libavcodec/h264.c:3461: error: Uninitialized Value
  The value read from id_list[_] was never initialized.

libavcodec/h264.c:3461:13: 
3459.             ref2frm[18 + 1] = -1;
3460.         for (i = 16; i < 48; i++)
3461.             ref2frm[i + 4] = 4 * id_list[(i - 16) >> 1] +
                  ^
3462.                              (h->ref_list[j][i].f.reference & 3);
3463.     }
