static int ass_split(ASSSplitContext *ctx, const char *buf)
{
    char c, section[16];
    int i;

    if (ctx->current_section >= 0)
        buf = ass_split_section(ctx, buf);

    while (buf && *buf) {
        if (sscanf(buf, "[%15[0-9A-Za-z+ ]]%c", section, &c) == 2) {
            buf += strcspn(buf, "\n");
            buf += !!*buf;
            for (i=0; i<FF_ARRAY_ELEMS(ass_sections); i++)
                if (!strcmp(section, ass_sections[i].section)) {
                    ctx->current_section = i;
                    buf = ass_split_section(ctx, buf);
                }
        } else {
            buf += strcspn(buf, "\n");
            buf += !!*buf;
        }
    }
    return buf ? 0 : AVERROR_INVALIDDATA;
}