Best compression format?

[Com807877]

Hi all,

Does anyone know what format of compression is best to compress data? (by best I mean will get the smallest compressed file size)

Thanks!

 

[Barnaby W. Füi]

Bzip2 is the best I know of.

 

[Com807877]

Hi,

Thanks for the response!

Do you know of any Bzip2 compressors with a GUI? Been looking and so far I can only find command line versions.

Thanks!

 

[Barnaby W. Füi]

It's a command line utility (it's unix software originally), I don't know of any gui frontends for it, there may be some on google though. BTW, bzip is *only* compression, not archival. It will take one file and compress it, but it won't take lots of files and turn them into one file, that's the job of an archiver. Generally you would use tar and bzip together on unix. I have no idea if there are any windows programs that will do this. I hear rar has good compression too, but I don't know how it compares to bzip.

 

[Sid59]

best or fastest? or perhaps a combination of both ..

 

[Com807877]

Just best. Speed isn't an issue, so long as it isn't some crazy amount of time. (like 24 hours or something )

 

[Thyme]

I've been using winace and winrar on win32. I don't know how good they really are, but the GUIs are pretty nice.

 

[Com807877]

Oh also - do any of you know what "dictionary" size means when you are compressing a file? I can choose on some programs anywhere between 1-4MB... though the help file doesn't say anything about it.

 

[glugglug]

RAR is a lot better than any of the zip variants, they really aren't even in the same ballpark.
UHarc can get a percent or 2 smaller than rar but then you are talking crazy amount of time.

 

[Barnaby W. Füi]

I wouldn't call bzip a "zip variant". It is a totally different algorithm than the traditional pkzip, and not at all compatible. Two totally different things.

On dictionary size -

Imagine that you are the compressing program itself. You go through a file byte by byte, and as you go, you keep the last X number of bytes in memory to look to as a reference. The way compression works is to take identical strings and change them to references, but you can only match them within the window of X bytes you have as a dictionary. Therefore I would assume that a larger dictionary would be slower but compress more. IIRC gzip uses only a 32k dictionary size. Not sure about anything else.

At least that's what I think it means by dictionary

 

[OrganizedChaos]

Depending on what your compressing 7z or HARC. Threre easy to work with also.

 

[glugglug]

I just got 7z, a few comments:

1. The source tree that you can download for the current beta is incomplete -- I tried to compile it myself and the dsp files refer to .c files that are not in the archive. Also for the projects that are complete within it, there are a few types not defined in the headers (although they are easy enough to figure out like typedef long * LONG_PTR , etc.)
2. The interface is not near as nice as RAR. I guess thats to be expected because it hasn't had as much time to mature.
3. It's SSSLLLOOOWWWW. Not crazy slow like UHARC, but pretty sluggish.

BTW where can I find HARC to try. I googled it and it turns out a lot of places use HARC as an acronym.

Also what is the determining factor in which one you use?

 

[OrganizedChaos]

Originally posted by: glugglug
I just got 7z, a few comments:

1. The source tree that you can download for the current beta is incomplete -- I tried to compile it myself and the dsp files refer to .c files that are not in the archive. Also for the projects that are complete within it, there are a few types not defined in the headers (although they are easy enough to figure out like typedef long * LONG_PTR , etc.)
2. The interface is not near as nice as RAR. I guess thats to be expected because it hasn't had as much time to mature.
3. It's SSSLLLOOOWWWW. Not crazy slow like UHARC, but pretty sluggish.

BTW where can I find HARC to try. I googled it and it turns out a lot of places use HARC as an acronym.

Also what is the determining factor in which one you use?

do a google search for uharc.zip

 

[glugglug]

So HARC and UHARC is the same thing?

 

[ZimZum]

For file size its pretty hard to beat CAB The latest revision of ACE is pretty good to.