libavcodec/amrwbdec.c:917: error: Uninitialized Value
  The value read from diff_isf[_] was never initialized.

libavcodec/amrwbdec.c:917:9: 
915.     diff_mean = 0.0;
916.     for (i = 2; i < LP_ORDER - 2; i++)
917.         diff_mean += diff_isf[i] * (1.0f / (LP_ORDER - 4));
             ^
918. 
919.     /* Find which is the maximum autocorrelation */
