Revision 2013 - #1 Wild demo

[Torlus]

 

Wow...

The interesting thing is that he manages to get 2 video outputs from a single composite signal

 

[sh3-rg]

Someone want to explain how...?

 

[GT Turbo]

Zero or Scpcd

 

 

[Zerosquare]

Actually, it's explained here in the description :

Basically, the idea behind it is very simple : it uses a special kind/setting of oscilloscopes named "waveform monitor", which is used a lot in video production to check a video luminosity (luma) levels. For each line of the original picture, the electron beam of the oscilloscope draws a line of the pixels' luminosity. So if you want to obtain a picture on the waveform monitor, you need to pay attention at the luminosity and horizontal position of the pixels, the vertical position is irrelevant. This demo also makes a clever use of analog glitches of waveform monitors that are not correctly simulated in this video, and generate grayscales on the waveform by duplicating pixels of the same luminosity on the original video.

 

The second part is a bit trickier, high luma pixels are used on the video to make an animation, and low luma pixels are used to show another animation on the bottom of the waveform monitor. By modifiying the setup of the oscilloscope to zoom on the lower part of the waveform, you can create the illusion of a second screen !

So they're not using a "standard" oscilloscope, as it would be impossible since it needs at least 2 different signals (X and Y ; otherwise you would just get a diagonal line). They're using an oscilloscope which has a special mode that causes it to render the video signal differently.

 

The "dual screen" feature is a simple trick, and almost cheating () : the two screens are calibrated differently, so each of them show a different part of the picture. In theory you could do the same thing with standard TVs or video monitors, but you would need to make the image twice wide (or as high), and normal screens don't allow such extreme ratios, unlike oscilloscopes.

 

It's still impressive of course

[Orion_]

oh, ok I understand now with this video, thank Zerosquare

I was wondering, why ps2 platform, and just thought it was a classic ps2 demo with graphic simulation of oscilloscope

Generating the weird video output from ps2 to make it looks good on an oscilloscope seems not quite the simplest things to do, nice challenge

 

 

[Torlus]

Actually, it's explained here in the description :

Basically, the idea behind it is very simple : it uses a special kind/setting of oscilloscopes named "waveform monitor", which is used a lot in video production to check a video luminosity (luma) levels. For each line of the original picture, the electron beam of the oscilloscope draws a line of the pixels' luminosity. So if you want to obtain a picture on the waveform monitor, you need to pay attention at the luminosity and horizontal position of the pixels, the vertical position is irrelevant. This demo also makes a clever use of analog glitches of waveform monitors that are not correctly simulated in this video, and generate grayscales on the waveform by duplicating pixels of the same luminosity on the original video.

 

The second part is a bit trickier, high luma pixels are used on the video to make an animation, and low luma pixels are used to show another animation on the bottom of the waveform monitor. By modifiying the setup of the oscilloscope to zoom on the lower part of the waveform, you can create the illusion of a second screen !

So they're not using a "standard" oscilloscope, as it would be impossible since it needs at least 2 different signals (X and Y ; otherwise you would just get a diagonal line). They're using an oscilloscope which has a special mode that causes it to render the video signal differently.

 

The "dual screen" feature is a simple trick, and almost cheating () : the two screens are calibrated differently, so each of them show a different part of the picture. In theory you could do the same thing with standard TVs or video monitors, but you would need to make the image twice wide (or as high), and normal screens don't allow such extreme ratios, unlike oscilloscopes.

 

It's still impressive of course

I was thinking about other ways of doing this kind of stuff.

First, the TV image is B&W so it would suggest that a low-pass filter could be used at the TV input to keep only the luminance part, leaving room to higher frequencies for the oscilloscope.

Then use something along the lines of a sync separator circuit to achieve a X/Y display for the scope.

Time-wise, it may be possible to use the blanking period too.

Well, looks more like Star Trek electronics than anything else, but maybe someday it would be worth a trry

[Zerosquare]

It's certainly possible, but I think part of the challenge of this demo was that no electronics was needed