libavformat/movenc.c:2033: error: Null Dereference
  pointer `pkt.data` last assigned on line 2032 could be null and is dereferenced at line 2033, column 13.

libavformat/movenc.c:2008:1: start of procedure mov_create_chapter_track()
2006. // QuickTime chapters involve an additional text track with the chapter names
2007. // as samples, and a tref pointing from the other tracks to the chapter one.
2008. static void mov_create_chapter_track(AVFormatContext *s, int tracknum)
      ^
2009. {
2010.     MOVMuxContext *mov = s->priv_data;

libavformat/movenc.c:2010:5: 
2008. static void mov_create_chapter_track(AVFormatContext *s, int tracknum)
2009. {
2010.     MOVMuxContext *mov = s->priv_data;
          ^
2011.     MOVTrack *track = &mov->tracks[tracknum];
2012.     AVPacket pkt = { .stream_index = tracknum, .flags = AV_PKT_FLAG_KEY };

libavformat/movenc.c:2011:5: 
2009. {
2010.     MOVMuxContext *mov = s->priv_data;
2011.     MOVTrack *track = &mov->tracks[tracknum];
          ^
2012.     AVPacket pkt = { .stream_index = tracknum, .flags = AV_PKT_FLAG_KEY };
2013.     int i, len;

libavformat/movenc.c:2012:5: 
2010.     MOVMuxContext *mov = s->priv_data;
2011.     MOVTrack *track = &mov->tracks[tracknum];
2012.     AVPacket pkt = { .stream_index = tracknum, .flags = AV_PKT_FLAG_KEY };
          ^
2013.     int i, len;
2014. 

libavformat/movenc.c:2015:5: 
2013.     int i, len;
2014. 
2015.     track->mode = mov->mode;
          ^
2016.     track->tag = MKTAG('t','e','x','t');
2017.     track->timescale = MOV_TIMESCALE;

libavformat/movenc.c:2016:5: 
2014. 
2015.     track->mode = mov->mode;
2016.     track->tag = MKTAG('t','e','x','t');
          ^
2017.     track->timescale = MOV_TIMESCALE;
2018.     track->enc = avcodec_alloc_context();

libavformat/movenc.c:2017:5: 
2015.     track->mode = mov->mode;
2016.     track->tag = MKTAG('t','e','x','t');
2017.     track->timescale = MOV_TIMESCALE;
          ^
2018.     track->enc = avcodec_alloc_context();
2019.     track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;

libavformat/movenc.c:2018:5: 
2016.     track->tag = MKTAG('t','e','x','t');
2017.     track->timescale = MOV_TIMESCALE;
2018.     track->enc = avcodec_alloc_context();
          ^
2019.     track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
2020. 

libavcodec/options.c:524:1: start of procedure avcodec_alloc_context()
  522. }
  523. 
  524. AVCodecContext *avcodec_alloc_context(void){
       ^
  525.     return avcodec_alloc_context2(AVMEDIA_TYPE_UNKNOWN);
  526. }

libavcodec/options.c:525:5: 
  523. 
  524. AVCodecContext *avcodec_alloc_context(void){
  525.     return avcodec_alloc_context2(AVMEDIA_TYPE_UNKNOWN);
           ^
  526. }
  527. 

libavcodec/options.c:510:1: start of procedure avcodec_alloc_context2()
    508. }
    509. 
    510. AVCodecContext *avcodec_alloc_context2(enum AVMediaType codec_type){
         ^
    511.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
    512. 

libavcodec/options.c:511:5: 
    509. 
    510. AVCodecContext *avcodec_alloc_context2(enum AVMediaType codec_type){
    511.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
             ^
    512. 
    513.     if(avctx==NULL) return NULL;

libavutil/mem.c:64:1: start of procedure av_malloc()
      62.    linker will do it automatically. */
      63. 
      64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
          ^
      65. {
      66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
      64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
      65. {
      66.     void *ptr = NULL;
              ^
      67. #if CONFIG_MEMALIGN_HACK
      68.     long diff;

libavutil/mem.c:72:8: Taking false branch
      70. 
      71.     /* let's disallow possible ambiguous cases */
      72.     if(size > (INT_MAX-16) )
                 ^
      73.         return NULL;
      74. 

libavutil/mem.c:83:9: Taking false branch
      81.     ((char*)ptr)[-1]= diff;
      82. #elif HAVE_POSIX_MEMALIGN
      83.     if (posix_memalign(&ptr,16,size))
                  ^
      84.         ptr = NULL;
      85. #elif HAVE_MEMALIGN

libavutil/mem.c:116:5: 
      114.     ptr = malloc(size);
      115. #endif
      116.     return ptr;
               ^
      117. }
      118. 

libavutil/mem.c:117:1: return from a call to av_malloc
      115. #endif
      116.     return ptr;
      117. }
           ^
      118. 
      119. void *av_realloc(void *ptr, FF_INTERNAL_MEM_TYPE size)

libavcodec/options.c:513:8: Taking false branch
    511.     AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));
    512. 
    513.     if(avctx==NULL) return NULL;
                ^
    514. 
    515.     avcodec_get_context_defaults2(avctx, codec_type);

libavcodec/options.c:515:5: Skipping avcodec_get_context_defaults2(): empty list of specs
    513.     if(avctx==NULL) return NULL;
    514. 
    515.     avcodec_get_context_defaults2(avctx, codec_type);
             ^
    516. 
    517.     return avctx;

libavcodec/options.c:517:5: 
    515.     avcodec_get_context_defaults2(avctx, codec_type);
    516. 
    517.     return avctx;
             ^
    518. }
    519. 

libavcodec/options.c:518:1: return from a call to avcodec_alloc_context2
    516. 
    517.     return avctx;
    518. }
         ^
    519. 
    520. void avcodec_get_context_defaults(AVCodecContext *s){

libavcodec/options.c:526:1: return from a call to avcodec_alloc_context
  524. AVCodecContext *avcodec_alloc_context(void){
  525.     return avcodec_alloc_context2(AVMEDIA_TYPE_UNKNOWN);
  526. }
       ^
  527. 
  528. int avcodec_copy_context(AVCodecContext *dest, const AVCodecContext *src)

libavformat/movenc.c:2019:5: 
2017.     track->timescale = MOV_TIMESCALE;
2018.     track->enc = avcodec_alloc_context();
2019.     track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
          ^
2020. 
2021.     for (i = 0; i < s->nb_chapters; i++) {

libavformat/movenc.c:2021:10: 
2019.     track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
2020. 
2021.     for (i = 0; i < s->nb_chapters; i++) {
               ^
2022.         AVChapter *c = s->chapters[i];
2023.         AVMetadataTag *t;

libavformat/movenc.c:2021:17: Loop condition is true. Entering loop body
2019.     track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
2020. 
2021.     for (i = 0; i < s->nb_chapters; i++) {
                      ^
2022.         AVChapter *c = s->chapters[i];
2023.         AVMetadataTag *t;

libavformat/movenc.c:2022:9: 
2020. 
2021.     for (i = 0; i < s->nb_chapters; i++) {
2022.         AVChapter *c = s->chapters[i];
              ^
2023.         AVMetadataTag *t;
2024. 

libavformat/movenc.c:2025:9: 
2023.         AVMetadataTag *t;
2024. 
2025.         int64_t end = av_rescale_q(c->end, c->time_base, (AVRational){1,MOV_TIMESCALE});
              ^
2026.         pkt.pts = pkt.dts = av_rescale_q(c->start, c->time_base, (AVRational){1,MOV_TIMESCALE});
2027.         pkt.duration = end - pkt.dts;

libavutil/mathematics.c:133:1: start of procedure av_rescale_q()
  131. }
  132. 
  133. int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
       ^
  134.     int64_t b= bq.num * (int64_t)cq.den;
  135.     int64_t c= cq.num * (int64_t)bq.den;

libavutil/mathematics.c:134:5: 
  132. 
  133. int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
  134.     int64_t b= bq.num * (int64_t)cq.den;
           ^
  135.     int64_t c= cq.num * (int64_t)bq.den;
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);

libavutil/mathematics.c:135:5: 
  133. int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
  134.     int64_t b= bq.num * (int64_t)cq.den;
  135.     int64_t c= cq.num * (int64_t)bq.den;
           ^
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
  137. }

libavutil/mathematics.c:136:5: Skipping av_rescale_rnd(): empty list of specs
  134.     int64_t b= bq.num * (int64_t)cq.den;
  135.     int64_t c= cq.num * (int64_t)bq.den;
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
           ^
  137. }
  138. 

libavutil/mathematics.c:137:1: return from a call to av_rescale_q
  135.     int64_t c= cq.num * (int64_t)bq.den;
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
  137. }
       ^
  138. 
  139. int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b){

libavformat/movenc.c:2026:9: 
2024. 
2025.         int64_t end = av_rescale_q(c->end, c->time_base, (AVRational){1,MOV_TIMESCALE});
2026.         pkt.pts = pkt.dts = av_rescale_q(c->start, c->time_base, (AVRational){1,MOV_TIMESCALE});
              ^
2027.         pkt.duration = end - pkt.dts;
2028. 

libavutil/mathematics.c:133:1: start of procedure av_rescale_q()
  131. }
  132. 
  133. int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
       ^
  134.     int64_t b= bq.num * (int64_t)cq.den;
  135.     int64_t c= cq.num * (int64_t)bq.den;

libavutil/mathematics.c:134:5: 
  132. 
  133. int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
  134.     int64_t b= bq.num * (int64_t)cq.den;
           ^
  135.     int64_t c= cq.num * (int64_t)bq.den;
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);

libavutil/mathematics.c:135:5: 
  133. int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){
  134.     int64_t b= bq.num * (int64_t)cq.den;
  135.     int64_t c= cq.num * (int64_t)bq.den;
           ^
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
  137. }

libavutil/mathematics.c:136:5: Skipping av_rescale_rnd(): empty list of specs
  134.     int64_t b= bq.num * (int64_t)cq.den;
  135.     int64_t c= cq.num * (int64_t)bq.den;
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
           ^
  137. }
  138. 

libavutil/mathematics.c:137:1: return from a call to av_rescale_q
  135.     int64_t c= cq.num * (int64_t)bq.den;
  136.     return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);
  137. }
       ^
  138. 
  139. int av_compare_ts(int64_t ts_a, AVRational tb_a, int64_t ts_b, AVRational tb_b){

libavformat/movenc.c:2027:9: 
2025.         int64_t end = av_rescale_q(c->end, c->time_base, (AVRational){1,MOV_TIMESCALE});
2026.         pkt.pts = pkt.dts = av_rescale_q(c->start, c->time_base, (AVRational){1,MOV_TIMESCALE});
2027.         pkt.duration = end - pkt.dts;
              ^
2028. 
2029.         if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {

libavformat/movenc.c:2029:14: Taking true branch
2027.         pkt.duration = end - pkt.dts;
2028. 
2029.         if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
                   ^
2030.             len = strlen(t->value);
2031.             pkt.size = len+2;

libavformat/movenc.c:2030:13: 
2028. 
2029.         if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
2030.             len = strlen(t->value);
                  ^
2031.             pkt.size = len+2;
2032.             pkt.data = av_malloc(pkt.size);

libavformat/movenc.c:2031:13: 
2029.         if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
2030.             len = strlen(t->value);
2031.             pkt.size = len+2;
                  ^
2032.             pkt.data = av_malloc(pkt.size);
2033.             AV_WB16(pkt.data, len);

libavformat/movenc.c:2032:13: 
2030.             len = strlen(t->value);
2031.             pkt.size = len+2;
2032.             pkt.data = av_malloc(pkt.size);
                  ^
2033.             AV_WB16(pkt.data, len);
2034.             memcpy(pkt.data+2, t->value, len);

libavutil/mem.c:64:1: start of procedure av_malloc()
  62.    linker will do it automatically. */
  63. 
  64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
      ^
  65. {
  66.     void *ptr = NULL;

libavutil/mem.c:66:5: 
  64. void *av_malloc(FF_INTERNAL_MEM_TYPE size)
  65. {
  66.     void *ptr = NULL;
          ^
  67. #if CONFIG_MEMALIGN_HACK
  68.     long diff;

libavutil/mem.c:72:8: Taking true branch
  70. 
  71.     /* let's disallow possible ambiguous cases */
  72.     if(size > (INT_MAX-16) )
             ^
  73.         return NULL;
  74. 

libavutil/mem.c:73:9: 
  71.     /* let's disallow possible ambiguous cases */
  72.     if(size > (INT_MAX-16) )
  73.         return NULL;
              ^
  74. 
  75. #if CONFIG_MEMALIGN_HACK

libavutil/mem.c:117:1: return from a call to av_malloc
  115. #endif
  116.     return ptr;
  117. }
       ^
  118. 
  119. void *av_realloc(void *ptr, FF_INTERNAL_MEM_TYPE size)

libavformat/movenc.c:2033:13: 
2031.             pkt.size = len+2;
2032.             pkt.data = av_malloc(pkt.size);
2033.             AV_WB16(pkt.data, len);
                  ^
2034.             memcpy(pkt.data+2, t->value, len);
2035.             ff_mov_write_packet(s, &pkt);

libavutil/bswap.h:58:1: start of procedure av_bswap16()
  56. 
  57. #ifndef av_bswap16
  58. static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
      ^
  59. {
  60.     x= (x>>8) | (x<<8);

libavutil/bswap.h:60:5: 
  58. static av_always_inline av_const uint16_t av_bswap16(uint16_t x)
  59. {
  60.     x= (x>>8) | (x<<8);
          ^
  61.     return x;
  62. }

libavutil/bswap.h:61:5: 
  59. {
  60.     x= (x>>8) | (x<<8);
  61.     return x;
          ^
  62. }
  63. #endif

libavutil/bswap.h:62:1: return from a call to av_bswap16
  60.     x= (x>>8) | (x<<8);
  61.     return x;
  62. }
      ^
  63. #endif
  64. 

static void mov_create_chapter_track(AVFormatContext *s, int tracknum)
{
    MOVMuxContext *mov = s->priv_data;
    MOVTrack *track = &mov->tracks[tracknum];
    AVPacket pkt = { .stream_index = tracknum, .flags = AV_PKT_FLAG_KEY };
    int i, len;
    track->mode = mov->mode;
    track->tag = MKTAG('t','e','x','t');
    track->timescale = MOV_TIMESCALE;
    track->enc = avcodec_alloc_context();
    track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
    for (i = 0; i < s->nb_chapters; i++) {
        AVChapter *c = s->chapters[i];
        AVMetadataTag *t;
        int64_t end = av_rescale_q(c->end, c->time_base, (AVRational){1,MOV_TIMESCALE});
        pkt.pts = pkt.dts = av_rescale_q(c->start, c->time_base, (AVRational){1,MOV_TIMESCALE});
        pkt.duration = end - pkt.dts;
        if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {
            len = strlen(t->value);
            pkt.size = len+2;
            pkt.data = av_malloc(pkt.size);
            AV_WB16(pkt.data, len);
            memcpy(pkt.data+2, t->value, len);
            ff_mov_write_packet(s, &pkt);
            av_freep(&pkt.data);
        }
    }
}
['static void mov_create_chapter_track(AVFormatContext *s, int tracknum)\n{\n    MOVMuxContext *mov = s->priv_data;\n    MOVTrack *track = &mov->tracks[tracknum];\n    AVPacket pkt = { .stream_index = tracknum, .flags = AV_PKT_FLAG_KEY };\n    int i, len;\n    track->mode = mov->mode;\n    track->tag = MKTAG(\'t\',\'e\',\'x\',\'t\');\n    track->timescale = MOV_TIMESCALE;\n    track->enc = avcodec_alloc_context();\n    track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;\n    for (i = 0; i < s->nb_chapters; i++) {\n        AVChapter *c = s->chapters[i];\n        AVMetadataTag *t;\n        int64_t end = av_rescale_q(c->end, c->time_base, (AVRational){1,MOV_TIMESCALE});\n        pkt.pts = pkt.dts = av_rescale_q(c->start, c->time_base, (AVRational){1,MOV_TIMESCALE});\n        pkt.duration = end - pkt.dts;\n        if ((t = av_metadata_get(c->metadata, "title", NULL, 0))) {\n            len = strlen(t->value);\n            pkt.size = len+2;\n            pkt.data = av_malloc(pkt.size);\n            AV_WB16(pkt.data, len);\n            memcpy(pkt.data+2, t->value, len);\n            ff_mov_write_packet(s, &pkt);\n            av_freep(&pkt.data);\n        }\n    }\n}', 'AVCodecContext *avcodec_alloc_context(void){\n    return avcodec_alloc_context2(AVMEDIA_TYPE_UNKNOWN);\n}', 'AVCodecContext *avcodec_alloc_context2(enum AVMediaType codec_type){\n    AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));\n    if(avctx==NULL) return NULL;\n    avcodec_get_context_defaults2(avctx, codec_type);\n    return avctx;\n}', 'void *av_malloc(FF_INTERNAL_MEM_TYPE size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    if(size > (INT_MAX-16) )\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size+16);\n    if(!ptr)\n        return ptr;\n    diff= ((-(long)ptr - 1)&15) + 1;\n    ptr = (char*)ptr + diff;\n    ((char*)ptr)[-1]= diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr,16,size))\n        ptr = NULL;\n#elif HAVE_MEMALIGN\n    ptr = memalign(16,size);\n#else\n    ptr = malloc(size);\n#endif\n    return ptr;\n}', 'int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq){\n    int64_t b= bq.num * (int64_t)cq.den;\n    int64_t c= cq.num * (int64_t)bq.den;\n    return av_rescale_rnd(a, b, c, AV_ROUND_NEAR_INF);\n}', 'static av_always_inline av_const uint16_t av_bswap16(uint16_t x)\n{\n    x= (x>>8) | (x<<8);\n    return x;\n}']