private void but_rtspurl_Click(object sender, EventArgs e)
{
string url = "rtsp://192.168.1.252/";
InputBox.Show("video address", "enter video address", ref url);
factory = new Factory();
media = factory.CreateMedia(url);
player = factory.CreatePlayer();
renderer = player.Renderer;
player.Open(media);
renderer.SetFormat(new BitmapFormat(512, 512, ChromaType.RV32));
player.Play();
}