Editing Wikifang:Telefang 1 Translation Patch/NatsumeGB compression

Malias compression is the compression used in numerous Natsume games, namely, at least Telefang and Medarot.  It is a modified implementation of the LZ77 algorithm, which works by referencing previously decompressed data using length-distance pairs.  [http://en.wikipedia.org/wiki/LZ77_and_LZ78_%28algorithms%29 Wikipedia] has a good description of the algorithm.

Malias compression is named after [http://s15.zetaboards.com/Tulunk_Village/topic/515644/ Malias], the person who wrote the first decompresser.

Implementation of the Malias compression in pseudocode:

<pre>compressed = readbyte()
if compressed != 0x00:
    total = readshort()             # Total length of the graphics
    while bytes < total:            # bytes is number of bytes decompressed
        modes = readshort()         # Contains modes for the next 10 bytes
        for mode in bits(modes):
            if mode == 0x1:         # Copy mode
                loc = -(readshort() & 0x7ff)
                num = lastbyte >> 3 & 0x1f + 0x03
                loc += bytes-1
                do num times:
                    data += data[loc]
                    loc += 1
            else:                   # Insert mode
                data += readbyte()</pre>
== Games that use the compression ==
* Keitai Denjuu Telefang
* Medarot 1
* Medarot 2
* Medarot 3
* Medarot 4 (assumed)
* Medarot 5 (assumed)
* Croc 2
== Decompression tools ==
* [http://s15.zetaboards.com/Tulunk_Village/topic/515644/ Malias' Telefang Tools] can decompress and recompress the graphics with ease, provided locations.
* [https://github.com/Sanky/romhacking/blob/master/telefang/punika.py punika] is a simple implementation in Python which decompresses all compressed graphics at once, working off tables in the ROM.