MediaElementAudioSourceNode

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构造函数
特性
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MediaElementAudioSourceNode interface represents an audio source consisting of an HTML5 <audio> or <video> element. It is an AudioNode that acts as an audio source.

A MediaElementSourceNode has no inputs and exactly one output, and is created using the AudioContext.createMediaElementSource() method. The amount of channels in the output equals the number of channels of the audio referenced by the HTMLMediaElement used in the creation of the node, or is 1 if the HTMLMediaElement has no audio.

输入数	`0`
输出数	`1`
通道计数	defined by the media in the `HTMLMediaElement` passed to the `AudioContext.createMediaElementSource` method that created it.

构造函数

MediaElementAudioSourceNode(): 创建新的 MediaElementAudioSourceNode 对象实例。

特性

继承的特性来自其父级， AudioNode .

mediaElement 只读: HTMLMediaElement used when constructing this MediaStreamAudioSourceNode .

方法

继承方法来自其父级 AudioNode .

范例

This simple example creates a source from an <audio> element using createMediaElementSource() , then passes the audio through a GainNode before feeding it into the AudioDestinationNode for playback. When the mouse pointer is moved, the updatePage() function is invoked, which calculates the current gain as a ratio of mouse Y position divided by overall window height. You can therefore increase and decrease the volume of the playing music by moving the mouse pointer up and down.

注意 : You can also view this example running live ，或 view the source .

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var myAudio = document.querySelector('audio');
var pre = document.querySelector('pre');
var myScript = document.querySelector('script');
pre.innerHTML = myScript.innerHTML;
// Create a MediaElementAudioSourceNode
// Feed the HTMLMediaElement into it
var source = audioCtx.createMediaElementSource(myAudio);
// Create a gain node
var gainNode = audioCtx.createGain();
// Create variables to store mouse pointer Y coordinate
// and HEIGHT of screen
var CurY;
var HEIGHT = window.innerHeight;
// Get new mouse pointer coordinates when mouse is moved
// then set new gain value
document.onmousemove = updatePage;
function updatePage(e) {
    CurY = (window.Event) ? e.pageY : event.clientY + (document.documentElement.scrollTop ? document.documentElement.scrollTop : document.body.scrollTop);
    gainNode.gain.value = CurY/HEIGHT;
}
// connect the AudioBufferSourceNode to the gainNode
// and the gainNode to the destination, so we can play the
// music and adjust the volume using the mouse cursor
source.connect(gainNode);
gainNode.connect(audioCtx.destination);

注意 : As a consequence of calling createMediaElementSource() , audio playback from the HTMLMediaElement will be re-routed into the processing graph of the AudioContext. So playing/pausing the media can still be done through the media element API and the player controls.

规范

规范	状态	注释
Web 音频 API The definition of 'MediaElementAudioSourceNode' 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
`MediaElementAudioSourceNode`	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
`MediaElementAudioSourceNode()` 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.
`mediaElement`	Chrome Yes	Edge ≤79	Firefox 70	IE 不支持 No	Opera Yes	Safari Yes	WebView Android Yes	Chrome Android Yes	Firefox Android 不支持 No	Opera Android Yes	Safari iOS Yes	Samsung Internet Android Yes

图例

完整支持
不支持
兼容性未知 ?

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使用 Web 音频 API

元数据

最后修改： Jun 3, 2020

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