Capturing the DVI signal

[lexxmac]

How would one go about capturing the signal from a DVI output on a video card? As far as I can tell DVI transmits in raw data or uncompressed. Another thing to keep in mind is the huge amount of data flying across DVI (For example 1024x768 @ 32 bits = 3MB per frame). Anyone know any devices that can do this?

 

[Peter]

Well, LCD screens do.

Ingredients of a DVI receiver are a TMDS deserializer chip, and a data capture device behind it. The former can be bought off the shelf, the latter will obviously depend on what you're going to do with the data.

 

[lexxmac]

I know you will need a TDMS receiver to recover the DVI signal, and Silicon Image makes the best ones as far as I know, considering they pretty much wrote the DVI spec. After that I'm not quite sure what to do with the data. I want to dump it to a RAID array, but I don't think the drives will be able to keep up with the amount of data being dumped. I don't want to compress it as I want to compare two images bit for bit and compression would make the frames useless for doing such.

 

[Lynx516]

Dump to RAM then to disk

 

[Peter]

Why don't you use framegrabber software on the machine itself?