Would it be possible to hook up something to a TV that could play pre-programmed subliminal messages on top of regular TV viewing? Do any of the existing plugs in the back allow for something like that? Thanks.
There are camcorders that allow you to superimpose titles, so I assume a box could be found. A normal TV probably wouldn’t do it, but if it had a video out and video in jack, you could run the signal through a title generating box, and back in.
Given the fact that subliminal advertising seems to be much more legend than fact… I’m going to say the answer to the question is “no,” regardless of the technical capabilities of the televisions of the world.
I’m talking about building a box myself. I don’t want to argue over the efficacy here, just whether it’s possible. By the way, most skeptics are back-peddling on their past
evaluations:
http://www.findarticles.com/p/articles/mi_m2843/is_5_23/ai_55683970/pg_2
There are all sorts of title and character generators that work on good ol’ composite video (the one that’s usually got the yellow plugs)
The trick would be in adjusting their intensity from 100%, which entirely blocks whatever image, down to what, 1 or 2%?
Actually they could be at full intensity if they could be flashed for microseconds. Can those title generators work during normal tv watching?
Thanks for the links to the subliminal article.
If you get it to work, let us know what your total investment was. I’m thinking about testing the effectiveness of a Turn off Letterman and Let’s Get Busy! message on the bedroom TV.
Microseconds - no. The entire electonic operation of a standard NTSC (normal definition US) television is geared to 60 half-frames per second, so the minimum time for any full screen subliminal image would be 16,666 microseconds. It takes about 70 microseconds to draw a single horizontal line of the TV image.
The two half-screens of a full frame are interlaced (i.e. the TV first draws the odd numbered lines, and then goes back and fills in the even lines on the next half-frrame) so I suppose that you might be able to use a half-frame to create a subliminal image in text. With a subliminal image, your results would vary, depending on how the “real” image interacted with the subliminal one. For subliminal images, you might want to go to a full frame (two half frames) which would take 33,333 microseconds. A computer monitor at 100Hz could flash a full image in just 10,000 microseconds, because they don’t interlace.
Europe, and many other countries, operate on 50 Hz power, not 60 Hz, and early TVs chse to run at a frame rate equal to the power line frequency (else the line power would be an incredibly powerful source of interference, in crude terms). They have 50 half-frames/sec.
Any decent home computer with a decent TV in/out video card has the electronics and horsepower to insert single frames. I bet there’s even free software to do it…
Yup, a quick search shows… Virtual Hypnotist, Subliminal Message Flash 2.1, and many more. I haven’t tried any, but with so many choices. it’s likely that one may meet your needs, outputting NTSC (TV, not computer) video through the TV-out of a video card.
I’ve built several HTPCs (home theater PCs) that process NTSC, HDTV or other video sources in real time. It’s really not hard at all, even with a rather moderate PC/CPU.
It’s not practical in the general sense, since you don’t have access to the baseband video signal path in a typical TV. You could theoretically capture every possible channel coming into the television, demodulate it, remodulate it with your stuff encoded into it, then feed that into the television, but that would be ungodly expensive.
If your TV has a cable box (like mine) then it gets simpler, because now you only have to deal with one signal, which is always modulated to be on channel 3.
The first step is to demodulate the signal so you are dealing with the baseband video signal. Next you have to add in your “change” to the signal. This can be done with analog circuits, which is how they used to overlay text on video in the olden days before digital signal processing, but if you want it to look good and not flicker so much (you don’t want your subliminal stuff to be noticable, right?) then you’ll do better processing it digitally. The tricky part is that you can’t just “add” in a signal, it has to be synchronized with what is on the screen. You need to wait for the screen sync pulse, then time your additions to the signal as it scans across the screen. You then have to resync with each line as the line syncs come in from the original video. You could even theoretically insert a frame or two of your own periodically, by discarding the incoming signal and using your own in its place, again, syncing yourself to the vertical sync. Of course, if you are generating your own data, you’ll have to generate your own line syncs as well, but this isn’t that hard of a task.
Something like this wouldn’t be difficult for anyone with a EE degree to do, but would be far beyond the ability of someone with no experience at electronics. Did you say you wanted to build this yourself?
Whoops. I meant milliseconds, and 17 milliseconds is more than short enough. I think 50-200 milliseconds is standard. I’m familiar with the computer software programs but you’re saying I could send the output from that software to a TV relatively easily?
Well, or get one built. Sounds like the latter. How much do you think it would cost to build one?
If you have access to an old computer that would be the way to go, assuming the PC is free, a TV-in and a TV-out card would be about a $100 and you’ll probably be able to find free software solution that would allow this. Custom EE work is going to be expensive unless you can find somebody you could bribe with brownies.
Or coerce with a subliminal message.
Quick question e_c_g - instead of doing all of that demodulation/modulation stuff couldn’t you just build a simple box that passes the original signal straight through but interrupts it with your desired message at the desired interval and duration?
It’s that age old problem of “you can’t subliminally persuade an electronics engineer without a subliminal persuasion box but you can’t get a subliminal persuasion box without having subliminally persuaded an electroinics engineer to build one.”