正文
使用Chrome采集摄像头并生成视频下载
提示：扫一扫查出行【扫一扫了解最新限行尾号】
复制提示
主要使用2个技术点：WebRtc 的 getUserMedia 和 MediaRecorder
注意点
- 开始录制调用 start 方法要传入一个采样间隔，这样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.
- demo地址：https://young-cowboy.github.io/gallery/MediaRecorder.html
参考资料
- https://developer.mozilla.org/en-US/docs/Web/API/MediaRecorder
代码如下
<!DOCTYPE html>
<html lang="en">
<head>
<title></title>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<video width="400" height="300" controls id="video" autoplay></video>
<div>
<button type="button" id="record">record</button>
<button type="button" id="pause">pause</button>
<button type="button" id="resume">resume</button>
<button type="button" id="stop">stop</button>
<button type="button" id="finish">finish</button>
<a href="#" target="_blank" id="download">download</a>
</div>
<div>
<button type="button" id="info">info</button>
<button type="button" id="isTypeSupported">isTypeSupported</button>
</div>
<script type="text/javascript">
(function () {
let mediaRecorder = null;
let mediaStream = null;
let chunks = [];
function getMediaStream(params) {
var constraints = {
audio: true,
video: true
};
return navigator
.mediaDevices
.getUserMedia(constraints);
}
function attachMedia() {
getMediaStream()
.then(stream => {
document.querySelector('#video').srcObject = stream;
mediaStream = stream;
})
.catch(err => alert(`${err.name}: ${err.message}`));
}
function record() {
mediaRecorder = new MediaRecorder(mediaStream, { mimeType:"video/webm" });
mediaRecorder.addEventListener('dataavailable', e => {
console.log('dataavailable %o', e);
chunks.push(e.data);
});
mediaRecorder.addEventListener('error', e => console.log('error %o', e));
mediaRecorder.addEventListener('pause', e => console.log('pause %o', e));
mediaRecorder.addEventListener('resume', e => console.log('resume %o', e));
mediaRecorder.addEventListener('start', e => console.log('start %o', e));
mediaRecorder.addEventListener('stop', e => console.log('stop %o', e));
// 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.start(10);
}
function stop() {
mediaRecorder.stop();
}
function pause() {
mediaRecorder.pause();
}
function resume() {
mediaRecorder.resume();
}
function stop() {
mediaRecorder.stop();
}
function download() {
var blob = new Blob(chunks, {type: "video/webm"});
chunks = [];
var downloadLink = document.querySelector('a#download');
var videoURL = window.URL.createObjectURL(blob);
var rand = Math.floor((Math.random() * 10000000));
var name = "video_"+rand+".webm" ;
downloadLink.href = videoURL;
downloadLink.setAttribute( "download", name);
downloadLink.setAttribute( "name", name);
}
function info() {
console.log(`mimeType ${mediaRecorder.mimeType}`);
console.log(`state ${mediaRecorder.state}`);
console.log(`stream ${mediaRecorder.stream}`);
console.log(`videoBitsPerSecond %o`, mediaRecorder.videoBitsPerSecond);
console.log(`audioBitsPerSecond ${mediaRecorder.audioBitsPerSecond}`);
}
function isTypeSupported() {
var types = [
"video/webm",
"audio/webm",
"video/webm\;codecs=vp8",
"video/webm\;codecs=daala",
"video/webm\;codecs=h264",
"audio/webm\;codecs=opus",
"video/mpeg"
];
for (var i in types) {
console.log(`Is ${types[i]} supported? ${MediaRecorder.isTypeSupported(types[i] ? "Maybe!" : "No")}`);
}
}
document.querySelector('#record').addEventListener('click', e => record());
document.querySelector('#pause').addEventListener('click', e => pause());
document.querySelector('#resume').addEventListener('click', e => resume());
document.querySelector('#stop').addEventListener('click', e => stop());
document.querySelector('#finish').addEventListener('click', e => download());
document.querySelector('#info').addEventListener('click', e => info());
document.querySelector('#isTypeSupported').addEventListener('click', e => isTypeSupported());
attachMedia();
})()
</script>
</body>
</html>
