+ def extract_subtitles(track_list):
+ if not isinstance(track_list, list):
+ return
+ for track in track_list:
+ if not isinstance(track, dict):
+ continue
+ if track.get('kind') != 'captions':
+ continue
+ src = track.get('src')
+ if not src or not isinstance(src, compat_str):
+ continue
+ lang = track.get('language') or track.get(
+ 'srclang') or track.get('label')
+ sub_dict = automatic_captions if track.get(
+ 'autogenerated') is True else subtitles
+ sub_dict.setdefault(lang, []).append({
+ 'url': src,
+ })
+