How to use the ykdl.extractors.iqiyi.util.cmd5x function in ykdl

# keys above are relative to cookies
        'tvid': tvid,
        'bid': bid,
        'vid': vid,
        'src': '01010031010000000000',
        'vt': 0,
        'rs': 1,
        'ori': 'pcw',
        'ps': 1,
        'pt': 0,
        'd': 0,
        's': '',
        'lid': '',
        'cf': '',
        'ct': '',
        'authKey': cmd5x('{}{}{}'.format(cmd5x(''), tm, tvid)),
        'k_tag': 1,
        'ost': 0,
        'ppt': 0,
        'locale': 'zh_cn',
        'prio': '{"ff":"f4v","code":2}',
        'k_err_retries': 0,
        'up': '',
        'qd_v': 2,
        'tm': tm,
        'qdy': 'a',
        'qds': 0,
        'ut': 0, # 600 bid isn't available
        # relative to encode
        #'k_ft1': ,
        #'k_ft4': ,
        #'k_ft5': ,

'locale': 'zh_cn',
        'prio': '{"ff":"f4v","code":2}',
        'k_err_retries': 0,
        'up': '',
        'qd_v': 2,
        'tm': tm,
        'qdy': 'a',
        'qds': 0,
        'ut': 0, # 600 bid isn't available
        # relative to encode
        #'k_ft1': ,
        #'k_ft4': ,
        #'k_ft5': ,
    }
    src = '/dash?{}'.format(urlencode(params))
    vf = cmd5x(src)
    req_url = '{}{}&vf={}'.format(host, src, vf)
    html = get_content(req_url)
    return json.loads(html)