在网页中访问网络摄像头

Question

我正在开发一个网络应用程序。

在我的访客注册页面我需要访问网络摄像头为客人拍照。

我拍摄的图像可以存储在指定的位置。

这将是执行此操作的最佳方式。

欢迎使用java，JSP，html，java脚本或任何其他方法。

Answer 1

的jQuery插件摄像头的辛勤工作为您提供：

http://www.xarg.org/project/jquery-webcam-plugin/

Answer 2

回答自己的问题，因为没有使用HTML5提供一个更好的办法。

选项1，从系统

HTML

Video Tag 
<br/> 
<div class="camera"> 
    <video id="video">Video stream not available.</video> 
    <button id="startbutton">Take photo</button> 
</div> 
<br/> 
Canvas 
<br/> 
<canvas id="canvas"></canvas> 

访问默认的摄像头脚本

var width = 320; 
var height = 0; 
var streaming = false; 

navigator.mediaDevices.getUserMedia({video: true, audio: false}) 
     .then(function (stream) { 
      video.srcObject = stream; 
      video.play(); 
     }) 
     .catch(function (err) { 
      console.log("An error occured! " + err); 
     }); 

video.addEventListener('canplay', function (ev) { 
    if (!streaming) { 
     height = video.videoHeight/(video.videoWidth/width); 
     video.setAttribute('width', width); 
     video.setAttribute('height', height); 
     canvas.setAttribute('width', width); 
     canvas.setAttribute('height', height); 

     streaming = true; 
    } 
}, false); 

startbutton.addEventListener('click', function (ev) { 
    takepicture(); 
    ev.preventDefault(); 
}, false); 

clearphoto(); 

function clearphoto() { 
    var context = canvas.getContext('2d'); 
    context.fillStyle = "#AAA"; 
    context.fillRect(0, 0, canvas.width, canvas.height); 
} 

function takepicture() { 
    var context = canvas.getContext('2d'); 
    if (width && height) { 
     canvas.width = width; 
     canvas.height = height; 
     context.drawImage(video, 0, 0, width, height); 

     var dataURL = canvas.toDataURL("image/jpeg", 0.95); 
     if (dataURL && dataURL != "data:,") { 
      var fileName = generateImageName(); 
      uploadimage(dataURL, fileName); 
     } else { 
      alert("Image not available"); 
     } 
    } else { 
     clearphoto(); 
    } 
} 

function generateImageName() { 
    ... generate image name logic here ... 
    return imageName; 
} 

function uploadimage(dataurl, filename) { 
    ... upload logic here ... 
} 

截屏

选项2，提供系统中可用摄像机的列表，并让用户选择相机。

HTML

<select id="videoSelect"></select> 
    <button id="startCameraButton">Start Camera</button> 
    <br/> 
    Video Tag 
    <br/> 
    <div class="camera"> 
     <video id="video">Video stream not available.</video> 
     <button id="takePictureButton">Take photo</button> 
    </div> 
    <br/> 
    Canvas 
    <br/> 
    <canvas id="canvas"> 
    </canvas> 

脚本

var width = 320; 
var height = 0; 
var streaming = false; 
var localstream = null; 

startCameraButton.onclick = start; 
takePictureButton.onclick = takepicture; 

navigator.mediaDevices.enumerateDevices() 
     .then(gotDevices) 
     .catch(function (err) { 
      console.log("An error occured while getting device list! " + err); 
     }); 

function gotDevices(deviceInfos) { 
    while (videoSelect.firstChild) { 
     videoSelect.removeChild(videoSelect.firstChild); 
    } 

    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 || 'Camera ' + (videoSelect.length + 1); 
      videoSelect.appendChild(option); 
     } 
    } 
} 

function start() { 
    stopVideo(); 
    clearphoto(); 
    var videoSource = videoSelect.value; 
    var constraints = { 
     audio: false, 
     video: {deviceId: videoSource ? {exact: videoSource} : undefined} 
    }; 
    navigator.mediaDevices.getUserMedia(constraints). 
      then(gotStream).then(gotDevices).catch(handleError); 
} 



function gotStream(stream) { 
    localstream = stream; 
    video.srcObject = stream; 
    video.play(); 
    // Refresh button list in case labels have become available 
    return navigator.mediaDevices.enumerateDevices(); 
} 

function handleError(error) { 
    console.log('navigator.getUserMedia error: ', error); 
} 

video.addEventListener('canplay', function (ev) { 
    if (!streaming) { 
     height = video.videoHeight/(video.videoWidth/width); 
     video.setAttribute('width', width); 
     video.setAttribute('height', height); 
     canvas.setAttribute('width', width); 
     canvas.setAttribute('height', height); 

     streaming = true; 
    } 
}, false); 

clearphoto(); 

function clearphoto() { 
    var context = canvas.getContext('2d'); 
    context.fillStyle = "#AAA"; 
    context.fillRect(0, 0, canvas.width, canvas.height); 
} 

function takepicture() { 
    var context = canvas.getContext('2d'); 
    if (width && height) { 
     canvas.width = width; 
     canvas.height = height; 
     context.drawImage(video, 0, 0, width, height); 

     var dataURL = canvas.toDataURL("image/jpeg", 0.95); 
     if (dataURL && dataURL != "data:,") { 
      var fileName = generateImageName(); 
      fileName = fileName + ".txt" 
      uploadimage(dataURL, fileName); 
     } else { 
      console.log("Image not available"); 
     } 
    } else { 
     clearphoto(); 
    } 
} 

    function generateImageName() { 
    ... generate image name logic here ... 
    return imageName; 
} 

function uploadimage(dataurl, filename) { 
    ... upload logic here ... 
} 

function stopVideo() { 
    if (localstream) { 
     localstream.getTracks().forEach(function (track) { 
      track.stop(); 
      localstream = null; 
     }); 
    } 
} 

屏幕截图

选项3，让用户选择音频和视频源和音频输出

在选项2中，用户可以选择任何特定的摄像机。最重要的是，如果用户还想选择音频源和音频输出源，请修改上面的代码，修改如下。

HTML

  audioInputSelect 
      <br/> 
      <select id="audioInputSelect"></select> 
      <br/> 
      audioOutputSelect 
      <select id="audioOutputSelect"></select> 

脚本

function gotDevices(deviceInfos) { 
    while (videoSelect.firstChild) { 
     videoSelect.removeChild(videoSelect.firstChild); 
    } 

    for (var i = 0; i !== deviceInfos.length; ++i) { 
     var deviceInfo = deviceInfos[i]; 
     var option = document.createElement('option'); 
     option.value = deviceInfo.deviceId; 
     if (deviceInfo.kind === 'audioinput') { 
      option.text = deviceInfo.label || 'Microphone ' + (audioInputSelect.length + 1); 
      audioInputSelect.appendChild(option); 
     } else if (deviceInfo.kind === 'audiooutput') { 
      option.text = deviceInfo.label || 'Speaker ' + (audioOutputSelect.length + 1); 
      audioOutputSelect.appendChild(option); 
     } else if (deviceInfo.kind === 'videoinput') { 
      option.text = deviceInfo.label || 'Camera ' + (videoSelect.length + 1); 
      videoSelect.appendChild(option); 
     } 
    } 
} 

function start() { 
    stopVideo(); 
    clearphoto(); 
    var audioSource = audioInputSelect.value; 
    var videoSource = videoSelect.value; 
    var constraints = { 
     audio: {deviceId: audioSource ? {exact: audioSource} : undefined}, 
     video: {deviceId: videoSource ? {exact: videoSource} : undefined} 
    }; 
    navigator.mediaDevices.getUserMedia(constraints). 
      then(gotStream).then(gotDevices).catch(handleError); 
}