A simple script for removing high-pitched hissing sounds from bad quality lecture recordings. Add this script to a folder of videos and start it from there. You can play around with the values for lowpass and highpass for best results.

ffmpeg_audio_filter.py

import os

for filename in os.listdir():
    if ".py" not in filename:
        print("start with:")
        print("ffmpeg -i " + filename + " -af lowpass=1000,highpass=200 " + filename + "out.mp4")
        os.system("ffmpeg -i " + filename + " -af lowpass=1000,highpass=200 " + filename + "out.mp4")