rustdesk/vendor/fdeflate

fdeflate

A fast deflate implementation.

This crate contains an optimized implementation of the deflate algorithm tuned to compress PNG images. It is compatible with standard zlib, but make a bunch of simplifying assumptions that drastically improve encoding performance:

• Exactly one block per deflate stream.
• No distance codes except for run length encoding of zeros.
• A single fixed huffman tree trained on a large corpus of PNG images.
• All huffman codes are <= 12 bits.

It also contains a fast decompressor that supports arbitrary zlib streams but does especially well on streams that meet the above assumptions.

Inspiration

The algorithms in this crate take inspiration from multiple sources:

• fpnge
• zune-inflate
• RealTime Data Compression blog