Crate img4avif 

img4avif

Converts JPEG, PNG, WebP, and HEIC/HEIF images to AVIF using the pure-Rust rav1e AV1 encoder. Designed for serverless workloads (AWS Lambda x86_64 / aarch64) with built-in guards against memory exhaustion and malformed input.

Quick start

use img4avif::{Config, Converter};

let jpeg_bytes = std::fs::read("photo.jpg")?;

let config = Config::default()
    .quality(9)
    .speed(6)
    .strip_exif(true); // default

let converter = Converter::new(config)?;
let avif_bytes = converter.convert(&jpeg_bytes)?;

std::fs::write("photo.avif", &avif_bytes)?;

Supported input formats

Format	Extensions	Feature flag	AVIF output bit-depth
JPEG	.jpg, .jpeg	(always on)	10-bit (ravif auto)
PNG (8-bit)	.png	(always on)	10-bit (ravif auto)
PNG (16-bit / HDR10)	.png	(always on)	10-bit (encode_raw_planes_10_bit)
WebP	.webp	(always on)	10-bit (ravif auto)
HEIC / HEIF	.heic, .heif	heic-experimental	10-bit (ravif auto)

HDR10

16-bit PNG files (a standard still-image HDR10 format) are decoded at full precision and encoded as genuine 10-bit AVIF using ravif’s encode_raw_planes_10_bit. Each 16-bit channel is scaled to 10 bits (right-shift by 6) and then converted to YCbCr BT.601, preserving 1 024 distinct levels per channel instead of the 256 available in 8-bit output.

Note on CICP metadata: The AVIF colour primaries and transfer characteristics fields will reflect BT.601 / sRGB because ravif 0.13 hardcodes those values in the raw-planes encoder path. True HDR10 CICP metadata (BT.2020 primaries + PQ / HLG transfer) requires a future upgrade to a newer rav1e version.

HEIC files that carry HDR10 colour profiles are decoded by libheif when the heic-experimental feature is enabled.

Security model

• Input-size cap (Config::max_input_bytes, default 100 MiB) — rejected before any bytes are decompressed.
• Decompression-bomb protection (Config::max_pixels) — the decoder allocation budget is derived from max_pixels * 8 + 64 MiB; an image that claims huge dimensions is rejected before the pixel buffer lands in RAM.
• RSS guard (Config::memory_limit_bytes, default 512 MiB) — checked before and after decode; breaches return Error::MemoryExceeded.
• No unsafe code — enforced by #![forbid(unsafe_code)].

Output resolution control

By default img4avif encodes images at their original resolution. Set Config::output_resolutions to resize before encoding:

use img4avif::{Config, Converter, OutputResolution};

let src = std::fs::read("photo.jpg")?;

// Single output at 1080 px wide:
let config = Config::default()
    .output_resolutions(vec![OutputResolution::Width1080]);
let avif_1080 = Converter::new(config)?.convert(&src)?;

// All three sizes in one decode pass:
let config_all = Config::default()
    .output_resolutions(vec![
        OutputResolution::Original,
        OutputResolution::Width2560,
        OutputResolution::Width1080,
    ]);
let outputs = Converter::new(config_all)?.convert_multi(&src)?;
for out in &outputs {
    println!("{:?}: {} bytes", out.resolution, out.data.len());
}

Feature flags

Flag	Default	Notes
dev-logging	off	Structured pipeline logging via the log crate. Enable to get DEBUG/INFO/WARN/ERROR records from every pipeline stage. Zero cost when disabled.
heic-experimental	off	HEIC/HEIF support via the libheif C library. Linking libheif makes the binary LGPL-encumbered.
raw-experimental	off	Pure Rust RAW camera format support via rawloader. Unstable API.

Re-exports

pub use config::Config;

pub use error::Error;

pub use memory_guard::MemoryGuard;

pub use resize::OutputResolution;

Modules

config

Configuration — see Config.

error

Error types — see Error.

memory_guard

RSS memory guard — see MemoryGuard.

metadata

EXIF / metadata stripping utilities.

resize

Output resolution control and image resizing — see OutputResolution. Output resolution control and image resizing.

Structs

ConversionOutput

A single AVIF output produced by Converter::convert_multi.

Converter

The main conversion entry-point.