--- title: AudioBuffer.duration slug: Web/API/AudioBuffer/duration translation_of: Web/API/AudioBuffer/duration ---

{{ APIRef("Web Audio API") }}

{{domxref("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;

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
{{SpecName('Web Audio API', '#widl-AudioBuffer-duration', 'duration')}} {{Spec2('Web Audio API')}}  

浏览器兼容性

{{CompatibilityTable}}
Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 14 {{property_prefix("webkit")}} {{CompatVersionUnknown}} 23 {{CompatNo}} 15 {{property_prefix("webkit")}}
22 (unprefixed)
6 {{property_prefix("webkit")}}
Feature Android Chrome Edge Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support {{CompatNo}} 28 {{property_prefix("webkit")}} {{CompatVersionUnknown}} 25 1.2 {{CompatNo}} {{CompatNo}} 6 {{property_prefix("webkit")}}

See also