oxx*_*xxi 10 javascript html5 html5-audio web-audio-api
尝试学习Audio API,但我得到BufferLoader类的Uncaught引用错误.我正在使用Chrome,它是最新的.本班不应该没有问题吗？
<html>
<head>
<script type=text/javascript>
window.onload = init;
var context;
var bufferLoader;
function init(){
context = new webkitAudioContext();
bufferLoader = new BufferLoader(
context,
[
' https://dl.dropboxusercontent.com/u/1957768/kdFFO3.wav',
' https://dl.dropboxusercontent.com/u/1957768/geniuse%20meodies.wav',
],
finishedLoading
);
bufferLoader.load();
}
function finishedLoading(bufferList){
//make two sources and play them
var source1 = context.createBufferSource();
var source2 = context.createBufferSource();
source1.buffer = bufferList[0];
source2.buffer = bufferList[1];
source1.connect(context.destination);
source2.connect(context.destination);
source1.start(0);
source2.start(0);
}
</script>
</head>
<body>
</body>
</html>
Ian*_*Ian 15
在BufferLoader"类"是创建抽象使用网络音频API的自定义函数.它不是内置功能,必须包含在您的页面中才能使用; Chrome有这个没什么特别的.这是一个解释它的例子:http://www.html5rocks.com/en/tutorials/webaudio/intro/#toc-abstract
要使用,请在使用前包含此代码:
function BufferLoader(context, urlList, callback) {
this.context = context;
this.urlList = urlList;
this.onload = callback;
this.bufferList = new Array();
this.loadCount = 0;
}
BufferLoader.prototype.loadBuffer = function(url, index) {
// Load buffer asynchronously
var request = new XMLHttpRequest();
request.open("GET", url, true);
request.responseType = "arraybuffer";
var loader = this;
request.onload = function() {
// Asynchronously decode the audio file data in request.response
loader.context.decodeAudioData(
request.response,
function(buffer) {
if (!buffer) {
alert('error decoding file data: ' + url);
return;
}
loader.bufferList[index] = buffer;
if (++loader.loadCount == loader.urlList.length)
loader.onload(loader.bufferList);
},
function(error) {
console.error('decodeAudioData error', error);
}
);
}
request.onerror = function() {
alert('BufferLoader: XHR error');
}
request.send();
}
BufferLoader.prototype.load = function() {
for (var i = 0; i < this.urlList.length; ++i)
this.loadBuffer(this.urlList[i], i);
}