UDP-VideoTransmission

[Debran]

Hi, I have a problem trying to transmit video with UDP .Does anyone know how to implement UDP for transmiting this kind of data?

Thank you.

[Jim_M]

Hi Debran,

             There are a number of resources available that you can search for on ni.com that describe how to transfer images over a network.  Perhaps you can use this information to help you get started with your project.  Check out this.  Let me know if I can assist you further.

[varmasim]

Hi, I tried what you recommended, but I have to many problems.

I´m using an ip camera, so it displays me an error that it's not the correct type of image on the server.vi, and the client.vi shows me an 74 error for the unflatted string.

Besides that, when I run the program like a localhost it runs correctly, but when I want to connect two computers in the same network, the client computer doesn't display anything in the image out. I already checked the ports, the firewall, but the connection it's ok.

What can I do?

[altenbach]

OK, I don't quite understand your setup.

• You talk about an "IP camera", a "client", and a "server".
• In a simple setup, the camera is the server and the client tries to get data from it.
• Is your situation more complex, e.g. one PC gets the images from the camera and then tries to send them to another PC?
• What kind of camera is it? Is it LabVIEW based?
• Your title talks about video transmission, but in the text you talk about images.
• UDP is just a transport for strings of bytes. It is up to the sender and receiver to flatten/unflatten according to the type of data. If it works locally, it should also work over the network.

Can you explain in more detail and maybe attach some of your code?

[Debran]

Hi, I'm sorry if my explanation wasn't clear.

The system is like that: I have one computer that acts like the server, and another like the client.

The server receives video from an ip camara; and I'm trying to send that video to the client. When I check both programs (client-server) with localhost in the server computer it works well, altough an error 74 appears when I stop the program. But when I try to do the same with the two computers,which are in the same network, the server program works correctly, but the client program doesn't display the video.

Could you help me?

[Debran]

?

Message Edited by Debran on 06-28-2008 03:20 PM

[altenbach]

So far we you were talking about UDP. So why are you now suddenly using TCP everywhere???

TCP is connection based (while UDP is connectionless). Did you look at some of the examples from the example finder?

[Debran]

Hi, I started programming with UDP, but reading some articles and looking some examples, I realized that it could be better to use TCP.

And now my problem is that the client program doesn't display the information that supposedly is receiving.

[Kevin_S]

Hi Debran,

First off, do you have LabVIEW installed on both computers?  Are you using VIs or executables?  What are you using to acquire and then display your video, and is this software available on both computers?  (Are you're using NI-Vision?)

Get the shipping examples that come with LabVIEW working first, and then see what the difference between them and your two programs are.  For TCP, try the programs "Data Client" and "Data Server".  For UDP, try the programs "UDP Receiver" and "UDP Sender".  Getting these examples to work will at least verify that data can be transmitted across your network.

I hope this helps,
Kevin S.
Applications Engineer
National Instruments