FileForums - Compression Detecting?

Hello!

I have been making conversions for a month or two now, and one of the biggest pitfalls I come across, is when files in a game are already compressed into a .pak etc, so I cant really compress it any more. This happened in Lego Star Wars (complete saga), however there was a great tool (quickbms) which allowed me to decompress the files, and after compression I of course ended up with a much much higher compression ratio. Problem is though, there is of course, no tool(s) to decompress every game file, and/or files made by a third party.

I was just wondering if there is a tool out there that can detect what method of compression was used to create a file. (Or really any useful information about the file) Im sure from there I could figure something out. It does feel like a program like that would be too good to be true, but Im still hoping.

Thank you for any help I get :)
And sorry if I am missing anything obvious :o