Simple Python program to simulate playing a track at a different speed on a turntable

vinyl.py

#!/usr/bin/env python3

#          _                   _
# __   __ (_)  _ __    _   _  | |      _ __    _   _
# \ \ / / | | | '_ \  | | | | | |     | '_ \  | | | |
#  \ V /  | | | | | | | |_| | | |  _  | |_) | | |_| |
#   \_/   |_| |_| |_|  \__, | |_| (_) | .__/   \__, |
#                      |___/          |_|      |___/

# This command-line program allows you to change the playback speed of an
# audio file to simulate playing it at 33 RPM, 45 RPM, or 78 RPM, similar
# to a turntable. Accepts any common audio format for input and output.

# Usage:
# ./vinyl.py <input-file> <output-file> <original-speed> <target-speed>

# Examples
# ========
# ./vinyl.py input.mp3 output.mp3 33 45
# ./vinyl.py input.aif output.wav 78 45
# ./vinyl.py input.flac output.ogg 45 33

import argparse
from pydub import AudioSegment

def change_speed(sound, start_speed, target_speed):
    speed_ratio = target_speed / start_speed
    sound_with_altered_frame_rate = sound._spawn(sound.raw_data, overrides={
         "frame_rate": int(sound.frame_rate * speed_ratio)
      })
    return sound_with_altered_frame_rate.set_frame_rate(sound.frame_rate)

def process_audio(input_file, output_file, start_speed, target_speed):
    sound = AudioSegment.from_file(input_file)
    altered_sound = change_speed(sound, start_speed, target_speed)
    altered_sound.export(output_file, format=output_file.split('.')[-1])

if __name__ == "__main__":
    parser = argparse.ArgumentParser(description='Change the speed of a sound file from a starting RPM to a target RPM.')
    parser.add_argument('input_file', type=str, help='The input sound file')
    parser.add_argument('output_file', type=str, help='The output sound file')
    parser.add_argument('start_speed', type=int, choices=[33, 45, 78], help='The starting speed in RPM')
    parser.add_argument('target_speed', type=int, choices=[33, 45, 78], help='The target speed in RPM')

    args = parser.parse_args()

    process_audio(args.input_file, args.output_file, args.start_speed, args.target_speed)