libavcodec/flac.c:301: error: Uninitialized Value
  The value read from a was never initialized.

libavcodec/flac.c:301:30: 
299.         case 2:
300.             for (i = pred_order; i < blocksize; i++)
301.                 decoded[i] = a += b += decoded[i];
                                  ^
302.             break;
303.         case 3:
