AudioBuffer.numberOfChannels

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.

AudioBuffer接口的numberOfChannels属性返回一个整数，该整数表示由缓冲区中存储的 PCM 数据描述的离散音频通道的数量

语法

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

返回值

一个整数。

示例

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.numberOfChannels);
};

规范

Specification
Web Audio API
# dom-audiobuffer-numberofchannels

浏览器兼容性

BCD tables only load in the browser

参见