4 ms·
Is not just "slightly better" in some cases. An obvious one is repeated files. If RAR encounters a file ten times, it will compress once and store it and nine p
by tropin 5y ago
Is not just "slightly better" in some cases. An obvious one is repeated files. If RAR encounters a file ten times, it will compress once and store it and nine pointers. lzma and zstd guis i've tested will store ten compressed copies. It happens all the time in backups.
- daneel_w 5y ago> "lzma and zstd guis i've tested will store ten compressed copies" It depends on dictionary size, word size, the actual data etc.
- jsjohnst 5y ago> If RAR encounters a file ten times, it will compress once and store it and nine pointers. A bunch of compression formats do that. Even zip files can, which leads to interesting tricks like: https://www.bamsoftware.com/hacks/zipbomb/ https://www.bamsoftware.com/hacks/zipbomb/
- anonu 5y agoHandling multiple identical files is certainly desirable - but this is not the "core" compression algo. Its a cute optimization trick...