libavcodec/vp3.c:1775: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1767 could be null and is dereferenced by call to `get_bits1()` at line 1775, column 20.

libavcodec/vp3.c:1756:1: start of procedure vp3_decode_frame()
1754.  * This is the ffmpeg/libavcodec API frame decode function.
1755.  */
1756. static int vp3_decode_frame(AVCodecContext *avctx,
      ^
1757.                             void *data, int *data_size,
1758.                             AVPacket *avpkt)

libavcodec/vp3.c:1760:5: 
1758.                             AVPacket *avpkt)
1759. {
1760.     const uint8_t *buf = avpkt->data;
          ^
1761.     int buf_size = avpkt->size;
1762.     Vp3DecodeContext *s = avctx->priv_data;

libavcodec/vp3.c:1761:5: 
1759. {
1760.     const uint8_t *buf = avpkt->data;
1761.     int buf_size = avpkt->size;
          ^
1762.     Vp3DecodeContext *s = avctx->priv_data;
1763.     GetBitContext gb;

libavcodec/vp3.c:1762:5: 
1760.     const uint8_t *buf = avpkt->data;
1761.     int buf_size = avpkt->size;
1762.     Vp3DecodeContext *s = avctx->priv_data;
          ^
1763.     GetBitContext gb;
1764.     static int counter = 0;

libavcodec/vp3.c:1764:5: 
1762.     Vp3DecodeContext *s = avctx->priv_data;
1763.     GetBitContext gb;
1764.     static int counter = 0;
          ^
1765.     int i;
1766. 

libavcodec/vp3.c:1767:5: 
1765.     int i;
1766. 
1767.     init_get_bits(&gb, buf, buf_size * 8);
          ^
1768. 
1769.     if (s->theora && get_bits1(&gb))

libavcodec/get_bits.h:494:1: start of procedure init_get_bits()
  492.  * responsible for checking for the buffer end yourself (take advantage of the padding)!
  493.  */
  494. static inline void init_get_bits(GetBitContext *s,
       ^
  495.                    const uint8_t *buffer, int bit_size)
  496. {

libavcodec/get_bits.h:497:5: 
  495.                    const uint8_t *buffer, int bit_size)
  496. {
  497.     int buffer_size= (bit_size+7)>>3;
           ^
  498.     if(buffer_size < 0 || bit_size < 0) {
  499.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:498:8: Taking true branch
  496. {
  497.     int buffer_size= (bit_size+7)>>3;
  498.     if(buffer_size < 0 || bit_size < 0) {
              ^
  499.         buffer_size = bit_size = 0;
  500.         buffer = NULL;

libavcodec/get_bits.h:499:9: 
  497.     int buffer_size= (bit_size+7)>>3;
  498.     if(buffer_size < 0 || bit_size < 0) {
  499.         buffer_size = bit_size = 0;
               ^
  500.         buffer = NULL;
  501.     }

libavcodec/get_bits.h:500:9: 
  498.     if(buffer_size < 0 || bit_size < 0) {
  499.         buffer_size = bit_size = 0;
  500.         buffer = NULL;
               ^
  501.     }
  502. 

libavcodec/get_bits.h:503:5: 
  501.     }
  502. 
  503.     s->buffer= buffer;
           ^
  504.     s->size_in_bits= bit_size;
  505.     s->buffer_end= buffer + buffer_size;

libavcodec/get_bits.h:504:5: 
  502. 
  503.     s->buffer= buffer;
  504.     s->size_in_bits= bit_size;
           ^
  505.     s->buffer_end= buffer + buffer_size;
  506. #ifdef ALT_BITSTREAM_READER

libavcodec/get_bits.h:505:5: 
  503.     s->buffer= buffer;
  504.     s->size_in_bits= bit_size;
  505.     s->buffer_end= buffer + buffer_size;
           ^
  506. #ifdef ALT_BITSTREAM_READER
  507.     s->index=0;

libavcodec/get_bits.h:507:5: 
  505.     s->buffer_end= buffer + buffer_size;
  506. #ifdef ALT_BITSTREAM_READER
  507.     s->index=0;
           ^
  508. #elif defined LIBMPEG2_BITSTREAM_READER
  509.     s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));

libavcodec/get_bits.h:517:1: return from a call to init_get_bits
  515.     skip_bits_long(s, 0);
  516. #endif
  517. }
       ^
  518. 
  519. static inline void align_get_bits(GetBitContext *s)

libavcodec/vp3.c:1769:9: Taking false branch
1767.     init_get_bits(&gb, buf, buf_size * 8);
1768. 
1769.     if (s->theora && get_bits1(&gb))
              ^
1770.     {
1771.         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");

libavcodec/vp3.c:1775:20: 
1773.     }
1774. 
1775.     s->keyframe = !get_bits1(&gb);
                         ^
1776.     if (!s->theora)
1777.         skip_bits(&gb, 1);

libavcodec/get_bits.h:414:1: start of procedure get_bits1()
  412. }
  413. 
  414. static inline unsigned int get_bits1(GetBitContext *s){
       ^
  415. #ifdef ALT_BITSTREAM_READER
  416.     unsigned int index= s->index;

libavcodec/get_bits.h:416:5: 
  414. static inline unsigned int get_bits1(GetBitContext *s){
  415. #ifdef ALT_BITSTREAM_READER
  416.     unsigned int index= s->index;
           ^
  417.     uint8_t result= s->buffer[ index>>3 ];
  418. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/get_bits.h:417:5: 
  415. #ifdef ALT_BITSTREAM_READER
  416.     unsigned int index= s->index;
  417.     uint8_t result= s->buffer[ index>>3 ];
           ^
  418. #ifdef ALT_BITSTREAM_READER_LE
  419.     result>>= (index&0x07);
