libavcodec/smacker.c:583: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 581 could be null and is dereferenced by call to `get_bits1()` at line 583, column 9.

libavcodec/smacker.c:567:1: start of procedure smka_decode_frame()
565.  * Decode Smacker audio data
566.  */
567. static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
     ^
568. {
569.     GetBitContext gb;

libavcodec/smacker.c:572:5: 
570.     HuffContext h[4];
571.     VLC vlc[4];
572.     int16_t *samples = data;
         ^
573.     int val;
574.     int i, res;

libavcodec/smacker.c:577:5: 
575.     int unp_size;
576.     int bits, stereo;
577.     int pred[2] = {0, 0};
         ^
578. 
579.     unp_size = AV_RL32(buf);

libavcodec/smacker.c:579:5: 
577.     int pred[2] = {0, 0};
578. 
579.     unp_size = AV_RL32(buf);
         ^
580. 
581.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

libavcodec/smacker.c:581:5: 
579.     unp_size = AV_RL32(buf);
580. 
581.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
         ^
582. 
583.     if(!get_bits1(&gb)){

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/smacker.c:583:9: 
581.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
582. 
583.     if(!get_bits1(&gb)){
             ^
584.         av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
585.         *data_size = 0;

libavcodec/bitstream.h:686:1: start of procedure get_bits1()
  684. }
  685. 
  686. static inline unsigned int get_bits1(GetBitContext *s){
       ^
  687. #ifdef ALT_BITSTREAM_READER
  688.     int index= s->index;

libavcodec/bitstream.h:688:5: 
  686. static inline unsigned int get_bits1(GetBitContext *s){
  687. #ifdef ALT_BITSTREAM_READER
  688.     int index= s->index;
           ^
  689.     uint8_t result= s->buffer[ index>>3 ];
  690. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/bitstream.h:689:5: 
  687. #ifdef ALT_BITSTREAM_READER
  688.     int index= s->index;
  689.     uint8_t result= s->buffer[ index>>3 ];
           ^
  690. #ifdef ALT_BITSTREAM_READER_LE
  691.     result>>= (index&0x07);

static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)
{
    GetBitContext gb;
    HuffContext h[4];
    VLC vlc[4];
    int16_t *samples = data;
    int val;
    int i, res;
    int unp_size;
    int bits, stereo;
    int pred[2] = {0, 0};
    unp_size = AV_RL32(buf);
    init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
    if(!get_bits1(&gb)){
        av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
        *data_size = 0;
        return 1;
    }
    stereo = get_bits1(&gb);
    bits = get_bits1(&gb);
    if (unp_size & 0xC0000000 || (unp_size << !bits) > *data_size) {
        av_log(avctx, AV_LOG_ERROR, "Frame is too large to fit in buffer\n");
        return -1;
    }
    memset(vlc, 0, sizeof(VLC) * 4);
    memset(h, 0, sizeof(HuffContext) * 4);
    for(i = 0; i < (1 << (bits + stereo)); i++) {
        h[i].length = 256;
        h[i].maxlength = 0;
        h[i].current = 0;
        h[i].bits = av_mallocz(256 * 4);
        h[i].lengths = av_mallocz(256 * sizeof(int));
        h[i].values = av_mallocz(256 * sizeof(int));
        skip_bits1(&gb);
        smacker_decode_tree(&gb, &h[i], 0, 0);
        skip_bits1(&gb);
        if(h[i].current > 1) {
            res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,
                    h[i].lengths, sizeof(int), sizeof(int),
                    h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);
            if(res < 0) {
                av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");
                return -1;
            }
        }
    }
    if(bits) {
        for(i = stereo; i >= 0; i--)
            pred[i] = bswap_16(get_bits(&gb, 16));
        for(i = 0; i < stereo; i++)
            *samples++ = pred[i];
        for(i = 0; i < unp_size / 2; i++) {
            if(i & stereo) {
                if(vlc[2].table)
                    res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[2].values[res];
                if(vlc[3].table)
                    res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[3].values[res] << 8;
                pred[1] += (int16_t)val;
                *samples++ = pred[1];
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val  = h[0].values[res];
                if(vlc[1].table)
                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                val |= h[1].values[res] << 8;
                pred[0] += val;
                *samples++ = pred[0];
            }
        }
    } else {
        for(i = stereo; i >= 0; i--)
            pred[i] = get_bits(&gb, 8);
        for(i = 0; i < stereo; i++)
            *samples++ = (pred[i] - 0x80) << 8;
        for(i = 0; i < unp_size; i++) {
            if(i & stereo){
                if(vlc[1].table)
                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[1] += (int8_t)h[1].values[res];
                *samples++ = (pred[1] - 0x80) << 8;
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[0] += (int8_t)h[0].values[res];
                *samples++ = (pred[0] - 0x80) << 8;
            }
        }
        unp_size *= 2;
    }
    for(i = 0; i < 4; i++) {
        if(vlc[i].table)
            free_vlc(&vlc[i]);
        if(h[i].bits)
            av_free(h[i].bits);
        if(h[i].lengths)
            av_free(h[i].lengths);
        if(h[i].values)
            av_free(h[i].values);
    }
    *data_size = unp_size;
    return buf_size;
}
['static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, const uint8_t *buf, int buf_size)\n{\n    GetBitContext gb;\n    HuffContext h[4];\n    VLC vlc[4];\n    int16_t *samples = data;\n    int val;\n    int i, res;\n    int unp_size;\n    int bits, stereo;\n    int pred[2] = {0, 0};\n    unp_size = AV_RL32(buf);\n    init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);\n    if(!get_bits1(&gb)){\n        av_log(avctx, AV_LOG_INFO, "Sound: no data\\n");\n        *data_size = 0;\n        return 1;\n    }\n    stereo = get_bits1(&gb);\n    bits = get_bits1(&gb);\n    if (unp_size & 0xC0000000 || (unp_size << !bits) > *data_size) {\n        av_log(avctx, AV_LOG_ERROR, "Frame is too large to fit in buffer\\n");\n        return -1;\n    }\n    memset(vlc, 0, sizeof(VLC) * 4);\n    memset(h, 0, sizeof(HuffContext) * 4);\n    for(i = 0; i < (1 << (bits + stereo)); i++) {\n        h[i].length = 256;\n        h[i].maxlength = 0;\n        h[i].current = 0;\n        h[i].bits = av_mallocz(256 * 4);\n        h[i].lengths = av_mallocz(256 * sizeof(int));\n        h[i].values = av_mallocz(256 * sizeof(int));\n        skip_bits1(&gb);\n        smacker_decode_tree(&gb, &h[i], 0, 0);\n        skip_bits1(&gb);\n        if(h[i].current > 1) {\n            res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,\n                    h[i].lengths, sizeof(int), sizeof(int),\n                    h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);\n            if(res < 0) {\n                av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\\n");\n                return -1;\n            }\n        }\n    }\n    if(bits) {\n        for(i = stereo; i >= 0; i--)\n            pred[i] = bswap_16(get_bits(&gb, 16));\n        for(i = 0; i < stereo; i++)\n            *samples++ = pred[i];\n        for(i = 0; i < unp_size / 2; i++) {\n            if(i & stereo) {\n                if(vlc[2].table)\n                    res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val  = h[2].values[res];\n                if(vlc[3].table)\n                    res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val |= h[3].values[res] << 8;\n                pred[1] += (int16_t)val;\n                *samples++ = pred[1];\n            } else {\n                if(vlc[0].table)\n                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val  = h[0].values[res];\n                if(vlc[1].table)\n                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                val |= h[1].values[res] << 8;\n                pred[0] += val;\n                *samples++ = pred[0];\n            }\n        }\n    } else {\n        for(i = stereo; i >= 0; i--)\n            pred[i] = get_bits(&gb, 8);\n        for(i = 0; i < stereo; i++)\n            *samples++ = (pred[i] - 0x80) << 8;\n        for(i = 0; i < unp_size; i++) {\n            if(i & stereo){\n                if(vlc[1].table)\n                    res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                pred[1] += (int8_t)h[1].values[res];\n                *samples++ = (pred[1] - 0x80) << 8;\n            } else {\n                if(vlc[0].table)\n                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);\n                else\n                    res = 0;\n                pred[0] += (int8_t)h[0].values[res];\n                *samples++ = (pred[0] - 0x80) << 8;\n            }\n        }\n        unp_size *= 2;\n    }\n    for(i = 0; i < 4; i++) {\n        if(vlc[i].table)\n            free_vlc(&vlc[i]);\n        if(h[i].bits)\n            av_free(h[i].bits);\n        if(h[i].lengths)\n            av_free(h[i].lengths);\n        if(h[i].values)\n            av_free(h[i].values);\n    }\n    *data_size = unp_size;\n    return buf_size;\n}', 'static inline void init_get_bits(GetBitContext *s,\n                   const uint8_t *buffer, int bit_size)\n{\n    int buffer_size= (bit_size+7)>>3;\n    if(buffer_size < 0 || bit_size < 0) {\n        buffer_size = bit_size = 0;\n        buffer = NULL;\n    }\n    s->buffer= buffer;\n    s->size_in_bits= bit_size;\n    s->buffer_end= buffer + buffer_size;\n#ifdef ALT_BITSTREAM_READER\n    s->index=0;\n#elif defined LIBMPEG2_BITSTREAM_READER\n    s->buffer_ptr = (uint8_t*)((intptr_t)buffer&(~1));\n    s->bit_count = 16 + 8*((intptr_t)buffer&1);\n    skip_bits_long(s, 0);\n#elif defined A32_BITSTREAM_READER\n    s->buffer_ptr = (uint32_t*)((intptr_t)buffer&(~3));\n    s->bit_count = 32 + 8*((intptr_t)buffer&3);\n    skip_bits_long(s, 0);\n#endif\n}', 'static inline unsigned int get_bits1(GetBitContext *s){\n#ifdef ALT_BITSTREAM_READER\n    int index= s->index;\n    uint8_t result= s->buffer[ index>>3 ];\n#ifdef ALT_BITSTREAM_READER_LE\n    result>>= (index&0x07);\n    result&= 1;\n#else\n    result<<= (index&0x07);\n    result>>= 8 - 1;\n#endif\n    index++;\n    s->index= index;\n    return result;\n#else\n    return get_bits(s, 1);\n#endif\n}']