MV_TYPE_BACK       69 libavfilter/vf_codecview.c         CONST("bp", "backward predicted MVs", MV_TYPE_BACK, "mv_type"),
MV_TYPE_BACK      260 libavfilter/vf_codecview.c                     const int is_bp = direction == 1 && (s->mv_type & MV_TYPE_BACK);