static int mov_write_udta_sdp(AVIOContext *pb, MOVTrack *track)
{
    AVFormatContext *ctx = track->rtp_ctx;
    char buf[1000] = "";
    int len;

    ff_sdp_write_media(buf, sizeof(buf), ctx->streams[0], track->src_track,
                       NULL, NULL, 0, 0, ctx);
    av_strlcatf(buf, sizeof(buf), "a=control:streamid=%d\r\n", track->track_id);
    len = strlen(buf);

    avio_wb32(pb, len + 24);
    ffio_wfourcc(pb, "udta");
    avio_wb32(pb, len + 16);
    ffio_wfourcc(pb, "hnti");
    avio_wb32(pb, len + 8);
    ffio_wfourcc(pb, "sdp ");
    avio_write(pb, buf, len);
    return len + 24;
}
Unknown