chrome浏览器调用摄像头


    //var 是定义变量
    var canvans = document.getElementById("canvas");
    var video = document.getElementById("video"); //获取video标签
    var context = canvas.getContext("2d");
    var con = {
   
        audio: false,
        video: {
   
            width: 1920,
            height: 1080
        }
    };

    //导航 获取用户媒体对象
    navigator.mediaDevices.getUserMedia(con)
        .then(function (stream) {
   
            video.srcObject = stream;
            video.onloadmetadate = function (e) {
   
                video.play();
            };
        });

    function query() {
   

        //把流媒体数据画到convas画布上去
        context.drawImage(video, 0, 0, 400, 300);
        var imgData = canvans.toDataURL();
        var imgData_ = imgData.split("base64,")[1];//获取图片
		//上传服务器
        $.ajax({
   
            type: "post",
            url: "",
            data: {
    "img": imgData_ },
            success: function (data) {
   

                if (result) {
   
                    alert("登录成功");
                } else {
   
                    alert("面容识别失败,请继续验证");
                }
            }
        });
    }