document.documentElement.style.height = window.innerHeight + 'px';

document.documentElement.addEventListener('touchmove', function(e){
 e.preventDefault();
});

var lib = {
 _keyStr : "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",

 decodeArrayBuffer: function(input) {
 var bytes = (input.length/4) * 3;
 var ab = new ArrayBuffer(bytes);
 this.decode(input, ab);

 return ab;
 },

 decode: function(input, arrayBuffer) {
 var lkey1 = this._keyStr.indexOf(input.charAt(input.length-1)); 
 var lkey2 = this._keyStr.indexOf(input.charAt(input.length-2)); 

 var bytes = (input.length/4) * 3;
 if (lkey1 == 64) bytes--;
 if (lkey2 == 64) bytes--;

 var uarray;
 var chr1, chr2, chr3;
 var enc1, enc2, enc3, enc4;
 var i = 0;
 var j = 0;

 if (arrayBuffer)
 uarray = new Uint8Array(arrayBuffer);
 else
 uarray = new Uint8Array(bytes);

 input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");

 for (i=0; i<bytes; i+=3) { 
 enc1 = this._keyStr.indexOf(input.charAt(j++));
 enc2 = this._keyStr.indexOf(input.charAt(j++));
 enc3 = this._keyStr.indexOf(input.charAt(j++));
 enc4 = this._keyStr.indexOf(input.charAt(j++));

 chr1 = (enc1 << 2) | (enc2 >> 4);
 chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
 chr3 = ((enc3 & 3) << 6) | enc4;

 uarray[i] = chr1; 
 if (enc3 != 64) uarray[i+1] = chr2;
 if (enc4 != 64) uarray[i+2] = chr3;
 }

 return uarray; 
 }, 
 getScript: function(url, callback, charset){
 var head = document.getElementsByTagName("head")[0] || document.documentElement,
 script = document.createElement("script");
 script.src = url;
 charset && (script.charset = charset);

 script.onload = script.onreadystatechange = function() {
 if ((!this.readyState || this.readyState === "loaded" || this.readyState === "complete") ) {
 callback && callback();
 script.onload = script.onreadystatechange = null;
 if (head && script.parentNode) head.removeChild(script);
 }
 };
 head.appendChild(script);
 return script;
 }
}


var QAudio = function(config){
 this.config = config;
 this.init();
}
QAudio.prototype.init = function(){
 var config = this.config;
 this.src = config.src;
 this.base64 = config.base64; 

 if ('AudioContext' in window) {
 this.audioContext = new AudioContext();
 } else if ('webkitAudioContext' in window) {
 this.audioContext = new webkitAudioContext();
 } else {
 this.audio = document.createElement('audio');
 this.audio.preload = 'auto';
 this.audio.src = this.src;
 }

 // base64数据处理
 if(this.audioContext) {
 this._handleBase64();
 }

 this.load();
}
QAudio.prototype._handleBase64 = function(){
 var self = this;
 window[this.config.callback] = function(data){
 var arrayBuff = lib.decodeArrayBuffer(data);
 self.audioContext.decodeAudioData(arrayBuff, function(audioData) {
 self._arrayBuff = audioData;
 });
 }
} 
QAudio.prototype.load = function(){
 // 如果支持Web Audio，加载base64音频
 if(this.audioContext) {
 lib.getScript(this.base64);
 } else if(this.audio) {
 this.audio.load();
 }
} 
QAudio.prototype.play = function(){
 if(this.audioContext) {
 var mySource = this.audioContext.createBufferSource();
 mySource.buffer = this._arrayBuff;
 mySource.connect(this.audioContext.destination);

 if ('AudioContext' in window) {
 mySource.start(0);
 } else if ('webkitAudioContext' in window) {
 mySource.noteOn(0);
 }
 } else if(this.audio) {
 this.audio.play();
 }

} 

new QAudio({src: './audio/pop1.mp3', base64: './audio/pop1.js', callback: 'cbPop1'});