libavcodec/mpegvideo.c:831: error: Uninitialized Value
  The value read from mv_table_size was never initialized.

libavcodec/mpegvideo.c:831:25: 
829.                 for (j = 0; j < 2; j++) {
830.                     for (k = 0; k < 2; k++) {
831.                         FF_ALLOCZ_OR_GOTO(s->avctx,
                             ^
832.                                           s->b_field_mv_table_base[i][j][k],
833.                                           mv_table_size * 2 * sizeof(int16_t),
