libavcodec/smacker.c:608: error: Null Dereference
  pointer `&gb->buffer` last assigned on line 606 could be null and is dereferenced by call to `get_bits1()` at line 608, column 9.

libavcodec/smacker.c:582:1: start of procedure smka_decode_frame()
580.  * Decode Smacker audio data
581.  */
582. static int smka_decode_frame(AVCodecContext *avctx, void *data,
     ^
583.                              int *got_frame_ptr, AVPacket *avpkt)
584. {

libavcodec/smacker.c:585:5: 
583.                              int *got_frame_ptr, AVPacket *avpkt)
584. {
585.     SmackerAudioContext *s = avctx->priv_data;
         ^
586.     const uint8_t *buf = avpkt->data;
587.     int buf_size = avpkt->size;

libavcodec/smacker.c:586:5: 
584. {
585.     SmackerAudioContext *s = avctx->priv_data;
586.     const uint8_t *buf = avpkt->data;
         ^
587.     int buf_size = avpkt->size;
588.     GetBitContext gb;

libavcodec/smacker.c:587:5: 
585.     SmackerAudioContext *s = avctx->priv_data;
586.     const uint8_t *buf = avpkt->data;
587.     int buf_size = avpkt->size;
         ^
588.     GetBitContext gb;
589.     HuffContext h[4] = { { 0 } };

libavcodec/smacker.c:589:5: 
587.     int buf_size = avpkt->size;
588.     GetBitContext gb;
589.     HuffContext h[4] = { { 0 } };
         ^
590.     VLC vlc[4]       = { { 0 } };
591.     int16_t *samples;

libavcodec/smacker.c:590:5: 
588.     GetBitContext gb;
589.     HuffContext h[4] = { { 0 } };
590.     VLC vlc[4]       = { { 0 } };
         ^
591.     int16_t *samples;
592.     uint8_t *samples8;

libavcodec/smacker.c:597:5: 
595.     int unp_size;
596.     int bits, stereo;
597.     int pred[2] = {0, 0};
         ^
598. 
599.     if (buf_size <= 4) {

libavcodec/smacker.c:599:9: Taking false branch
597.     int pred[2] = {0, 0};
598. 
599.     if (buf_size <= 4) {
             ^
600.         av_log(avctx, AV_LOG_ERROR, "packet is too small\n");
601.         return AVERROR(EINVAL);

libavcodec/smacker.c:604:5: 
602.     }
603. 
604.     unp_size = AV_RL32(buf);
         ^
605. 
606.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

libavutil/ppc/intreadwrite.h:44:1: start of procedure AV_RL32()
  42. 
  43. #define AV_RL32 AV_RL32
  44. static av_always_inline uint32_t AV_RL32(const void *p)
      ^
  45. {
  46.     uint32_t v;

libavutil/ppc/intreadwrite.h:47:5: Skipping __infer_skip_gcc_asm_stmt(): function or method not found
  45. {
  46.     uint32_t v;
  47.     __asm__ ("lwbrx   %0, %y1" : "=r"(v) : "Z"(*(const uint32_t*)p));
          ^
  48.     return v;
  49. }

libavutil/ppc/intreadwrite.h:48:5: 
  46.     uint32_t v;
  47.     __asm__ ("lwbrx   %0, %y1" : "=r"(v) : "Z"(*(const uint32_t*)p));
  48.     return v;
          ^
  49. }
  50. 

libavutil/ppc/intreadwrite.h:49:1: return from a call to AV_RL32
  47.     __asm__ ("lwbrx   %0, %y1" : "=r"(v) : "Z"(*(const uint32_t*)p));
  48.     return v;
  49. }
      ^
  50. 
  51. #define AV_WL32 AV_WL32

libavcodec/smacker.c:606:5: 
604.     unp_size = AV_RL32(buf);
605. 
606.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
         ^
607. 
608.     if(!get_bits1(&gb)){

libavcodec/get_bits.h:372:1: start of procedure init_get_bits()
  370.  * @return 0 on success, AVERROR_INVALIDDATA if the buffer_size would overflow.
  371.  */
  372. static inline int init_get_bits(GetBitContext *s, const uint8_t *buffer,
       ^
  373.                                 int bit_size)
  374. {

libavcodec/get_bits.h:376:5: 
  374. {
  375.     int buffer_size;
  376.     int ret = 0;
           ^
  377. 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {

libavcodec/get_bits.h:378:9: Taking true branch
  376.     int ret = 0;
  377. 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {
               ^
  379.         buffer_size = bit_size = 0;
  380.         buffer = NULL;

libavcodec/get_bits.h:379:9: 
  377. 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {
  379.         buffer_size = bit_size = 0;
               ^
  380.         buffer = NULL;
  381.         ret = AVERROR_INVALIDDATA;

libavcodec/get_bits.h:380:9: 
  378.     if (bit_size > INT_MAX - 7 || bit_size <= 0) {
  379.         buffer_size = bit_size = 0;
  380.         buffer = NULL;
               ^
  381.         ret = AVERROR_INVALIDDATA;
  382.     }

libavcodec/get_bits.h:381:9: 
  379.         buffer_size = bit_size = 0;
  380.         buffer = NULL;
  381.         ret = AVERROR_INVALIDDATA;
               ^
  382.     }
  383. 

libavcodec/get_bits.h:384:5: 
  382.     }
  383. 
  384.     buffer_size = (bit_size + 7) >> 3;
           ^
  385. 
  386.     s->buffer       = buffer;

libavcodec/get_bits.h:386:5: 
  384.     buffer_size = (bit_size + 7) >> 3;
  385. 
  386.     s->buffer       = buffer;
           ^
  387.     s->size_in_bits = bit_size;
  388. #if !UNCHECKED_BITSTREAM_READER

libavcodec/get_bits.h:387:5: 
  385. 
  386.     s->buffer       = buffer;
  387.     s->size_in_bits = bit_size;
           ^
  388. #if !UNCHECKED_BITSTREAM_READER
  389.     s->size_in_bits_plus8 = bit_size + 8;

libavcodec/get_bits.h:389:5: 
  387.     s->size_in_bits = bit_size;
  388. #if !UNCHECKED_BITSTREAM_READER
  389.     s->size_in_bits_plus8 = bit_size + 8;
           ^
  390. #endif
  391.     s->buffer_end   = buffer + buffer_size;

libavcodec/get_bits.h:391:5: 
  389.     s->size_in_bits_plus8 = bit_size + 8;
  390. #endif
  391.     s->buffer_end   = buffer + buffer_size;
           ^
  392.     s->index        = 0;
  393.     return ret;

libavcodec/get_bits.h:392:5: 
  390. #endif
  391.     s->buffer_end   = buffer + buffer_size;
  392.     s->index        = 0;
           ^
  393.     return ret;
  394. }

libavcodec/get_bits.h:393:5: 
  391.     s->buffer_end   = buffer + buffer_size;
  392.     s->index        = 0;
  393.     return ret;
           ^
  394. }
  395. 

libavcodec/get_bits.h:394:1: return from a call to init_get_bits
  392.     s->index        = 0;
  393.     return ret;
  394. }
       ^
  395. 
  396. /**

libavcodec/smacker.c:608:9: 
606.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);
607. 
608.     if(!get_bits1(&gb)){
             ^
609.         av_log(avctx, AV_LOG_INFO, "Sound: no data\n");
610.         *got_frame_ptr = 0;

libavcodec/get_bits.h:268:1: start of procedure get_bits1()
  266. }
  267. 
  268. static inline unsigned int get_bits1(GetBitContext *s)
       ^
  269. {
  270.     unsigned int index = s->index;

libavcodec/get_bits.h:270:5: 
  268. static inline unsigned int get_bits1(GetBitContext *s)
  269. {
  270.     unsigned int index = s->index;
           ^
  271.     uint8_t result = s->buffer[index>>3];
  272. #ifdef BITSTREAM_READER_LE

libavcodec/get_bits.h:271:5: 
  269. {
  270.     unsigned int index = s->index;
  271.     uint8_t result = s->buffer[index>>3];
           ^
  272. #ifdef BITSTREAM_READER_LE
  273.     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] = { { 0 } };
    VLC vlc[4]       = { { 0 } };
    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 = ff_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];
    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] = sign_extend(av_bswap16(get_bits(&gb, 16)), 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)
            ff_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] = { { 0 } };\n    VLC vlc[4]       = { { 0 } };\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 = ff_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    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] = sign_extend(av_bswap16(get_bits(&gb, 16)), 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            ff_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 int init_get_bits(GetBitContext *s, const uint8_t *buffer,\n                                int bit_size)\n{\n    int buffer_size;\n    int ret = 0;\n    if (bit_size > INT_MAX - 7 || bit_size <= 0) {\n        buffer_size = bit_size = 0;\n        buffer = NULL;\n        ret = AVERROR_INVALIDDATA;\n    }\n    buffer_size = (bit_size + 7) >> 3;\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    return ret;\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 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}']