Binary file to base64 nodejs

Question

I'm getting a binary audio file when I call the api tts.speech.microsoft.com and I would like to transform this binary into a base64 string.

I've been trying a lot of things, for example:

Buffer.from(body, "binary").toString("base64");

does not work.

I'm not sure 'binary' is the exact word, but it's not a readable format.

Thank you for your help.

Can you clarify "does not work"? The code looks correct. Also where does the binary data come from? Some things such as fs.readFile has shortcuts to convert to base64. — Dominic, Jan 29 '19 at 14:50
I call this endpoint from a phone, and try to play the sound. When I try to do it with another base64 string it works so I know the code on this part is ok. @Dominic — GuillaumeC, Jan 29 '19 at 14:54
Where does the other base64 string come from? My hunch is that your original binary content is not correct/the same format as the working one — Dominic, Jan 29 '19 at 14:58
when I try to save the file from my computer and read it with: require("fs").writeFile("out.mp3", content, "base64", function(err) { console.log(err); }); — GuillaumeC, Jan 29 '19 at 15:03
You can see here there is nothing wrong with the conversion code - https://repl.it/@DominicTobias/WorstUtilizedComputers (converting binary "apple" to base64 and back). So the issue is in code you haven't posted, most likely your binary data is incorrect compared to the working one — Dominic, Jan 29 '19 at 15:04
Yeah I can see this part is correct, but when I try to save the file and read it locally from my computer, the file is not readable: const content = Buffer.from(body, "binary").toString("base64"); require("fs").writeFile("out.wav", content, "base64", function(err) { console.log(err); }); Maybe the response is not in binary ? — GuillaumeC, Jan 29 '19 at 15:18
What format is `body` in? Is it just incoming as a buffer/byte array? — Alex, Jan 29 '19 at 16:34
@Alex body is a string. The only solution I found is to save the file with createwritestream , and then read the file in base64 and send it. This is not ideal of course, but I've been playing with it for hours... — GuillaumeC, Jan 30 '19 at 09:16

score 6 · Accepted Answer · answered Jan 30 '19 at 11:22

I guess you were following the section Make a request and save the response of the offical document Quickstart: Convert text-to-speech using Node.js to write your code, as below.

var request = require('request');

let options = {
    method: 'POST',
    baseUrl: 'https://westus.tts.speech.microsoft.com/',
    url: 'cognitiveservices/v1',
    headers: {
        'Authorization': 'Bearer ' + accessToken,
        'cache-control': 'no-cache',
        'User-Agent': 'YOUR_RESOURCE_NAME',
        'X-Microsoft-OutputFormat': 'riff-24khz-16bit-mono-pcm',
        'Content-Type': 'application/ssml+xml'
    },
    body: body
};

function convertText(error, response, body){
  if (!error && response.statusCode == 200) {
    console.log("Converting text-to-speech. Please hold...\n")
  }
  else {
    throw new Error(error);
  }
  console.log("Your file is ready.\n")
}
// Pipe the response to file.
request(options, convertText).pipe(fs.createWriteStream('sample.wav'));

So I change the offical code above to create a function encodeWithBase64 to encode body with Base64.

function encodeWithBase64(error, response, body){
  if (!error && response.statusCode == 200) {
    var strBase64 = Buffer.from(body).toString('base64');
    console.log(strBase64);
  }
  else {
    throw new Error(error);
  }
  console.log("Your file is encoded with Base64.\n")
}
// Pipe the response to file.
request(options, convertText);

Or you can use the npm packages base64-stream and get-stream to get the string with Base64 from body.

var base64 = require('base64-stream');
const getStream = require('get-stream');
(async () => {
    var encoder = new base64.Base64Encode();
    var b64s = request(options).pipe(encoder);
    var strBase64 = await getStream(b64s);
    console.log(strBase64);
})();

Otherwise, stream-string also can do it.

var base64 = require('base64-stream');
const ss = require('stream-string');
var encoder = new base64.Base64Encode();
var b64s = request(options).pipe(encoder);
ss(b64s).then(data => {
  console.log(data);
})

Binary file to base64 nodejs

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