Simple OGM chapters generator for MKVToolNix

ogm-chapters.py

# Simple OGM chapters generator for MKV Video
# -------------------------------------------
# Use it like this:
# $ python ogm-chapters.py times.txt [chapters.txt]
# Where times.txt contains timestamps separated by a whitespace or comma

import sys
from pathlib import Path
import re

prefix = 'Chapter '

if len(sys.argv) <= 1:
    print('Input file not specified')
    sys.exit(1)

inputFileName = Path(sys.argv[1])
if not inputFileName.is_file():
    print('Input file does not exist')
    sys.exit(1)

outputFile = sys.stdout
if len(sys.argv) > 2:
    outputFile = open(Path(sys.argv[2]), 'w', encoding='utf-8')

with open(inputFileName, 'r', encoding='utf-8') as inputFile:
    times = re.split(r'[\s,]+', inputFile.read())
    i = 0
    digits = len(str(len(times)))
    for t in times:
        t = t.strip()
        if re.fullmatch(r'[0-9.:]{2,}', t):
            outputFile.write(f'CHAPTER{i:0{digits}d}={t}\n')
            outputFile.write(f'CHAPTER{i:0{digits}d}NAME={prefix}{i+1:0{digits}d}\n')
            i += 1

if outputFile != sys.stdout:
    outputFile.close()