AudioBuffer.duration
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
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
js
var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);
myArrayBuffer.duration;
值
双精度值
例子
js
// 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 |
|---|
| Web Audio API # dom-audiobuffer-duration |