AudioBuffer.getChannelData()

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句法
范例
规范
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getChannelData() 方法在 AudioBuffer Interface returns a Float32Array containing the PCM data associated with the channel, defined by the channel parameter (with 0 representing the first channel).

句法

var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);
var nowBuffering = myArrayBuffer.getChannelData(channel);

参数

channel: The channel property is an index representing the particular channel to get data for. An index value of 0 represents the first channel. If the channel index value is greater than of equal to AudioBuffer.numberOfChannels ， INDEX_SIZE_ERR exception will be thrown.

返回值

A Float32Array .

范例

In the following example we create a two second buffer, fill it with white noise, and then play it via an AudioBufferSourceNode . The comments should clearly explain what is going on. You can also run the code live ，或 view the source .

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var button = document.querySelector('button');
var pre = document.querySelector('pre');
var myScript = document.querySelector('script');
pre.innerHTML = myScript.innerHTML;
// 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;
   }
  }
  // Get an AudioBufferSourceNode.
  // This is the AudioNode to use when we want to play an AudioBuffer
  var source = audioCtx.createBufferSource();
  // set the buffer in the AudioBufferSourceNode
  source.buffer = myArrayBuffer;
  // connect the AudioBufferSourceNode to the
  // destination so we can hear the sound
  source.connect(audioCtx.destination);
  // start the source playing
  source.start();
}

规范

规范	状态	注释
Web 音频 API The definition of 'getChannelData' in that specification.	工作草案

浏览器兼容性

The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`getChannelData`	Chrome 14	Edge 12	Firefox 25	IE 不支持 No	Opera 15	Safari 6	WebView Android Yes	Chrome Android 18	Firefox Android 26	Opera Android 14	Safari iOS Yes	Samsung Internet Android 1.0

图例

完整支持
不支持

另请参阅

使用 Web 音频 API

元数据

最后修改： 2019 年 3 月 23 日

Web 音频 API
AudioBuffer
构造函数
1. AudioBuffer()
特性
方法
1. copyFromChannel()
2. copyToChannel()
3. getChannelData()
Related pages for Web Audio API

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句法

参数

返回值

范例

规范

浏览器兼容性

图例

另请参阅

相关话题