@ -912,7 +912,7 @@ class YoutubeDL(object):
selected_format = {
'requested_formats': formats_info,
'format': rf,
'ext': formats_info[0]['ext'],
'ext': self.params['merge_output_format'] if self.params['merge_output_format'] is not None else formats_info[0]['ext'],
}
else:
selected_format = None