What is the compression format of various skin, themes, game data files?

As a start, I need to know the compression format of the file extensions listed on http://www.zipzag.com/features.html under the "Game Levels and Data Files" and "Skins, Themes, and Collections".  

Secondly, how did you determine this information.  How can I find out the format of similar files?

katoaAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

bhagyeshtCommented:
in most cases there are no compressions programmers normally change the extention from png or bmp to dat
various files including zip or lha mention the compression like zip mentions as pk in the file, lha as lh, rar mentions rar
this is normally stored as text in the first few characters. open the file in any decent editor (if the file size is small notepad will do) and you can identify the compression.
katoaAuthor Commented:
Where can I find samples of these files to view them in a text/hex editor, as suggested?
bhagyeshtCommented:
now thats a difficult question to answer. try hitting download and the extention in google
Big Business Goals? Which KPIs Will Help You

The most successful MSPs rely on metrics – known as key performance indicators (KPIs) – for making informed decisions that help their businesses thrive, rather than just survive. This eBook provides an overview of the most important KPIs used by top MSPs.

rod4nillosCommented:
well, i've had some experience in skins, and so far a lot of skins used in programs like those in Winamp is basically bitmap (bmp), usually you can find freeware that will help you create skins for certain applications. with themes, the same also applies. for games, usually they use their own native format for images, but are usually derived from image file format such as TIFF. game data files depend on the game, but some are actually naming it using "custom" file extensions like MIX, or something. and some can be opened in Notepad much like Windows' config.sys (e.g. some MIX files found on Red Alert games). for examples, look for files with the .mix extension in C & C: Red Alert, some can actually be viewed in a text editor. new games also use mp3 files for sound.

Rod
void_mainCommented:
I think the common used compression algorythm is "Lempel-Ziv". "Huffman" tree compression is out nowadays and RLE is useless for complex structures.
Zip uses Lempel Ziv
Rar too(I'm quite sure) but It does not format the compressed bitstream like zip

other games (quake I, II, III, IV?) have for example .pk? files (this is zip with changed extension). Thief I and II have .crf extension (its zip too).
Operationflashpoint has .pbo files which are packed and encrypted (here you need a special editor)
tga and bmp files are not packed.
jpg is jpeg compressed
and gif are vectors

wav files are not compressed.
mp3 and ogg are mpeg compressed.

did it help?
katoaAuthor Commented:
Great, void_main.  This is what I was looking for.  Let me summarize so far:

1. Quake I,2,3 - .pk?    (Renamed zip)
2. Thief 1,2    - .crf     (Renamed zip)
3. Operation Flashpoint - .pbo    (Propietary packed and encrypted)

I had a hunch that most of the files were renamed common compression formats.  Any ideas which others (including the skin and theme files) are also renamed zip files?   Others renamed .rar, .lzh, .arj, etc.?
bhagyeshtCommented:
katoa : Remember that knowing the format of compression is okay. but if you are looking into changing some data into it take care that you dont cross EULA.
void_mainCommented:
@katoa:
I think I lied with quake I and quake II. There is a program called "unpack.exe" (One version for quake I and another for quake II). But Quake 3 IS compressed with zip! To get the program take a look at ftp://ftp.idsoftware.com .
Here is a important statement:
ALL games which are using any engines from ID (RTCW, SOF, JK][, Half-Life, CStrike, ...) are using the compression the engine they use depends on. So RTCW and JK ][ are using ZIP, where the others are using pak2 (possibly renamed)

Other games, UT and UT2003 are using some weired format which is encrypted. (I've never seen an unpacker)
Serious Sam 1 and 2 is/are compressed with zip too.

commonly sounds are ".wav" in games. Nowadays they are using ".mp3" and other games are using ".ogg" for sound/music.
Skins and textures are (In Thief) ".pcx". Quake 1 is using ".wad" files for textures (and resources). Quake II textures are unknown to me. Quake III and all games depending on the Quake III engine are using ".tga" and ".jpeg" for graphics. Where TGA is not compressed.

I think Doom3 will use zip too.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Programming

From novice to tech pro — start learning today.