And if your browser is also HTML5 File API ready, you can play your audio wave file (locally stored in your PC), such as Morsecode.wav, and show waveforms, etc. in animation.
Plese click HERE and give it a try.
As you can see from the source code, it is assumed that fsample=44.1kHz, and nchannel=2. Improvement to get these parameters from the header of the file is necessary.
<!doctype html>
<head>
<meta charset="utf-8" />
<title>Wavefile Read</title>
<script src="Three.js"></script>
<script src="flotr2.min.js"></script>
<link href='http://fonts.googleapis.com/css?family=Righteous' rel='stylesheet' type='text/css'>
<style type="text/css">
div#canvas-frame{
border: none;
cursor: pointer;
width: 610px;
height: 300px;
background-color: #eeffee;
margin-top: 5px;
margin-bottom: 5px;
margin-left: 5px;
margin-right: 5px;
}
div#canvas-frame2{
border: none;
cursor: pointer;
width: 300px;
height: 300px;
background-color: #eeeeff;
margin-top: 5px;
margin-bottom: 5px;
margin-left: 5px;
margin-right: 5px;
}
div#canvas-frame3{
border: none;
cursor: pointer;
width: 300px;
height: 300px;
background-color: #f5deb3;
margin-top: 5px;
margin-bottom: 5px;
margin-left: 5px;
margin-right: 5px;
}
div#mymessage {
margin-top: 5px;
background-color: #ffffff;
margin-bottom: 5px;
}
div#mymessage2 {
margin-top: 5px;
width: 190px;
background-color: #ffffff;
margin-bottom: 5px;
}
div#slider {
margin-top: 5px;
margin-bottom: 5px;
margin-left: 0px;
margin-right: 5px;
width: 190px;
padding: 5px 5px 5px 5px;
border-color: #cccccc;
border-width: 1px;
border-style: solid;
background-color: #ffffff;
}
body {
font-family: 'Righteous', cursive;
}
</style>
<script>
var t, tb4= -1.0, istep = 0, ijump = 6;
var dt = 1.0/44100.0;
var dsize = 700;
var nbin = 100;
var index;
var start_time, elapsed_time, elapsed_timeb4 = -1.0;
function loop2() {
var d1 = []; var d2 = []; var d3 = []; var d4 = [];
var i;
if(t != tb4) {
index = Math.floor( t * (44100.0*1.0) ); /* fs * mono 1.0 */
tb4 = t;
for(i=0;i<nbin;i++) {
bin[i] = 0;
}
}
if( istep++ % ijump == 0) {
elapsed_time = new Date().getTime();
document.getElementById("mymessage2").innerHTML
= "Frame per second = "
+ (1000.0 / (elapsed_time - elapsed_timeb4)).toFixed(1);
elapsed_timeb4 = elapsed_time;
for(i=0;i<dsize;i++) {
d1.push([i, arr[index ]/32768.0]);
d2.push([i, arr[index+1]/32768.0]);
d3.push([ arr[index ]/32768.0, arr[index+1]/32768.0]);
ibin = Math.floor( (nbin/2)*(arr[index]/32768.0+1.0) );
bin[ibin]++;
index+=1; /* mono +=1 */
}
for(i=0;i<nbin;i++) {
d4.push([-1.0+2.0*(i/nbin), bin[i]]);
}
basic_legend (document.getElementById("canvas-frame" ), d1, d2);
basic_legend2(document.getElementById("canvas-frame2"), d3);
basic_legend3(document.getElementById("canvas-frame3"), d4);
}
window.requestAnimationFrame(loop2);
}
function basic_legend(container, d1, d2) {
var data, graph, i;
data = [
{ data : d1, label :'Ch Left' },
{ data : d2, label :'Ch Right' }
];
function labelFn (label) {
return label;
}
graph = Flotr.draw(container, data, {
legend : {
position : 'nw',
labelFormatter : labelFn,
backgroundColor : '#ffffcc'
},
yaxis : {
max : 1.1,
min : -1.1
},
HtmlText : false
});
}
function basic_legend2(container, d3) {
var data, graph, i;
data = [
{ data : d3, label :'Lissajous' }
];
function labelFn (label) {
return label;
}
graph = Flotr.draw(container, data, {
legend : {
position : 'nw',
labelFormatter : labelFn,
backgroundColor : '#ffffcc'
},
colors : [ '#ffa500' ],
xaxis : {
max : 1.1,
min : -1.1
},
yaxis : {
max : 1.1,
min : -1.1
},
HtmlText : false
});
}
function basic_legend3(container, d4) {
var data, graph, i;
data = [
{ data : d4, label :'Histogram' }
];
function labelFn (label) {
return label;
}
graph = Flotr.draw(container, data, {
legend : {
position : 'nw',
labelFormatter : labelFn,
backgroundColor : '#ffffcc'
},
colors : [ '#8a2be2' ],
xaxis : {
max : 1.1,
min : -1.1
},
yaxis : {
max : 420,
min : -20
},
HtmlText : false
});
}
</script>
<script>
function audioPlay() {
var files = document.getElementById('files').files;
var file = files[0];
if (!files.length) {
alert('Please select a wave file!');
return;
}
if (file.type.match(/audio.*/)) {
var reader2 = new FileReader();
reader2.onload = function(d) {
e = document.createElement("audio");
e.src = d.target.result;
e.setAttribute("type", file.type);
e.setAttribute("controls", "controls");
e.setAttribute("autoplay", "true");
document.getElementById("container").appendChild(e);
e.addEventListener("timeupdate", function() {
t=e.currentTime;
}, false);
};
reader2.readAsDataURL(file);
}
}
function readBlob() {
var files = document.getElementById('files').files;
if (!files.length) {
alert('Please select a wave file!');
return;
}
var file = files[0];
var header_length = 44; // wave file
var start = header_length; // skip header
var stop = file.size - 1; // read until EOF
var nbyte = file.size - header_length;
var ndata = nbyte / 2; // 2 byte per data for 16-bit PCM
var reader = new FileReader();
reader.onloadend = function(evt) {
if (evt.target.readyState == FileReader.DONE) { // DONE == 2
var buffer = reader.result;
arr = new Int16Array(buffer);
arrmax = 0;
arrmin = 0;
arrmax_pos = 0;
arrmin_pos = 0;
arr_pos = 0;
start_time = new Date().getTime();
bin = new Array();
var i;
for(i=0;i<nbin;i++) {
bin[i] = 0;
}
for(i=0;i<ndata;i++) {
if(arr[i] > arrmax) {
arrmax = arr[i];
arrmax_pos = i;
}
if(arr[i] < arrmin) {
arrmin = arr[i];
arrmin_pos = i;
}
}
if( arrmax > Math.abs(arrmin) ) {
arr_pos = arrmax_pos;
} else {
arr_pos = arrmin_pos;
}
index = 0;
t = index / (44100.0*2.0);
document.getElementById('mymessage').innerHTML
= "Positive peak: " + arrmax
+ ", Negative peak: " + arrmin;
loop2();
}
};
var blob = file.slice(start, stop + 1);
reader.readAsArrayBuffer(blob);
}
function upRate() {
ijump--;
if(ijump < 1) ijump = 1;
}
function downRate() {
ijump++;
if(ijump > 10) ijump = 10;
}
</script>
</head>
<body>
<div id="canvas-frame" style="float:left"></div>
<div id="canvas-frame2" style="float:left"></div>
<div id="canvas-frame3" style="float:left"></div>
<div style="clear:both"><h1>Wavefile Read</h1></dvi>
<input type="file" id="files" style="width:400px;" multiple/>
<div id="mymessage">Positive peak:______, Negative peak:_____</div>
<div id="slider">FPS slider
<input id="range01" type="range" min="1" max="10" step="1" onchange="showValue()"/>
<div id="mymessage2"></div>
</div>
<div id="container"></div>
<script type="text/javascript">
function showValue () {
ijump = document.getElementById("range01").value;
}
</script>
<script>
document.getElementById("files").addEventListener("change", readBlob, false);
document.getElementById("files").addEventListener("change", audioPlay, false);
</script>
</body>
</html>
