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Where do the other popular compression utilities (e.g. bzip2, xzip, lzma, 7zip) fit in to this?
by 404-universe 10y ago
Where do the other popular compression utilities (e.g. bzip2, xzip, lzma, 7zip) fit in to this?
- kbenson 10y agoHe covers all that, at least in passing. It's a fairly comprehensive rundown.
- TimMeade 10y agoAlmost every one as far as I know where based on the info-zip code by Mark Adler and Jean-loup Gailly. That was used as the base at the time for zip/unzip in linux, winzip, and gzip ultimately.
- gopalv 10y agoThe big picture is that there's a few compression algorithms. Run Length Encoding Huffman Encoding Lempel Ziv (LZ77) Burrows Wheeler Transform The interesting part of all these specific implementations is their own specialized way of extending or combining these algorithms for their own niche (or tradeoff point). Bzip2 is for example, compresses really well because BWT is expensive, but clever - rzip extends the LZ part of bzip2 to look further across the file (instead of a few hundred kb). Zlib itself has enough of these flags exposed out, so all Zlib isn't really the same - Z_FILTERED, Z_HUFFMAN_ONLY, Z_FIXED, Z_RLE etc. Look at something like Zopfli to see how they can be remixed, provided the tradeoffs of CPU change from the historic positions of Zlib.
- eln1 10y agoBeside Huffman coding, there is also arithmetic/range coding and now is becoming widely used ANS coding - e.g. LZFSE (Apple), ZSTD (Facebook), VP10 (Google): http://encode.ru/threads/2078-List-of-Asymmetric-Numeral-Systems-implementations http://encode.ru/threads/2078-List-of-Asymmetric-Numeral-Sys...
- rasz_pl 10y agogood video series straight from Google Developers https://www.youtube.com/watch?v=Eb7rzMxHyOk&list=PLOU2XLYxmsIJGErt5rrCqaSGTMyyqNt2H https://www.youtube.com/watch?v=Eb7rzMxHyOk&list=PLOU2XLYxms...