[Crimzan]

I am happy you guys putting in the time to answer my questions, thanks a lot!

Originally Posted by Masquerade

There's also this Zenhax page where Aluigi explains how to recognise different algorithms by their headers or magic numbers: https://zenhax.com/viewtopic.php?t=27

I don't know much about Hexadicmal, I do have HxD and tried a 7z (LZMA2) and a standard windows zip file (I suspect LZMA because it says so in the link?); however, none of the Headers shown in the link are actually seen in the Hexadecimal view of these files for some reason. Why is that? Could it be that the header is just offset or are some diferences in the Bytes to be expected? I expected to find pretty much the exact same Header in my file as in the link. Do you know why it differs on my end?

Originally Posted by KaktoR

To check a file, you can use xtool's verbose mode

Would you mind explaining in a bit more detail how to use the XTool Verbose mode? I created a standard zip and also a 7zip file (LZMA2) and created a batch file based on what you showed in the link you provided (also changed the algorithm from mzlib to lzma2 (hoping that it works that way), but no matter what file I yeet onto xtool, all I get is this:

[0] Performing scan from block 0000000000000000 to 0000000000502C9D (5254302)

Streams: 0/0
Time: 00:00:00 (00:00:00)
Memory: 128 MB (128 MB)

I didn't expect it to not find any lzma2 streams in an lzma2 file, or other files I tried out with the adjusted algorithm parameter. I expected, similar to the "Drop and Scan 4 ZLib" Application from Razor to have different values here, that recognize how many parts of a file actually correspond to the compression algorithm. Am I misunderstanding the function and expecting a result that this tool is not supposed to give? If it isn't too much to ask, could you maybe show me a working result on a file?

Originally Posted by KaktoR

After you find out, pick the file and compress it with different combinations

So, let's keep things simple for now and let's say I found a file is actually compressed with LZMA2 / 7zip -- I would use xtool to decompress it (precomp?), receive a larger file, and then use a more efficient combination to get a better compression ratio, right?

Originally Posted by KaktoR

my choice is in most cases 4x4:lzma.

What does the 4x4: stand for? are these parameters in xtool or where does it come from?

Once again, I really appreciate you answering all these noob-ish questions, I really hope they aren't too bothersome!
Have a nice day guys!

- Crim