libavcodec/h261dec.c:486: error: Integer Overflow L2
  ([0, +oo] - 1):unsigned32 by call to `bitstream_skip`.

libavcodec/h261dec.c:478:9: Call
476. 
477.     /* temporal reference */
478.     i = bitstream_read(&s->bc, 5); /* picture timestamp */
             ^
479.     if (i < (s->picture_number & 31))
480.         i += 32;

libavcodec/bitstream.h:182:1: Parameter `bc->bits_left`
  180. 
  181. /* Return n bits from the buffer. n has to be in the 0-32 range. */
  182. static inline uint32_t bitstream_read(BitstreamContext *bc, unsigned n)
       ^
  183. {
  184.     if (!n)

libavcodec/h261dec.c:486:5: Call
484. 
485.     /* PTYPE starts here */
486.     bitstream_skip(&s->bc, 1); /* split screen off */
         ^
487.     bitstream_skip(&s->bc, 1); /* camera  off */
488.     bitstream_skip(&s->bc, 1); /* freeze picture release off */

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:243:9: Call
  241. {
  242.     if (n < bc->bits_left)
  243.         skip_remaining(bc, n);
               ^
  244.     else {
  245.         n -= bc->bits_left;

libavcodec/bitstream.h:229:1: <LHS trace>
227. }
228. 
229. static inline void skip_remaining(BitstreamContext *bc, unsigned n)
     ^
230. {
231. #ifdef BITSTREAM_READER_LE

libavcodec/bitstream.h:229:1: Parameter `bc->bits_left`
    227. }
    228. 
    229. static inline void skip_remaining(BitstreamContext *bc, unsigned n)
         ^
    230. {
    231. #ifdef BITSTREAM_READER_LE

libavcodec/bitstream.h:229:1: <RHS trace>
227. }
228. 
229. static inline void skip_remaining(BitstreamContext *bc, unsigned n)
     ^
230. {
231. #ifdef BITSTREAM_READER_LE

libavcodec/bitstream.h:229:1: Parameter `n`
    227. }
    228. 
    229. static inline void skip_remaining(BitstreamContext *bc, unsigned n)
         ^
    230. {
    231. #ifdef BITSTREAM_READER_LE

libavcodec/bitstream.h:236:5: Binary operation: ([0, +oo] - 1):unsigned32 by call to `bitstream_skip` 
    234.     bc->bits <<= n;
    235. #endif
    236.     bc->bits_left -= n;
             ^
    237. }
    238. 

static inline void skip_remaining(BitstreamContext *bc, unsigned n)
{
#ifdef BITSTREAM_READER_LE
    bc->bits >>= n;
#else
    bc->bits <<= n;
#endif
    bc->bits_left -= n;
}
['static int h261_decode_picture_header(H261Context *h)\n{\n    MpegEncContext *const s = &h->s;\n    int format, i;\n    uint32_t startcode = 0;\n    for (i = bitstream_bits_left(&s->bc); i > 24; i -= 1) {\n        startcode = ((startcode << 1) | bitstream_read(&s->bc, 1)) & 0x000FFFFF;\n        if (startcode == 0x10)\n            break;\n    }\n    if (startcode != 0x10) {\n        av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\\n");\n        return -1;\n    }\n    i = bitstream_read(&s->bc, 5);\n    if (i < (s->picture_number & 31))\n        i += 32;\n    s->picture_number = (s->picture_number & ~31) + i;\n    s->avctx->framerate = (AVRational) { 30000, 1001 };\n    bitstream_skip(&s->bc, 1);\n    bitstream_skip(&s->bc, 1);\n    bitstream_skip(&s->bc, 1);\n    format = bitstream_read_bit(&s->bc);\n    if (format == 0) {\n        s->width     = 176;\n        s->height    = 144;\n        s->mb_width  = 11;\n        s->mb_height = 9;\n    } else {\n        s->width     = 352;\n        s->height    = 288;\n        s->mb_width  = 22;\n        s->mb_height = 18;\n    }\n    s->mb_num = s->mb_width * s->mb_height;\n    bitstream_skip(&s->bc, 1);\n    bitstream_skip(&s->bc, 1);\n    while (bitstream_read_bit(&s->bc) != 0)\n        bitstream_skip(&s->bc, 8);\n    s->pict_type = AV_PICTURE_TYPE_P;\n    h->gob_number = 0;\n    return 0;\n}', 'static inline uint32_t bitstream_read(BitstreamContext *bc, unsigned n)\n{\n    if (!n)\n        return 0;\n    if (n > bc->bits_left) {\n        refill_32(bc);\n        if (bc->bits_left < 32)\n            bc->bits_left = n;\n    }\n    return get_val(bc, n);\n}', 'static inline void bitstream_skip(BitstreamContext *bc, unsigned n)\n{\n    if (n < bc->bits_left)\n        skip_remaining(bc, n);\n    else {\n        n -= bc->bits_left;\n        bc->bits      = 0;\n        bc->bits_left = 0;\n        if (n >= 64) {\n            unsigned skip = n / 8;\n            n -= skip * 8;\n            bc->ptr += skip;\n        }\n        refill_64(bc);\n        if (n)\n            skip_remaining(bc, n);\n    }\n}', 'static inline void skip_remaining(BitstreamContext *bc, unsigned n)\n{\n#ifdef BITSTREAM_READER_LE\n    bc->bits >>= n;\n#else\n    bc->bits <<= n;\n#endif\n    bc->bits_left -= n;\n}']