libavcodec/on2avc.c:799: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 798 could be null and is dereferenced by call to `get_bits1()` at line 799, column 9.

libavcodec/on2avc.c:792:1: start of procedure on2avc_decode_subframe()
790. }
791. 
792. static int on2avc_decode_subframe(On2AVCContext *c, const uint8_t *buf,
     ^
793.                                   int buf_size, AVFrame *dst, int offset)
794. {

libavcodec/on2avc.c:798:5: 
796.     int i, ret;
797. 
798.     init_get_bits(&gb, buf, buf_size * 8);
         ^
799.     if (get_bits1(&gb)) {
800.         av_log(c->avctx, AV_LOG_ERROR, "enh bit set\n");

libavcodec/get_bits.h:376:1: start of procedure init_get_bits()
  374.  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
  375.  */
  376. static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  377.                                 int bit_size)
  378. {

libavcodec/get_bits.h:380:5: 
  378. {
  379.     int buffer_size;
  380.     int ret = 0;
           ^
  381. 
  382.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {

libavcodec/get_bits.h:382:9: Taking true branch
  380.     int ret = 0;
  381. 
  382.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {
               ^
  383.         bit_size    = 0;
  384.         buffer      = NULL;

libavcodec/get_bits.h:383:9: 
  381. 
  382.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {
  383.         bit_size    = 0;
               ^
  384.         buffer      = NULL;
  385.         ret         = AVERROR_INVALIDDATA;

libavcodec/get_bits.h:384:9: 
  382.     if (bit_size > INT_MAX - 7 || bit_size < 0 || !buffer) {
  383.         bit_size    = 0;
  384.         buffer      = NULL;
               ^
  385.         ret         = AVERROR_INVALIDDATA;
  386.     }

libavcodec/get_bits.h:385:9: 
  383.         bit_size    = 0;
  384.         buffer      = NULL;
  385.         ret         = AVERROR_INVALIDDATA;
               ^
  386.     }
  387. 

libavcodec/get_bits.h:388:5: 
  386.     }
  387. 
  388.     buffer_size = (bit_size + 7) >> 3;
           ^
  389. 
  390.     s->buffer             = buffer;

libavcodec/get_bits.h:390:5: 
  388.     buffer_size = (bit_size + 7) >> 3;
  389. 
  390.     s->buffer             = buffer;
           ^
  391.     s->size_in_bits       = bit_size;
  392. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:391:5: 
  389. 
  390.     s->buffer             = buffer;
  391.     s->size_in_bits       = bit_size;
           ^
  392. #if !UNCHECKED_BITSTREAM_READER
  393.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:393:5: 
  391.     s->size_in_bits       = bit_size;
  392. #if !UNCHECKED_BITSTREAM_READER
  393.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  394. #endif
  395.     s->buffer_end         = buffer + buffer_size;

libavcodec/get_bits.h:395:5: 
  393.     s->size_in_bits_plus8 = bit_size + 8;
  394. #endif
  395.     s->buffer_end         = buffer + buffer_size;
           ^
  396.     s->index              = 0;
  397. 

libavcodec/get_bits.h:396:5: 
  394. #endif
  395.     s->buffer_end         = buffer + buffer_size;
  396.     s->index              = 0;
           ^
  397. 
  398.     return ret;

libavcodec/get_bits.h:398:5: 
  396.     s->index              = 0;
  397. 
  398.     return ret;
           ^
  399. }
  400. 

libavcodec/get_bits.h:399:1: return from a call to init_get_bits
  397. 
  398.     return ret;
  399. }
       ^
  400. 
  401. /**

libavcodec/on2avc.c:799:9: 
797. 
798.     init_get_bits(&gb, buf, buf_size * 8);
799.     if (get_bits1(&gb)) {
             ^
800.         av_log(c->avctx, AV_LOG_ERROR, "enh bit set\n");
801.         return AVERROR_INVALIDDATA;

libavcodec/get_bits.h:272:1: start of procedure get_bits1()
  270. }
  271. 
  272. static inline unsigned int get_bits1(GetBitContext *s)
       ^
  273. {
  274.     unsigned int index = s->index;

libavcodec/get_bits.h:274:5: 
  272. static inline unsigned int get_bits1(GetBitContext *s)
  273. {
  274.     unsigned int index = s->index;
           ^
  275.     uint8_t result     = s->buffer[index >> 3];
  276. #ifdef BITSTREAM_READER_LE

libavcodec/get_bits.h:275:5: 
  273. {
  274.     unsigned int index = s->index;
  275.     uint8_t result     = s->buffer[index >> 3];
           ^
  276. #ifdef BITSTREAM_READER_LE
  277.     result >>= index & 7;
