[youtube] Fix multifeed extraction (closes #18531)

youtube_dl/extractor/youtube.py

@@ -1712,30 +1712,36 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
             else:
                 video_description = ''
 
-        if 'multifeed_metadata_list' in video_info and not smuggled_data.get('force_singlefeed', False):
+        if not smuggled_data.get('force_singlefeed', False):
             if not self._downloader.params.get('noplaylist'):
-                entries = []
-                feed_ids = []
-                multifeed_metadata_list = video_info['multifeed_metadata_list'][0]
-                for feed in multifeed_metadata_list.split(','):
-                    # Unquote should take place before split on comma (,) since textual
-                    # fields may contain comma as well (see
-                    # https://github.com/rg3/youtube-dl/issues/8536)
-                    feed_data = compat_parse_qs(compat_urllib_parse_unquote_plus(feed))
-                    entries.append({
-                        '_type': 'url_transparent',
-                        'ie_key': 'Youtube',
-                        'url': smuggle_url(
-                            '%s://www.youtube.com/watch?v=%s' % (proto, feed_data['id'][0]),
-                            {'force_singlefeed': True}),
-                        'title': '%s (%s)' % (video_title, feed_data['title'][0]),
-                    })
-                    feed_ids.append(feed_data['id'][0])
-                self.to_screen(
-                    'Downloading multifeed video (%s) - add --no-playlist to just download video %s'
-                    % (', '.join(feed_ids), video_id))
-                return self.playlist_result(entries, video_id, video_title, video_description)
-            self.to_screen('Downloading just video %s because of --no-playlist' % video_id)
+                multifeed_metadata_list = try_get(
+                    player_response,
+                    lambda x: x['multicamera']['playerLegacyMulticameraRenderer']['metadataList'],
+                    compat_str) or try_get(
+                    video_info, lambda x: x['multifeed_metadata_list'][0], compat_str)
+                if multifeed_metadata_list:
+                    entries = []
+                    feed_ids = []
+                    for feed in multifeed_metadata_list.split(','):
+                        # Unquote should take place before split on comma (,) since textual
+                        # fields may contain comma as well (see
+                        # https://github.com/rg3/youtube-dl/issues/8536)
+                        feed_data = compat_parse_qs(compat_urllib_parse_unquote_plus(feed))
+                        entries.append({
+                            '_type': 'url_transparent',
+                            'ie_key': 'Youtube',
+                            'url': smuggle_url(
+                                '%s://www.youtube.com/watch?v=%s' % (proto, feed_data['id'][0]),
+                                {'force_singlefeed': True}),
+                            'title': '%s (%s)' % (video_title, feed_data['title'][0]),
+                        })
+                        feed_ids.append(feed_data['id'][0])
+                    self.to_screen(
+                        'Downloading multifeed video (%s) - add --no-playlist to just download video %s'
+                        % (', '.join(feed_ids), video_id))
+                    return self.playlist_result(entries, video_id, video_title, video_description)
+            else:
+                self.to_screen('Downloading just video %s because of --no-playlist' % video_id)
 
         if view_count is None:
             view_count = extract_view_count(video_info)