使用Node Js将bin文件解码为mp3

Question

I am encoding a MP3 file to Base64 in Node Js using this method :

encodebase64 = function(mp3file){
var bitmap = fs.readFileSync(mp3file);
var encodedstring = new Buffer(bitmap).toString('base64');
fs.writeFileSync('encodedfile.bin', encodedstring);}

and then again I want to construct the MP3 file from the Base64 bin file, but the file created is missing some headers , so obviously there's a problem with the decoding. the decoding function is :

decodebase64 = function(encodedfile){
var bitmap = fs.readFileSync(encodedfile);
var decodedString = new Buffer(bitmap, 'base64');
fs.writeFileSync('decodedfile.mp3', decodedString);}

I wondered if anyone can help Thanks.

Answer 1

Perhaps it is an issue with the encoding parameter. See this answer for details. Try using utf8 when decoding to see if that makes a difference. What platforms are you running your code on?

Answer 2

@Noah mentioned an answer about base64 decoding using Buffers, but if you use the same code from the answer, and you try to create MP3 files with it, then they won't play and their file size will be larger than original ones just like you experienced in the beginning.

We should write the buffer directly to the mp3 file we want to create without converting it(the buffer) to an ASCII string:

// const buff = Buffer.from(audioContent, 'base64').toString('ascii'); // don't
const buff = Buffer.from(audioContent, 'base64');
fs.writeFileSync('test2.mp3', buff);

More info about fs.writeFile / fs.writeFileAsync