nodejs base64 to blob conversion - node.js

Question

Iam capturing webcam screenshot in reactjs(react-webcam). Screenshot is in the form of base64 encoded string. I am sending the base 64string to nodejs and I want to convert base64 String to .jpeg file, So that I can save in Azure Blob Storage.
Is there any method to convert base64 string to .jpeg file.

Answer 1

You can convert your Base64 string to Buffer and then try storing it to azure.
var base64String = "....."; // your base64 string
var bufferValue = Buffer.from(base64String,"base64");

Answer 2

I used this and it worked.
below is server side code(NodeJS)
var contentType = 'image/jpeg';
let base64String=req.body.img;
let base64Image = base64String.split(';base64,').pop();
let date=Date.now();
fs.writeFile(`./uploads/${date}.jpeg`, base64Image, {encoding: 'base64'}, function(err) {
console.log('File created');
sourceFilePath= path.resolve(`./uploads/${date}.jpeg`);
blobName=path.basename(sourceFilePath, path.extname(sourceFilePath));
//console.log(sourceFilePath);
blobService.createBlockBlobFromLocalFile(containerName, blobName, sourceFilePath, err => {
if (err) {
console.log(err);
}
else {
//resolve({ message: `Upload of '${blobName}' complete` });
console.log("UPLOADED")
}
});

Answer 3

Try this:
based-blob
(async function() {
const b = require('based-blob');
const base64String = 'some base64 data...';
const blob = b.toBlob(base64String);
const b64s = await b.toBase64(blob);
console.log(b64s == base64String); // true
})();

Answer 4

Hi i use this function
public b64toBlob = (b64Data: string = '', sliceSize?: number) => {
sliceSize = sliceSize || 512;
if ( b64Data !== null) {
let block = b64Data.split(';');
let dataType = block[0].split(':')[1];
let realData = block[1].split(',')[1];
let filename = this.makeid() + '.' + dataType.split('/')[1];
let byteCharacters = atob(realData);
let byteArrays = [];
for (let offset = 0; offset < byteCharacters.length; offset += sliceSize) {
let slice = byteCharacters.slice(offset, offset + sliceSize);
let byteNumbers = new Array(slice.length);
for (let i = 0; i < slice.length; i++) {
byteNumbers[i] = slice.charCodeAt(i);
}
let byteArray = new Uint8Array(byteNumbers);
byteArrays.push(byteArray);
}
let blob = new Blob(byteArrays, {type: dataType});
return blob ;
} else {
return '';
}
}