libavformat/movenc.c:1844: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32.

libavformat/movenc.c:1839:1: <LHS trace>
1837. }
1838. 
1839. static int utf8len(const uint8_t *b)
      ^
1840. {
1841.     int len=0;

libavformat/movenc.c:1839:1: Parameter `*b`
1837. }
1838. 
1839. static int utf8len(const uint8_t *b)
      ^
1840. {
1841.     int len=0;

libavformat/movenc.c:1844:9: Assignment
1842.     int val;
1843.     while(*b){
1844.         GET_UTF8(val, *b++, return -1;)
              ^
1845.         len++;
1846.     }

libavformat/movenc.c:1844:9: Assignment
1842.     int val;
1843.     while(*b){
1844.         GET_UTF8(val, *b++, return -1;)
              ^
1845.         len++;
1846.     }

libavformat/movenc.c:1844:9: Binary operation: ([0, +oo] - 1):unsigned32
1842.     int val;
1843.     while(*b){
1844.         GET_UTF8(val, *b++, return -1;)
              ^
1845.         len++;
1846.     }
