Creating the same data as the Web API

[samueleastdev]

Hi All,

I am using the following code to generate my data from an audio file.

window.AudioContext = window.AudioContext || window.webkitAudioContext;
const audioContext = new AudioContext();

const drawAudio = url => {
    fetch(url)
        .then(response => response.arrayBuffer())
        .then(arrayBuffer => audioContext.decodeAudioData(arrayBuffer))
        .then(audioBuffer => filterData(audioBuffer));
};

const filterData = audioBuffer => {
    const rawData = audioBuffer.getChannelData(0);
    console.log(rawData);

};

drawAudio('https://983yqbz442.s3.amazonaws.com/andyc.mp3');

I am trying to get the same data from a local file with the Node js library like this.

const fs = require('fs');

const AudioContext = require('web-audio-api').AudioContext;

const audioContext = new AudioContext;

let resp = fs.readFileSync('./samples/andyc.mp3');

audioContext.decodeAudioData(resp, buffer => {
    
    console.log(buffer);

});

But I get 2 different results.

If you look at the web api it produces.

You can check the console.log here https://output.jsbin.com/haloneb/1

first 4 values of array

0: 0.0031128879636526108
1: 0.0052797021344304085
2: -0.000030517578125
3: 0.0016174810007214546

But the Node js one produces this first 4 values of array

0: 0
1: 0
2: 0
3: 0

Am i missing something?