问题：希望在浏览器中调用摄像头，拍摄头像
解决：使用html5技术，取代Flash
方法：
<!DOCTYPE HTML>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>html5,js调用摄像头</title>
</head>
<body>
<!--
理想情况下我们应该先判断你的设备上是否
有摄像头或相机，但简单起见，我们在这里直接
写出了HTML标记，而不是用JavaScript先判断
然后动态生成这些标记
-->
<video id="video" width="640" height="480" autoplay></video>
<button id="snap">Snap Photo</button>
<canvas id="canvas" width="640" height="480"></canvas>
<script>
// Put event listeners into place
window.addEventListener("DOMContentLoaded", function() {
// Grab elements, create settings, etc.
var canvas = document.getElementById("canvas"),
context = canvas.getContext("2d"),
video = document.getElementById("video"),
videoObj = { video: true },
errBack = function(error) {
console.log("Video capture error: ", error.code);
};
// Put video listeners into place
if(navigator.getUserMedia) { // Standard
navigator.getUserMedia(videoObj, function(stream) {
video.src = stream;
video.play();
}, errBack);
} else if(navigator.webkitGetUserMedia) { // WebKit-prefixed
navigator.webkitGetUserMedia(videoObj, function(stream){
video.src = window.webkitURL.createObjectURL(stream);
video.play();
}, errBack);
}
else if(navigator.mozGetUserMedia) { // Firefox-prefixed
navigator.mozGetUserMedia(videoObj, function(stream){
video.src = window.URL.createObjectURL(stream);
video.play();
}, errBack);
}
// 触发拍照动作
document.getElementById("snap")
.addEventListener("click", function() {
context.drawImage(video, 0, 0, 640, 480);
});
}, false);
</script>
</body>
</html>
注：如果出现Video capture error: undefined 可能是摄像头被占用