Compression

File Format
Name	Compression
Ontology	Electronic File Formats Compression

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 in general

(including specific implementations used in multiple formats)

• Arithmetic coding
• DEFLATE
• Huffman coding
• Lempel-Ziv
• LZSS (Lempel–Ziv–Storer–Szymanski)
• LZW
• Run-length encoding
• zlib

Specific file formats/programs

• 7z
• 9CDR (Amiga FileImploder Clone)
• BARF (.x, .x??)
• bzip (.bz)
• bzip2 (.bz2)
• compress (.Z)
• 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)
• Inflate (.infl) - parody format that actually increases size
• JCalG1 (.jc, Commodore Amiga)
• LZIP (.lz)
• LZMA (.lzma)
• LZOP (.lzop)
• LZX
• MS-DOS installation compression (.??_)
• 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)
• Graphics (for image-specific compression)
• Video (for video-specific compression)
• Audio and Music (for audio-specific compression)