There are theoretical limits to the amount of compression you can get
without loss of information although different compression algorithms
would work better or worse depending on the stuff you are compressing.
The OP said he wanted his stuff compressed as small as humanly possible
but that would depend on his stuff. But zip, which is part of Mac OS,has
a parameter for whether you want more speed or more compression. I doubt
any other utility can do a lot better than zip. Like I said, there are
theoretical limits to how much compression you can get so I doubt you'll
get more than a few percent smaller files with some other tool.
Note: If you try to compress an already compressed file, like an mp3, it
will probably get bigger.
On 03/26/2015 10:26 AM, 'Chris Blouch' via MacVisionaries wrote:
I compressed my copy of Keynote, which is really made up of thousands
of files under the hood totaling 611,951,069 bytes (692.5 MB). To test
unix compress I did
tar -zcvf test.gz /Applications/Keynote.app/
which generated a compressed file of 428,440,218 bytes (428.4MB) or
about 61.9% of the original file size. Doing the same thing through
the finder I selected Keynote and then chose Compress from the File
menu. That generated a zip file of 453,379,578 butes (453.4 MB) or
65.5%. Just for the fun of it I also tried doing a 7-Zip. Downloaded a
7-Zip app for OSX from here:
http://www.updatestar.com/directdownload/7zx/2188433
which generated a .7z file of 375,098,819 bytes (375.1MB) or about
54%. So it looks like 7-zip is the smallest (11% smaller than plain
zip in my test) but the downside is that it's not very popular. If you
send this to someone else they will have to go through the bother of
finding, downloading and installing an app to uncompressed it. Pretty
much everyone can handle a zip file without much trouble.
As with all compression, the results are also based on what you are
compressing. Text, which has lots of repeating patterns, compresses
really well. Binary files such as audio, video and images might not
compress at all.
CB
On 3/25/15 7:38 PM, Joe Quinn wrote:
now that SArchiver’s gone down the tubes? what’s the best archiving
utility for the mac? i wanna be able to compress files as small as
humanly possible, but still retain quality. thanks for any info!
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