VGA to Ethernet device?

February 8, 2008 12:24 PM

Where can I find a standalone device that has a female DB-15 VGA port on one side and a female Cat-5 on the other, with a VNC server in between?

I work away from the office a lot, and I have yet to find a simple software solution for sharing screens over the net. I've tried oneclick VNC, NetMeeting, and the company's "solution."

Therefore, I'd like try and find a hardware doohickey that takes the VGA signal given to it, shoves it into a VNC server, and out the Cat-5 port on the other side. Has anyone heard of something like this? I suppose it doesn't have to be VNC.

If such a thing doesn't exist, how hard do you suppose it would be to make one? Think I could decode the VGA signal with a Gumstix-grade CPU?

posted by yellowbkpk to computers & internet (17 comments total)

Why do you think this would work better?
posted by unSane at 12:32 PM on February 8, 2008

If I'm understanding you right, this is known as KVM over IP. Googling for those terms will find you a ton of devices, although I can't recommend any personally.
posted by pocams at 12:35 PM on February 8, 2008

That's called a remote access card and servers use them. Typically they're only available for server-grade hardware. GoToMyPC doesn't work?
posted by GuyZero at 12:37 PM on February 8, 2008

unSane: This will work because I'll put it on a VGA splitter between the screen my coworkers use for meetings. They will not have to do anything beyond what they have to do anyway (plug in the VGA cable from the screen into the back of their laptop).

Thanks for the search terms everyone.
posted by yellowbkpk at 12:51 PM on February 8, 2008

I've had good luck with these USB VGA Capture devices and their higher-priced counterparts (the LR and the Pro models) as far as capturing the screen. They require USB 2.0 so a Gumstix might not cut it, but you might be able to grab frames and serve them over the net using one of those micro-PCs. Although Epiphan does provide Linux drivers.

Rose Electronics has some pretty okay KVM Over IP solutions although they tend more toward complete systems, not so much one-offs.

I suggest you give TightProjector a try if all you want is to broadcast your screen.
posted by ostranenie at 12:51 PM on February 8, 2008

What you are describing is exactly what a VNC server does. Instead of capturing from the VGA out port, it is capturing what is displayed on the screen, and outputs it over ethernet.

Have you tried Remote Desktop (assuming you are on windows) or Terminal Services?
posted by mphuie at 12:52 PM on February 8, 2008

Think I could decode the VGA signal with a Gumstix-grade CPU?

VGA is analog. Does a Gumstix have three 8-bit A/D converters, each capable of sampling at 25 MHZ? (Doesn't look like it.)
posted by Steven C. Den Beste at 12:52 PM on February 8, 2008

Regarding the Gumstix, I also have serious doubts as to whether a 400 MHz processor can do everything you want it to do at a rate of one pixel per 19 CPU clock cycles.

A hardware solution for this would have to be purpose-built, to include flash converters and a DSP running a lot faster than 400 MHz. It would also need to be set up to synchronize the A/D conversions to the VGA clock rate, and would need special hardware to detect the horizontal and vertical refresh edges.

It isn't going to be generic off-the-shelf hardware. And the code would be... challenging.
posted by Steven C. Den Beste at 1:03 PM on February 8, 2008

I think you need to explain how other solutions have failed you. Are they too complex for your coworkers? Or they're technically insufficient for some reason?
posted by knave at 1:05 PM on February 8, 2008

I wonder if there isn't a model of slingbox that might not support your desires.
posted by nomisxid at 1:21 PM on February 8, 2008

knave: So far, the closest working option has been a one-click VNC application that starts a VNC server on the presenter's computer and connects it back to my computer. The problem with that is that I have to send the application with the IP address of my computer every time a meeting starts. Sometimes the presenter doesn't remember to start the app, sometimes the connection fails and I have to interrupt them and ask them to start it again, etc.

nomisxid: That's a good thought. I'll have to check to see if there's a video output on the LCD that we display with to connect to.
posted by yellowbkpk at 1:31 PM on February 8, 2008

Our corporate solution involves a Batch file written around VNC, not sure how it'd work in the wild though. It connects to a pc, and installs the VNC Server service, and starts it. Once it's started it starts the VNC Client on my end. If a users logged in, they're prompted to accept the connection. If they're not I get a windows login screen. All this assumes that I have admin rights on the machine that I want to view. And I've not seen this anywhere other than our "wrapped" vnc program.
posted by TuxHeDoh at 1:37 PM on February 8, 2008

The Adderlink IP does exactly what you ask. It was developed by one of the people behind RealVNC, which I believe to be the direct successor to the AT&T research lab that initially developed VNC.

I've used a number of KVM over IP products, but they've generally either used a web/java client, or some sort of client software. Having one that works with just a VNC client is a huge plus.
posted by toxic at 1:42 PM on February 8, 2008

how hard do you suppose it would be to make one?

Well, the OKVM open source project might be a good place to start. Their design relies on a specific type of graphics processor, to take care of what amounts to realtime video capture.
posted by toxic at 1:59 PM on February 8, 2008

Understanding the question: there is a conference room where multiple people might give presentations that you'd like to view from a variety of locations?

If I'm understanding this right, something like this is a possibility. Might be overkill, but I have used Raritan's stuff to remotely view and manage, and it works pretty good.

Maybe this.
posted by gjc at 2:16 PM on February 8, 2008

GoToMyPC Free edition seems like it would do everything you need.
posted by SirStan at 7:19 PM on February 8, 2008

Multiview Ak500
posted by idledebonair at 6:50 PM on August 18, 2008