libavcodec/webp.c:249: error: Uninitialized Value
  The value read from re_size_plus8 was never initialized.

libavcodec/webp.c:249:9: 
247. 
248.     if (n < 0) {
249.         LAST_SKIP_BITS(re, gb, 8);
             ^
250.         UPDATE_CACHE(re, gb);
251. 
