Viewer Challange: Dual side TV Screen

From the description, which seems to be more obfuscated by every post, it seems you're playing a split screen game and want to run each split on a different monitor...

First, you can't easily rescale the images or they will look wrong. The Xbox will scale them correctly the first time. Or you can rescale them if you don't mind everything being stretched but you'll need expensive hardware to do that.

Second, you can run the same image to two monitors/TV's.. That's not too hard.

One possible solution - based on the analogue output capability - for either Video or RGB.

If you get someone with basic electronics knowledge to build a small circuit that resets on the vertical retrace signal and has a timer in it ( you could either count the horizontal retraces or for something like this, you could even use a pot/capacitor/resettable timer )

Then, set the counter/adjustable-timer for the "middle" of the screen and go for a vertical split screen. ( Top and bottom ).

Set the timer so it triggers in the middle of the screen image output and before it goes off, blank one screen then after it goes off, blank the other and restore the first.

Then reset on every vertical retrace signal.

The result? You can control what portion of signal goes to both monitors and as a result "mask" the undesired portion of the signal from the other monitor. So one monitor would only display the "top" image ( scaled correctly - only at the top ) and the other monitor would display the bottom image.

There would be ways to expand this method to allow a 4-player split screen and it would be terrible... You could even scale it but the complexity would increase. Still it's doable.

What you'd need to complete this project?

1. Learn about raster scanning, what a vertical retrace is and what a horizontal retrace is.

2. Work out what to do to blank the signals... High speed analogue switches? Amplifiers? There are many ways though a high speed analogue switch might be easiest... You'll need one for each color. Or if you're working with composite, you'll need to clip the signal to the black level.

3. How will you set the middle? A counter is precise but takes a few chips and is hardwired and dependant on resolution. At 50hz, a capacity-potentiometer charge circuit is fine and if reset correctly will find the middle of the screen everytime and is adjustable. You will also only need to sync off the vertical retrace simplifying a circuit.

4. Make it and have fun

Regards

David.

I figured out the scaling, there is no distortion associated with my method. When it comes to aspect ratios I'am an expert!

There would be no distortion in terms of stretching in one direction only, but you WOULD be stretching (albeit proportionally) in both directions.  This would definitely affect quality. It would be the equivalent of digital zoom on a camera.  I think your original picture could be clearer for people to understand if you added black borders on the left and right of the 4:3 image to show what the image would look like set to 4:3 on a 16:9 screen.

Maybe some measurements too.

In terms of pixels...  If we assume that we are working with a 1920x1080 screen, then each persons split screen would take 1440x540 pixels when set to 4:3 ratio.  If you upscale that to fit on a wide screen (multiplying both measurements by a common scale factor to hit 1920 wide or 1080 high, whichever hits first to prevent losing image off the sodes/top) we would need a scale factor of 1.333.... This would mean using 1920x720 pixels.  This would leave a black border of 1920x180 at the top and bottom.

It wouldnt be distorted but WOULD lose some sharpness

There would be no distortion in terms of stretching in one direction only, but you WOULD be stretching (albeit proportionally) in both directions.  This would definitely affect quality. It would be the equivalent of digital zoom on a camera.  I think your original picture could be clearer for people to understand if you added black borders on the left and right of the 4:3 image to show what the image would look like set to 4:3 on a 16:9 screen.

Maybe some measurements too.

In terms of pixels...  If we assume that we are working with a 1920x1080 screen, then each persons split screen would take 1440x540 pixels when set to 4:3 ratio.  If you upscale that to fit on a wide screen (multiplying both measurements by a common scale factor to hit 1920 wide or 1080 high, whichever hits first to prevent losing image off the sodes/top) we would need a scale factor of 1.333.... This would mean using 1920x720 pixels.  This would leave a black border of 1920x180 at the top and bottom.

It wouldnt be distorted but WOULD lose some sharpness

Hi,

I just wanted to say how much I agree with this idea. I wanted to have game-console/pc that has 2 Video outputs for mp since the days of the PS1.

Even back in 1996 I did not know why no video game OEM provided this feature.

And sorry for asking if the answear is obvious:

Does Ben "the maestro, the icon, the man" Heck himself post on this board (on occasion) or is this just for fans of the show?

best

involut

you know, the more I think about this, the easiest solution is a roll of black duct tape and some cardboard ( although it would be possible with just the roll of tape ) and a simple monitor splitter. ( One signal to two monitors )

Just mask off the half of the monitor that shouldn't be seen.

Scaling can be achieved by selection of the appropriate screen size...

And if you wanted to be really clever, you could make a small box to house both monitors back-to-back with an appropriate bezel to mask the action, while adjusting the height of each monitor so all images appeared at the same height.

It's nice to think of technical solutions, but for the life of me I can't see what you can do with technology here that can't be achieved with a roll of duct tape and even including the costs of two new monitors with larger screens, it's still going to be cheaper than the cost of scaling hardware which isn't all that cheap due tot he memory/hardware requirements.

Anyway, just a thought...  That maybe the easiest solution to this problem might just be worth considering....

Best of all, no loss of quality through scaling.

David. 

Ha, definitely easier.

Back in the day, we wanted to play 4 player Goldeneye in exactly this way.  Using newspapers, tape, the lid from the board game "The Game Of Life" , and extra TVs we managed exactly this setup in one small room.  It became a regular feature too and, by careful dismantling and shoring up/redesign of the "covers" we made, we could set the room up (including transporting TVs from other rooms, cabling, covering, powering up, being ready to play) in only 5 mins.  It worked a treat.

It would certainly be impressive to see the hack as set out in the original post but I have to agree that we played MANY an enjoyable game with our setup.