libavcodec/vp3.c:1862: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1854 could be null and is dereferenced by call to `get_bits1()` at line 1862, column 20.

libavcodec/vp3.c:1844:1: start of procedure vp3_decode_frame()
1842. }
1843. 
1844. static int vp3_decode_frame(AVCodecContext *avctx,
      ^
1845.                             void *data, int *data_size,
1846.                             AVPacket *avpkt)

libavcodec/vp3.c:1848:5: 
1846.                             AVPacket *avpkt)
1847. {
1848.     const uint8_t *buf = avpkt->data;
          ^
1849.     int buf_size = avpkt->size;
1850.     Vp3DecodeContext *s = avctx->priv_data;

libavcodec/vp3.c:1849:5: 
1847. {
1848.     const uint8_t *buf = avpkt->data;
1849.     int buf_size = avpkt->size;
          ^
1850.     Vp3DecodeContext *s = avctx->priv_data;
1851.     GetBitContext gb;

libavcodec/vp3.c:1850:5: 
1848.     const uint8_t *buf = avpkt->data;
1849.     int buf_size = avpkt->size;
1850.     Vp3DecodeContext *s = avctx->priv_data;
          ^
1851.     GetBitContext gb;
1852.     int i;

libavcodec/vp3.c:1854:5: 
1852.     int i;
1853. 
1854.     init_get_bits(&gb, buf, buf_size * 8);
          ^
1855. 
1856.     if (s->theora && get_bits1(&gb))

libavcodec/get_bits.h:306:1: start of procedure init_get_bits()
  304.  * responsible for checking for the buffer end yourself (take advantage of the padding)!
  305.  */
  306. static inline void init_get_bits(GetBitContext *s,
       ^
  307.                    const uint8_t *buffer, int bit_size)
  308. {

libavcodec/get_bits.h:309:5: 
  307.                    const uint8_t *buffer, int bit_size)
  308. {
  309.     int buffer_size = (bit_size+7)>>3;
           ^
  310.     if (buffer_size < 0 || bit_size < 0) {
  311.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:310:9: Taking true branch
  308. {
  309.     int buffer_size = (bit_size+7)>>3;
  310.     if (buffer_size < 0 || bit_size < 0) {
               ^
  311.         buffer_size = bit_size = 0;
  312.         buffer = NULL;

libavcodec/get_bits.h:311:9: 
  309.     int buffer_size = (bit_size+7)>>3;
  310.     if (buffer_size < 0 || bit_size < 0) {
  311.         buffer_size = bit_size = 0;
               ^
  312.         buffer = NULL;
  313.     }

libavcodec/get_bits.h:312:9: 
  310.     if (buffer_size < 0 || bit_size < 0) {
  311.         buffer_size = bit_size = 0;
  312.         buffer = NULL;
               ^
  313.     }
  314. 

libavcodec/get_bits.h:315:5: 
  313.     }
  314. 
  315.     s->buffer       = buffer;
           ^
  316.     s->size_in_bits = bit_size;
  317.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:316:5: 
  314. 
  315.     s->buffer       = buffer;
  316.     s->size_in_bits = bit_size;
           ^
  317.     s->buffer_end   = buffer + buffer_size;
  318.     s->index        = 0;

libavcodec/get_bits.h:317:5: 
  315.     s->buffer       = buffer;
  316.     s->size_in_bits = bit_size;
  317.     s->buffer_end   = buffer + buffer_size;
           ^
  318.     s->index        = 0;
  319. }

libavcodec/get_bits.h:318:5: 
  316.     s->size_in_bits = bit_size;
  317.     s->buffer_end   = buffer + buffer_size;
  318.     s->index        = 0;
           ^
  319. }
  320. 

libavcodec/get_bits.h:319:1: return from a call to init_get_bits
  317.     s->buffer_end   = buffer + buffer_size;
  318.     s->index        = 0;
  319. }
       ^
  320. 
  321. static inline void align_get_bits(GetBitContext *s)

libavcodec/vp3.c:1856:9: Taking false branch
1854.     init_get_bits(&gb, buf, buf_size * 8);
1855. 
1856.     if (s->theora && get_bits1(&gb))
              ^
1857.     {
1858.         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");

libavcodec/vp3.c:1862:20: 
1860.     }
1861. 
1862.     s->keyframe = !get_bits1(&gb);
                         ^
1863.     if (!s->theora)
1864.         skip_bits(&gb, 1);

libavcodec/get_bits.h:230:1: start of procedure get_bits1()
  228. }
  229. 
  230. static inline unsigned int get_bits1(GetBitContext *s){
       ^
  231.     unsigned int index = s->index;
  232.     uint8_t result = s->buffer[index>>3];

libavcodec/get_bits.h:231:5: 
  229. 
  230. static inline unsigned int get_bits1(GetBitContext *s){
  231.     unsigned int index = s->index;
           ^
  232.     uint8_t result = s->buffer[index>>3];
  233. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/get_bits.h:232:5: 
  230. static inline unsigned int get_bits1(GetBitContext *s){
  231.     unsigned int index = s->index;
  232.     uint8_t result = s->buffer[index>>3];
           ^
  233. #ifdef ALT_BITSTREAM_READER_LE
  234.     result >>= index & 7;
