Most of the previous questions were about getting rid of distortion in video
June 3, 2010 8:07 AM   Subscribe

People have/make distortion pedals for sound. Do people also make distortion pedals for video?

The way that I understand distortion pedals used in music, it's a box that modifies the electrical signal of the sound. Video is just an electrical signal, right? So couldn't you also make distortion pedals that you're running your video through? Is someone already doing something similar to this?
posted by codacorolla to Media & Arts (9 answers total) 8 users marked this as a favorite
A couple of friends of mine have written a few real-time video effect filters, which take input from a webcam and display the results in a monitor (or projector) facing you as if it's a mirror. Stuff like making moving areas blocky, picking out edges, rotating the colour pallete, etc. Some of them are set to display a consistent effect, while others are changed by whoever is running the show. VJs in clubs sometimes do similar things, throwing distortions and/or filters on pre-recorded videos or live video of the crowd.

I've never seen these things controlled by actual pedals, but I don't see any reason why you couldn't.
posted by metaBugs at 8:27 AM on June 3, 2010

I'm sure that they are, coda. I saw DJ Spooky during his Rebirth of a Nation tour, where he took several video streams through a mixing board & a laptop to orchestrate & the show was not the same either night. It was apparent that there were "effects" mixed in that added distortion etc., etc.

I also remember, way back in the early 70s that some folks at the art department of U Illinois, Chicago, were feeding video through feedback loops & apparati similar to synthesizers, so certainly, this is not new.

Google-fu turned up this as one of the results. No connection between me & the product from NuMark...

The NuVJ allows DJs to incorporate images and video clips in much the same way as mixing music. With the NuVJ the VJ can trigger images and video clips add effects to them mix them through an onboard DJ style crossfader and tweak them in order to create unique and spectacular shows. The hardware controller works seamlessly with existing DJ gear and the software is compatible with most computers and laptops. The NuVJ is simply easier better and more affordable than any other VJ product on the market.
posted by beelzbubba at 8:31 AM on June 3, 2010

I don’t know if anyone’s already doing this or how into this you would want to get, but there’s a processing library for filter video called GSVideo. Arduino’s have the ability to communicate with Processing and with analog devices. So if you had a soldering inclined friend look into that enough or visited a hackspace somewhere near you you might be able to find people who could help make it, should no one turn up in this thread with better answers.

On preview beelzbubba's got it, but I'm posting in case you are interested in DIY.
posted by edbles at 8:37 AM on June 3, 2010

The mechanism will be very different for digital video than for "analog" video formats like VHS, but both are done.

Here's some relevant wikipedia reading on analog video art: Video Art, Video synthesizer, VJing.
posted by bubukaba at 8:38 AM on June 3, 2010

Best answer: This can sort of be done, but the problem is that while electrically audio is basically WYSIWYG, video is encoded in various complex ways. At its core the issue is one of serialization of discrete frames - you have a few conductors that you're trying to cram a series of two dimensional images onto. Typically the encoding tends to dominate the electrical properties of the signal; a strong 60Hz component on the vertical retrace, and (for instance) a 15.7 khz component on the horizontal retrace. You need to preserve those components if you want your display device to sync up and put the signal back together in anything resembling the right way. So even if your filter doesn't throw things out of sync, nearly anything that in audio would be a time effect turns into an encoding-sensitive spatial effect (including frequency filters; high frequency vs low frequency audio corresponds to sharp vs smeared across the X axis in video.) So in practice it's really difficult to do anything more complicated than a subset of what you can do with Photoshop's curves tool (brightness, contrast, color balance).

Here's someone who did that - it's a cool effect, but it simplifies the image instead of adding richness/depth/complexity, which many guitar effects do. Compare the circuit to some random audio effect circuts.

If you had a big bundle of wires one per pixel (or maybe 3 if you want color), and decoded your video signal into that, you could do the same sort of effects you do on audio by filtering each of those simultaneously, but at that point it's way cheaper and easier and more flexible to just do it all digitally.

There are some video mixers that let you put various effects on the video, with sliders for control. There's software that takes a live video signal and filters it in various ways. Those could certainly be controlled by pedals, but the smarts wouldn't be in the pedal the way it is with audio.
posted by aubilenon at 9:00 AM on June 3, 2010

Response by poster: Great answers so far, thanks!
posted by codacorolla at 9:16 AM on June 3, 2010

Last I knew, more people were using the free signal-synthesis environment PD for video than sound.

posted by rhizome at 11:32 AM on June 3, 2010

Also, check out staring at the sun by TV on the radio for some great examples of real time video effects. I believe they used similar devices illustrated by mkb.
posted by wonderwonder at 3:44 PM on June 3, 2010

« Older me want   |   Using chimichurri as an example, what are some... Newer »
This thread is closed to new comments.