可用的浏览器,chrome, firefox, opera, safari暂不支持

<video src="" id="video" width=640 height=480 autoplay=""></video>      


var constraints = {video: true}
var video = document.getElementById("video")

navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia;

function successCallback(stream) {
    window.stream = stream;
  if(window.URL) {
      video.src = window.URL.createObjectURL(stream);
  } else if (window.webkitURL) {
    video.src = window.webkitURL.createObjectURL(stream);
  } else {
    video.src = steam;
  }
  video.play()
}

function errorCallback(error) {
    console.log("Video", error);
}

navigator.getUserMedia(constraints, successCallback, errorCallback);