Reverse engineering NanoZip compression algorithm

[birdie]

NanoZip features a relatively small decompressor, nz_w32c.sfx, which I guess could be used to at least somewhat easily reverse engineer/disassemble NanoZip compression format which obviously won't be enough to write an encoder but will shed light on how it works in general.

Is it feasible? Is it legal? Is it worthwhile? I haven't heard of any patents filed by its inventor, Sami Runsas.

I'm asking because NanoZip still heavily beats both 7zip/WinRAR/FreeArc (Next) in compression ratios while providing relatively fast decompression unlike state-of-the-art compression algorithms which are extremely excruciatingly slow.

If course, I won't ever do that 'cause I'm not even a programmer, let alone a low level assembler pro.

Thoughts?

[Shelwien]

https://encode.su/threads/3323-nanozip-decoder-source

[birdie]

https://encode.su/threads/3323-nanozip-decoder-source

How on Earth did we feel the same urge almost at the same time? Amazing. Not the first time it's happened to me though. Thank you for your effort! Hopefully you'll manage to decode it all and then someone will be able to figure out the compression algo.

[Shelwien]

nzdec is already able to decode -cO and -cc methods (-co without LZ too) and main preprocessors.
Unfortunately decompiling was done by another person (the same one who did rz), and he got bored of it, so further progress is unlikely.
I'm just refactoring the -cc codec source, since CM is symmetric and its easy to add encoding when you have decoding.