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Groups > comp.compression > #2290

Re: BWTS in Free Pascal

Newsgroups comp.compression
Date 2014-04-18 13:46 -0700
References <59c1d2cc-09eb-40a1-b05e-a39c9002252d@googlegroups.com>
Message-ID <bc4e658a-75e5-4c7e-b2fa-1e5fa3da89fa@googlegroups.com> (permalink)
Subject Re: BWTS in Free Pascal
From jacko <jackokring@gmail.com>

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Think "run of x" => "(run - 1) of 0" by calculating deltas, then doing a second BWTS before ZRLE encoding, you'd eventually reach a limit. The argument being that similar following context to different words which end the same is what causes oscillation between runs of zeros. As x maps almost to zero, and as RLE does not shrink a two byte run, then the saving of using ZRLE is not having to store run lengths for any other symbol but zero. MTF is also slower than simple delta of character calculation, and the general RLE process can introduce more data due to tracking infrequent value runs. The question then becomes, what advantage does the speed costly variable width symbol entropy post coding add?

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BWTS in Free Pascal jacko <jackokring@gmail.com> - 2014-04-18 05:09 -0700
  Re: BWTS in Free Pascal jacko <jackokring@gmail.com> - 2014-04-18 13:46 -0700

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