zenavif

Pure Rust AVIF image codec. Decodes and encodes AVIF images using rav1d-safe (AV1 decoder) and zenavif-parse (AVIF container parser).

What it does

• Decodes 8/10/12-bit AVIF with all chroma subsampling modes (4:2:0, 4:2:2, 4:4:4, monochrome)
• Handles alpha channels (straight and premultiplied)
• Supports full and limited color range, HDR color spaces (BT.2020, P3, etc.)
• Preserves EXIF, XMP, rotation, mirror, clean aperture, pixel aspect ratio, HDR metadata
• Decodes animated AVIF sequences with per-frame timing
• Decodes gain maps (ISO 21496-1) and depth auxiliary images from AVIF containers
• Encodes AVIF with optional gain map embedding via GainMapConfig (requires encode feature)
• Encodes AVIF via zenravif (optional encode feature)
• 100% safe Rust by default. Zero unsafe in the decode path.
• Cooperative cancellation via the enough crate

Quick Start

use zenavif::decode;

let avif_data = std::fs::read("image.avif").unwrap();
let image = decode(&avif_data).unwrap();
println!("{}x{}", image.width(), image.height());

Custom configuration

use zenavif::{decode_with, DecoderConfig};
use enough::Unstoppable;

let config = DecoderConfig::new()
    .threads(4)
    .apply_grain(true)
    .frame_size_limit(8192 * 8192);

let avif_data = std::fs::read("image.avif").unwrap();
let image = decode_with(&avif_data, &config, &Unstoppable).unwrap();

Animation

let avif_data = std::fs::read("animation.avif").unwrap();
let animation = zenavif::decode_animation(&avif_data).unwrap();
for frame in &animation.frames {
    println!("{}x{} frame, {}ms",
        frame.pixels.width(), frame.pixels.height(), frame.duration_ms);
}

Encoding (requires encode feature)

use zenavif::{encode, decode};

let image = decode(&std::fs::read("input.avif").unwrap()).unwrap();
let encoded = zenavif::encode(&image).unwrap();
std::fs::write("output.avif", &encoded.avif_file).unwrap();

Features

Feature	Description
(default)	Pure Rust decode via rav1d-safe. No unsafe code.
encode	AVIF encoding via zenravif (pure Rust)
encode-asm	Encoding with hand-written assembly (fastest, uses unsafe)
encode-threading	Multi-threaded encoding
encode-imazen	Encoding with zenrav1e fork extras (QM, lossless)
unsafe-asm	Decoding with hand-written assembly via C FFI (fastest, uses unsafe)
zencodec	Integration with zencodec trait hierarchy
zennode	Pipeline node definitions for zennode graph engine

Building

# Default safe decoder
cargo build --release

# With encoding
cargo build --release --features encode

# Fast assembly decoder (uses unsafe + C FFI)
cargo build --release --features unsafe-asm

# Run tests
cargo test

# Run with test vectors
just download-vectors
just test-integration

Credits

This project builds on excellent work by others:

• rav1d (BSD-2-Clause) — Pure Rust AV1 decoder (Rust port of dav1d). Provides the AV1 decoding backend via its managed safe API.

• zenavif-parse (MIT/Apache-2.0) — AVIF container parser for extracting image items and metadata from the ISOBMFF container.

• yuv (MIT) — YUV to RGB color conversion.

• libavif (BSD-2-Clause) — Reference AVIF implementation used for pixel-level verification and behavioral reference.

Limitations

• The encode feature is not yet available from a crates.io build (zenravif path dep needs wiring).

Image tech I maintain

State of the art codecs*	zenjpeg · zenpng · zenwebp · zengif · zenavif (rav1d-safe · zenrav1e · zenavif-parse · zenavif-serialize) · zenjxl (jxl-encoder · zenjxl-decoder) · zentiff · zenbitmaps · heic · zenraw · zenpdf · ultrahdr · mozjpeg-rs · webpx
Compression	zenflate · zenzop
Processing	zenresize · zenfilters · zenquant · zenblend
Metrics	zensim · fast-ssim2 · butteraugli · resamplescope-rs · codec-eval · codec-corpus
Pixel types & color	zenpixels · zenpixels-convert · linear-srgb · garb
Pipeline	zenpipe · zencodec · zencodecs · zenlayout · zennode
ImageResizer	ImageResizer (C#) — 24M+ NuGet downloads across all packages
Imageflow	Image optimization engine (Rust) — .NET · node · go — 9M+ NuGet downloads across all packages
Imageflow Server	The fast, safe image server (Rust+C#) — 552K+ NuGet downloads, deployed by Fortune 500s and major brands

_{* as of 2026}

General Rust awesomeness

archmage · magetypes · enough · whereat · zenbench · cargo-copter

And other projects · GitHub @imazen · GitHub @lilith · lib.rs/~lilith · NuGet (over 30 million downloads / 87 packages)

License

Dual-licensed: AGPL-3.0 or commercial.

I've maintained and developed open-source image server software — and the 40+ library ecosystem it depends on — full-time since 2011. Fifteen years of continual maintenance, backwards compatibility, support, and the (very rare) security patch. That kind of stability requires sustainable funding, and dual-licensing is how we make it work without venture capital or rug-pulls. Support sustainable and secure software; swap patch tuesday for patch leap-year.

Our open-source products

Your options:

• Startup license — $1 if your company has under $1M revenue and fewer than 5 employees. Get a key →
• Commercial subscription — Governed by the Imazen Site-wide Subscription License v1.1 or later. Apache 2.0-like terms, no source-sharing requirement. Sliding scale by company size. Pricing & 60-day free trial →
• AGPL v3 — Free and open. Share your source if you distribute.

See LICENSE-COMMERCIAL for details.

AI-Generated Code Notice

Developed with AI assistance (Claude, Anthropic). Not all code manually reviewed — review critical paths before production use.