A Script to normalize the audio of media files while also converting them to mp3s

normalize.py

#!/usr/bin/python3

#Tries to convert all the files in the directory where it is executed into normalized mp3s.
#All resulting mp3s are placed in a folder called 'normalized'

import multiprocessing as mp
import subprocess
import re
import json
import os
from os import listdir
from os.path import isfile, join

def convertFile(filename):

	FILE_EXT_REGEX = re.compile(r'(.*)\..*')
	JSON_REGEX = re.compile(r'{(.|\n)*}')

	file_without_ext = FILE_EXT_REGEX.match(filename).group(1)

	info_cmd = ["ffmpeg", "-hide_banner","-i", filename, "-af", "loudnorm=I=-16:TP=-1.5:LRA=11:print_format=json", "-f", "null", "-"]
	cmd_out = subprocess.run(info_cmd, stderr=subprocess.PIPE)
	out_string = cmd_out.stderr.decode('UTF-8')

	try:
		json_payload = JSON_REGEX.search(out_string).group(0)
	except AttributeError:
		return
	data = json.loads(json_payload)

	convert_cmd = ["ffmpeg", "-loglevel", "fatal", "-i", filename, "-af", f"loudnorm=I=-16:TP=-1.5:LRA=11:measured_I={data['input_i']}:measured_LRA={data['input_lra']}:measured_TP={data['input_tp']}:measured_thresh={data['input_thresh']}:offset={data['target_offset']}:linear=true:print_format=summary", f"./normalized/{file_without_ext}.mp3"]

	subprocess.run(convert_cmd)

def runner(queue):
	while not queue.empty():
		cur = queue.get(block=False)
		if cur is not None:
			convertFile(cur)
			print(f'Converted "{cur}"')
	print("Terminating a runner!")

try:
	os.mkdir('normalized')
except:
	print("normalized dir couldn't be created")

filenames = [f for f in listdir(os.getcwd()) if isfile(join(os.getcwd(), f))]

queue = mp.Queue()

for filename in filenames:
	queue.put(filename)

#Change this to use less processes
thread_num = mp.cpu_count()
threads = list()

for i in range(0, thread_num):
	print(f"Started process {i}")
	process = mp.Process(target=runner, args=(queue,))
	process.start()
	threads.append(process)

for thread in threads:
	thread.join()
	print("One process finished!")