Wireless video link

[x1600c]

I had an idea about a year ago and I came back to it recently.. what if you were to multiplex the video signals from a computer monitor and transmit them via a wireless RF link and have a reciever/ demultiplexer on the other end so you just plug that box into the monitor and you can place the screen anywhere you want. how much bandwidth is needed to transmit the information from a VGA connector (those 15-pin d-subs). and what frequency is ideal for this type of operation.

 

[theshadow27]

VGA video signals, from what I understand, are super high bandwidth, high freeq, ect...

ive seen composite and s-video wireless links run on 900mhz and 2.4ghz... you would probably need 4 of these to get the same quality as a VGA cable. if it could be multiplexed w/o loss, they would have done it already

but i guarantee you that it would be faster, cheaper, and easier to have a mini-atx or micro-atx pc with a 802.11b PCMCIA card and a 9500 radion sitting in a box by your CRT (i assume crt cause LCD uses DVI). Then that runs VNC, or if you need higher quality, streaming video from your pc. This will get the job done very quickly with off the shelf parts (i.e. reliable, affordable, ect).

But if you want to be [h] about it…id start here

 

[x1600c]

actually I choose VGA because most if not all computer monitors have VGA, but not all monitors have DVI... and this streaming video... how much lag is there?

 

[theshadow27]

actually I choose VGA because most if not all computer monitors have VGA, but not all monitors have DVI

actually, i said DVI and not VGA because DVI is back compatible to VGA, but VGA isn’t forward compatible with DVI... but anyway

this streaming video... how much lag is there?

VNC over a 54 mbps wireless card is as fast as the computer's video card, with the latency of your network being the limiting factor... if you can ping from one computer to the other with 30ms, that will be the lag.

For MPEG streaming video, the limiting factor is going to be the receiving computer's ability to decode... depending on what the CPU is, probably 40 or 50 fps real-time at 1200/1600 32million colors if you don’t use anything else on the 802.11g

as a note, mpeg streaming is going to be a lot harder, you may need a rather high end video card in the host computer. VNC is going to be easier, but you may need to tweak the program to allow higher refresh rates (it was designed for dial up)

 

[mattg2k4]

VNC is not going to provide you with a very satisfying solution. Even over over a 100mbit wired network, it can be laggy. It requires a decent amount of CPU time on either end, and not all of what is output to the monitor will be transmitted over VNC (at least this is how it was the last time I used VNC). I seem to recall most video players didn't work over VNC.

If you use a wireless network link, performance will be even worse than with a wired network, and you have the added problem of losing signal every now and then.

A remote desktop program, such as the Windows XP built in one, or the commercial PCAnywhere will provide much better performance than VNC, but you still have network lag time to contend with.

A dedicated wireless transmitter will provide you with the best performance, but unfortunately I don't have the knowledge to tell you how to do it. However, here are some rough numbers: if you have a 1280x1024 display, you have 1.3 million pixels. If you have 32 bit color, that is 41943040 bits of data, or 40 megabits. Refresh that at 70Hz, and you have 2800 megabits per second for a full quality display, plus overhead. It won't be terribly easy to transmit all of this without compression, but compressing that on the fly without a computer would be extremely difficult

I wish you the best of luck, but this isn't an easy task.