转至https://blog.csdn.net/journey191/article/details/40744015 (如有冒犯联系我删掉谢谢)
最近公司做的app涉及摄像头,由于我们使用HTML5开发app,自然了解到getUserMedia接口。
关键是使用的问题,所以直接贴代码(通过互联网搜集资料整理)。
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<!DOCTYPE html>
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<html xmlns="http://www.w3.org/1999/xhtml">
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<head>
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<title>HTML5 GetUserMedia Demo</title>
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<meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />
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</head>
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<body>
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<input type="button" title="开启摄像头" value="开启摄像头" onclick="getMedia();" /><br />
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<video height="120px" autoplay="autoplay"></video><hr />
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<input type="button" title="拍照" value="拍照" onclick="getPhoto();" /><br />
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<canvas id="canvas1" height="120px" ></canvas><hr />
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<input type="button" title="视频" value="视频" onclick="getVedio();" /><br />
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<canvas id="canvas2" height="120px"></canvas>
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<script type="text/javascript">
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var video = document.querySelector('video');
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var audio, audioType;
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var canvas1 = document.getElementById('canvas1');
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var context1 = canvas1.getContext('2d');
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var canvas2 = document.getElementById('canvas2');
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var context2 = canvas2.getContext('2d');
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navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
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window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL;
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var exArray = []; //存储设备源ID
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MediaStreamTrack.getSources(function (sourceInfos) {
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for (var i = 0; i != sourceInfos.length; ++i) {
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var sourceInfo = sourceInfos[i];
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//这里会遍历audio,video,所以要加以区分
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if (sourceInfo.kind === 'video') {
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exArray.push(sourceInfo.id);
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}
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}
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});
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function getMedia() {
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if (navigator.getUserMedia) {
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navigator.getUserMedia({
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'video': {
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'optional': [{
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'sourceId': exArray[1] //0为前置摄像头,1为后置
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}]
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},
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'audio':true
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}, successFunc, errorFunc); //success是获取成功的回调函数
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}
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else {
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alert('Native device media streaming (getUserMedia) not supported in this browser.');
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}
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}
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function successFunc(stream) {
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//alert('Succeed to get media!');
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if (video.mozSrcObject !== undefined) {
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//Firefox中,video.mozSrcObject最初为null,而不是未定义的,我们可以靠这个来检测Firefox的支持
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video.mozSrcObject = stream;
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}
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else {
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video.src = window.URL && window.URL.createObjectURL(stream) || stream;
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}
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//video.play();
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// 音频
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audio = new Audio();
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audioType = getAudioType(audio);
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if (audioType) {
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audio.src = 'polaroid.' + audioType;
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audio.play();
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}
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}
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function errorFunc(e) {
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alert('Error!'+e);
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}
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// 将视频帧绘制到Canvas对象上,Canvas每60ms切换帧,形成肉眼视频效果
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function drawVideoAtCanvas(video,context) {
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window.setInterval(function () {
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context.drawImage(video, 0, 0,90,120);
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}, 60);
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}
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//获取音频格式
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function getAudioType(element) {
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if (element.canPlayType) {
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if (element.canPlayType('audio/mp4; codecs="mp4a.40.5"') !== '') {
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return ('aac');
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} else if (element.canPlayType('audio/ogg; codecs="vorbis"') !== '') {
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return ("ogg");
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}
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}
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return false;
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}
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// vedio播放时触发,绘制vedio帧图像到canvas
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// video.addEventListener('play', function () {
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// drawVideoAtCanvas(video, context2);
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// }, false);
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//拍照
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function getPhoto() {
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context1.drawImage(video, 0, 0,90,120); //将video对象内指定的区域捕捉绘制到画布上指定的区域,实现拍照。
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}
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//视频
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function getVedio() {
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drawVideoAtCanvas(video, context2);
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}
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</script>
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</body>
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</html>
在安卓的Chrome(版本Beta 39.0.2171.44)上测试的效果截图:
现在遇到一个问题:如何实现视频录制效果,也就是以视频文件保存到本地?
将Canvas获取的所有的帧图像组织起来,通过算法转换?
如果高见,望赐教!