Convert samples to mono

monoise.py

#!/usr/bin/env python
"""
mo' noise
monome + noise
mono-ise
"""
#
# You will need sox and pysox
#   https://github.com/rabitt/pysox#install
#
#
# Run in the directory containing the samples, with
#
#   python /wherever/you/saved/monoise.py
#
# or make it executable and add the location to your PATH.
#
#
# The defaults are WAV file inputs and a target of 48Khz / 24-bit files.
# You can change this with the switches -e (or --ext), -r (or --rate), and -b
# (or --bits):
#
#   python -e aiff -r 44100 -b 16 /wherever/you/saved/monoise.py
#
# There is a shortcut for 44.1KHz / 16 bits, -R (or --radio).
#
#
# This will create a "monoise" directory at that location, and recreate
# the original directory structure inside that, with all files converted
# to mono. It will refuse to run if the "monoise" directory already exists.
#

import os
import sys

from argparse import ArgumentParser
from shutil import copyfile

import sox


P = ArgumentParser()
P.add_argument('-e', '--ext', type=str, default='wav',
               help='File extension to look for')
P.add_argument('-r', '--rate', type=int, default=48000,
               help='Target sample rate')
P.add_argument('-b', '--bits', type=int, default=24,
               help='Target bit rate')
P.add_argument('-R', '--radio', action='store_true')
ARGS = P.parse_args()

EXT = f'.{ARGS.ext}'
TARGET_EXT = 'wav'
RADIO_RATE = 44100
RADIO_BITS = 16
OUTPUT_DIR = 'monoise'

if ARGS.radio:
    RATE = RADIO_RATE
    BITS = RADIO_BITS
else:
    RATE = ARGS.rate
    BITS = ARGS.bits

if os.path.exists(OUTPUT_DIR):
    print(f'A "{OUTPUT_DIR}" directory already exists, bailing out.')
    sys.exit(1)
else:
    os.mkdir(OUTPUT_DIR)

TFM = sox.Transformer()
TFM.set_output_format(file_type=TARGET_EXT, rate=RATE, bits=BITS, channels=1)

# 1. walk dir and look for input files
# 3. if the file has more than 1 channel
# 4.   convert to mono
# 5.   write out to 'monoise/...' # easier than looking for them afterward
# 6. else
# 7.   copy to 'monoise/...'
for root, _, files in os.walk('.'):
    if root.startswith(os.path.join('.', OUTPUT_DIR)):
        continue

    for file in files:
        if file.endswith(EXT):
            current = os.path.join(root, file)
            dir_name = root.replace('./', '')
            target_dir = os.path.join('.', OUTPUT_DIR, dir_name)
            file_name, _ = os.path.splitext(file)
            mono_file = os.path.join(target_dir, f'{file_name}.{TARGET_EXT}')

            if not os.path.exists(target_dir):
                os.makedirs(target_dir)

            if (
                    sox.file_info.channels(current) != 1
                    or sox.file_info.sample_rate(current) != RATE
                    or sox.file_info.bitdepth(current) != BITS
            ):
                TFM.build(current, mono_file)
            else:
                copyfile(current, mono_file)