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)