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 2015年7月.
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
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