libavcodec/vp9block.c:613: error: Buffer Overrun L1
  Offset: 4 (⇐ 3 + 1) Size: 4 by call to `ff_vp9_fill_mv`.

libavcodec/vp9block.c:44:1: Parameter `b->mv[*]`
42. 
43. // differential forward probability updates
44. static void decode_mode(VP9Context *s, VP9Block *const b)
    ^
45. {
46.     static const uint8_t left_ctx[N_BS_SIZES] = {

libavcodec/vp9block.c:613:21: Call
611.                                                   s->prob.p.mv_mode[c]);
612.                     s->counts.mv_mode[c][b->mode[3] - 10]++;
613.                     ff_vp9_fill_mv(s, b->mv[3], b->mode[3], 3);
                         ^
614.                 } else {
615.                     b->mode[3] = b->mode[2];

libavcodec/vp9mvs.c:284:1: <Length trace>
282. }
283. 
284. void ff_vp9_fill_mv(VP9Context *s, VP56mv *mv, int mode, int sb)
     ^
285. {
286.     VP9Block *b = s->b;

libavcodec/vp9mvs.c:284:1: Parameter `*mv`
  282. }
  283. 
  284. void ff_vp9_fill_mv(VP9Context *s, VP56mv *mv, int mode, int sb)
       ^
  285. {
  286.     VP9Block *b = s->b;

libavcodec/vp9mvs.c:330:44: Array access: Offset: 4 (⇐ 3 + 1) Size: 4 by call to `ff_vp9_fill_mv` 
  328.             if ((mode == NEWMV || sb == -1) &&
  329.                 !(hp = s->highprecisionmvs &&
  330.                   abs(mv[1].x) < 64 && abs(mv[1].y) < 64)) {
                                                  ^
  331.                 if (mv[1].y & 1) {
  332.                     if (mv[1].y < 0)
