MediaRecorder
Baseline
Widely available
*
This feature is well established and works across many devices and browser versions. It’s been available across browsers since 2021年4月.
* Some parts of this feature may have varying levels of support.
MediaRecorder 是 MediaStream Recording API 提供的用来进行媒体轻松录制的接口,他需要通过调用 MediaRecorder() 构造方法进行实例化。
构造函数
MediaRecorder.MediaRecorder()-
创建一个新的
MediaRecorder对象,对指定的MediaStream对象进行录制,支持的配置项包括设置容器的 MIME 类型 (例如"video/webm"或者"video/mp4") 和音频及视频的码率或者二者同用一个码率
配置项
MediaRecorder.mimeType只读-
返回
MediaRecorder对象创建时选择器选择的录制容器的 MIME type MediaRecorder.state只读-
返回录制对象
MediaRecorder的当前状态 (闲置中,录制中或者暂停 ) (inactive,recording, orpaused.) MediaRecorder.stream只读-
返回录制器对象
MediaRecorder创建时构造函数传入的 stream 对象 MediaRecorder.ignoreMutedMedia-
用以指定
MediaRecorder是否录制无声的输入源。如果这个属性是 false. 录制器对象MediaRecorder会录制无声的音频或者黑屏的视频,默认值是 false MediaRecorder.videoBitsPerSecond只读-
返回视频采用的编码比率。它可能和构造函数的设置比率不同。(if it was provided).
MediaRecorder.audioBitsPerSecond只读-
返回音频采用的编码比率,它可能和构造函数中设置的比率不同。(if it was provided).
方法
MediaRecorder.isTypeSupported()-
返回一个
Boolean值,来表示设置的 MIME type 是否被当前用户的设备支持。 MediaRecorder.pause()-
暂停媒体录制
MediaRecorder.requestData()-
请求一个从开始到当前接收到的,存储为
Blob类型的录制内容。(或者是返回从上一次调用requestData()方法之后到现在的内容). 调用这个方法后,录制将会继续进行,但是会创建一个新的Blob对象 MediaRecorder.resume()-
继续录制之前被暂停的录制动作。
MediaRecorder.start()-
开始录制媒体,这个方法调用时可以通过给
timeslice参数设置一个毫秒值,如果设置这个毫秒值,那么录制的媒体会按照你设置的值进行分割成一个个单独的区块,而不是以默认的方式录制一个非常大的整块内容。 MediaRecorder.stop()-
停止录制。同时触发
dataavailable事件,返回一个存储Blob内容的录制数据。之后不再记录
静态方法
MediaRecorder.isTypeSupported()-
静态方法,判断给定的 MIME 类型是否支持。返回
Boolean类型的值。
事件处理
MediaRecorder.ondataavailable-
调用它用来处理
dataavailable事件,该事件可用于获取录制的媒体资源 (在事件的data属性中会提供一个可用的Blob对象.) MediaRecorder.onerror-
An event handler called to handle the
recordingerrorevent, including reporting errors that arise with media recording. These are fatal errors that stop recording. MediaRecorder.onpause-
用来处理
pause事件,该事件在媒体暂停录制时触发(MediaRecorder.pause()). MediaRecorder.onresume-
用来处理
resume事件,该事件在暂停后回复录制视频时触发(MediaRecorder.resume()). MediaRecorder.onstart-
用来处理
start事件,该事件在媒体开始录制时触发(MediaRecorder.start()). MediaRecorder.onstop-
用来处理
stop事件,该事件会在媒体录制结束时、媒体流(MediaStream)结束时、或者调用MediaRecorder.stop()方法后触发。
事件
Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.
示例
if (navigator.mediaDevices) {
console.log("支持 getUserMedia。");
const constraints = { audio: true };
let chunks = [];
navigator.mediaDevices
.getUserMedia(constraints)
.then((stream) => {
const mediaRecorder = new MediaRecorder(stream);
record.onclick = () => {
mediaRecorder.start();
console.log(mediaRecorder.state);
console.log("录制开始");
record.style.background = "red";
record.style.color = "black";
};
stop.onclick = () => {
mediaRecorder.stop();
console.log(mediaRecorder.state);
console.log("录制停止");
record.style.background = "";
record.style.color = "";
};
mediaRecorder.onstop = (e) => {
console.log("数据将在调用 MediaRecorder.stop() 后可用。");
const clipName = prompt("输入音频片段的名称");
const clipContainer = document.createElement("article");
const clipLabel = document.createElement("p");
const audio = document.createElement("audio");
const deleteButton = document.createElement("button");
const mainContainer = document.querySelector("body");
clipContainer.classList.add("clip");
audio.setAttribute("controls", "");
deleteButton.textContent = "Delete";
clipLabel.textContent = clipName;
clipContainer.appendChild(audio);
clipContainer.appendChild(clipLabel);
clipContainer.appendChild(deleteButton);
mainContainer.appendChild(clipContainer);
audio.controls = true;
const blob = new Blob(chunks, { type: "audio/ogg; codecs=opus" });
chunks = [];
const audioURL = URL.createObjectURL(blob);
audio.src = audioURL;
console.log("录制停止");
deleteButton.onclick = (e) => {
const evtTgt = e.target;
evtTgt.parentNode.parentNode.removeChild(evtTgt.parentNode);
};
};
mediaRecorder.ondataavailable = (e) => {
chunks.push(e.data);
};
})
.catch((err) => {
console.error(`发生以下错误:${err}`);
});
}
备注: This code sample is inspired by the Web Dictaphone demo. Some lines have been omitted for brevity; refer to the source for the complete code.
Specifications
| Specification |
|---|
| MediaStream Recording> # mediarecorder-api> |
Browser compatibility
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See also
- Using the MediaRecorder API
- Web Dictaphone: MediaRecorder + getUserMedia + Web Audio API visualization demo, by Chris Mills (source on Github.)
- Recording a media element
- simpl.info MediaStream Recording demo, by Sam Dutton.
navigator.mediaDevices.getUserMedia- FingerSpell: Sign Language Fingerspelling practice using MediaDevices and the MediaStream Recording API to create and download recordings, MediaRecorder API supported desktop browsers only (source on GitHub)