acs1899 / quirc-wasm

Quirc Decoder QR in the form of WASM

Quirc-JpegLib WASM

Wasm Module to decode qr code image based on quirc and jpeglib. Source codes written in C and WASM module compiled using Emscripten.

How to install?

The npm package available at https://www.npmjs.com/package/quirc-wasm-emcc.

yarn add quirc-wasm-emcc

Size of WASM module

The size of the raw WASM module is 251 KB, the gzipped version is 75 KB. The Javascript glue code size is 25 KB, the gzipped version is 7.4 KB.

References

Quirc Library - https://github.com/dlbeer/quirc, Jpeg Library - https://github.com/libjpeg-turbo/libjpeg-turbo, and Emscripten JpegLib - https://github.com/AntoineViau/webassembly-jpeg

Quirc-Wasm Scanner Demo

Change to scanner directory :

cd scanner

Install dependencies :

yarn install 

Launch a local server :

yarn start

And play with the app on localhost:8080/index.html

Quirc-Wasm Decode Local Jpeg Image File

Install Emscripten from https://kripken.github.io/emscripten-site/index.html

Change to wasm directory :

cd wasm

Install dependencies :

yarn install 

Download the JPEG lib from the Independent Jpeg Group (IJG) website to project directory :

http://www.ijg.org/files/

Let's say you downloaded jpegsrc.v9b.tar.gz

Untar & unzip the jpeg lib :

mkdir libjpeg
tar xvzf jpegsrc.v9b.tar.gz -C ./libjpeg --strip-components=1

The first step is to configure the Jpeg lib build environment. Usually, you would launch the configure script, but since our target is not the host architecture/operating system but WASM, we use emconfigure to wrap this process :

cd libjpeg
emconfigure ./configure
# You may have an error message about the dynamic linker. Just ignore it.

We can now build the library in WASM format. We use the emmake wrapper :

emmake make

We have now a WASM Jpeg library ready to be included into our project.
Let's build our app :

cd ..
./compile.sh

Launch a local server :

yarn start

And play with the app on localhost:8080/index.html