Giving Rust a chance for in-kernel codecs

But it certainly _is_ possible to develop a language where a machine tool can follow along with the discrete maths needed to see that we're in bounds when we do this, or point to where our code doesn't do what we thought it did (e.g. it's mandatory for videos in our encoding to have width multiple of 16, and so we didn't check that but our code assumes it's true, leaving a gap for anybody to just lie)

We only need to: Develop that language (for conventional software codecs it exists, it's named WUFFS) and teach the handful of people who write new codecs how to use this purpose made language and then sit back and enjoy the high performance totally safe results.