mnzip

It's based on the BWT + MTF variant [...] + snows/ffv1s range coder with a state transition table borrowed from bbb/paq 8 source code under GPL is of course available too.the program website 2009, March 25

First to compress our data we run an mtf transform over it, we store the mtf table after the whole transform (this is not strictly needed but simplifies things). Next we encode the indexes from the end to the begin each time moving the zero entry of our table to the point pointed to by the index, each time we do know the symbol before the index and so can use it as context. This really is nothing else as the MTF coder in reverse. the author explaining the MTF variant, quoted from here.

The compressor is featured in the BWT comparison.

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