[轉] HTML5利用WebRTC的getUserMedia獲取攝像頭信息模擬拍照及視頻（完整示例）

時間 2019-11-17

標籤 html5 html 利用 webrtc getusermedia 獲取攝像頭信息模擬拍照視頻完整示例欄目 HTML5 简体版

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<!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="開啓攝像頭" value="開啓攝像頭" 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="視頻" value="視頻" 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 = []; //存儲設備源ID
MediaStreamTrack.getSources(function (sourceInfos) {
for (var i = 0; i != sourceInfos.length; ++i) {
var sourceInfo = sourceInfos[i];
//這裏會遍歷audio,video，因此要加以區分
if (sourceInfo.kind === 'video') {
exArray.push(sourceInfo.id);
}
}
});

function getMedia() {
if (navigator.getUserMedia) {
navigator.getUserMedia({
'video': {
'optional': [{
'sourceId': exArray[1] //0爲前置攝像頭，1爲後置
}]
},
'audio':true
}, successFunc, errorFunc); //success是獲取成功的回調函數
}
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最初爲null，而不是未定義的，咱們能夠靠這個來檢測Firefox的支持
video.mozSrcObject = stream;
}
else {
video.src = window.URL && window.URL.createObjectURL(stream) || stream;
}

//video.play();

// 音頻
audio = new Audio();
audioType = getAudioType(audio);
if (audioType) {
audio.src = 'polaroid.' + audioType;
audio.play();
}
}
function errorFunc(e) {
alert('Error！'+e);
}


// 將視頻幀繪製到Canvas對象上,Canvas每60ms切換幀，造成肉眼視頻效果
function drawVideoAtCanvas(video,context) {
window.setInterval(function () {
context.drawImage(video, 0, 0,90,120);
}, 60);
}

//獲取音頻格式
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播放時觸發，繪製vedio幀圖像到canvas
// video.addEventListener('play', function () {
// drawVideoAtCanvas(video, context2);
// }, false);

//拍照
function getPhoto() {
context1.drawImage(video, 0, 0,90,120); //將video對象內指定的區域捕捉繪製到畫布上指定的區域，實現拍照。
}

//視頻
function getVedio() {
drawVideoAtCanvas(video, context2);
}

</script>
</body>
</html>