libavcodec/smacker.c:611: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 609 could be null and is dereferenced by call to `get_bits1()` at line 611, column 9.

libavcodec/smacker.c:585:1: start of procedure smka_decode_frame()
583.  * Decode Smacker audio data
584.  */
585. static int smka_decode_frame(AVCodecContext *avctx, void *data,
     ^
586.                              int *got_frame_ptr, AVPacket *avpkt)
587. {

libavcodec/smacker.c:588:5: 
586.                              int *got_frame_ptr, AVPacket *avpkt)
587. {
588.     SmackerAudioContext *s = avctx->priv_data;
         ^
589.     const uint8_t *buf = avpkt->data;
590.     int buf_size = avpkt->size;

libavcodec/smacker.c:589:5: 
587. {
588.     SmackerAudioContext *s = avctx->priv_data;
589.     const uint8_t *buf = avpkt->data;
         ^
590.     int buf_size = avpkt->size;
591.     GetBitContext gb;

libavcodec/smacker.c:590:5: 
588.     SmackerAudioContext *s = avctx->priv_data;
589.     const uint8_t *buf = avpkt->data;
590.     int buf_size = avpkt->size;
         ^
591.     GetBitContext gb;
592.     HuffContext h[4];

libavcodec/smacker.c:600:5: 
598.     int unp_size;
599.     int bits, stereo;
600.     int pred[2] = {0, 0};
         ^
601. 
602.     if (buf_size <= 4) {

libavcodec/smacker.c:602:9: Taking false branch
600.     int pred[2] = {0, 0};
601. 
602.     if (buf_size <= 4) {
             ^
603.         av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
604.         return AVERROR(EINVAL);

libavcodec/smacker.c:607:5: 
605.     }
606. 
607.     unp_size = AV_RL32(buf);
         ^
608. 
609.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

libavcodec/smacker.c:609:5: 
607.     unp_size = AV_RL32(buf);
608. 
609.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
         ^
610. 
611.     if(!get_bits1(&gb)){

libavcodec/get_bits.h:343:1: start of procedure init_get_bits()
  341.  * @param bit_size the size of the buffer in bits
  342.  */
  343. static inline void init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  344.                                  int bit_size)
  345. {

libavcodec/get_bits.h:346:5: 
  344.                                  int bit_size)
  345. {
  346.     int buffer_size = (bit_size+7)>>3;
           ^
  347.     if (buffer_size < 0 || bit_size < 0) {
  348.         buffer_size = bit_size = 0;

libavcodec/get_bits.h:347:9: Taking true branch
  345. {
  346.     int buffer_size = (bit_size+7)>>3;
  347.     if (buffer_size < 0 || bit_size < 0) {
               ^
  348.         buffer_size = bit_size = 0;
  349.         buffer = NULL;

libavcodec/get_bits.h:348:9: 
  346.     int buffer_size = (bit_size+7)>>3;
  347.     if (buffer_size < 0 || bit_size < 0) {
  348.         buffer_size = bit_size = 0;
               ^
  349.         buffer = NULL;
  350.     }

libavcodec/get_bits.h:349:9: 
  347.     if (buffer_size < 0 || bit_size < 0) {
  348.         buffer_size = bit_size = 0;
  349.         buffer = NULL;
               ^
  350.     }
  351. 

libavcodec/get_bits.h:352:5: 
  350.     }
  351. 
  352.     s->buffer       = buffer;
           ^
  353.     s->size_in_bits = bit_size;
  354. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:353:5: 
  351. 
  352.     s->buffer       = buffer;
  353.     s->size_in_bits = bit_size;
           ^
  354. #if !UNCHECKED_BITSTREAM_READER
  355.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:355:5: 
  353.     s->size_in_bits = bit_size;
  354. #if !UNCHECKED_BITSTREAM_READER
  355.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  356. #endif
  357.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:357:5: 
  355.     s->size_in_bits_plus8 = bit_size + 8;
  356. #endif
  357.     s->buffer_end   = buffer + buffer_size;
           ^
  358.     s->index        = 0;
  359. }

libavcodec/get_bits.h:358:5: 
  356. #endif
  357.     s->buffer_end   = buffer + buffer_size;
  358.     s->index        = 0;
           ^
  359. }
  360. 

libavcodec/get_bits.h:359:1: return from a call to init_get_bits
  357.     s->buffer_end   = buffer + buffer_size;
  358.     s->index        = 0;
  359. }
       ^
  360. 
  361. static inline void align_get_bits(GetBitContext *s)

libavcodec/smacker.c:611:9: 
609.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
610. 
611.     if(!get_bits1(&gb)){
             ^
612.         av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
613.         *got_frame_ptr = 0;

libavcodec/get_bits.h:259:1: start of procedure get_bits1()
  257. }
  258. 
  259. static inline unsigned int get_bits1(GetBitContext *s)
       ^
  260. {
  261.     unsigned int index = s->index;

libavcodec/get_bits.h:261:5: 
  259. static inline unsigned int get_bits1(GetBitContext *s)
  260. {
  261.     unsigned int index = s->index;
           ^
  262.     uint8_t result = s->buffer[index>>3];
  263. #ifdef ALT_BITSTREAM_READER_LE

libavcodec/get_bits.h:262:5: 
  260. {
  261.     unsigned int index = s->index;
  262.     uint8_t result = s->buffer[index>>3];
           ^
  263. #ifdef ALT_BITSTREAM_READER_LE
  264.     result >>= index & 7;

static int smka_decode_frame(AVCodecContext *avctx, void *data,
                             int *got_frame_ptr, AVPacket *avpkt)
{
    SmackerAudioContext *s = avctx->priv_data;
    const uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    GetBitContext gb;
    HuffContext h[4];
    VLC vlc[4];
    int16_t *samples;
    uint8_t *samples8;
    int val;
    int i, res, ret;
    int unp_size;
    int bits, stereo;
    int pred[2] = {0, 0};
    if (buf_size <= 4) {
        av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
        return AVERROR(EINVAL);
    }
    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");
        *got_frame_ptr = 0;
        return 1;
    }
    stereo = get_bits1(&gb);
    bits = get_bits1(&gb);
    if (stereo ^ (avctx->channels != 1)) {
        av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");
        return AVERROR(EINVAL);
    }
    if (bits && avctx->sample_fmt == AV_SAMPLE_FMT_U8) {
        av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");
        return AVERROR(EINVAL);
    }
    s->frame.nb_samples = unp_size / (avctx->channels * (bits + 1));
    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }
    samples  = (int16_t *)s->frame.data[0];
    samples8 =            s->frame.data[0];
    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] = av_bswap16(get_bits(&gb, 16));
        for(i = 0; i <= stereo; i++)
            *samples++ = pred[i];
        for(; 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] += sign_extend(val, 16);
                *samples++ = av_clip_int16(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] += sign_extend(val, 16);
                *samples++ = av_clip_int16(pred[0]);
            }
        }
    } else {
        for(i = stereo; i >= 0; i--)
            pred[i] = get_bits(&gb, 8);
        for(i = 0; i <= stereo; i++)
            *samples8++ = pred[i];
        for(; 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] += sign_extend(h[1].values[res], 8);
                *samples8++ = av_clip_uint8(pred[1]);
            } else {
                if(vlc[0].table)
                    res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);
                else
                    res = 0;
                pred[0] += sign_extend(h[0].values[res], 8);
                *samples8++ = av_clip_uint8(pred[0]);
            }
        }
    }
    for(i = 0; i < 4; i++) {
        if(vlc[i].table)
            free_vlc(&vlc[i]);
        av_free(h[i].bits);
        av_free(h[i].lengths);
        av_free(h[i].values);
    }
    *got_frame_ptr   = 1;
    *(AVFrame *)data = s->frame;
    return buf_size;
}
['static int smka_decode_frame(AVCodecContext *avctx, void *data,\n                             int *got_frame_ptr, AVPacket *avpkt)\n{\n    SmackerAudioContext *s = avctx->priv_data;\n    const uint8_t *buf = avpkt->data;\n    int buf_size = avpkt->size;\n    GetBitContext gb;\n    HuffContext h[4];\n    VLC vlc[4];\n    int16_t *samples;\n    uint8_t *samples8;\n    int val;\n    int i, res, ret;\n    int unp_size;\n    int bits, stereo;\n    int pred[2] = {0, 0};\n    if (buf_size <= 4) {\n        av_log(avctx, AV_LOG_ERROR, "packet is too small\\n");\n        return AVERROR(EINVAL);\n    }\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        *got_frame_ptr = 0;\n        return 1;\n    }\n    stereo = get_bits1(&gb);\n    bits = get_bits1(&gb);\n    if (stereo ^ (avctx->channels != 1)) {\n        av_log(avctx, AV_LOG_ERROR, "channels mismatch\\n");\n        return AVERROR(EINVAL);\n    }\n    if (bits && avctx->sample_fmt == AV_SAMPLE_FMT_U8) {\n        av_log(avctx, AV_LOG_ERROR, "sample format mismatch\\n");\n        return AVERROR(EINVAL);\n    }\n    s->frame.nb_samples = unp_size / (avctx->channels * (bits + 1));\n    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {\n        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\\n");\n        return ret;\n    }\n    samples  = (int16_t *)s->frame.data[0];\n    samples8 =            s->frame.data[0];\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] = av_bswap16(get_bits(&gb, 16));\n        for(i = 0; i <= stereo; i++)\n            *samples++ = pred[i];\n        for(; 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] += sign_extend(val, 16);\n                *samples++ = av_clip_int16(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] += sign_extend(val, 16);\n                *samples++ = av_clip_int16(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            *samples8++ = pred[i];\n        for(; 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] += sign_extend(h[1].values[res], 8);\n                *samples8++ = av_clip_uint8(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                pred[0] += sign_extend(h[0].values[res], 8);\n                *samples8++ = av_clip_uint8(pred[0]);\n            }\n        }\n    }\n    for(i = 0; i < 4; i++) {\n        if(vlc[i].table)\n            free_vlc(&vlc[i]);\n        av_free(h[i].bits);\n        av_free(h[i].lengths);\n        av_free(h[i].values);\n    }\n    *got_frame_ptr   = 1;\n    *(AVFrame *)data = s->frame;\n    return buf_size;\n}', 'static inline void init_get_bits(GetBitContext *s, const uint8_t *buffer,\n                                 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#if !UNCHECKED_BITSTREAM_READER\n    s->size_in_bits_plus8 = bit_size + 8;\n#endif\n    s->buffer_end   = buffer + buffer_size;\n    s->index        = 0;\n}', 'static inline unsigned int get_bits1(GetBitContext *s)\n{\n    unsigned int index = s->index;\n    uint8_t result = s->buffer[index>>3];\n#ifdef ALT_BITSTREAM_READER_LE\n    result >>= index & 7;\n    result &= 1;\n#else\n    result <<= index & 7;\n    result >>= 8 - 1;\n#endif\n#if !UNCHECKED_BITSTREAM_READER\n    if (s->index < s->size_in_bits_plus8)\n#endif\n        index++;\n    s->index = index;\n    return result;\n}']