Re: OT: Processing video signals as audio?

[Suit & Tie Guy <erwill@suitandtieguy.com>]

On Jun 1, 2004, at 10:16 PM, Jesse Ray Lucas wrote:
> So I had this idea the other night to take a video signal and run it 
> through some audio processors, but I didn't know if the signal would 
> damage devices meant to process guitar level signals. 

i don't think you can damage anything doing this. however, i am 
definitely inexperienced with video synthesis.

i would recommend starting here: 
http://www.audiovisualizers.com/toolshak/vsynths.htm   It's a good 
starting point for learning about the black art of video synthesis, 
something which scares me so much i stay the hell away from it. i 
restrict myself to "howl-round" and other video feedback experiments 
(see http://www.suitandtieguy.com/sights/stg_santa_fe.mov for an 
example of my feeble video work. i had the nerve to use that at Santa 
Fe's Center for Contemporary Art, at a show that could have had Jim 
Crutchfield at it. that would have been like me taking my Yamaha PSR47 
and DOD DFX94 to Robert Fripp's house to "show him my stuff".)

pay close attention to the part about the Vasulkas. they used to have a 
modular video synthesiser which "mated" with Subotnick's Buchla in some 
exciting private event. i heard about it from a friend, i don't know if 
there are any fruits of that particular event.

i used to work at a television station, and tried to pay attention to 
the techs when they were maintaining the video stuff. something that's 
important to keep in mind about video signals is that they are very 
similar to audio signals, but at a much higher frequency range. also, 
delay has an interesting effect on video. if two video signals are out 
of phase with one another they will appear separately as OK, but when 
you mix them in a vision mixer they change colour. so microsecond 
(mabye picosecond?) delays are used in television to time correct 
different sources (which even blackburst won't totally correct for).

for looping content, i'll point out that Jim Coker uses a program 
called Isadora to do video looping with feedback processing. it's real 
freaky. hopefully he'll get some examples up on his site soon.
---
Eric Williamson
www.suitandtieguy.com