@ -2370,7 +2370,7 @@ class YoutubeIE(YoutubeBaseInfoExtractor):
mpd_url, video_id, fatal=dash_mpd_fatal,
formats_dict=self._formats):
if not df.get('filesize'):
df['filesize'] = _extract_filesize(df['url'])
df['filesize'] = _extract_filesize(df.get('fragment_base_url') or df['url'])
# Do not overwrite DASH format found in some previous DASH manifest
if df['format_id'] not in dash_formats:
dash_formats[df['format_id']] = df