Made by: Liam L & Alexander S for a paper at the University of Waikato.

NOTE: The BITPACKER DOES NOT HANDLE DICTIONARY PHRASE NUMBERs >256

Alexander made the Encoder & the Bitpacker
Liam made the decoder & the Bitunpacker

LZW-Encode-Decode

LZW Compression algorithm - Encodes, Decodes (Extra feature: Bitpacking included)

cat <file> | java LZWencode.java -> will encode HEX (0-9A-F) to a series of LZW Phrase Numbers

cat <file> | java LZWdecode.java -> will decode LZW Phrase Numbers to HEX

Compiling for faster execution

javac -d . src/com/skwangles/LZWencode.java
javac -d . src/com/skwangles/LZWdecode.java

To execute just run:

java com.skwangles.LZWencode for encoding

or

java com.skwangles.LZWdecode for decoding

Test encoding/decoding in one line:

echo "AAABC00FFA2" | java LZWencode.java | java LZWdecode.java

Doing it a ridiculous number of times:

echo "AAABC00FFA2" | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java | java LZWencode.java | java LZWdecode.java

Test encoding, packing, unpacking and decoding in one line:

cat test.txt | java LZWencode.java | java LZWpack.java | java LZWunpack.java | java LZWdecode.java > out.hex

Known issues

The bitpacker has an issue where the # of phrase numbers exceeds 256 (i.e. the max possible size of the next phrase will be more than a single byte) - the packer does not correctly interpret wrap the bits around and will get confused.