = np.mean(sample_track)

    # a-value
    est_std = 3 * np.std(sample_track) / (math.sqrt(2))

    bass_factor = int(round((est_std - est_mean) * 0.005))

    return bass_factor

for filename in listdir(song_dir):
    sample = AudioSegment.from_mp3(song_dir + "/" + filename)
    filtered = sample.low_pass_filter(bass_line_freq(sample.get_array_of_samples()))

    combined = (sample - attenuate_db).overlay(filtered + accentuate_db)
    combined.export("exports/" + filename.replace(".mp3", "") + "-export.mp3", format="mp3")