Compression ratio is not consistent with 7z software（larger than 7z software）

rikyoz / bit7z

A C++ static library offering a clean and simple interface to the 7-zip shared libraries.

https://rikyoz.github.io/bit7z

Mozilla Public License 2.0

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Compression ratio is not consistent with 7z software（larger than 7z software） #39

Open lcx1988fei opened 4 years ago

lcx1988fei commented 4 years ago

9.03M source file: use bit7z with LZMA(19.00): 44.8KB use 7z software(19.00): 1.7KB

lcx1988fei commented 4 years ago

By the way, use compress(std::vector files, std::wstring file> to compress multiple files as ***.7z

rikyoz commented 4 years ago

Hi! Thank you for using bit7z!

9.03M source file: use bit7z with LZMA(19.00): 44.8KB use 7z software(19.00): 1.7KB

This is strange. Usually, problems like this depend on having used different algorithm parameters in the two operations (e.g., different compression level, dictionary size, word size, method, solid compression enabled or not, etc...). Could you give me more insights about this?