Projector Letter Boxing

I'm Starting with a fresh Ubuntu 10.10 install 64 bit. I'll do posts on how to configure everything with windows after the science fair. No matter what size you screen is, or how you adjust the projector, I doubt you'll get the screen to fit perfectly with the proper resolution. That's why I present to you: a tutorial on modelines!

If you open a terminal and type:

gtf width height refreshrate

If that doesn’t work try:

cvt width height

It will return a result. In my case, I used 1024x768 (later I’ll use 1600x1200) because that’s the native resolution for my projector, at 60 hertz.

# 1024x768 @ 60.00 Hz (GTF) hsync: 47.70 kHz; pclk: 64.11 MHz
Modeline "1024x768_60.00" 64.11 1024 1080 1184 1344 768 769 772 795 -HSync +Vsync

You’ll copy everything after Modeline.

Now, in terminal, open xorg.conf as root

Under the “monitor” or “device” section, whichever you want to add a letterbox, paste:

Modeline "1024x768_60.00" 64.11 1024 1080 1184 1344 768 769 772 795 -HSync +Vsync

Or whatever yours was.You can check online to see what all of these values mean, It took me a while. The second number after “1024x768_60.00” is the one I changed to 786. I did this because I wanted a 1:1 ratio 786x786. The two numbers after that shift the horizontal position. Adding 100 to each of these will shift the image 100 pixels to the right (further away from the left). Once you have the values you want, save the xorg.conf, and restart the x-server. Now you should be able to select the 768x768 resolution, and have the letterbox!