Repository: yt-dlp/yt-dlp
File: yt_dlp/extractor/facebook.py (Python)

Code before:
    def _extract_from_url(self, url, video_id):
        webpage = self._download_webpage(
            url.replace('://m.facebook.com/', '://www.facebook.com/'), video_id)

        def extract_metadata(webpage):
            post_data = [self._parse_json(j, video_id, fatal=False) for j in re.findall(
                r'data-sjs>({.*?ScheduledServerJS.*?})</script>', webpage)]
            post = traverse_obj(post_data, (
                ..., 'require', ..., ..., ..., '__bbox', 'require', ..., ..., ..., '__bbox', 'result', 'data'), expected_type=dict) or []

            automatic_captions, subtitles = {}, {}
            subs_data = traverse_obj(post, (..., 'video', ..., 'attachments', ..., lambda k, v: (
                k == 'media' and str(v['id']) == video_id and v['__typename'] == 'Video')))
            is_video_broadcast = get_first(subs_data, 'is_video_broadcast', expected_type=bool)
            captions = get_first(subs_data, 'video_available_captions_locales', 'captions_url')
            if url_or_none(captions):  # if subs_data only had a 'captions_url'
                locale = self._html_search_meta(['og:locale', 'twitter:locale'], webpage, 'locale', default='en_US')
                subtitles[locale] = [{'url': captions}]
            # or else subs_data had 'video_available_captions_locales', a list of dicts
            for caption in traverse_obj(captions, (
                {lambda x: sorted(x, key=lambda c: c['locale'])}, lambda _, v: v['captions_url'])
            ):
                subs = {
                    'url': caption['captions_url'],
                    'name': join_nonempty('localized_language', 'localized_country', from_dict=caption),
                }
                if caption.get('localized_creation_method') or is_video_broadcast:
                    automatic_captions.setdefault(caption['locale'], []).append(subs)
                else:
                    subtitles.setdefault(caption['locale'], []).append(subs)

            media = traverse_obj(post, (..., 'attachments', ..., lambda k, v: (
                k == 'media' and str(v['id']) == video_id and v['__typename'] == 'Video')), expected_type=dict)
            title = get_first(media, ('title', 'text'))
            description = get_first(media, ('creation_story', 'comet_sections', 'message', 'story', 'message', 'text'))
            uploader_data = (
                get_first(media, ('owner', {dict}))
                or get_first(post, (..., 'video', lambda k, v: k == 'owner' and v['name']))
                or get_first(post, ('node', 'actors', ..., {dict})) or {})

            page_title = title or self._html_search_regex((
                r'<h2\s+[^>]*class="uiHeaderTitle"[^>]*>(?P<content>[^<]*)</h2>',
                r'(?s)<span class="fbPhotosPhotoCaption".*?id="fbPhotoPageCaption"><span class="hasCaption">(?P<content>.*?)</span>',
                self._meta_regex('og:title'), self._meta_regex('twitter:title'), r'<title>(?P<content>.+?)</title>'
            ), webpage, 'title', default=None, group='content')
            description = description or self._html_search_meta(
                ['description', 'og:description', 'twitter:description'],
                webpage, 'description', default=None)
            uploader = uploader_data.get('name') or (
                clean_html(get_element_by_id('fbPhotoPageAuthorName', webpage))
                or self._search_regex(

Review comment (suggestion):
```suggestion
                lang = caption.get('localized_language') or ''
                subs = {
                    'url': caption['captions_url'],
                    'name': format_field(caption, 'localized_country', f'{lang} (%s)', default=lang),
                }
```

Code after:
    def _extract_from_url(self, url, video_id):
        webpage = self._download_webpage(
            url.replace('://m.facebook.com/', '://www.facebook.com/'), video_id)

        def extract_metadata(webpage):
            post_data = [self._parse_json(j, video_id, fatal=False) for j in re.findall(
                r'data-sjs>({.*?ScheduledServerJS.*?})</script>', webpage)]
            post = traverse_obj(post_data, (
                ..., 'require', ..., ..., ..., '__bbox', 'require', ..., ..., ..., '__bbox', 'result', 'data'), expected_type=dict) or []

            automatic_captions, subtitles = {}, {}
            subs_data = traverse_obj(post, (..., 'video', ..., 'attachments', ..., lambda k, v: (
                k == 'media' and str(v['id']) == video_id and v['__typename'] == 'Video')))
            is_video_broadcast = get_first(subs_data, 'is_video_broadcast', expected_type=bool)
            captions = get_first(subs_data, 'video_available_captions_locales', 'captions_url')
            if url_or_none(captions):  # if subs_data only had a 'captions_url'
                locale = self._html_search_meta(['og:locale', 'twitter:locale'], webpage, 'locale', default='en_US')
                subtitles[locale] = [{'url': captions}]
            # or else subs_data had 'video_available_captions_locales', a list of dicts
            for caption in traverse_obj(captions, (
                {lambda x: sorted(x, key=lambda c: c['locale'])}, lambda _, v: v['captions_url'])
            ):
                lang = caption.get('localized_language') or ''
                subs = {
                    'url': caption['captions_url'],
                    'name': format_field(caption, 'localized_country', f'{lang} (%s)', default=lang),
                }
                if caption.get('localized_creation_method') or is_video_broadcast:
                    automatic_captions.setdefault(caption['locale'], []).append(subs)
                else:
                    subtitles.setdefault(caption['locale'], []).append(subs)

            media = traverse_obj(post, (..., 'attachments', ..., lambda k, v: (
                k == 'media' and str(v['id']) == video_id and v['__typename'] == 'Video')), expected_type=dict)
            title = get_first(media, ('title', 'text'))
            description = get_first(media, ('creation_story', 'comet_sections', 'message', 'story', 'message', 'text'))
            uploader_data = (
                get_first(media, ('owner', {dict}))
                or get_first(post, (..., 'video', lambda k, v: k == 'owner' and v['name']))
                or get_first(post, ('node', 'actors', ..., {dict})) or {})

            page_title = title or self._html_search_regex((
                r'<h2\s+[^>]*class="uiHeaderTitle"[^>]*>(?P<content>[^<]*)</h2>',
                r'(?s)<span class="fbPhotosPhotoCaption".*?id="fbPhotoPageCaption"><span class="hasCaption">(?P<content>.*?)</span>',
                self._meta_regex('og:title'), self._meta_regex('twitter:title'), r'<title>(?P<content>.+?)</title>'
            ), webpage, 'title', default=None, group='content')
            description = description or self._html_search_meta(
                ['description', 'og:description', 'twitter:description'],
                webpage, 'description', default=None)
            uploader = uploader_data.get('name') or (
                clean_html(get_element_by_id('fbPhotoPageAuthorName', webpage))