DynamicsCompressorNode

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构造函数
特性
方法
范例
规范
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DynamicsCompressorNode interface provides a compression effect, which lowers the volume of the loudest parts of the signal in order to help prevent clipping and distortion that can occur when multiple sounds are played and multiplexed together at once. This is often used in musical production and game audio. DynamicsCompressorNode 是 AudioNode that has exactly one input and one output; it is created using the AudioContext.createDynamicsCompressor() 方法。

输入数	`1`
输出数	`1`
通道计数模式	`"clamped-max"`
通道计数	`2`
通道解释	`"speakers"`

构造函数

DynamicsCompressorNode(): Creates a new instance of an DynamicsCompressorNode 对象。

特性

继承的特性来自其父级， AudioNode .

DynamicsCompressorNode.threshold 只读: 是 k-rate AudioParam representing the decibel value above which the compression will start taking effect.
DynamicsCompressorNode.knee 只读: 是 k-rate AudioParam containing a decibel value representing the range above the threshold where the curve smoothly transitions to the compressed portion.
DynamicsCompressorNode.ratio 只读: 是 k-rate AudioParam representing the amount of change, in dB, needed in the input for a 1 dB change in the output.
DynamicsCompressorNode.reduction 只读: 是 float representing the amount of gain reduction currently applied by the compressor to the signal.
DynamicsCompressorNode.attack 只读: 是 k-rate AudioParam representing the amount of time, in seconds, required to reduce the gain by 10 dB.
DynamicsCompressorNode.release 只读: 是 k-rate AudioParam representing the amount of time, in seconds, required to increase the gain by 10 dB.

方法

No specific methods; inherits methods from its parent, AudioNode .

范例

The below code demonstrates a simple usage of createDynamicsCompressor() to add compression to an audio track. For a more complete example, have a look at our basic Compressor example ( view the source code ).

// Create a MediaElementAudioSourceNode
// Feed the HTMLMediaElement into it
var source = audioCtx.createMediaElementSource(myAudio);
// Create a compressor node
var compressor = audioCtx.createDynamicsCompressor();
compressor.threshold.setValueAtTime(-50, audioCtx.currentTime);
compressor.knee.setValueAtTime(40, audioCtx.currentTime);
compressor.ratio.setValueAtTime(12, audioCtx.currentTime);
compressor.attack.setValueAtTime(0, audioCtx.currentTime);
compressor.release.setValueAtTime(0.25, audioCtx.currentTime);
// connect the AudioBufferSourceNode to the destination
source.connect(audioCtx.destination);
button.onclick = function() {
  var active = button.getAttribute('data-active');
  if(active == 'false') {
    button.setAttribute('data-active', 'true');
    button.innerHTML = 'Remove compression';
    source.disconnect(audioCtx.destination);
    source.connect(compressor);
    compressor.connect(audioCtx.destination);
  } else if(active == 'true') {
    button.setAttribute('data-active', 'false');
    button.innerHTML = 'Add compression';
    source.disconnect(compressor);
    compressor.disconnect(audioCtx.destination);
    source.connect(audioCtx.destination);
  }
}

规范

规范	状态	注释
Web 音频 API The definition of 'DynamicsCompressorNode' 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
`DynamicsCompressorNode`	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
`DynamicsCompressorNode()` 构造函数	Chrome 55	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 注意事项 55 注意事项 Before Chrome 59, the default values were not supported.	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.
`attack`	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
`knee`	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
`ratio`	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
`reduction`	Chrome 14 注意事项 14 注意事项 Before version 52, this was an `AudioParam.` .	Edge 12	Firefox 25	IE 不支持 No	Opera 15	Safari 6	WebView Android Yes 注意事项 Yes 注意事项 Before version 52, this was an `AudioParam.` .	Chrome Android 18 注意事项 18 注意事项 Before version 52, this was an `AudioParam.` .	Firefox Android 26	Opera Android 14	Safari iOS Yes	Samsung Internet Android 1.0 注意事项 1.0 注意事项 Before Samsung Internet 6.0, this was an `AudioParam.` .
`release`	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
`threshold`	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
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兼容性未知 ?

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使用 Web 音频 API

元数据

最后修改： Jan 25, 2020

Web 音频 API
DynamicsCompressorNode
构造函数
1. DynamicsCompressorNode()
特性
1. attack
2. knee
3. ratio
4. reduction
5. release
6. threshold
继承：
1. AudioNode
2. EventTarget
Related pages for Web Audio API

在此页

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