Function parse_adaptation_sets

libavformat/dashenc.c:798–1000

}

static int parse_adaptation_sets(AVFormatContext *s)
{
    DASHContext *c = s->priv_data;
    const char *p = c->adaptation_sets;
    enum { new_set, parse_default, parsing_streams, parse_seg_duration, parse_frag_duration } state;
    AdaptationSet *as;
    int i, n, ret;

    // default: one AdaptationSet for each stream
    if (!p) {
        for (i = 0; i < s->nb_streams; i++) {
            if ((ret = add_adaptation_set(s, &as, s->streams[i]->codecpar->codec_type)) < 0)
                return ret;
            as->id = i;

            c->streams[i].as_idx = c->nb_as;
            ++as->nb_streams;
        }
        goto end;
    }

    // syntax id=0,streams=0,1,2 id=1,streams=3,4 and so on
    // option id=0,descriptor=descriptor_str,streams=0,1,2 and so on
    // option id=0,seg_duration=2.5,frag_duration=0.5,streams=0,1,2
    //        id=1,trick_id=0,seg_duration=10,frag_type=none,streams=3 and so on
    // descriptor is useful to the scheme defined by ISO/IEC 23009-1:2014/Amd.2:2015
    // descriptor_str should be a self-closing xml tag.
    // seg_duration and frag_duration have the same syntax as the global options of
    // the same name, and the former have precedence over them if set.
    state = new_set;
    while (*p) {
        if (*p == ' ') {
            p++;
            continue;
        } else if (state == new_set && av_strstart(p, "id=", &p)) {
            char id_str[10], *end_str;

            n = strcspn(p, ",");
            snprintf(id_str, sizeof(id_str), "%.*s", n, p);

            i = strtol(id_str, &end_str, 10);
            if (id_str == end_str || i < 0 || i > c->nb_as) {
                av_log(s, AV_LOG_ERROR, "\"%s\" is not a valid value for an AdaptationSet id\n", id_str);
                return AVERROR(EINVAL);
            }

            if ((ret = add_adaptation_set(s, &as, AVMEDIA_TYPE_UNKNOWN)) < 0)
                return ret;
            as->id = i;

            p += n;
            if (*p)
                p++;
            state = parse_default;
        } else if (state != new_set && av_strstart(p, "seg_duration=", &p)) {
            state = parse_seg_duration;
        } else if (state != new_set && av_strstart(p, "frag_duration=", &p)) {
            state = parse_frag_duration;