I have a cheap 1080p projector, mounted in almost the perfect position. the ceiling mount that I had on hand was a tad short and incidentally had to tilt the projector down.
Tilting made the image go into a 'trapezoid'. Now, yes, this projector has the arbitrary "keystone", but that uses a plastic fresnel lens and blurs out the top and bottom of the image except for a tiny horizontal area in the middle.
I've been googling and came across a couple of projects, namely
1. mpc-hc (1.7.10.252) + ffdshow (both projects shutdown)
2. Multi-Point Keystone Video Player (made only for Mac, but the creator says the library can be compiled for Windows as well. Not even sure what would be involved to do it by myself)
Seeing as both the projects mentioned above do have the source code available as open source, would it be possible to include a feature built-in to Kodi for this?
I have like 5 or 10 degrees of tilt to correct, and I'm fine with a little compression (literally bootstrapped a 7.1 ht setup under $250, so I'm fine with compromises) (setup: $100 projector, $60 5.1 with ac3-in modded to 7.1, $40 7.1 HDMI audio extractor, $50 misc.)