AudioBuffer | Web API

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AudioBuffer interface represents a short audio asset residing in memory, created from an audio file using the AudioContext.decodeAudioData() method, or from raw data using AudioContext.createBuffer() . Once put into an AudioBuffer, the audio can then be played by being passed into an AudioBufferSourceNode .

Objects of these types are designed to hold small audio snippets, typically less than 45 s. For longer sounds, objects implementing the MediaElementAudioSourceNode are more suitable. The buffer contains data in the following format: non-interleaved IEEE754 32-bit linear PCM with a nominal range between -1 and +1 , that is, 32bits floating point buffer, with each samples between -1.0 and 1.0. If the AudioBuffer has multiple channels, they are stored in separate buffer.

构造函数

AudioBuffer(): 创建并返回新 AudioBuffer 对象实例。

特性

AudioBuffer.sampleRate 只读
AudioBuffer.length 只读
AudioBuffer.duration 只读
AudioBuffer.numberOfChannels 只读

方法

AudioBuffer.getChannelData(): 返回 Float32Array containing the PCM data associated with the channel, defined by the channel parameter (with 0 representing the first channel).
AudioBuffer.copyFromChannel(): Copies the samples from the specified channel of the AudioBuffer 到 destination 数组。
AudioBuffer.copyToChannel(): Copies the samples to the specified channel of the AudioBuffer , from the source 数组。

范例

The following simple example shows how to create an AudioBuffer and fill it with random white noise. You can find the full source code at our webaudio-examples repository; a running live version is also available.

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
// Create an empty three-second stereo buffer at the sample rate of the AudioContext
var myArrayBuffer = audioCtx.createBuffer(2, audioCtx.sampleRate * 3, audioCtx.sampleRate);
// Fill the buffer with white noise;
// just random values between -1.0 and 1.0
for (var channel = 0; channel < myArrayBuffer.numberOfChannels; channel++) {
  // This gives us the actual array that contains the data
  var nowBuffering = myArrayBuffer.getChannelData(channel);
  for (var i = 0; i < myArrayBuffer.length; 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 'AudioBuffer' in that specification.	工作草案	初始定义。

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
`AudioBuffer`	Chrome 14	Edge ≤18	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
`AudioBuffer()` 构造函数	Chrome 55 注意事项 55 注意事项 `context` parameter was supported up until version 57, but has now been removed.	Edge ≤79	Firefox 53	IE 不支持 No	Opera 42 注意事项 42 注意事项 `context` parameter was supported up until version 44, but has now been removed.	Safari ?	WebView Android 55 注意事项 55 注意事项 `context` parameter was supported up until version 57, but has now been removed.	Chrome Android 55 注意事项 55 注意事项 `context` parameter was supported up until version 57, but has now been removed.	Firefox Android 53	Opera Android 42 注意事项 42 注意事项 `context` parameter was supported up until version 44, but has now been removed.	Safari iOS ?	Samsung Internet Android 6.0 注意事项 6.0 注意事项 `context` parameter was supported up until Samsung Internet 7.0, but has now been removed.
`copyFromChannel`	Chrome 14	Edge 13	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 ?	Samsung Internet Android 1.0
`copyToChannel`	Chrome 14	Edge 13	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 ?	Samsung Internet Android 1.0
`duration`	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
`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
`length`	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
`numberOfChannels`	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
`sampleRate`	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

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使用 Web 音频 API

元数据

最后修改： 2020 年 1 月 22 日

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构造函数

特性

方法

范例

规范

浏览器兼容性

图例

另请参阅

相关话题