H5的video标签设置摄像头

这次给大家带来H5的video标签操作摄像头，H5的video标签操作摄像头注意事项有哪些，下面就是实战案例，一起来看一下。

详解HTML5 使用video标签实现选择摄像头功能

1. html

// jquery reference  
// <script src="http://ajax.googleapis.com/ajax/libs/jquery/2.0.2/jquery.min.js"></script> 
// 
  <input type="hidden" name="imgValue" id="imgValue" /> 
  <button id="btnOpen1" class="btn btn-default" type="button" >Open WebCam</button> 
  <select id="videoSource" ></select> 
  <p id="vdoOne" style="display:none"> 
    <video id="video" style="margin-top:15px;margin-bottom:15px;" width="300" autoplay></video> 
    <canvas id="canvasPreview" style="margin-top:15px;" width="300" height="224"></canvas> 
    <canvas id="canvasUpload" style="display:none;" width='300' height='224'></canvas> 
    <button id="snap" class="btn btn-default" type="button">Snap Photo</button> 
  </p>

2. javascript

<script>  
//// Elements for taking the snapshot 
    var canvasPreview = document.getElementById('canvasPreview'); 
    var canvasUpload = document.getElementById('canvasUpload'); 
    var contextPreview = canvasPreview.getContext('2d'); 
    var contextUpload = canvasUpload.getContext('2d'); 
    //#################### Video Source #######################3 
    var videoElement = document.querySelector('video'); 
    var videoSelect = document.querySelector('select#videoSource'); 
    navigator.mediaDevices.enumerateDevices() 
      .then(gotDevices).then(getStream).catch(handleError); 
    videoSelect.onchange = getStream;  
    function gotDevices(deviceInfos) { 
      for (var i = 0; i < deviceInfos.length; ++i) { 
        var deviceInfo = deviceInfos[i]; 
        var option = document.createElement('option'); 
        option.value = deviceInfo.deviceId; 
        if (deviceInfo.kind === 'videoinput') { 
          option.text = deviceInfo.label 

关键词：H5的video标签设置摄像头