libavcodec/vp3.c:1762: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1754 could be null and is dereferenced by call to `get_bits1()` at line 1762, column 20.

libavcodec/vp3.c:1743:1: start of procedure vp3_decode_frame()
1741.  * This is the ffmpeg/libavcodec API frame decode function.
1742.  */
1743. static int vp3_decode_frame(AVCodecContext *avctx,
      ^
1744.                             void *data, int *data_size,
1745.                             AVPacket *avpkt)

libavcodec/vp3.c:1747:5: 
1745.                             AVPacket *avpkt)
1746. {
1747.     const uint8_t *buf = avpkt->data;
          ^
1748.     int buf_size = avpkt->size;
1749.     Vp3DecodeContext *s = avctx->priv_data;

libavcodec/vp3.c:1748:5: 
1746. {
1747.     const uint8_t *buf = avpkt->data;
1748.     int buf_size = avpkt->size;
          ^
1749.     Vp3DecodeContext *s = avctx->priv_data;
1750.     GetBitContext gb;

libavcodec/vp3.c:1749:5: 
1747.     const uint8_t *buf = avpkt->data;
1748.     int buf_size = avpkt->size;
1749.     Vp3DecodeContext *s = avctx->priv_data;
          ^
1750.     GetBitContext gb;
1751.     static int counter = 0;

libavcodec/vp3.c:1751:5: 
1749.     Vp3DecodeContext *s = avctx->priv_data;
1750.     GetBitContext gb;
1751.     static int counter = 0;
          ^
1752.     int i;
1753. 

libavcodec/vp3.c:1754:5: 
1752.     int i;
1753. 
1754.     init_get_bits(&gb, buf, buf_size * 8);
          ^
1755. 
1756.     if (s->theora && get_bits1(&gb))

libavcodec/get_bits.h:473:1: start of procedure init_get_bits()
  471.  * responsible for checking for the buffer end yourself (take advantage of the padding)!
  472.  */
  473. static inline void init_get_bits(GetBitContext *s,
       ^
  474.                    const uint8_t *buffer, int bit_size)
  475. {

libavcodec/get_bits.h:476:5: 
  474.                    const uint8_t *buffer, int bit_size)
  475. {
  476.     int buffer_size= (bit_size+7)>>3;
           ^
  477.     if(buffer_size < 0 || bit_size < 0) {
  478.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:477:8: Taking true branch
  475. {
  476.     int buffer_size= (bit_size+7)>>3;
  477.     if(buffer_size < 0 || bit_size < 0) {
              ^
  478.         buffer_size = bit_size = 0;
  479.         buffer = NULL;

libavcodec/get_bits.h:478:9: 
  476.     int buffer_size= (bit_size+7)>>3;
  477.     if(buffer_size < 0 || bit_size < 0) {
  478.         buffer_size = bit_size = 0;
               ^
  479.         buffer = NULL;
  480.     }

libavcodec/get_bits.h:479:9: 
  477.     if(buffer_size < 0 || bit_size < 0) {
  478.         buffer_size = bit_size = 0;
  479.         buffer = NULL;
               ^
  480.     }
  481. 

libavcodec/get_bits.h:482:5: 
  480.     }
  481. 
  482.     s->buffer= buffer;
           ^
  483.     s->size_in_bits= bit_size;
  484.     s->buffer_end= buffer + buffer_size;

libavcodec/get_bits.h:483:5: 
  481. 
  482.     s->buffer= buffer;
  483.     s->size_in_bits= bit_size;
           ^
  484.     s->buffer_end= buffer + buffer_size;
  485. #ifdef ALT_BITSTREAM_READER

libavcodec/get_bits.h:484:5: 
  482.     s->buffer= buffer;
  483.     s->size_in_bits= bit_size;
  484.     s->buffer_end= buffer + buffer_size;
           ^
  485. #ifdef ALT_BITSTREAM_READER
  486.     s->index=0;

libavcodec/get_bits.h:486:5: 
  484.     s->buffer_end= buffer + buffer_size;
  485. #ifdef ALT_BITSTREAM_READER
  486.     s->index=0;
           ^
  487. #elif defined LIBMPEG2_BITSTREAM_READER
  488.     s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));

libavcodec/get_bits.h:496:1: return from a call to init_get_bits
  494.     skip_bits_long(s, 0);
  495. #endif
  496. }
       ^
  497. 
  498. static inline void align_get_bits(GetBitContext *s)

libavcodec/vp3.c:1756:9: Taking false branch
1754.     init_get_bits(&gb, buf, buf_size * 8);
1755. 
1756.     if (s->theora && get_bits1(&gb))
              ^
1757.     {
1758.         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");

libavcodec/vp3.c:1762:20: 
1760.     }
1761. 
1762.     s->keyframe = !get_bits1(&gb);
                         ^
1763.     if (!s->theora)
1764.         skip_bits(&gb, 1);

libavcodec/get_bits.h:393:1: start of procedure get_bits1()
  391. }
  392. 
  393. static inline unsigned int get_bits1(GetBitContext *s){
       ^
  394. #ifdef ALT_BITSTREAM_READER
  395.     unsigned int index= s->index;

libavcodec/get_bits.h:395:5: 
  393. static inline unsigned int get_bits1(GetBitContext *s){
  394. #ifdef ALT_BITSTREAM_READER
  395.     unsigned int index= s->index;
           ^
  396.     uint8_t result= s->buffer[ index>>3 ];
  397. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/get_bits.h:396:5: 
  394. #ifdef ALT_BITSTREAM_READER
  395.     unsigned int index= s->index;
  396.     uint8_t result= s->buffer[ index>>3 ];
           ^
  397. #ifdef ALT_BITSTREAM_READER_LE
  398.     result>>= (index&0x07);
