PAQ file types
PAQ is a family lossless file compression algorithms, top ranking in data compression contests like Hutter Prize and holding several records for maximum compressio ratio in those competitions.
PAQ algorithm family is based on multiple stategies to reduce redundancies in data, including neural networks, and aims to reduce compressed size of the data as near as possible to the quantity of information enthropy contained in the input - which cannot be further reduced without loss of information.
LPAQ file types
LPAQ is a related project form same author, Matt Mahoney, and provides less computing-intensive faster compression, roughly one order of magnitude, at the cost of inferior compression compated to PAQ, but still comparable or superior to mainstream compression formats like 7Z, ARC, RAR, ZIPX at maximum copression settings.
LPAQ is a pure compression format, unlike paq and zpaq, so multiple files needs to be consolidated in a single TAR container before lpaq compression, creating a .tar.lpaq archive.
ZPAQ file format
ZPAQ designates the current evolution of PAQ/LPAQ project, providing a backward compatible standard format supporting incremental archiving and journaling, and AES256 encryption.
ZPAQ executable is multi threaded, and features a more flexible compression mechanism, ranging from speed / compression ratio tradeoff similar to Deflate for lower compression settings up to better than PAQ for highest compression settings.
Zpaqfranz (Franco Corbelli, Mit License) provides a modern, multi platform, implementation of Zpaq standard, and it is used in PeaZip project.
See file compression benchmark, and maximum compression benchmark pages to see how ZPAQ compares for compression ratio and speed to strongest compressor algorithms, as LZMA/PPMD employed in 7Z, ARC, RAR and ZIPX formars.
Scopes of PAQ, LPAQ, ZPAQ file formats
| When is PAQ compression recommended PAQ family is unrivaled in the field of maximum compression, but it is very computing intensive; those formats are recommended when it is desired to effectively reach the best possibile copression ratio.
ZPAQ, being also capable of faster and lighter compression, in the range of Deflate-based formats (ZIP, GZip) is more eclectic and is suitable to be used as general purpose compressor, especially for user-level backup tasks due the built in capability of incremental archiving / incremental backup (add newer and modified files only) and journaling (maintaing multiple copies of modified files).
| 
|
Read more about *PAQ project: PAQ family official domain, ZPAQ project, PAQ page on Wikipedia
PeaZip supports creation and extraction of paq, lpaq, and zpaq files: create, open, browse, test, and extract *paq archives, optionally extract all revision of files contained in the archive, convert any supported archive to paq and zpaq format and vice-versa.
|
|
|
|
|
| .ZPAQ | Author Matt Mahoney, 2009
2^32 max number of files
250 TB bytes max input size
| |
| SPEED  ZPAQ is extremely flexible in terms of speed.
The algorithm is very computing intensive as compression level increases, but multithreading support, and several optimizations over its PAQ predecessor, makes it usable for general purpose at least at medium compression levels on current generation machines.
At lower compression settings speed / compression tradeoff is quite similar to Deflate, making it compete with fast archiving formats.
|
|
|
|
|
|
|
| COMPRESSION RATIO  ZPAQ compression algorithm provides state of art compression ratio, outperforming even high compression formats like 7Z, RAR, and ZIPX at maximum compression settings
|
| ADVANCED OPTIONS 
ZPAQ format natively supports journaling and incremental archiving / incremental backup, and natively supports AES256 encryption,
Error recovery is currently not supported.
|
|
|
|
|
|
| |
Synopsis: What is PAQ file compression format and how does it compare to 7z, arc, rar, zipx. What is PAQ family, which provides maximum compression ratio, with ZPAQ format implementing strongest compression algorithm currently available. *PAQ format family extensions: paq, lpaq, and zpaq file types.
Topics: PAQ file extension specs, lpaq and zpaq file format
PeaZip > FAQ > PAQ, LPAQ, ZPAQ file extensions
|
