+ @staticmethod
+ def _extract_chapters(description, duration):
+ if not description:
+ return None
+ chapter_lines = re.findall(
+ r'(?:^|<br\s*/>)([^<]*<a[^>]+onclick=["\']yt\.www\.watch\.player\.seekTo[^>]+>(\d{1,2}:\d{1,2}(?::\d{1,2})?)</a>[^>]*)(?=$|<br\s*/>)',
+ description)
+ if not chapter_lines:
+ return None
+ chapters = []
+ for next_num, (chapter_line, time_point) in enumerate(
+ chapter_lines, start=1):
+ start_time = parse_duration(time_point)
+ if start_time is None:
+ continue
+ end_time = (duration if next_num == len(chapter_lines)
+ else parse_duration(chapter_lines[next_num][1]))
+ if end_time is None:
+ continue
+ chapter_title = re.sub(
+ r'<a[^>]+>[^<]+</a>', '', chapter_line).strip(' \t-')
+ chapter_title = re.sub(r'\s+', ' ', chapter_title)
+ chapters.append({
+ 'start_time': start_time,
+ 'end_time': end_time,
+ 'title': chapter_title,
+ })
+ return chapters
+