libavcodec/vp3.c:735: error: Uninitialized Value
  The value read from motion_y[_] was never initialized.

libavcodec/vp3.c:735:21: 
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 {
737.                     s->all_fragments[current_fragment].motion_x = motion_x[0];
