let mut mv_f = self.predict_b_mv_component(sstate, mvi, mbinfo, mbtype, true);
let mut mv_b = self.predict_b_mv_component(sstate, mvi, mbinfo, mbtype, false);
let mut mv_f = self.predict_b_mv_component(sstate, mvi, mbinfo, mbtype, true);
let mut mv_b = self.predict_b_mv_component(sstate, mvi, mbinfo, mbtype, false);