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Tuesday, 1 July 2014

JavaScript code for maintaining Graphic equalizer for audio songs

<!doctype html>
<html>
<head>
<style type="text/css">
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:#002D3C; float:left; }
</style>
<script>
// Create a new instance of an audio object and adjust some of its properties
var audio = new Audio();
audio.src = 'http://www.w3schools.com/html/horse.mp3';/*source for mp3 you can place your song location here*/
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);
try {
    // Fix up for prefixing
    window.AudioContext = window.AudioContext||window.webkitAudioContext;
    context = new AudioContext();
  }
  catch(e) {
    console.log('Web Audio API is not supported in this browser');
  }
try{
//context = new webkitAudioContext(); // AudioContext object instance
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();
}catch(e){console.log("errormsg????????????????????????"+e);}
}
// frameLooper() animates any style of graphics you wish to the audio frequency
// Looping at the default frame rate that the browser provides(approx. 60 FPS)
function 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 = '#00CCFF'; // 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>
</head>
<body>
<div id="mp3_player">
  <div id="audio_box"></div>
  <canvas id="analyser_render"></canvas>
</div>
</body>
</html>

OUTPUT:

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