libavcodec/vp3.c:760: error: Uninitialized Value
  The value read from motion_y[_] was never initialized.

libavcodec/vp3.c:760:35: 
758.                 if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
759.                     motion_x[0] = RSHIFT(motion_x[0] + motion_x[1], 1);
760.                     motion_y[0] = RSHIFT(motion_y[0] + motion_y[1], 1);
                                       ^
761.                     motion_x[1] = RSHIFT(motion_x[2] + motion_x[3], 1);
762.                     motion_y[1] = RSHIFT(motion_y[2] + motion_y[3], 1);
