mototroller / ax.lzw

LZW-based lightweight encoder/decoder

LZW-based data encoder/decoder

Header-only library lzw.hpp contains implementation of original LZW compression/decompression algorithms.

Features:

• Input and Packing dictionaries are fully customizable by symbol ranges, can be piecewise.

  Predefined: BINARY_256_common, ASCII_128_common, UTF16_pack (output), URI_pack (output). See lzw.hpp tail for definitions examples.

• Specific codec can be instantiated from template: lzw_codec<InputDict, PackDict>.

  Predefined: string_to_string, binary_to_binary, string_to_UTF16, string_to_URI. See lzw.hpp tail for definitions examples.

• Encoding with fixed bit depth (choses by maximum used code).

• Dense bit packing (library uses as many bits as possible).

• Header-only and STL-only open source.

• STL-compatible codec interface: same as std::copy(first, last, d_first).

• Tests with usage examples and simple performance measurements are included.

• RELEASE typical performance:

  encode = ~200 us/Ksymbol

  decode = ~30 us/Ksymbol

  zip_ratio < ~0.3 (dst.length/src.length)

WASM

Library initially was designed as native LZW extension to be used with WASM and Emscripten Embind.

To be continued