libavcodec/h261dec.c:296: error: Integer Overflow L2
  (2 - [`h->s.bc.bits_left`, `h->s.bc.bits_left` + 32]):unsigned32 by call to `bitstream_skip`.

libavcodec/h261dec.c:259:1: Parameter `h->s.bc.bits_left`
257.  * @return <0 if an error occurred
258.  */
259. static int h261_decode_block(H261Context *h, int16_t *block, int n, int coded)
     ^
260. {
261.     MpegEncContext *const s = &h->s;

libavcodec/h261dec.c:293:21: Call
291.         // 0    1       1s
292.         // *    *       0*
293.         int check = bitstream_peek(&s->bc, 2);
                         ^
294.         i = 0;
295.         if (check & 0x2) {

libavcodec/bitstream.h:214:1: Parameter `n`
  212. /* Return n bits from the buffer, but do not change the buffer state.
  213.  * n has to be in the 0-32 range. */
  214. static inline unsigned bitstream_peek(BitstreamContext *bc, unsigned n)
       ^
  215. {
  216.     if (n > bc->bits_left)

libavcodec/h261dec.c:296:13: Call
294.         i = 0;
295.         if (check & 0x2) {
296.             bitstream_skip(&s->bc, 2);
                 ^
297.             block[0] = (check & 0x1) ? -1 : 1;
298.             i        = 1;

libavcodec/bitstream.h:240:1: <LHS trace>
238. 
239. /* Skip n bits in the buffer. */
240. static inline void bitstream_skip(BitstreamContext *bc, unsigned n)
     ^
241. {
242.     if (n < bc->bits_left)

libavcodec/bitstream.h:240:1: Parameter `n`
  238. 
  239. /* Skip n bits in the buffer. */
  240. static inline void bitstream_skip(BitstreamContext *bc, unsigned n)
       ^
  241. {
  242.     if (n < bc->bits_left)

libavcodec/bitstream.h:240:1: <RHS trace>
238. 
239. /* Skip n bits in the buffer. */
240. static inline void bitstream_skip(BitstreamContext *bc, unsigned n)
     ^
241. {
242.     if (n < bc->bits_left)

libavcodec/bitstream.h:240:1: Parameter `n`
  238. 
  239. /* Skip n bits in the buffer. */
  240. static inline void bitstream_skip(BitstreamContext *bc, unsigned n)
       ^
  241. {
  242.     if (n < bc->bits_left)

libavcodec/bitstream.h:245:9: Binary operation: (2 - [h->s.bc.bits_left, h->s.bc.bits_left + 32]):unsigned32 by call to `bitstream_skip` 
  243.         skip_remaining(bc, n);
  244.     else {
  245.         n -= bc->bits_left;
               ^
  246.         bc->bits      = 0;
  247.         bc->bits_left = 0;
