libavcodec/h264.c:3456: error: Uninitialized Value
  The value read from id_list[_] was never initialized.

libavcodec/h264.c:3456:13: 
3454.             ref2frm[1] = -1;
3455.         for (i = 0; i < 16; i++)
3456.             ref2frm[i + 2] = 4 * id_list[i] +
                  ^
3457.                              (h->ref_list[j][i].f.reference & 3);
3458.         ref2frm[18 + 0]     =
