myisaak / zbar-wasi

Webassembly (WASI) port of Zbar barcode scanner

zbar-wasi

Scan barcodes in web browsers

This library allows web browsers to scan barcodes with a Webassembly and WASI backend.

Why?

• Unlike most Webassembly projects this one is compiled with WASI instead of Emscripten.
• Optimized for size with a WASM binary size of 161.98 KB gzipped (244.40 KB uncompressed).
• Works perfectly on mobile devices and desktop

Demo

Try scanning barcodes with your camera: https://myisaak.github.io/zbar-wasi/ Watch your command line for found barcodes.

Installation

npm install zbar-wasi

Usage

import { scanImage, createZbar } from "zbar-wasi";

const start = async () => {
  // move ./node_modules/zbar-wasi/dist/zbar.wasm to your web directory"
  const ZBAR = await createZbar({ wasmpath: "./zbar.wasm" });
  const imageData = ctx.getImageData(0, 0, width, height);
  const results = scanImage(imageData);
  console.log(results);
  // outputs [ barcode1, barcode2, ... ]
}
start();

zbar-wasi's Issues

Performance improvment

Compile with performance improvements instead of size improvements.

demo doesn't function on Safari (iOS)

The video freezes after taking the first shot from camera and executing the scan via WASM. Seems to be a common issue with Safari browsers.

Problem on old versions of chrome

Hi Isaak

First of all thank you for the great work.

I'm facing a problem with old versions of chrome and webkit based browsers on android (chrome, edge etc.).

The exception i'm getting is

Uncaught TypeError: wasm function signature contains illegal type
    at /wasm-function[11]:28
    at /wasm-function[63]:34
    at /wasm-function[62]:7
    at scanImage (zbar-wasi.esm.js:5186)
    at renderLoop ((index):25)
    at track ((index):70)
    at HTMLVideoElement.domVideo.addEventListener ((index):62)

I was able to reproduce it by using an old version of chromium for windows 72.0.3579.0, which can be downloaded here:

https://commondatastorage.googleapis.com/chromium-browser-snapshots/index.html?prefix=Win_x64/599392/

I have reasons to believe that this exception is also causing #2 , since in the past I noticed a certain coherence between the behaviours of this version of chrome and iOS Safari.

This is as far as I can reach with my limited knwledge of wasm.

Could you please look into it?

Thank you again

Daniele