libavcodec/vp3.c:1776: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1774 could be null and is dereferenced by call to `get_bits1()` at line 1776, column 22.

libavcodec/vp3.c:1763:1: start of procedure vp3_decode_frame()
1761.  * This is the ffmpeg/libavcodec API frame decode function.
1762.  */
1763. static int vp3_decode_frame(AVCodecContext *avctx,
      ^
1764.                             void *data, int *data_size,
1765.                             AVPacket *avpkt)

libavcodec/vp3.c:1767:5: 
1765.                             AVPacket *avpkt)
1766. {
1767.     const uint8_t *buf = avpkt->data;
          ^
1768.     int buf_size = avpkt->size;
1769.     Vp3DecodeContext *s = avctx->priv_data;

libavcodec/vp3.c:1768:5: 
1766. {
1767.     const uint8_t *buf = avpkt->data;
1768.     int buf_size = avpkt->size;
          ^
1769.     Vp3DecodeContext *s = avctx->priv_data;
1770.     GetBitContext gb;

libavcodec/vp3.c:1769:5: 
1767.     const uint8_t *buf = avpkt->data;
1768.     int buf_size = avpkt->size;
1769.     Vp3DecodeContext *s = avctx->priv_data;
          ^
1770.     GetBitContext gb;
1771.     static int counter = 0;

libavcodec/vp3.c:1771:5: 
1769.     Vp3DecodeContext *s = avctx->priv_data;
1770.     GetBitContext gb;
1771.     static int counter = 0;
          ^
1772.     int i;
1773. 

libavcodec/vp3.c:1774:5: 
1772.     int i;
1773. 
1774.     init_get_bits(&gb, buf, buf_size * 8);
          ^
1775. 
1776.     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:1776:9: Taking true branch
1774.     init_get_bits(&gb, buf, buf_size * 8);
1775. 
1776.     if (s->theora && get_bits1(&gb))
              ^
1777.     {
1778.         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");

libavcodec/vp3.c:1776:22: 
1774.     init_get_bits(&gb, buf, buf_size * 8);
1775. 
1776.     if (s->theora && get_bits1(&gb))
                           ^
1777.     {
1778.         av_log(avctx, AV_LOG_ERROR, "Header packet passed to frame decoder, skipping\n");

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);
