docs: def set_h264_frm_ref_mode(self, mode=1, callback=None):
          '''
          Set frame shipping reference mode of H264 encode stream.
          params:
              `mode`: see docstr of meth::get_h264_frm_ref_mode
          '''
          params = {'mode': mode}
          return self.execute_command('setH264FrmRefMode', params, callback)