Current compressing techniques guidance

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Originally Posted by Spexxos

I am also trying to get into the whole compression thing. In my case its primarily for compressing savegames. For that matter I would be interested in the current state of things aswell. I think a might be a bit ahead of you in my knowledge, JoeKkerr, since I dont want to open up another thread with the same topic I am going to add my questions here. I am sure we both can benefit from this. Here we go:

1. What is DELTA and when to use it?
2. When to use what precompressor or any of the programs following? (precomp, srep, pzlib, ztool, xtool, PrecompMT, msc )
I have seen different versions of precompressors delivering different results. Sometimes older versions worked better than newer ones?
3. Why is FreeArc alsways the recommended tool? Depending on my files I got better results with also 7z (lzma2) and rar? Is it because of the ease of use for external compressors?
4. Whats are the benefits of xz? (In my unterstanding its just a container, am i right?)
5. Is there any benefit in using FreeArcs successor (FreeArcNext(?)?)
6. Most importantly: Are there any already written guides that I have missed that have answers to my questions?

Cheers

1. DELTA is a preprocessor for executables and wav audio files. You get better ratio by using delta+lzma rather than just lzma for those files.
2. Know your data, use Razor12911's GFS for testing what to use. If your data contains zlib, use pzlib from ztool/xtool/normal pZlib v3, if contains lz4, use plz4 from ztool, if it has .forge archives from AC games, use AFR, if game is from unreal engine, use uelr and etc. etc. Use msc before anything if your data contains multimedia data.
3. Yep, external compressors, you can't use them with rar and you need to learn coding for using them with 7zip, and with FreeArc you can use them just by editing arc.ini
4. Yeah, xz is a container for LZMA2 compression which has better decompression speed and multithreading which doesn't exist in lzma
5. Yes, you get more speed, but they aren't much matured yet.
6. Check the forum, you may find more.



Joekkerr and others, if you want to know something, ask questions, don't say that I want to know everything, be specific, it will be help for others to answer.