“Coding theorists are concerned with two things. Firstly and most importantly they are concerned with the private lives of two people called Alice and Bob.” From 01984, giving an #introduction to #compression and #crypto. #humor
on 02026-07-30#bzip2 #compression #algorithms can be implemented in a few kilobytes of code, handy for the ComputerCraft mod for #Minecraft. #small-is-beautiful
on 02026-03-12"TS_Zip" #compression with #RWKV-LM #neural-networks by #Bellard succeeding his #NNCP
on 02026-01-12DDJ’s copy of Mark Nelson’s DDJ article on #BWT #compression. #algorithms
on 02025-10-10#Ryg’s article on #BWT #compression. #algorithms
on 02025-10-10Mark Nelson’s DDJ article on #BWT #compression. #algorithms
on 02025-10-10#LZ4 #compression #file-format explained: the literal length and match length are each packed into a 4-bit field in a “token” byte, but if they’re more than 14, the 4-bit field is 15 and extra bytes are appended (elsewhere, in the case of match length) to sum up to the correct value with the 15; the sequence of extra bytes is terminated by the first byte that’s less than 255.
on 02024-01-12Dominic Szablewski’s #image #compression #file-format: “[Quite OK Image] is fast. It losslessly compresses images to a similar size of PNG, while offering 20x-50x faster encoding and 3x-4x faster decoding. QOI is simple. The reference en-/decoder fits in about 300 lines of C. The file format specification is a single page PDF.” Again, maybe worthwhile for the Zorzpad.
on 02023-08-09Dominic Szablewski’s #audio #DSP #codec #file-format "qoa" for fast, lossy #compression: “[Quite OK Audio] is fast. It decodes audio 3x faster than Ogg-Vorbis, while offering better quality and compression (278 kbits/s for 44khz stereo) than ADPCM. QOA is simple. The reference en-/decoder fits in about 400 lines of C. The file format specification is a single page PDF.” This might be worthwhile for low-CPU-power audio recorders and maybe the Zorzpad, especially for games. Now supported systemwide in SerenityOS. Based on 4-tap linear prediction? With the weights varying over time?
on 02023-08-09"Heatshrink" LZSS data #compression library in C for memory-constrained embedded systems, by silentbicycle, though in some simple tests it seems to be 20 times slower than LZF at compressing (and slower than gzip too). Still, looks easy to use.
on 02023-06-12#zstd #compression #algorithms and file format
on 02022-09-16the confusing parts of the #gzip and #deflate #compression #algorithms
on 02022-09-16#gzip #compression #algorithms and file format in depth
on 02022-09-16an explanation of the #Zstd #compression #algorithm from RFC 8748, which is faster and compresses smaller than zlib, almost as fast as LZ4 (by the same author!)
on 02022-05-21"shoco" short string #compression #algorithm never expands 7-bit ASCII and usually compresses it some (using the 8th bit), using an English bigram model.
on 02021-09-12Champion #code-golf #esolang Osabie, has some 400 built-in stack operations, including perfect shuffle, matrix diagonal, Lucas numbers, lcm, #shoco decompression and so on. I’m not sure what character set these are supposed to be in but it contains both Å and ζ. #compression
on 02021-09-12"Butteraugli" #graphics #compression #psychovisual assessment algorithm.
on 02017-08-06#DSSIM #graphics #compression #psychovisual image quality assessment algorithm #source-code.
on 02017-08-06"DSSIM" is a #graphics #compression #psychovisual image quality assessment algorithm.
on 02017-08-06#SSIMULACRA #graphics #compression #psychovisual image quality assessment algorithm #source-code. It’s based on DSSIM.
on 02017-08-06"SSIMULACRA" is a #graphics #compression assessment algorithm; it does #psychovisual image quality assessment.
on 02017-08-06A CLI interface to Snappy #compression, written in Node JS
on 02017-04-26#compression #algorithms #performance testing for end-of-buffer with branchless I/O etc. by #ryg
on 02016-09-29#compression codec #algorithms using #ryg’s rANS: Oodle LZNA and BitKnit #toread
on 02016-09-29another #lz77 variant lossless #compression codec, “with a compression ratio similar to LZMA but with 1.5x-8x faster decompression speed”, with up to a 512MB window size.
on 02015-11-05interesting idea for transmitting file diffs by using a data #compression algorithm.
on 02015-11-05data #compression with #grammars
on 02015-08-10gzx is a C #gzip #compression library that supports fast random reads with a #FUSE client on top.
on 02015-08-05Tarelli reports problems with PierreC’s #JS #LZ4 #compression implementation in #Chrome and #Firefox
on 02015-08-05#LZ4 #compression implementation catalog, including incompatible #OCaml and #Lua implementations
on 02015-08-05#lz4 #compression implementations by Adrien Grand in #Java
on 02015-08-05