thumbnmail = xpath_text(playlist, './info/thumburl', 'thumbnail')
upload_date = unified_strdate(xpath_text(playlist, './info/date', 'upload date'))
duration = parse_duration(xpath_text(playlist, './info/duration', 'duration'))
thumbnmail = xpath_text(playlist, './info/thumburl', 'thumbnail')
upload_date = unified_strdate(xpath_text(playlist, './info/date', 'upload date'))
duration = parse_duration(xpath_text(playlist, './info/duration', 'duration'))