HTML5 Graphic Lector of MP3 in a Canvas made with javascript

A nice MP3 Player, made with Javascript, Canvas and HTML5.
The Istance of AudioContext is cross browser!
Remember to change the music.mp3 with your local file.
Here you have the entire code, just copy and paste:


<style>
  div#mp3_player{ width:500px; height:60px; background:#000; padding:5px; margin:50px auto; }
  div#mp3_player > div > audio{ width:500px; background:#000; float:left; }
  div#mp3_player > canvas{ width:500px; height:30px; background:#ffaa00; float:left; }
</style>
<script>
var context;
window.addEventListener('load', init, false);
function init() {
  try {
    window.AudioContext = window.AudioContext||window.webkitAudioContext;
    context = new AudioContext();
  }
  catch(e) {
    alert('Web Audio API is not supported in this browser');
  }
}
// Create a new instance of an audio object and adjust some of its properties
var audio = new Audio();
audio.src = "myfile.mp3";  // <---- HERE yOU PUT YOUR MP3 FILES
audio.controls = true;
audio.loop = true;
audio.autoplay = true;
// Establish all variables that your Analyser will use
var canvas, ctx, source, context, analyser, fbc_array, bars, bar_x, bar_width, bar_height;
// Initialize the MP3 player after the page loads all of its HTML into the window
window.addEventListener("load", initMp3Player, false);
function initMp3Player(){
  document.getElementById("audio_box").appendChild(audio);
  analyser = context.createAnalyser(); // AnalyserNode method
  canvas = document.getElementById("analyser_render");
  ctx = canvas.getContext("2d");
  // Re-route audio playback into the processing graph of the AudioContext
  source = context.createMediaElementSource(audio);
  source.connect(analyser);
  analyser.connect(context.destination);
  frameLooper();
}
function frameLooper(){
  var requestAnimationFrame = window.requestAnimationFrame(frameLooper) ||
  window.webkitRequestAnimationFrame(frameLooper) ||
  window.mozRequestAnimationFrame(frameLooper) ||
  window.oRequestAnimationFrame(frameLooper) ||
  window.msRequestAnimationFrame(frameLooper);
  //window.webkitRequestAnimationFrame(frameLooper);
  fbc_array = new Uint8Array(analyser.frequencyBinCount);
  analyser.getByteFrequencyData(fbc_array);
  ctx.clearRect(0, 0, canvas.width, canvas.height); // Clear the canvas
  ctx.fillStyle = "#ffaa00"; // Color of the bars
  bars = 100;
  for (var i = 0; i < bars; i++) {
    bar_x = i * 3;
    bar_width = 2;
    bar_height = -(fbc_array[i] / 2);
    // fillRect( x, y, width, height ) // Explanation of the parameters below
    ctx.fillRect(bar_x, canvas.height, bar_width, bar_height);
  }
}
</script>


<div id="mp3_player">
<div id="audio_box"></div>
<canvas id="analyser_render"></canvas>
</div>

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