我用 html5 创建了一个流式网络摄像头。目前我可以通过我的网络摄像头拍照，但我想知道是否可以从列表中选择媒体流设备，例如我有两个网络摄像头，我想选择要激活的网络摄像头。我怎样才能用 html5 getUserMedia() 调用来做到这一点？ 谢谢!
最佳答案
获取网络摄像头列表
<!DOCTYPE html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>Video Camera List</title>
<script src="//ajax.googleapis.com/ajax/libs/jquery/2.0.3/jquery.min.js" ></script>
<style type="text/css" media="screen">
video {
border:1px solid gray;
}
</style>
</head>
<body>
<script>
if (!MediaStreamTrack) document.body.innerHTML = '<h1>Incompatible Browser Detected. Try <strong style="color:red;">Chrome Canary</strong> instead.</h1>';
var videoSources = [];
MediaStreamTrack.getSources(function(media_sources) {
console.log(media_sources);
// alert('media_sources : '+media_sources);
media_sources.forEach(function(media_source){
if (media_source.kind === 'video') {
videoSources.push(media_source);
}
});
getMediaSource(videoSources);
});
var get_and_show_media = function(id) {
var constraints = {};
constraints.video = {
optional: [{ sourceId: id}]
};
navigator.webkitGetUserMedia(constraints, function(stream) {
console.log('webkitGetUserMedia');
console.log(constraints);
console.log(stream);
var mediaElement = document.createElement('video');
mediaElement.src = window.URL.createObjectURL(stream);
document.body.appendChild(mediaElement);
mediaElement.controls = true;
mediaElement.play();
}, function (e)
{
// alert('Hii');
document.body.appendChild(document.createElement('hr'));
var strong = document.createElement('strong');
strong.innerHTML = JSON.stringify(e);
alert('strong.innerHTML : '+strong.innerHTML);
document.body.appendChild(strong);
});
};
var getMediaSource = function(media) {
console.log(media);
media.forEach(function(media_source) {
if (!media_source) return;
if (media_source.kind === 'video')
{
// add buttons for each media item
var button = $('<input/>', {id: media_source.id, value:media_source.id, type:'submit'});
$("body").append(button);
// show video on click
$(document).on("click", "#"+media_source.id, function(e){
console.log(e);
console.log(media_source.id);
get_and_show_media(media_source.id);
});
}
});
}
</script>
</body>
</html>
关于HTML5 getUserMedia() 媒体源，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/18061536/