GET_PTS_DIFF      478 libavcodec/rv34.c     int refdist = GET_PTS_DIFF(r->next_pts, r->last_pts);
GET_PTS_DIFF      479 libavcodec/rv34.c     int dist = dir ? -GET_PTS_DIFF(r->next_pts, r->cur_pts) : GET_PTS_DIFF(r->cur_pts, r->last_pts);