手机端：HTML5利用WebRTC的getUserMedia获取摄像头信息模拟拍照及视频（完整示例）

冷不防 2022-05-14 23:46 315阅读 0赞

<!DOCTYPE html>
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
        <title>HTML5 GetUserMedia Demo</title>
        <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0" />
    </head>
    <body>
        <input type="button" title="开启摄像头" value="开启摄像头" onclick="getMedia();" /><br />
        <video height="120px" autoplay="autoplay"></video><hr />
        <input type="button" title="拍照" value="拍照" onclick="getPhoto();" /><br />
        <canvas id="canvas1" height="120px" ></canvas><hr />
        <input type="button" title="视频" value="视频" onclick="getVedio();" /><br />
        <canvas id="canvas2" height="120px"></canvas>
     
        <script type="text/javascript">
            var video = document.querySelector('video');
            var audio, audioType;
     
            var canvas1 = document.getElementById('canvas1');
            var context1 = canvas1.getContext('2d');
     
            var canvas2 = document.getElementById('canvas2');
            var context2 = canvas2.getContext('2d');
     
            navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
            window.URL = window.URL || window.webkitURL || window.mozURL || window.msURL;
     
            var exArray = []; //存储设备源ID
            MediaStreamTrack.getSources(function (sourceInfos) {
                for (var i = 0; i != sourceInfos.length; ++i) {
                    var sourceInfo = sourceInfos[i];
                    //这里会遍历audio,video，所以要加以区分
                    if (sourceInfo.kind === 'video') {
                        exArray.push(sourceInfo.id);
                    }
                }
            });
     
            function getMedia() {
                if (navigator.getUserMedia) {
                    navigator.getUserMedia({
                        'video': {
                            'optional': [{
                                'sourceId': exArray[1] //0为前置摄像头，1为后置
                            }]
                        },
                        'audio':true
                    }, successFunc, errorFunc);    //success是获取成功的回调函数
                }
                else {
                    alert('Native device media streaming (getUserMedia) not supported in this browser.');
                }
            }
     
            function successFunc(stream) {
                //alert('Succeed to get media!');
                if (video.mozSrcObject !== undefined) {
                    //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
                    video.mozSrcObject = stream;
                }
                else {
                    video.src = window.URL && window.URL.createObjectURL(stream) || stream;
                }
     
                //video.play();
     
                // 音频
                audio = new Audio();
                audioType = getAudioType(audio);
                if (audioType) {
                    audio.src = 'polaroid.' + audioType;
                    audio.play();
                }
            }
            function errorFunc(e) {
                alert('Error！'+e);
            }
     
            
            // 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
            function drawVideoAtCanvas(video,context) {
                window.setInterval(function () {
                    context.drawImage(video, 0, 0,90,120);
                }, 60);
            }
     
            //获取音频格式
            function getAudioType(element) {
                if (element.canPlayType) {
                    if (element.canPlayType('audio/mp4; codecs="mp4a.40.5"') !== '') {
                        return ('aac');
                    } else if (element.canPlayType('audio/ogg; codecs="vorbis"') !== '') {
                        return ("ogg");
                    }
                }
                return false;
            }
     
            // vedio播放时触发，绘制vedio帧图像到canvas
    //        video.addEventListener('play', function () {
    //            drawVideoAtCanvas(video, context2);
    //        }, false);
     
            //拍照
            function getPhoto() {
                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。
            }
     
            //视频
            function getVedio() {
                drawVideoAtCanvas(video, context2);
            }
     
        </script>
    </body>
    </html>

原文链接：[https://blog.csdn.net/journey191/article/details/40744015][https_blog.csdn.net_journey191_article_details_40744015]

[https_blog.csdn.net_journey191_article_details_40744015]: https://blog.csdn.net/journey191/article/details/40744015