wavesurfer.js

var samplePromise = require('get-audio-sample-promise');
var rand = require('random-float');
var waveSurfer = require('wavesurfer.js')

// let [foo, bar] = await Promise.all([getFoo(), getBar()]);

// let audiobuf = await samplePromise(ctx, 'raven.mp3');

function randomDoubleFromInterval(min, max){
    return Math.random()*(max-min);
}

let promise = samplePromise(ctx, 'raven.mp3').then(function(instrument){

    // console.log('loaded');
    // Promise success. You have a simple audioBufferInstrument
    // Which you can get and connect
    var audioBuf = instrument.get();
    
    console.log(audioBuf);
    var length = audioBuf.buffer.duration;
    console.log(length);
    var random = rand(0, length);
    console.log(random);

    //audioBuf.connect(ctx.destination);
    
    
    // audioBuf.start(2);

    

}).catch(function(err){
    console.log(err)
});

var wavesurfer = WaveSurfer.create({
    container: '#waveform'
});

wavesurfer.load('http://ia902606.us.archive.org/35/items/shortpoetry_047_librivox/song_cjrg_teasdale_64kb.mp3');
wavesurfer.on('ready', function () {
    // wavesurfer.play();
    console.log('ok');
});

wavesurfer.on('audioprocess', function (e) {
    // console.log(e);
});