libavcodec/qdm2.c:1230: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 1229 could be null and is dereferenced by call to `qdm2_decode_sub_packet_header()` at line 1230, column 5.

libavcodec/qdm2.c:1213:1: start of procedure qdm2_decode_super_block()
1211.  * @param q    context
1212.  */
1213. static void qdm2_decode_super_block (QDM2Context *q)
      ^
1214. {
1215.     GetBitContext gb;

libavcodec/qdm2.c:1218:5: 
1216.     QDM2SubPacket header, *packet;
1217.     int i, packet_bytes, sub_packet_size, sub_packets_D;
1218.     unsigned int next_index = 0;
          ^
1219. 
1220.     memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));

libavcodec/qdm2.c:1220:5: 
1218.     unsigned int next_index = 0;
1219. 
1220.     memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));
          ^
1221.     memset(q->tone_level_idx_mid, 0, sizeof(q->tone_level_idx_mid));
1222.     memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));

libavcodec/qdm2.c:1221:5: 
1219. 
1220.     memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));
1221.     memset(q->tone_level_idx_mid, 0, sizeof(q->tone_level_idx_mid));
          ^
1222.     memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));
1223. 

libavcodec/qdm2.c:1222:5: 
1220.     memset(q->tone_level_idx_hi1, 0, sizeof(q->tone_level_idx_hi1));
1221.     memset(q->tone_level_idx_mid, 0, sizeof(q->tone_level_idx_mid));
1222.     memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));
          ^
1223. 
1224.     q->sub_packets_B = 0;

libavcodec/qdm2.c:1224:5: 
1222.     memset(q->tone_level_idx_hi2, 0, sizeof(q->tone_level_idx_hi2));
1223. 
1224.     q->sub_packets_B = 0;
          ^
1225.     sub_packets_D = 0;
1226. 

libavcodec/qdm2.c:1225:5: 
1223. 
1224.     q->sub_packets_B = 0;
1225.     sub_packets_D = 0;
          ^
1226. 
1227.     average_quantized_coeffs(q); // average elements in quantized_coeffs[max_ch][10][8]

libavcodec/qdm2.c:1227:5: Skipping average_quantized_coeffs(): empty list of specs
1225.     sub_packets_D = 0;
1226. 
1227.     average_quantized_coeffs(q); // average elements in quantized_coeffs[max_ch][10][8]
          ^
1228. 
1229.     init_get_bits(&gb, q->compressed_data, q->compressed_size*8);

libavcodec/qdm2.c:1229:5: 
1227.     average_quantized_coeffs(q); // average elements in quantized_coeffs[max_ch][10][8]
1228. 
1229.     init_get_bits(&gb, q->compressed_data, q->compressed_size*8);
          ^
1230.     qdm2_decode_sub_packet_header(&gb, &header);
1231. 

libavcodec/bitstream.h:758:1: start of procedure init_get_bits()
  756.  * @param bit_size the size of the buffer in bits
  757.  */
  758. static inline void init_get_bits(GetBitContext *s,
       ^
  759.                    const uint8_t *buffer, int bit_size)
  760. {

libavcodec/bitstream.h:761:5: 
  759.                    const uint8_t *buffer, int bit_size)
  760. {
  761.     int buffer_size= (bit_size+7)>>3;
           ^
  762.     if(buffer_size < 0 || bit_size < 0) {
  763.         buffer_size = bit_size = 0;

libavcodec/bitstream.h:762:8: Taking true branch
  760. {
  761.     int buffer_size= (bit_size+7)>>3;
  762.     if(buffer_size < 0 || bit_size < 0) {
              ^
  763.         buffer_size = bit_size = 0;
  764.         buffer = NULL;

libavcodec/bitstream.h:763:9: 
  761.     int buffer_size= (bit_size+7)>>3;
  762.     if(buffer_size < 0 || bit_size < 0) {
  763.         buffer_size = bit_size = 0;
               ^
  764.         buffer = NULL;
  765.     }

libavcodec/bitstream.h:764:9: 
  762.     if(buffer_size < 0 || bit_size < 0) {
  763.         buffer_size = bit_size = 0;
  764.         buffer = NULL;
               ^
  765.     }
  766. 

libavcodec/bitstream.h:767:5: 
  765.     }
  766. 
  767.     s->buffer= buffer;
           ^
  768.     s->size_in_bits= bit_size;
  769.     s->buffer_end= buffer + buffer_size;

libavcodec/bitstream.h:768:5: 
  766. 
  767.     s->buffer= buffer;
  768.     s->size_in_bits= bit_size;
           ^
  769.     s->buffer_end= buffer + buffer_size;
  770. #ifdef ALT_BITSTREAM_READER

libavcodec/bitstream.h:769:5: 
  767.     s->buffer= buffer;
  768.     s->size_in_bits= bit_size;
  769.     s->buffer_end= buffer + buffer_size;
           ^
  770. #ifdef ALT_BITSTREAM_READER
  771.     s->index=0;

libavcodec/bitstream.h:771:5: 
  769.     s->buffer_end= buffer + buffer_size;
  770. #ifdef ALT_BITSTREAM_READER
  771.     s->index=0;
           ^
  772. #elif defined LIBMPEG2_BITSTREAM_READER
  773.     s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));

libavcodec/bitstream.h:781:1: return from a call to init_get_bits
  779.     skip_bits_long(s, 0);
  780. #endif
  781. }
       ^
  782. 
  783. static inline void align_get_bits(GetBitContext *s)

libavcodec/qdm2.c:1230:5: 
1228. 
1229.     init_get_bits(&gb, q->compressed_data, q->compressed_size*8);
1230.     qdm2_decode_sub_packet_header(&gb, &header);
          ^
1231. 
1232.     if (header.type < 2 || header.type >= 8) {

libavcodec/qdm2.c:423:1: start of procedure qdm2_decode_sub_packet_header()
  421.  * @param sub_packet    packet under analysis
  422.  */
  423. static void qdm2_decode_sub_packet_header (GetBitContext *gb, QDM2SubPacket *sub_packet)
       ^
  424. {
  425.     sub_packet->type = get_bits (gb, 8);

libavcodec/qdm2.c:425:5: 
  423. static void qdm2_decode_sub_packet_header (GetBitContext *gb, QDM2SubPacket *sub_packet)
  424. {
  425.     sub_packet->type = get_bits (gb, 8);
           ^
  426. 
  427.     if (sub_packet->type == 0) {

libavcodec/bitstream.h:655:1: start of procedure get_bits()
    653.  * Note, the alt bitstream reader can read up to 25 bits, but the libmpeg2 reader can't
    654.  */
    655. static inline unsigned int get_bits(GetBitContext *s, int n){
         ^
    656.     register int tmp;
    657.     OPEN_READER(re, s)

libavcodec/bitstream.h:657:5: 
    655. static inline unsigned int get_bits(GetBitContext *s, int n){
    656.     register int tmp;
    657.     OPEN_READER(re, s)
             ^
    658.     UPDATE_CACHE(re, s)
    659.     tmp= SHOW_UBITS(re, s, n);

libavcodec/bitstream.h:658:5: 
    656.     register int tmp;
    657.     OPEN_READER(re, s)
    658.     UPDATE_CACHE(re, s)
             ^
    659.     tmp= SHOW_UBITS(re, s, n);
    660.     LAST_SKIP_BITS(re, s, n)
