[YoutubeDL] Allow bestvideo+bestaudio/best strategy for ted extractor

youtube_dl/YoutubeDL.py

@@ -1092,7 +1092,7 @@ class YoutubeDL(object):
         req_format = self.params.get('format')
         if req_format is None:
             req_format_list = []
-            if info_dict['extractor'] == 'youtube' and FFmpegMergerPP(self).available:
+            if info_dict['extractor'] in ['youtube', 'ted'] and FFmpegMergerPP(self).available:
                 req_format_list.append('bestvideo+bestaudio')
             req_format_list.append('best')
             req_format = '/'.join(req_format_list)