ScriptProcessorNode.onaudioprocess

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句法
范例
规范
浏览器兼容性
另请参阅
相关话题

注意 : As of the August 29 2014 Web Audio API spec publication, this feature has been marked as deprecated, and is soon to be replaced by Audio Workers .

onaudioprocess event handler of the ScriptProcessorNode interface represents the EventHandler to be called for the audioprocess event that is dispatched to ScriptProcessorNode node types. An event of type AudioProcessingEvent will be dispatched to the event handler.

句法

var audioCtx = new AudioContext();
var scriptNode = audioCtx.createScriptProcessor(4096, 1, 1);
scriptNode.onaudioprocess = function() { ... }

范例

The following example shows basic usage of a ScriptProcessorNode to take a track loaded via AudioContext.decodeAudioData() , process it, adding a bit of white noise to each audio sample of the input track (buffer) and play it through the AudioDestinationNode . For each channel and each sample frame, the scriptNode.onaudioprocess function takes the associated audioProcessingEvent and uses it to loop through each channel of the input buffer, and each sample in each channel, and add a small amount of white noise, before setting that result to be the output sample in each case.

注意 : For a full working example, see our script-processor-node github repo (also view the 源代码 )。

var myScript = document.querySelector('script');
var myPre = document.querySelector('pre');
var playButton = document.querySelector('button');
// Create AudioContext and buffer source
var audioCtx = new AudioContext();
source = audioCtx.createBufferSource();
// Create a ScriptProcessorNode with a bufferSize of 4096 and a single input and output channel
var scriptNode = audioCtx.createScriptProcessor(4096, 1, 1);
console.log(scriptNode.bufferSize);
// load in an audio track via XHR and decodeAudioData
function getData() {
  request = new XMLHttpRequest();
  request.open('GET', 'viper.ogg', true);
  request.responseType = 'arraybuffer';
  request.onload = function() {
    var audioData = request.response;
    audioCtx.decodeAudioData(audioData, function(buffer) {
    myBuffer = buffer;
    source.buffer = myBuffer;
  },
    function(e){"Error with decoding audio data" + e.err});
  }
  request.send();
}
// Give the node a function to process audio events
scriptNode.onaudioprocess = function(audioProcessingEvent) {
  // The input buffer is the song we loaded earlier
  var inputBuffer = audioProcessingEvent.inputBuffer;
  // The output buffer contains the samples that will be modified and played
  var outputBuffer = audioProcessingEvent.outputBuffer;
  // Loop through the output channels (in this case there is only one)
  for (var channel = 0; channel < outputBuffer.numberOfChannels; channel++) {
    var inputData = inputBuffer.getChannelData(channel);
    var outputData = outputBuffer.getChannelData(channel);
    // Loop through the 4096 samples
    for (var sample = 0; sample < inputBuffer.length; sample++) {
      // make output equal to the same as the input
      outputData[sample] = inputData[sample];
      // add noise to each output sample
      outputData[sample] += ((Math.random() * 2) - 1) * 0.2;
    }
  }
}
getData();
// wire up play button
playButton.onclick = function() {
  source.connect(scriptNode);
  scriptNode.connect(audioCtx.destination);
  source.start();
}
// When the buffer source stops playing, disconnect everything
source.onended = function() {
  source.disconnect(scriptNode);
  scriptNode.disconnect(audioCtx.destination);
}

规范

规范	状态	注释
Web 音频 API The definition of 'onaudioprocess' 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
`onaudioprocess` 弃用	Chrome 14 Prefixed 14 Prefixed Prefixed Implemented with the vendor prefix: webkit	Edge 12	Firefox 25	IE 不支持 No	Opera 22 22 15 Prefixed Prefixed Implemented with the vendor prefix: webkit	Safari 6 Prefixed 6 Prefixed Prefixed Implemented with the vendor prefix: webkit	WebView Android Yes	Chrome Android Yes	Firefox Android 25	Opera Android 22 22 14 Prefixed Prefixed Implemented with the vendor prefix: webkit	Safari iOS 6 Prefixed 6 Prefixed Prefixed Implemented with the vendor prefix: webkit	Samsung Internet Android Yes

图例

完整支持
不支持
弃用。不要用于新网站。
要求使用供应商前缀或不同名称。

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
ScriptProcessorNode
特性
1. bufferSize
2. onaudioprocess
继承：
1. AudioNode
2. EventTarget
Related pages for Web Audio API

在此页

句法

范例

规范

浏览器兼容性

图例

另请参阅

相关话题