Precomp is a command line precompressor that can be used to further compress files that are already compressed. It improves compression on some file-/streamtypes - works on files and streams that are compressed with zLib or the Deflate compression method (like PDF, PNG, ZIP and many more), bZip2, GIF, JPG and MP3. Precomp tries to decompress the streams, and if they can be decompressed and "re-"compressed so that they are bit-to-bit-identical with the original stream, the decompressed stream can be used instead of the compressed one.
The result of Precomp is either a smaller, LZMA2 compressed file with extension .pcf (PCF = PreCompressedFile) or, when using
-cn, a file containing decompressed data from the original file together with reconstruction data. In this case, the file is larger than the original file, but can be compressed with any compression algorithm stronger than Deflate to get better compression.
Since version 0.4.3, Precomp is available for Linux/*nix/macOS, too. The different versions are completely compatible, PCF files are exchangeable between Windows/Linux/*nix/macOS systems.
(or download from here)
|We want to compress this file (the Silesia compression corpus).
Size: 67,633,896 bytes (100,0%)
||Compressing with 7-Zip LZMA2, setting "Ultra".
Size: 67,405,052 bytes (99,7%)
||Compressing with Precomp results in
Size: 47,122,779 bytes (69,7%)
||This restores the original file to a new file named
||Compares the original file to the result file, they're identical|
low hanging fruitstag
Official GitHub releases for both Windows and Linux.
Alternative binary download of the latest official release for both Windows and Linux.
Binaries for older version can be found at this Google Drive folder.
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Copyright 2006-2021 Christian Schneider
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
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