webpage = self._download_webpage(req, video_id)
files_base64 = self._search_regex(
r'data-files="([^"]+)"', webpage, 'data files')
files = self._parse_json(
webpage = self._download_webpage(req, video_id)
files_base64 = self._search_regex(
r'data-files="([^"]+)"', webpage, 'data files')
files = self._parse_json(