static int open_in(HLSContext *c, AVIOContext **in, const char *url)
{
    AVDictionary *tmp = NULL;
    int ret;

    av_dict_copy(&tmp, c->avio_opts, 0);

    ret = avio_open2(in, url, AVIO_FLAG_READ, c->interrupt_callback, &tmp);

    av_dict_free(&tmp);
    return ret;
}