Crate lzw

LZW decoder and encoder

This crates provides a LzwEncoder and LzwDecoder. The code words are written from and to bit streams where it is possible to write either the most or least significant bit first. The maximum possible code size is 16 bits. Both types rely on RAII to produced correct results.

The de- and encoder expect the LZW stream to start with a clear code and end with an end code which are defined as follows:

• CLEAR_CODE == 1 << min_code_size
• END_CODE == CLEAR_CODE + 1

Examplary use of the encoder:

use lzw::{LsbWriter, Encoder};
let size = 8;
let data = b"TOBEORNOTTOBEORTOBEORNOT";
let mut compressed = vec![];
{
    let mut enc = Encoder::new(LsbWriter::new(&mut compressed), size).unwrap();
    enc.encode_bytes(data).unwrap();
}

Structs

Decoder	Decoder for a LZW compressed stream (this algorithm is used for GIF files).
DecoderEarlyChange	Decoder for a LZW compressed stream using an “early change” algorithm (used in TIFF files).
Encoder	LZW encoder using the algorithm of GIF files.
LsbReader	Reads bits from a byte stream, LSB first.
LsbWriter	Writes bits to a byte stream, LSB first.
MsbReader	Reads bits from a byte stream, MSB first.
MsbWriter	Writes bits to a byte stream, MSB first.

Enums

Bits	Containes either the consumed bytes and reconstructed bits or only the consumed bytes if the supplied buffer was not bit enough

Traits

BitReader	A bit reader.
BitWriter	A bit writer.

Functions

encode

Convenience function that reads and compresses all bytes from R.