AudioBuffer.duration - Web API 接口参考 编辑

AudioBuffer接口的duration属性返回一个双精度数，表示缓冲区中存储的PCM数据的持续时间（以秒为单位）

语法

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

值

双精度值

例子

// 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;
    }
  }

  console.log(myArrayBuffer.duration);
}

规范

Specification	Status	Comment
Web Audio API duration	Working Draft

浏览器兼容性

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

• Desktop
• Mobile

Feature	Chrome	Edge	Firefox (Gecko)	Internet Explorer	Opera	Safari (WebKit)
Basic support	14 webkit	(Yes)	23	未实现	15 webkit 22 (unprefixed)	6 webkit

Feature	Android	Chrome	Edge	Firefox Mobile (Gecko)	Firefox OS	IE Phone	Opera Mobile	Safari Mobile
Basic support	未实现	28 webkit	(Yes)	25	1.2	未实现	未实现	6 webkit

See also

• Using the Web Audio API