libavcodec/vp3.c:1926: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1924 could be null and is dereferenced by call to `get_bits1()` at line 1926, column 22.

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:370:1: start of procedure init_get_bits()
  368.  * @param bit_size the size of the buffer in bits
  369.  */
  370. static inline void init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  371.                                  int bit_size)
  372. {

libavcodec/get_bits.h:373:5: 
  371.                                  int bit_size)
  372. {
  373.     int buffer_size = (bit_size+7)>>3;
           ^
  374.     if (buffer_size < 0 || bit_size < 0) {
  375.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:374:9: Taking true branch
  372. {
  373.     int buffer_size = (bit_size+7)>>3;
  374.     if (buffer_size < 0 || bit_size < 0) {
               ^
  375.         buffer_size = bit_size = 0;
  376.         buffer = NULL;

libavcodec/get_bits.h:375:9: 
  373.     int buffer_size = (bit_size+7)>>3;
  374.     if (buffer_size < 0 || bit_size < 0) {
  375.         buffer_size = bit_size = 0;
               ^
  376.         buffer = NULL;
  377.     }

libavcodec/get_bits.h:376:9: 
  374.     if (buffer_size < 0 || bit_size < 0) {
  375.         buffer_size = bit_size = 0;
  376.         buffer = NULL;
               ^
  377.     }
  378. 

libavcodec/get_bits.h:379:5: 
  377.     }
  378. 
  379.     s->buffer       = buffer;
           ^
  380.     s->size_in_bits = bit_size;
  381. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:380:5: 
  378. 
  379.     s->buffer       = buffer;
  380.     s->size_in_bits = bit_size;
           ^
  381. #if !UNCHECKED_BITSTREAM_READER
  382.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:382:5: 
  380.     s->size_in_bits = bit_size;
  381. #if !UNCHECKED_BITSTREAM_READER
  382.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  383. #endif
  384.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:384:5: 
  382.     s->size_in_bits_plus8 = bit_size + 8;
  383. #endif
  384.     s->buffer_end   = buffer + buffer_size;
           ^
  385.     s->index        = 0;
  386. }

libavcodec/get_bits.h:385:5: 
  383. #endif
  384.     s->buffer_end   = buffer + buffer_size;
  385.     s->index        = 0;
           ^
  386. }
  387. 

libavcodec/get_bits.h:386:1: return from a call to init_get_bits
  384.     s->buffer_end   = buffer + buffer_size;
  385.     s->index        = 0;
  386. }
       ^
  387. 
  388. static inline void align_get_bits(GetBitContext *s)

libavcodec/vp3.c:1926:9: Taking true 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:1926:22: 
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/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;
