AntcuFaalb said:
... DeFish with an fov of 84°.
Unfortunately, those are just as inaccurate as my proof-of-concept attempts further up. Lens correction is not the right approach. Getting a Cinerama screen look is a continuously variable perspective correction problem.
Properly done, the edges of the screen would become thinner and taller and the center of the screen would remain normal proportioned. It also means the widescreen picture would become more fullscreen-ish.
Automatic re-proportion would be great (a resize equation) but manual grid re-positioning (if there is such an Avisynth filter) should do as well, granted with one-shot grid-adjustment work.
And if I may be so bold to add ... the released Cinerama simulations are just that ... simulations and wrong. :)
Can you see how in How The West Was Won?