Fun With Video Manipulation

Back in the 90s I ran the camera for my school’s morning news production. It wasn’t exactly a well equipped production; we just used the video out from a crappy RCA VHS camcorder on a tripod and a plastic Radio Shack mic plugged into the thing’s audio input.

One day I aimed the camera at the monitor (which was just the usual television set on a rolling cart with a VCR on the shelf below it, standard 90s classroom fare…) and it created this fabulous “infinity mirror” kind of pattern. If I aimed it just right, it’d keep going, otherwise it’d repeatedly erase itself to white or black and just flash.

Apparently I’m far from the only one who appreciates this kind of silliness.

The original “Scanimate” systems used video feedback through analog circuitry to work their amazing magic.

Here’s a 1984 exploration of video feedback dynamics by Jim Crutchfield:

I only kinda recently discovered what hilarious things you can do on a video mixer/switcher, and it seems almost like the cheezier the device is, the better? The ones that are made for home video editing seem to be particularly great as they have built in frame sync. In fact, it sometimes amazes me that the big HD professional switchers for live production and editing DON’T handle unsynchronized sources elegantly. I could see it for oldschool analog ones.

The Snell & Wilcox Kahuna switcher at WSVN had me spoiled – as long as the video input format on any given port matched what you set it to expect in the engineering config page, it took it just fine, regardless of sync. You only needed it to be synchronized accurately if you wanted to avoid some otherwise unavoidable latency (up to a frame or two – hardly terrible, but SOMETIMES noticeable as a slight lip-sync issue).

The Sony switcher “tub” – usually this gets controlled by some remarkably boring automation.

The Sony switchers where I work now will exhibit vertical roll problems if you don’t have things in sync, which is, um, special. A fair number of Evertz converters and black burst timing distribution to everything keep it all happy for the most part.

Now, this is all basically fine if you are using professional grade equipment with a correctly operating master timing generator. Each video source (VTRs, cameras, etc) will use a phase locked loop to synchronize their video timing to the sync pulses and burst phase of the master generator. In the old days, it was necessary to use delay lines, either built into distribution amps, standalone, or implemented using long pieces of cable to match the delays throughout the facility to make sure everything reached the switcher in the same timing. Nowadays with HD video, SOME buffering is added to give you a few lines of leeway. I’m not sure exactly how much in any given case, but the Grass Valley Group CQX switches are advertised as buffering and time-shifting by up to three video lines in the event that the sources hit it a LITTLE out of sync, so they can provide perfectly timed output. They can also do some basic clean cut and crossfade transitions onboard.

Nowadays since there’s no analog color subcarrier to deal with phase synchronizing, and it’s basically just more important to have a robust sync pulse than a whole video waveform, trilevel sync is becoming more commonplace. That’s just basically a pulse that tells everything “please start your first video line here”.

The really cheezy wonderful switchers that are the most fun to play with were designed to work with consumer grade equipment that gave you none of these luxuries. They just had to deal with the video coming in at whatever timing it did, so they incorporate a frame sync buffer on at least one input. While this can lead to some delay, it offers a lot more flexibility as to sources.

It also allows you to create some amazing feedback loops with video coming back not quite in phase and essentially crapping rainbows.

I’ve already babbled about the underlying technology more than I intended to, here are some pretty pictures.

The Videonics unit used here is actually a rather powerful little device; it’s a microprocessor driven unit with onscreen display and menus brought out to your preview monitor. Downside to this is, you have to use a monitor just to see what you’re doing on it. Eh, ok.

Examples of raw video feedback:

In high def!

In many cases it is possible to use a video mixer looped back to itself with no external sources to synthesize some trippy shit. 😀
It tends to lend itself to a flashier dynamic, which I don’t like as much, but you can with careful manipulation of the controls get it to generate some more stable effects.
(Definite epilepsy warning on this video!!)

This video has more of the slow moving, blown out full saturation effects I prefer:

Dreamy little seascape….

So there were also some really bizarre devices made that didn’t bother with the whole sync thing and let you basically fade/wipe to a solid color, pause recording on your VCR, switch source, then fade/wipe back in. Here’s a video review of one of them I have. This thing… is…. HEAVY. It’s also fun to add into a feedback loop.

Raw video from a Sony XV-T33F which is a bizarre title generator with drawing tablet for input. It can also do the offline fades/wipes, but it can also do some peculiar color animations and stuff that are amazing in and of themselves.

I should draw a bunch of shopping mall interiors on mine.
(Not really electronically manipulated, but this video is the inspiration for the thought above)

Lots of 1990s computer graphics set to the Macintosh Plus “Floral Shoppe” album (all we’re missing is a broken transmitter in the middle of the everglades)

Here comes the sun

So, what’s odd is, while I’ve seen a number of examples of the mixers (particularly the Panasonic WJ-MX12) being circuit bent, along with the Sony video sketch titler… really most of the bends I’ve seen just give them some extra glitchy “blinds” effects. All of my video toys are unmodified as I’ve never really seen the need to get in there and mess with them to get those. The WJ-MX50 has a nice blinds effect and other cheezy stuff baked in from the factory. It’s advisable to print out the pages from the manual that lists all the wipe patterns and hang it on the wall next to the switcher; it’s got like 64 of them or something sufficiently absurd. Conspicously missing is a star wipe. (The Sony switcher shown at the top here can star wipe. If it doesn’t have a wipe you want, you can also store custom patterns in it. It also has a smoke wipe. This… uh, may or may not get used by our directors when coming out of marijuana-related news stories.)

Star wipe, and where to use it:

The wipe being accompanied by a whooshing sound amuses me far too much. The switcher at WSVN was set up with pretty much EVERY one of the weird shiny-circle-7 wipes accompanied by a whoosh. Thankfully, it was only a whoosh, and even the “NEWS ALERT” used on that station was a whoosh or a little musical bit – it was not the abrasive terrible wshEEEWWWWWWWW-CLONG!!! used by Fox News Channel.

I’m fairly sure the cheezeball Datavideo titler/switcher unit I have can do the star wipe.
Most of the Datavideo stuff I’ve seen was from the mid to late 90s. I didn’t realize they actually go waaaaaaaaaaaay back:

Datavideo’s still around and they make some really fun looking switchers and streaming production systems.

Most of my stuff is still in boxes from moving, but I’m planning to set up a nice little rack with various cheezeball video boxes and matrix switches to route video between them. Expect to see a lot of silliness come from this soon.

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