Video Wall



Over the years I have been collecting the old Commodore-64 1702 monitors, because they are all-around incredible. They are a decent size, aren't too heavy, have recessed handles, accept a composite RCA video feed, have octagonal versus rectangular pixels - thus boast higher apparent resolution and clarity than TV's, and lastly they are square, and they stack well onto each other. I now own 61 of them, although at the present time they are scattered around the city, lent to various friends, as I don't take all of them out to shows too much any more.
What I used to do, and still do occasionally, is build huge crazy video sculptures, pyramids, matrices, you name it, and pump multiple channels of sequenced, strobing video through them. Quite wild looking, although be prepared for a back ache after you've made the four cumulative trips that are required to take them from home to van, van to rave, rave to van, then van to home, to sleep...

Rather than just taking a video feed and pumping it to a distribution amplifier, then out to the monitors, I initially set out to discover how to build myself a real videowall. To make a long story short, I'm still not quite educated enough ( at least in the video engineering field ), to design and construct a videowall controller capable of digitizing 60 fields of video per second, and then sending selected portions of the framestore to up to 64 different screens ( 8 by 8 matrix ), before resizing the info in real-time, and so on... It gets a bit complex ( I'm slowly learning more and working on it though...I'll update you when I come up with something. ) Until that time, I decided to use what electronics know-how I had to create a multiplexed 4 by 4 grid sequencer.


Did you ever watch the TV-show "Knight Rider" ? Assuming you did, you know the lights that scan back and forth on the front of the car ? - Well, that was my thought-process inspiration for my current videowall controller prototype. What it is actually is a controller that illuminates 16 L.E.D.'s in different sequences. If I position them in a 4 by 4 matrix, just like how my monitors will be set-up, we can see the more than 200 different patterns available. I can spin the lights in a vortex in either direction, checkerboard them, sequence the columns and rows, and all sorts of weirdness. To control the video in the same manner as the lights, I initially connected relays to the LED connections, to switch my video signals as the LED's did so as well. This worked, but there was too much of a propagation delay, or glitch as I sequenced the different patterns. So I switched from relays to transistors and opto-couplers, and stripped the video sync before passing the main signal through my circuit, then added it back in on the other side. So far this is working quite beautifully, and my next modification will be a sample and hold feature, so I can retain trails of fading video, & I hope to add the possibility to input multiple channels of video. One quick solution to that is to add a 2nd video channel to the OFF portion of the opto-coupler, so when it isn't activated by the main feed, it will default to the secondary signal. However I dream of having multiple streams of video chase each other in all sorts of crazy patterns as I build whacked out video sculptures, and someday figuring out how to stretch my image in real-time to cover the whole matrix!
Special Highlight:
OVT
's Custom VideoWall Router Matrix Controller:

I recently had a chat with Brian from OVT about his custom videowall controller, shown here.  It runs on an industry standard Knox routing switcher, with dual TBC's to stabilize the input signal syncing. 

Here are two .mpg streaming (if you have a fast connection) videos of the controller in action:

   MPG #1      MPG #2
   

-go onto the next piece of VJ Gear, or select from a menu option below: