7-Zip ZS 22.01-v1.5.2-Release 1 pre-release version update, it is a development branch of 7-Zip. According to the official changelog, the last version update 21.03-v1.5.0-Release 2 was still updated on October 6, 2021.
official changelog.
New features and bug fixes:
Update 7-Zip to version 22.01
Update LZ4 to version 1.9.4
Updated Zstandard to version 1.5.2
Compression compilers in this version:
Brotli Version 1.0.9
Fast LZMA2 1.0.1
Lizard Version 1.0
LZ4 Version 1.9.4
LZ5 Version 1.5
Zstandard Version 1.5.2
With the compiler-related introduction (the following information is from the web).
Brotli:
A general-purpose lossless compression algorithm that uses a combination of a modern variant of the LZ77 algorithm, Hoffman coding, and second-order context modeling to compress data at a rate comparable to the best currently available general-purpose compression methods. It is similar in speed to deflate, but provides more intensive compression.
Fast LZMA2:
An LZMA2 compression algorithm that is 20% to 100% faster than regular LZMA2 at levels 5 and above, but with a slightly lower compression ratio. It uses a parallel buffered basis matcher and some optimizations of Zstandard. The codec uses much less extra memory per thread compared to standard LZMA2.
Lizard:
It is an efficient compressor for fast decompression. It achieves compression ratios comparable to zip / zlib and zstd / brotli (at low and medium compression levels) at 1000 MB/s and faster decompression speeds.
Level 10…19 (fastLZ4) is designed to provide about 10% higher decompression speed than LZ4
Levels 20…29 (LIZv1) are designed to provide better ratios than LZ4 and maintain a decompression speed of 75%
Level 30..39 (fastLZ4 + Huffman) adds Hoffman coding to fastLZ4
Level 40..49 (LIZv1 + Huffman) gives the best ratio, comparable to zlib and lower level zstd / brotli, but with faster decompression speed
LZ4:
Lossless compression algorithm, providing 400 MB/s (0.16 bytes/cycle) compression per core. It has an extremely fast decoder with speeds of several GB/s (0.71 bytes/cycle) per core. A high compression derivative called LZ4_HC can be used, trading customizable CPU time for compression.
LZ5:
is a modification of LZ4 designed to get a better ratio at the cost of slower compression and decompression. It has now been replaced by Lizard.
Zstandard:
A real-time compression algorithm that provides high compression ratios. It offers a very wide range of compression/speed tradeoffs while being supported by a very fast decoder.
