Compression

Revision as of 22:43, 18 February 2013

Stream compression formats

A stream format takes a stream of bytes, and outputs a different, hopefully smaller, stream of bytes. These compression formats are often used internally in other data structures to compress data, as well as in network protocols, such as http. Used stand-alone, a stream compression format does not offer archiving capability, however in the UNIX doctrine, an archiver like tar can be combined with an archive format to produce a proper compressed archive.

Compression schemes used in multiple formats

• DEFLATE
• Huffman encoding
• Lempel-Zev
• LZW
• LZX

Specific formats/programs

• 7z
• 9CDR (Amiga FileImploder Clone)
• BARF (.x, .x??)
• bzip (.bz)
• bzip2 (.bz2)
• CCITT Group 4
• CrLZH (.?y?)
• CRN (.crn) - compressed text files used for PC-Write manual
• Crunch (.?z?)
• DiskDoubler
• DUPA (Amiga FileImploder Clone)
• Error Code Modeler (.ecm)
• File Imploder (Amiga) (.imp)
• Freeze/Melt (Unix) (.F)
• gzip (.gz)
• JCalG1 (.jc, Commodore Amiga)
• LZIP (.lz)
• LZMA (.lzma)
• LZOP (.lzop)
• pack (.z)
• RK (WinRK)
• Softdisk Text Compressor (.ctx)
• Squash - single file compression on RISC OS
• Squeeze/SQ (.?q?)
• XZ (.xz)

See also

• Archiving (for formats that place multiple files together in one file, with or without compression)