Compressing a Byte array [Resolved]

[Electroman]

I have an array of Bytes and I need to compress it, no certain algorithm I just need to create an algorithm that will look for common patterns in the byte array then say replace them for a shorter pateren that is defined at the begining. The only problem is I don't know an algorithm that will definitely work, if someone has already done this it would be a grat help, otherwise I guess i'm going to have to do it from scratch.

Thanx for any help.

[phinds]

look up Hoffman encoding on the internet --- it's the most common compression algorithm and is fairly simple as compression algorithms go and you'll find tons of existing code examples.

[Electroman]

Thanx i'll try that.

[CVMichael]

Try using the ZLib.dll, it's very easy to use... it has only 2 functions, compress/decompress

http://www.winimage.com/zLibDll/
http://www.gzip.org/zlib/

[Electroman]

Isn't the ZLib.dll for files tho?

[Electroman]

I think its Huffman you meant not Hoffman. Anyway I found some source code at this link http://www.planet-source-code.com/xq...s/ShowCode.htm, I haven't tryed it just yet but if anyone else wants it theres the link.

[CVMichael]

ZLib.dll compresses data in memory, you can compress anything you whant...

[riis]

Zlib uses the LZ77 algorithm. Information about this algorithm can be found here.
The LZ77 algorithm isn't proprietary, in contrary with LZW (used by GIF files).

[riis]

Originally posted by Electroman
Isn't the ZLib.dll for files tho?

The only two differences between a file and a byte array I can think of is that a file is written to the disk and has a name. A file is still a bytearray imho, even text files.

[Electroman]

I can't find ZLib.dll on my PC so i've downloaded a copy and it won't register, does anyone know why or can someone post a copy they know works cos it might jus be I'v got a dodgy dll.

[Electroman]

Opps my fault, I didn't realise the ZLib procedures were APIs, I was expecting it to contain a class. Oh well thanx, problem solved.