图片 音频等文件转成base64编码

var fs = require('fs');

// function to encode file data to base64 encoded string
function base64_encode(file) {
// read binary data
var bitmap = fs.readFileSync(file);
// convert binary data to base64 encoded string
return new Buffer(bitmap).toString('base64');
}

// function to create file from base64 encoded string
function base64_decode(base64str, file) {
// create buffer object from base64 encoded string, it is important to tell the constructor that the string is base64 encoded
var bitmap = new Buffer(base64str, 'base64');
// write buffer to file
fs.writeFileSync(file, bitmap);
console.log('******** File created from base64 encoded string ********');
}
function base64_file(base64str,file){
var bitmap = new Buffer(base64str);
fs.writeFileSync(file, bitmap);
console.log('******** base64 encoded string ********');
}
// input
var base64str = base64_encode('1.png');
// output
base64_file(base64str,'1.png.base64.txt')