MediaStreamAudioDestinationNode.stream

在此页

句法
范例
规范
浏览器兼容性
另请参阅
相关话题

stream 特性为 AudioContext 接口表示 MediaStream containing a single audio MediaStreamTrack with the same number of channels as the node itself.

You can use this property to get a stream out of the audio graph and feed it into another construct, such as a Media Recorder .

句法

var audioCtx = new AudioContext();
var destination = audioCtx.createMediaStreamDestination();
var myStream = destination.stream;

值

A MediaStream containing a single audio track. The audio track is a MediaStreamTrack whose kind is audio .

范例

In the following simple example, we create a MediaStreamAudioDestinationNode ， OscillatorNode 和 MediaRecorder (the example will therefore only work in Firefox and Chrome at this time.) The MediaRecorder is set up to record information from the MediaStreamDestinationNode .

When the button is clicked, the oscillator starts, and the MediaRecorder is started. When the button is stopped, the oscillator and MediaRecorder both stop. Stopping the MediaRecorder causes the dataavailable event to fire, and the event data is pushed into the chunks array. After that, the stop event fires, a new blob is made of type opus — which contains the data in the chunks array, and a new window (tab) is then opened that points to a URL created from the blob.

From here, you can play and save the opus file.

<!DOCTYPE html>
<html>
  <head>
    <title>createMediaStreamDestination() demo</title>
  </head>
  <body>
    <h1>createMediaStreamDestination() demo</h1>
    <p>Encoding a pure sine wave to an Opus file </p>
    <button>Make sine wave</button>
    <audio controls></audio>
    <script>
     var b = document.querySelector("button");
     var clicked = false;
     var chunks = [];
     var ac = new AudioContext();
     var osc = ac.createOscillator();
     var dest = ac.createMediaStreamDestination();
     var mediaRecorder = new MediaRecorder(dest.stream);
     osc.connect(dest);
     b.addEventListener("click", function(e) {
       if (!clicked) {
           mediaRecorder.start();
           osc.start(0);
           e.target.innerHTML = "Stop recording";
           clicked = true;
         } else {
           mediaRecorder.stop();
           osc.stop(0);
           e.target.disabled = true;
         }
     });
     mediaRecorder.ondataavailable = function(evt) {
       // push each chunk (blobs) in an array
       chunks.push(evt.data);
     };
     mediaRecorder.onstop = function(evt) {
       // Make blob out of our blobs, and open it.
       var blob = new Blob(chunks, { 'type' : 'audio/ogg; codecs=opus' });
       document.querySelector("audio").src = URL.createObjectURL(blob);
     };
    </script>
  </body>
</html>

注意 : You can view this example live ，或 study the source code , on Github.

规范

规范	状态	注释
Web 音频 API The definition of 'stream' 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
`stream`	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

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： Aug 28, 2020

Web 音频 API
MediaStreamAudioDestinationNode
构造函数
1. MediaStreamAudioDestinationNode()
特性
1. stream
继承：
1. AudioNode
2. EventTarget
Related pages for Web Audio API

在此页

句法

值

范例

规范

浏览器兼容性

图例

另请参阅

相关话题