# Cyan4973/FiniteStateEntropy

New generation entropy codecs : Finite State Entropy and Huff0

Repository: https://github.com/Cyan4973/FiniteStateEntropy
Canonical: https://ross.abutalabs.com/products/finitestateentropy
Language: C
License: BSD-2-Clause
License Family: permissive
Topics: huffman, c, fse, compression, entropy
Last push: 2024-03-21T18:01:36+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 4644, "days_push": 895, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1496, forks 164 (observed 2026-08-28T04:04:53.725124+00:00)

## What it is
A C library providing two high-speed entropy codecs: Huff0, a Huffman coder optimized for modern out-of-order CPUs, and FSE, an ANS-based entropy encoder achieving near-Shannon-limit compression accuracy. It is the entropy-coding core used in projects like Zstandard.

## Use cases
- compress data with a fast entropy codec in C
- replace zlib's Huffman encoder with a faster alternative
- achieve compression ratios beyond the 1-bit-per-symbol Huffman limit
- integrate FSE or Huff0 into a custom compression format
- benchmark entropy coding speed and ratio

## When to choose
- you need extremely fast compression or decompression in C
- you want near-arithmetic-coding accuracy at high speed via ANS
- you're building a custom compression pipeline needing an entropy stage

## When to avoid
- you need a complete file or archive format rather than a raw codec
- you need cross-language bindings beyond C without writing your own
- you need dictionary or windowed compression features of a full compressor like zstd

## Facets
- artifact type: library
- maturity: stable
- function: compression
- domain: performance, developer-tools
- platform: cross-platform, c
- tags: entropy-coding, huffman, ans, fse, huff0, codec, algorithms

## Member repositories
- Cyan4973/FiniteStateEntropy (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:53.725124+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:33:11.102774+00:00, confidence not recorded.
  - readme: https://github.com/Cyan4973/FiniteStateEntropy (fetched 2026-08-28T04:04:53.725124+00:00, sha 2b7249867b77)
- Data as of 2026-08-30T08:39:29.467469+00:00.