ComprLib Data Manipulation Library

• ComprLib SourceForge Page
• Source Code via CVS
• comprlib-devel Mailing List
• comprlib-users Mailing List
• comprlib-announce Mailing List

ComprLib is a C++ data compression library. Update 20040708: A CVS snapshot of ComprLib 2.0 from 2000-06-14 as well as ComprLib 1.0 (including WinCompr) is now available in a Zip archive. If you have any questions contact me. ComprLib is no longer actively maintained; if you came here looking for a portable, high- quality, maintained compression library, I recommend libbzip2 or zlib.

ComprLib Class Hierarchy

I/O Classes

An I/O class is required to compress or decompress data. It must implement the following methods:

• int end_of_data() - true if read_byte() will fail
• int read_byte() - read a single byte from input, advance position by one
• int write_byte(int c) - write a byte to output stream
• int beginning_of_data() - rewind to start of data
• long stream_size() - retreive length of data
• int write_array(void* v, int size) - write multiple bytes efficiently
• int write_block(char c, int number) - write c number times

Codec Classes

Codec classes provide algorithms to compress, decompress, encrypt, decrypt, etc. Presently, the following codecs are fully or partially supported:

Lossless Compression:

• Arithmetic encoding
• DMC
• Huffman
• LZARI
• LZHUF
• LZO (please use the official LZO library instead)
• LZRW
• LZSS
• LZW
• RLE (3 methods)
• Splay

Lossy Compression

• Collapse: for 7-bit ASCII text
• Spread: for 7-bit ASCII text

Trivial Encryption

• Add/Sub
• XOR

Miscellaneous

• UUEncoding
• XXEncoding
• Copy

Except where noted, the compression schemes where adopted from publically available sources. The original source is included in the CVS.