libavcodec/vp3.c:734: error: Uninitialized Value
  The value read from motion_x[_] was never initialized.

libavcodec/vp3.c:734:21: 
732.                     BLOCK_Y*s->fragment_width[0] + BLOCK_X;
733.                 if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
734.                     s->all_fragments[current_fragment].motion_x = motion_x[k];
                         ^
735.                     s->all_fragments[current_fragment].motion_y = motion_y[k];
736.                 } else {
