html5 中获取摄像头设备 2018-10-25
<!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
navigator.mediaDevices.enumerateDevices()
.then(function (devices) {
devices.forEach(function (device) {
var option =document.createElement('option');
option.value = device.deviceId;
if (device.kind ==='videoinput') {
option.text = device.label ||'camera' + (videoSelect.length +1);
videoSelect.appendChild(option);
}else if (device.kind =='audioinput') {
option.text = device.label ||'mic' + (audioSelect.length +1);
audioSelect.appendChild(option);
}
});
})
.catch(function (err) {
console.log(err.name +": " + err.message);
});
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.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>
