[ted] Fix hls audio/video-only formats

youtube_dl/extractor/ted.py

@@ -198,7 +198,10 @@ class TEDIE(InfoExtractor):
                 hls_formats = self._extract_m3u8_formats(
                     resources.get('stream'), video_name, 'mp4', m3u8_id=format_id)
                 for f in hls_formats:
-                    f['acodec'] = 'none'
+                    if not f.get('height'):
+                        f['vcodec'] = 'none'
+                    else:
+                        f['acodec'] = 'none'
                 formats.extend(hls_formats)
 
         audio_download = talk_info.get('audioDownload')