hello, all
This is an implementation of the Lempel-Ziv 77 compression algorithm written by comrade in Win32 assembly. I did a test code.
when the z1_2. exe compresses a exe file, the sizes of compressed file became bigger than the original exe file. but other type files(*.txt,*.doc,*.bmp) works ok.
what's wrong of my usage?
regards
This is an implementation of the Lempel-Ziv 77 compression algorithm written by comrade in Win32 assembly. I did a test code.
when the z1_2. exe compresses a exe file, the sizes of compressed file became bigger than the original exe file. but other type files(*.txt,*.doc,*.bmp) works ok.
what's wrong of my usage?
regards
the implementation is lame and it probably could not find any recurrences in the EXE file (which is most likely already compressed with UPX or like)
hello, comrade
Thanks you.
it is efficacious about bmp,dwg file. here is a tested result of comparing with a commercial soft winRAR.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?the Lempel-Ziv 77?
=============================================? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?pdf? ? ? ?? doc? ? ? ? ?bmp? ? ? ?dwg? ? ? ? ?exe
original file sizes? ? ? ? ? ? ? ?4.815M? ? 9.461M? ?1.583M? ?2.095M? 17.199M
compressed file sizes? ? ? ? 5.192M? ? 7.972M? ?0.061M? ?0.935M? 18.914M
percentage? ? ? ? ? ? ? ? ? ?? ?107.8%? ?84.3%? ? ?3.85%? ? 44.63%? 109.97%
=============================================
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?winRAR
**********************************************************? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?pdf? ? ? ?? doc? ? ? ? ?bmp? ? ? ?dwg? ? ? ? ?exe
original file sizes? ? ? ? ? ? ? ?4.815M? ? 9.461M? ?1.583M? ?2.095M? 17.199M
compressed file sizes? ? ? ? 4.417M? ? 6.008M? ?0.013M? ?0.622M? 16.492M
percentage? ? ? ? ? ? ? ? ? ?? ? 91.73%? ?63.5%? ? ?0.82%? ? 29.69%? 95.89%
**********************************************************
regards
Thanks you.
it is efficacious about bmp,dwg file. here is a tested result of comparing with a commercial soft winRAR.
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?the Lempel-Ziv 77?
=============================================? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?pdf? ? ? ?? doc? ? ? ? ?bmp? ? ? ?dwg? ? ? ? ?exe
original file sizes? ? ? ? ? ? ? ?4.815M? ? 9.461M? ?1.583M? ?2.095M? 17.199M
compressed file sizes? ? ? ? 5.192M? ? 7.972M? ?0.061M? ?0.935M? 18.914M
percentage? ? ? ? ? ? ? ? ? ?? ?107.8%? ?84.3%? ? ?3.85%? ? 44.63%? 109.97%
=============================================
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?winRAR
**********************************************************? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?pdf? ? ? ?? doc? ? ? ? ?bmp? ? ? ?dwg? ? ? ? ?exe
original file sizes? ? ? ? ? ? ? ?4.815M? ? 9.461M? ?1.583M? ?2.095M? 17.199M
compressed file sizes? ? ? ? 4.417M? ? 6.008M? ?0.013M? ?0.622M? 16.492M
percentage? ? ? ? ? ? ? ? ? ?? ? 91.73%? ?63.5%? ? ?0.82%? ? 29.69%? 95.89%
**********************************************************
regards
dcskm4200,
My math is pretty bad but how can you compress something to more than 100% of its size ?
I think there is an issue in the math.
My math is pretty bad but how can you compress something to more than 100% of its size ?
I think there is an issue in the math.
I think it means, that the "compressed" file actually grew instead of shrinking ;)
James_Ladd, you need to check back with your high-school science class, and realize that some materials expand when heated, while others contract.