A lot of new releases have 7zip compressed windows installers, (with impressive space savings, i love 7zip), because at the same time im seeing plugin updates suddenly weighing 5x more for not apparent reason.
what happened, and can some exes can be compressed while others cant?

before, even if the installer was massive it would be uncompressed at the same point as the rest of the archive, not an extra layer

 

i think i figured out what they are doing is checking "Compress Shared Files" in 7zip dialog, but i dont know why they used LZMA instead of LZMA2.
it doesnt always work, i dont know much about algos, cryptography & compression

 

As far as I remember R2R has used the double compression layer always (no idea why, some tradition perhaps). And also the .rar format for the final compressed archive.
They've switched to 7zip recently because it compresses way more in many cases.

 

If you pack an .exe into an installer that does nor mean the same as using a packer that compresses files (lossless or not). Making a setup is just collecting all files the program needs to be executed.
The files a program uses may be of a multitude of types. While some are packed (like e.g. .jpg, .mp3) others may be uncompressed, like e.g. .wav, .tif etc.
If the setup.exe only contains already compressed file types one will not be able to compress the file.
In some cases, where the software vendors are really wasteful with the file size, R2R compresses the files - in our sense.
In fact, I have the impression that some manufacturers like large setups, even if it does not bring any benefit. It's not just sloppy work, it's a kind of dorky sales psychology.

And, the style how programs are release differs quit much, so I dont think R2R is only one perso or one small group but several people or groups with each their own styles how to release software packages.

 

Last edited: Aug 16, 2023

7zip is the best compressor (on Mac for me) and, by now, it's the only one I use.

Unfortunately, however, when inside the folder to be compressed there are audio files with a bitrate higher than 1.441kbps the compression is much lower (I don't know why).

However - since I don't use files with bitrate higher than 1.441 - it's not a big problem for me because, before compress folders, I convert all the .wav/aiff files to 1.441. In some cases I have seen the content reduced by 70% (always with files at 1.441kbps).

 

Last edited: Aug 17, 2023

Compressed runtimes can produce false positive virus alerts. That's why a lot of keygens are flagged as viruses. Same with demoscene releases. I guess software developers just want to avoid that and don't mind the bigger file size.

 

Yes, that may occur sometimes.
There are really bad virusscanners out there. To be honest most of them are not as trustworthy as most people think.

I don't think so. Taking compressed filetypes instead of compressed files (e.g. .jpg instead of .tif) won't give a false positive as long as not the .exe file itself is packed. Besides, no developer needs to distribute the whole payload in one single file.
And even a really bad virus scanner can recognize that sound files, pictures, viedeos ..., e.g. in .cab files, are what they seem to be. Ofc as long as they are not encrypted.

 

Last edited: Aug 16, 2023

https://peazip.github.io/peazip-com... better,fast extraction are desired qualities.

 

That makes sense, cheers
And about that shitbrained sales psychology, many KONTAKT library makers really love that one, some live by it

Im still not sure why they used LMZA compression in 7zip (Reveal Sound Spire), maybe it is less buggy compared to LMZA2. It seems to be faster, with multithread support

 

Last edited: Aug 15, 2023

7Zip has a lot of settings, different algos, im not sure how this table translates to real world use

 

I don't know about other virus scanners, but windows defender (or security, or whatever it's being called now), can't/doesn't scan any of my 7zip archives. As soon as I acquire an exe or keygen file, I 7zip it!

 

Yup, there are mostly like a placebo in my opinion and bad for performance. Windows Defender consumed 3-4 % CPU time and 200 MB on Windows 11.

That's true, I was only talking about executable files. Viruses attach themselves to them, because they will be run with admin rights unlike jpgs and files like that. Some runtime packers use a similar method like viruses to hide themselves. That actually an outdated way to compromise a system. Certificates and hardware exploits are much better for that. Some governments know all about it. ;)

 

You should use a question mark at the end of the title...

 

Really? I don't use a virus scanner, like @Zoketula said "... there are mostly like a placebo" but if defender does not scan 7zip files (they have benn around a long time though [since 1999 according to wikipedia]), this means my computer can hold a bunch of viruses and defender won't know it.
Not very impressing

 

I you think programmers are not as lazy as we are, you're wrong.

LMZA was born 1996, 7zip around 1999. The 7zip creator took what he could freely distribute and what was nicely tested at that time.
And then never lokked back.
The motto is: never change a running system.

And that's the problem with shareware/freeware, after some time devs don't change anything in the code when it's not really necessary.
So LMZA runs fairly well. Why change it?

AND: The devs are getting older. just like us. and with free programs there is no pressure to make money that makes me revise the program, even though I don't really like to.
So... for example:: I don't earn anything from it and the program comes from a time when I was a student and had a lot of time. Today I am a father of three and an employee at an insurance company with hardly no spare time ...

 

It seems so for at least Windows 10, but it can be enabled according to this : https://windowsloop.com/force-windows-defender-to-scan-zip-rar-cab-archives/
I believe it doesn't scan archives within archives, meaning if a file is packed multiple times it won't be scanned completely.

 

No they havent they always used rar that was splitted in whatever sized they choosed the 7zip started this year.

 

That's exactly what Xupito said.

 

The author said on GitHub that all packers were tested on their default settings.

 

Maybe he's only disagreeing with the double compression thing? Doesn't seem like it though.

But I'm almost positive they've been using that for a long time, with the final .rar instead of .7z.
I mean there are threads here of people new to this thing asking how it works.