libavcodec/xan.c:169: error: Uninitialized Value
  The value read from opcode was never initialized.

libavcodec/xan.c:169:5: 
167.     }
168. 
169.     size = opcode & 3;
         ^
170.     memcpy(dest, src, size);  dest += size;  src += size;
171. }
