AudioContext.createBufferSource()

createBufferSource() 方法用于创建一个新的AudioBufferSourceNode接口,该接口可以通过AudioBuffer 对象来播放音频数据。AudioBuffer对象可以通过AudioContext.createBuffer 来创建或者通过 AudioContext.decodeAudioData成功解码音轨后获取。

语法

var audioCtx = new AudioContext();
var source = audioCtx.createBufferSource();

返回

一个AudioBufferSourceNode对象。

例子

在这个例子中,我们将会创建一个 2 秒的缓冲器,并用白噪音填充它,然后通过AudioBufferSourceNode来播放它.

备注: You can also run the code live, or view the source.

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var button = document.querySelector('button');
var pre = document.querySelector('pre');
var myScript = document.querySelector('script');

pre.innerHTML = myScript.innerHTML;

// Stereo
var channels = 2;
// Create an empty two second stereo buffer at the
// sample rate of the AudioContext
var frameCount = audioCtx.sampleRate * 2.0;

var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);

button.onclick = function() {
  // Fill the buffer with white noise;
  //just random values between -1.0 and 1.0
  for (var channel = 0; channel < channels; channel++) {
   // This gives us the actual ArrayBuffer that contains the data
   var nowBuffering = myArrayBuffer.getChannelData(channel);
   for (var i = 0; i < frameCount; i++) {
     // Math.random() is in [0; 1.0]
     // audio needs to be in [-1.0; 1.0]
     nowBuffering[i] = Math.random() * 2 - 1;
   }
  }

  // Get an AudioBufferSourceNode.
  // This is the AudioNode to use when we want to play an AudioBuffer
  var source = audioCtx.createBufferSource();
  // set the buffer in the AudioBufferSourceNode
  source.buffer = myArrayBuffer;
  // connect the AudioBufferSourceNode to the
  // destination so we can hear the sound
  source.connect(audioCtx.destination);
  // start the source playing
  source.start();
}

规范

Specification
Web Audio API
# dom-baseaudiocontext-createbuffersource

浏览器支持

BCD tables only load in the browser

See also