ref_xml_url = ref_xml_url.replace('.html', ',view,asPlayerXml.xml')
ref_xml = self._download_webpage(ref_xml_url, video_id, note=u'Downloading metadata')
ref_xml_doc = xml.etree.ElementTree.fromstring(ref_xml)
ref_xml_url = ref_xml_url.replace('.html', ',view,asPlayerXml.xml')
ref_xml = self._download_webpage(ref_xml_url, video_id, note=u'Downloading metadata')
ref_xml_doc = xml.etree.ElementTree.fromstring(ref_xml)