@saschazar/wasm-avif
v2.0.1
Published
Encodes and decodes AVIF images using WebAssembly
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📦 WebAssembly AVIF decoder/encoder
A dependency-free AVIF decoder/encoder written in WebAssembly
It encodes raw RGB(A) pixels in a Uint8Array
into AVIF-encoded image data and vice versa.
Installation
yarn add @saschazar/wasm-avif
or
npm install --save @saschazar/wasm-avif
Usage
It supports usage in the browser, in a Web Worker and of course Node.js.
// Node.js
import wasm_avif from '@saschazar/wasm-avif';
import defaultOptions from '@saschazar/wasm-avif/options';
// Web Worker - see: https://developer.mozilla.org/en-US/docs/Web/API/WorkerGlobalScope/importScripts
importScripts('wasm_avif.js');
// -------- Browser/Web Worker/Node.js code below --------
// Decoding example:
// Load encoded AVIF image data in Uint8Array
const array = new Uint8Array(['some', 'encoded', 'AVIF', 'image', 'data']);
let result;
// Initialize the WebAssembly Module
const avifModule = wasm_avif({
onRuntimeInitialized() {
const alpha = true; // return RGBA buffer, instead of RGB
result = avifModule.decode(array, array.length, alpha); // decode image data and return a new Uint8Array
avifModule.free(); // clean up memory after encoding is done
},
});
// Encoding example:
// Load raw RGB(A) pixels in Uint8Array
const array = new Uint8Array(['some', 'raw', 'RGB', 'image', 'data']);
const width = 800;
const height = 600;
let result;
// Initialize the WebAssembly Module
const avifModule = wasm_avif({
onRuntimeInitialized() {
const channels = 4; // 4 representing RGBA buffer in source array, 3 RGB
const chroma = 3; // chroma subsampling: 1 for 4:4:4, 2 for 4:2:2, 3 for 4:2:0
result = avifModule.encode(
array,
width,
height,
channels,
defaultOptions,
chroma
); // encode image data and return a new Uint8Array
avifModule.free(); // clean up memory after encoding is done
},
});
Example
A working example is available on RunKit.
Status
The main backbone of the project is the libavif library.
Both decoding and encoding is done via the AOM AV1 codec. Encoding is still very slow, since helpers such as multithreading and/or runtime CPU detection have to be disabled in order to successfully compile to WebAssembly.
Help needed
Concerning the encoding functionality, a few trials have been made towards using the more performant rav1e encoder, but it constantly fails during linking.
As soon as encoding is done via rav1e
, decoding could be switched back to dav1d again.
Credits
This module uses the AOMediaCodec/libavif's source code and most of the code is written according to the examples provided in that repository.
License
Licensed under the MIT license.
Copyright ©️ 2020—2021 Sascha Zarhuber