libavcodec/h264.c:1029: error: Uninitialized Value
  The value read from ref[_] was never initialized.

libavcodec/h264.c:1029:18: 
1027.                 *mb_type &= ~MB_TYPE_L1;
1028.             sub_mb_type &= ~MB_TYPE_L1;
1029.         }else if(ref[0] < 0){
                       ^
1030.             if(!is_b8x8)
1031.                 *mb_type &= ~MB_TYPE_L0;
