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_context3(NULL);
    track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;
    for (i = 0; i < s->nb_chapters; i++) {
        AVChapter *c = s->chapters[i];
        AVDictionaryEntry *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_dict_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_context3(NULL);\n    track->enc->codec_type = AVMEDIA_TYPE_SUBTITLE;\n    for (i = 0; i < s->nb_chapters; i++) {\n        AVChapter *c = s->chapters[i];\n        AVDictionaryEntry *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_dict_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_context3(AVCodec *codec){\n    AVCodecContext *avctx= av_malloc(sizeof(AVCodecContext));\n    if(avctx==NULL) return NULL;\n    if(avcodec_get_context_defaults3(avctx, codec) < 0){\n        av_free(avctx);\n        return NULL;\n    }\n    return avctx;\n}', 'void *av_malloc(size_t size)\n{\n    void *ptr = NULL;\n#if CONFIG_MEMALIGN_HACK\n    long diff;\n#endif\n    assert(size);\n    if (size > (INT_MAX-32) || !size)\n        return NULL;\n#if CONFIG_MEMALIGN_HACK\n    ptr = malloc(size+32);\n    if(!ptr)\n        return ptr;\n    diff= ((-(long)ptr - 1)&31) + 1;\n    ptr = (char*)ptr + diff;\n    ((char*)ptr)[-1]= diff;\n#elif HAVE_POSIX_MEMALIGN\n    if (posix_memalign(&ptr,32,size))\n        ptr = NULL;\n#elif HAVE_MEMALIGN\n    ptr = memalign(32,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{\n    return av_rescale_q_rnd(a, bq, cq, AV_ROUND_NEAR_INF);\n}', 'int64_t av_rescale_q_rnd(int64_t a, AVRational bq, AVRational cq,\n                         enum AVRounding rnd)\n{\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, rnd);\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}']