apultra -- a new, opensource optimal compressor for the apLib format
apultra is a command-line tool and a library that compresses bitstreams in the apLib format.
The tool produces files that are 5 to 7% smaller on average than appack, the apLib compressor. Unlike the similar cap compressor, apultra can compress files larger than 64K (for files smaller than 64K, cap compresses 0.05% better on average).
apultra is written in portable C. It is fully open-source under a liberal license. You can continue to use the regular apLib decompression libraries for your target environment. You can do whatever you like with it.
Example compression with vmlinux-5.3.0-1-amd64 original 27923676 (100,00%) appack 7370129 (26,39%) gzip 1.8 7166179 (25,66%) apultra 1.0.6 6910794 (24,75%)
- cap by Sven-Åke Dahl.
- Charles Bloom's compression blog.
- LZ4 by Yann Collet.
- spke for help and support
- The apultra code is available under the Zlib license.
- The match finder (matchfinder.c) is available under the CC0 license due to using portions of code from Eric Bigger's Wimlib in the suffix array-based matchfinder.