Okay, this may be a dumb question, and if it's answered elsewhere please point me to it.
I had been considering a 2.35 screen as wide as my room could accommodate, with masking to allow me to mask down to 1.78. However, after doing some further research, I'm now thinking that I want to be able to do 1.78 at the maximum width my room will allow (for things like IMAX or Planet Earth).
To accommodate this, I think I want to use a 1.78 screen with a variable top horizontal mask, and with vertical masks that can mask it down to 1.33.
What I want to do is to be able to show Blu-ray content at the full width of the screen, and if it's 2.35 content, I want to reposition that letterboxed image to the bottom edge of the screen, then drop the horizontal mask to mask off the unused top portion. The screen size I'm looking at would give me a 40 degree viewing angle, which I'm told is just about perfect for Blu-ray content.
For most DVDs, I would want to go to a 30-degree horizontal viewing angle to account for the lower intrinsic resolution of the content. Fortunately, dropping those vertical masks produces a 30-degree viewing angle, so if the scaler can inset the image to fit within the vertical masks, and then shift it down to the bottom of the screen, I can drop the horizontal mask to top edge of the image and be properly masked. This would work for everything except 4:3 DVD content, and I don't have much of that apart from Looney Tunes.
I would like to do all of this without having to zoom or lens shift the projector, so what I'm looking for is a scaler that can output 1080p to the projector, but scale and reposition the image as required to fit within the masks.
Can the RadianceXD do what I'm after? It seems, looking at the serial protocol, that the "output shrink" command is probably what I'd want, but I wanted to be sure.
For example, in the 1080p 2.35 case described above, I would want the top, left corner of the image to be at (top: 263, left: 0) and a bottom right of (bottom: 1080, right: 1920). For a 2.35 DVD, similarly, I'd want (top: 466, left: 238) and (bottom: 1080, right: 1682).
I guess the Radiance actually takes 0-255 values for these, so for a top point of 466, would I pass it 110? (466/1080*255)?