libavcodec/vp3.c:1932: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1924 could be null and is dereferenced by call to `get_bits1()` at line 1932, column 20.

libavcodec/vp3.c:1914:1: start of procedure vp3_decode_frame()
1912. }
1913. 
1914. static int vp3_decode_frame(AVCodecContext *avctx,
      ^
1915.                             void *data, int *got_frame,
1916.                             AVPacket *avpkt)

libavcodec/vp3.c:1918:5: 
1916.                             AVPacket *avpkt)
1917. {
1918.     const uint8_t *buf = avpkt->data;
          ^
1919.     int buf_size = avpkt->size;
1920.     Vp3DecodeContext *s = avctx->priv_data;

libavcodec/vp3.c:1919:5: 
1917. {
1918.     const uint8_t *buf = avpkt->data;
1919.     int buf_size = avpkt->size;
          ^
1920.     Vp3DecodeContext *s = avctx->priv_data;
1921.     GetBitContext gb;

libavcodec/vp3.c:1920:5: 
1918.     const uint8_t *buf = avpkt->data;
1919.     int buf_size = avpkt->size;
1920.     Vp3DecodeContext *s = avctx->priv_data;
          ^
1921.     GetBitContext gb;
1922.     int i;

libavcodec/vp3.c:1924:5: 
1922.     int i;
1923. 
1924.     init_get_bits(&gb, buf, buf_size * 8);
          ^
1925. 
1926.     if (s->theora && get_bits1(&gb))

libavcodec/get_bits.h:372:1: start of procedure init_get_bits()
  370.  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
  371.  */
  372. static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  373.                                 int bit_size)
  374. {

libavcodec/get_bits.h:376:5: 
  374. {
  375.     int buffer_size;
  376.     int ret = 0;
           ^
  377. 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {

libavcodec/get_bits.h:378:9: Taking true branch
  376.     int ret = 0;
  377. 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {
               ^
  379.         buffer_size = bit_size = 0;
  380.         buffer = NULL;

libavcodec/get_bits.h:379:9: 
  377. 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {
  379.         buffer_size = bit_size = 0;
               ^
  380.         buffer = NULL;
  381.         ret = AVERROR_INVALIDDATA;

libavcodec/get_bits.h:380:9: 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {
  379.         buffer_size = bit_size = 0;
  380.         buffer = NULL;
               ^
  381.         ret = AVERROR_INVALIDDATA;
  382.     }

libavcodec/get_bits.h:381:9: 
  379.         buffer_size = bit_size = 0;
  380.         buffer = NULL;
  381.         ret = AVERROR_INVALIDDATA;
               ^
  382.     }
  383. 

libavcodec/get_bits.h:384:5: 
  382.     }
  383. 
  384.     buffer_size = (bit_size + 7) >> 3;
           ^
  385. 
  386.     s->buffer       = buffer;

libavcodec/get_bits.h:386:5: 
  384.     buffer_size = (bit_size + 7) >> 3;
  385. 
  386.     s->buffer       = buffer;
           ^
  387.     s->size_in_bits = bit_size;
  388. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:387:5: 
  385. 
  386.     s->buffer       = buffer;
  387.     s->size_in_bits = bit_size;
           ^
  388. #if !UNCHECKED_BITSTREAM_READER
  389.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:389:5: 
  387.     s->size_in_bits = bit_size;
  388. #if !UNCHECKED_BITSTREAM_READER
  389.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  390. #endif
  391.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:391:5: 
  389.     s->size_in_bits_plus8 = bit_size + 8;
  390. #endif
  391.     s->buffer_end   = buffer + buffer_size;
           ^
  392.     s->index        = 0;
  393.     return ret;

libavcodec/get_bits.h:392:5: 
  390. #endif
  391.     s->buffer_end   = buffer + buffer_size;
  392.     s->index        = 0;
           ^
  393.     return ret;
  394. }

libavcodec/get_bits.h:393:5: 
  391.     s->buffer_end   = buffer + buffer_size;
  392.     s->index        = 0;
  393.     return ret;
           ^
  394. }
  395. 

libavcodec/get_bits.h:394:1: return from a call to init_get_bits
  392.     s->index        = 0;
  393.     return ret;
  394. }
       ^
  395. 
  396. static inline void align_get_bits(GetBitContext *s)

libavcodec/vp3.c:1926:9: Taking false branch
1924.     init_get_bits(&gb, buf, buf_size * 8);
1925. 
1926.     if (s->theora && get_bits1(&gb))
              ^
1927.     {
1928.         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");

libavcodec/vp3.c:1932:20: 
1930.     }
1931. 
1932.     s->keyframe = !get_bits1(&gb);
                         ^
1933.     if (!s->theora)
1934.         skip_bits(&gb, 1);

libavcodec/get_bits.h:268:1: start of procedure get_bits1()
  266. }
  267. 
  268. static inline unsigned int get_bits1(GetBitContext *s)
       ^
  269. {
  270.     unsigned int index = s->index;

libavcodec/get_bits.h:270:5: 
  268. static inline unsigned int get_bits1(GetBitContext *s)
  269. {
  270.     unsigned int index = s->index;
           ^
  271.     uint8_t result = s->buffer[index>>3];
  272. #ifdef BITSTREAM_READER_LE

libavcodec/get_bits.h:271:5: 
  269. {
  270.     unsigned int index = s->index;
  271.     uint8_t result = s->buffer[index>>3];
           ^
  272. #ifdef BITSTREAM_READER_LE
  273.     result >>= index & 7;
