mp3chapter adding tool, originally written by rui314

mp3chapters.py

#!/usr/bin/env python3
import re
import string
import sys
import yaml
from mutagen import id3
from os import path, environ
from collections import namedtuple

Chapter = namedtuple('Chapter', ['title', 'start', 'end'])

def parse_time(s):
  m = re.match('(\d+):(\d+):(\d+)', s)
  if m is not None:
    return (int(m.group(1)) * 3600 + int(m.group(2)) * 60 + int(m.group(3))) * 1000
  m = re.match('(\d+):(\d+)', s)
  if m is not None:
    return (int(m.group(1)) * 60 + int(m.group(2))) * 1000
  print("bad timestamp:", s)
  exit(1)

def get_chapters(ep, end):
  ret = []
  for chapter in reversed(ep['chapters']):
    m = re.match('([\d:]+)\s+(.+)$', chapter)
    if m is None:
      continue
    start = parse_time(m.group(1))
    ret.append(Chapter(m.group(2).strip(), start, end))
    end = start
  return list(reversed(ret))

mp3file  = sys.argv[1]
datafile = sys.argv[2]  

ep = yaml.load(open(datafile))

# Add metadata
tag = id3.ID3(mp3file)

# Add chapters
chapters = get_chapters(ep, int(str(tag['TLEN'])))

if len(chapters) > 0:
  tag.add(id3.CTOC(element_id=u"toc", flags=id3.CTOCFlags.TOP_LEVEL | id3.CTOCFlags.ORDERED,
                   child_element_ids=['chp{:02d}'.format(i) for i in range(len(chapters))],
                   sub_frames=[id3.TIT2(encoding=id3.Encoding.UTF8, text=[u"Table of Contents"])]))

  for i, c in enumerate(chapters):
    tag.add(id3.CHAP(element_id=u'chp{:02d}'.format(i), start_time=c.start, end_time=c.end,
                     sub_frames=[id3.TIT2(encoding=id3.Encoding.UTF8, text=[c.title])]))
    
tag.save(mp3file)