AudioBufferSourceNode

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构造函数
特性
方法
范例
规范
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AudioBufferSourceNode interface is an AudioScheduledSourceNode which represents an audio source consisting of in-memory audio data, stored in an AudioBuffer . It's especially useful for playing back audio which has particularly stringent timing accuracy requirements, such as for sounds that must match a specific rhythm and can be kept in memory rather than being played from disk or the network. To play sounds which require accurate timing but must be streamed from the network or played from disk, use a AudioWorkletNode to implement its playback.

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An AudioBufferSourceNode has no inputs and exactly one output, which has the same number of channels as the AudioBuffer indicated by its buffer property. If there's no buffer set—that is, if buffer is null —the output contains a single channel of silence (every sample is 0).

An AudioBufferSourceNode can only be played once; after each call to start() , you have to create a new node if you want to play the same sound again. Fortunately, these nodes are very inexpensive to create, and the actual AudioBuffer s can be reused for multiple plays of the sound. Indeed, you can use these nodes in a "fire and forget" manner: create the node, call start() to begin playing the sound, and don't even bother to hold a reference to it. It will automatically be garbage-collected at an appropriate time, which won't be until sometime after the sound has finished playing.

Multiple calls to stop() are allowed. The most recent call replaces the previous one, if the AudioBufferSourceNode has not already reached the end of the buffer.

The AudioBufferSourceNode takes the content of an AudioBuffer and m

输入数	`0`
输出数	`1`
通道计数	defined by the associated `AudioBuffer`

构造函数

AudioBufferSourceNode(): 创建并返回新 AudioBufferSourceNode object. An AudioBufferSourceNode can be instantiated using the AudioContext.createBufferSource() 方法。

特性

继承的特性来自其父级， AudioNode .

AudioBufferSourceNode.buffer: AudioBuffer that defines the audio asset to be played, or when set to the value null , defines a single channel of silence (in which every sample is 0.0).
AudioBufferSourceNode.detune: 是 k-rate AudioParam representing detuning of playback in cents . This value is compounded with playbackRate to determine the speed at which the sound is played. Its default value is 0 (meaning no detuning), and its nominal range is -∞ to ∞.
AudioBufferSourceNode.loop: A Boolean attribute indicating if the audio asset must be replayed when the end of the AudioBuffer is reached. Its default value is false .
AudioBufferSourceNode.loopStart 可选: A floating-point value indicating the time, in seconds, at which playback of the AudioBuffer must begin when loop is true . Its default value is 0 (meaning that at the beginning of each loop, playback begins at the start of the audio buffer).
AudioBufferSourceNode.loopEnd 可选: A floating-point number indicating the time, in seconds, at which playback of the AudioBuffer stops and loops back to the time indicated by loopStart ，若 loop is true 。默认值为 0 .
AudioBufferSourceNode.playbackRate: An a-rate AudioParam that defines the speed factor at which the audio asset will be played, where a value of 1.0 is the sound's natural sampling rate. Since no pitch correction is applied on the output, this can be used to change the pitch of the sample. This value is compounded with detune to determine the final playback rate.

事件处理程序

Inherits event handlers from its parent, AudioScheduledSourceNode .

方法

继承方法来自其父级 AudioScheduledSourceNode .

AudioBufferSourceNode.start()

范例

In this example, we create a two-second buffer, fill it with white noise, and then play it using 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)();
// 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 ArrayBuffer 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();

对于 decodeAudioData() example, see the AudioContext.decodeAudioData() 页面。

规范

规范	状态	注释
Web 音频 API The definition of 'AudioBufferSourceNode' 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
`AudioBufferSourceNode`	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
`AudioBufferSourceNode()` 构造函数	Chrome 55 注意事项 55 注意事项 Before version 59, the default values were not supported.	Edge ≤79	Firefox 53	IE 不支持 No	Opera 42	Safari ?	WebView Android 55 注意事项 55 注意事项 Before version 59, the default values were not supported.	Chrome Android 55	Firefox Android 53	Opera Android 42	Safari iOS ?	Samsung Internet Android 6.0 注意事项 6.0 注意事项 Before Samsung Internet 7.0, the default values were not supported.
`buffer`	Chrome 14	Edge 12	Firefox 25 注意事项 25 注意事项 Firefox currently handles the value `null` incorrectly. Instead of producing a node that generates a single channel of silence, the node becomes unusable and will be ignored if you attempt to connect it to anything.	IE 不支持 No	Opera 15	Safari 6	WebView Android Yes	Chrome Android 18	Firefox Android 26 注意事项 26 注意事项 Firefox currently handles the value `null` incorrectly. Instead of producing a node that generates a single channel of silence, the node becomes unusable and will be ignored if you attempt to connect it to anything.	Opera Android 14	Safari iOS Yes	Samsung Internet Android 1.0
`detune`	Chrome 44	Edge 13	Firefox 40	IE 不支持 No	Opera 31	Safari 不支持 No	WebView Android 44	Chrome Android 44	Firefox Android 40	Opera Android 32	Safari iOS ?	Samsung Internet Android 4.0
`loop`	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
`loopEnd`	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
`loopStart`	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
`onended`	Chrome 14	Edge 12	Firefox ?	IE 不支持 No	Opera 不支持 ? — 44	Safari ?	WebView Android Yes	Chrome Android 18	Firefox Android ?	Opera Android 不支持 ? — 43	Safari iOS ?	Samsung Internet Android 1.0
`playbackRate`	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
`start`	Chrome 不支持 14 — 57	Edge 不支持 12 — 79	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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元数据

最后修改： Jan 25, 2020

Web 音频 API
AudioBufferSourceNode
构造函数
1. AudioBufferSourceNode()
特性
1. buffer
2. detune
3. loop
4. loopEnd
5. loopStart
6. playbackRate
方法
1. start()
继承：
Related pages for Web Audio API

在此页

构造函数

特性

事件处理程序

方法

范例

规范

浏览器兼容性

图例

另请参阅

相关话题