前言
最近在整理一些自己写过的东西，也算是重新熟悉一下并且优化一下吧。
需求：获取本地USB摄像头视频显示，并且获取图片数据给底层做人脸识别。
记得当时直接采用H5已经做好了，调试好了。。。。结果放上去使用发现必须需要证书才可以，
然后因为某些原因（没办法自己写一个ssl证书）只能重写了一个之前使用Activex做的USB控件。
H5调用USB摄像头参考：
开发
引用：AForge.dll，AForge.Video.DirectShow.dll，AForge.Video.dll
首先创建一个用户控件>放入一个pictureBox1>放入一个lable
将用户控件调成灰色（明显。。。）大小随便后面可以调整，pictureBox1在父容器停靠，lab用于错误提示，效果如下：
添加一个 IObjectSafety
/*
IObjectSafety 接口用于通知浏览器：“浏览器，我是安全的”
*/
[ComImport, Guid("887FC3C3-A970-4A36-92EF-D4EB31541C40")]
[InterfaceTypeAttribute(ComInterfaceType.InterfaceIsIUnknown)]
public interface IObjectSafety
{
[PreserveSig]
int GetInterfaceSafetyOptions(ref Guid riid, [MarshalAs(UnmanagedType.U4)] ref int pdwSupportedOptions, [MarshalAs(UnmanagedType.U4)] ref int pdwEnabledOptions);
[PreserveSig()]
int SetInterfaceSafetyOptions(ref Guid riid, [MarshalAs(UnmanagedType.U4)] int dwOptionSetMask, [MarshalAs(UnmanagedType.U4)] int dwEnabledOptions);
}
View Code
添加一个基础类，用于数据返回处理。
public class USBInfo
{
/// <summary>
/// 返回消息
/// </summary>
public class ReturnMessage
{
public bool result { get; set; }//结果
public string message { get; set; }//消息
}
/// <summary>
/// 返回视频分辨率
/// </summary>
public class GetResolvingPower
{
public int index { get; set; }//下标 -1（不存在摄像头），-2（发生意外错误）
public VideoCapabilities Capabilities { get; set; }//信息
public string error { get; set; }//错误
}
}
View Code
用户控件中实现：
/// <summary>
/// 继承IObjectSafety
/// </summary>
[ProgId("USBCamera")]
[ClassInterface(ClassInterfaceType.AutoDual)]
[Guid("887FC3C3-A970-4A36-92EF-D4EB31541C40")]
[ComVisible(true)]
public partial class USBCamera : UserControl, IObjectSafety
{
FilterInfoCollection videoDevices;//设备
VideoCaptureDevice videoSource;//设备信息
MemoryStream frameData;//图片数据
static Thread th_usb;//监听线程
static int sl_usb = 10000;//多久检查一次
static int index_usb;//第一次打开选择的分辨率
public USBCamera()
{
InitializeComponent();
frameData = new MemoryStream();
}
//句柄销毁
protected override void OnHandleDestroyed(EventArgs e)
{
Stop();
base.OnHandleDestroyed(e);
}
/// <summary>
/// 设置窗体相关大小
/// </summary>
/// <param name="width">宽</param>
/// <param name="height">高</param>
/// <param name="fontformat">字体熟悉</param>
/// <param name="fontsize">字体大小</param>
/// <param name="promptInfo">提示信息</param>
/// <param name="sleep">监听间隔</param>
public void FormSize(int width, int height, string fontFormat, int fontSize, string promptInfo, int sleep)
{
this.Size = new Size(width, height);//窗体大小
this.lab_Prompt.Font = new Font(fontFormat, fontSize, FontStyle.Bold); //字体熟悉
this.lab_Prompt.ForeColor = Color.Red;//字体颜色
this.lab_Prompt.Text = promptInfo;//提示信息
//设置字体高宽
var lab_width = (width / 3);
var lab_height = (height / 3);
this.lab_Prompt.Location = new System.Drawing.Point(lab_width, lab_height);
sl_usb = sleep;//监听时间
}
/// <summary>
/// 打开视频
/// </summary>
/// <param name="index">USB可用分辨率数组下标</param>
public void Start(int index)
{
index_usb = index;
if (videoSource != null)
{
videoSource.NewFrame -= new NewFrameEventHandler(video_NewFrame);
videoSource.SignalToStop();
videoSource = null;
}
// 创建视频源
Trace.WriteLine("usbcamera have cameras" + videoDevices.Count.ToString());
videoSource = new VideoCaptureDevice(videoDevices[0].MonikerString);
// 设置新帧事件处理程序
videoSource.NewFrame += new NewFrameEventHandler(video_NewFrame);
// 启动视频源
try
{
videoSource.VideoResolution = this.videoSource.VideoCapabilities[index];
videoSource.Start();
if (th_usb == null || !th_usb.IsAlive)
{
th_usb = new Thread(GetUSB);
th_usb.Start();
}
this.lab_Prompt.Text = null;
}
catch (Exception ex)
{
Trace.WriteLine("usbcamera Start()遇到错误" + ex.Message + ex.StackTrace);
}
}
/// <summary>
/// 停止视频
/// </summary>
public void Stop()
{
if (videoSource != null)
{
videoSource.NewFrame -= new NewFrameEventHandler(video_NewFrame);
//当不再需要捕捉时，发出停止的信号
videoSource.SignalToStop();
videoSource = null;
Trace.WriteLine("usbcamera stop()....");
if (pictureBox1.Image != null)//清空控件
{
pictureBox1.Image.Dispose();
pictureBox1.Image = null;
}
this.lab_Prompt.Text = null;
}
}
/// <summary>
/// 视频帧获取回调
/// </summary>
/// <param name="sender"></param>
/// <param name="eventArgs"></param>
private void video_NewFrame(object sender, NewFrameEventArgs eventArgs)
{
try
{
lab_Prompt.Text = null;
Trace.WriteLine("usbcamera video_NewFrame()....");
eventArgs.Frame.Save(frameData, ImageFormat.Bmp);
if (pictureBox1.InvokeRequired)
{
//写入数据
pictureBox1.BeginInvoke((MethodInvoker)delegate ()
{
try
{
if (pictureBox1.Image != null)
{
Image img = pictureBox1.Image;
img.Dispose();
}
pictureBox1.Image = new Bitmap(frameData);
}
catch (Exception ex)
{
if (pictureBox1.Image != null)
{
pictureBox1.Image.Dispose();
pictureBox1.Image = null;
}
}
});
}
else
{
pictureBox1.Image = new Bitmap(frameData);
}
}
catch (Exception ex)
{
if (pictureBox1.Image != null)
{
pictureBox1.Image.Dispose();
pictureBox1.Image = null;
}
}
}
/// <summary>
/// 获取USB（USB连接不正常），不存在给出提示，存在重新Start
/// </summary>
public void GetUSB()
{
while (true)
{
var usb = new FilterInfoCollection(FilterCategory.VideoInputDevice);
if (usb.Count <= 0)
{
Stop();
lab_Prompt.BeginInvoke((MethodInvoker)delegate ()
{
this.lab_Prompt.Text = "未连接上摄像头，检查连接是否正常。";
});
}
else
{
//重新连接上 执行Start
if (!string.IsNullOrWhiteSpace(this.lab_Prompt.Text))
{
Start(index_usb);
}
}
Thread.Sleep(sl_usb);
}
}
#region USB视频操作
/// <summary>
/// 测试Activex是否可用
/// </summary>
/// <returns>true/false</returns>
public bool Connection()
{
return true;
}
/// <summary>
/// 获取截图
/// </summary>
/// <returns></returns>
public ReturnMessage GetScreenshots()
{
try
{
return new ReturnMessage()
{
result = true,
message = Convert.ToBase64String(frameData.ToArray())
};
}
catch (Exception EX)
{
Trace.WriteLine("usbcamera GetImage() 错误...." + EX.Message + EX.StackTrace);
return new ReturnMessage() { result = false, message = EX.Message + " " + EX.StackTrace };
}
}
/// <summary>
/// 获取USB摄像头分辨率
/// </summary>
/// <returns>json(GetResolvingPower)</returns>
public string GetResolution()
{
var list = new List<GetResolvingPower>();
try
{
videoDevices = new FilterInfoCollection(FilterCategory.VideoInputDevice);
if (videoDevices.Count > 0)
{
videoSource = new VideoCaptureDevice(videoDevices[0].MonikerString);
for (int i = 0; i < videoSource.VideoCapabilities.Length; i++)
{
list.Add(new GetResolvingPower
{
index = i,
Capabilities = videoSource.VideoCapabilities[i],
});
}
}
else
{
list.Add(new GetResolvingPower
{
index = -1,
Capabilities = null,
error = "不存在USB摄像头",
});
}
}
catch (Exception EX)
{
list.Add(new GetResolvingPower
{
index = -2,
Capabilities = null,
error = EX.Source + " " + EX.Message
});
}
return Newtonsoft.Json.JsonConvert.SerializeObject(list);
}
#endregion
#region IObjectSafety 成员直接复制
private const string _IID_IDispatch = "{00020400-0000-0000-C000-000000000046}";
private const string _IID_IDispatchEx = "{a6ef9860-c720-11d0-9337-00a0c90dcaa9}";
private const string _IID_IPersistStorage = "{0000010A-0000-0000-C000-000000000046}";
private const string _IID_IPersistStream = "{00000109-0000-0000-C000-000000000046}";
private const string _IID_IPersistPropertyBag = "{37D84F60-42CB-11CE-8135-00AA004BB851}";
private const int INTERFACESAFE_FOR_UNTRUSTED_CALLER = 0x00000001;
private const int INTERFACESAFE_FOR_UNTRUSTED_DATA = 0x00000002;
private const int S_OK = 0;
private const int E_FAIL = unchecked((int)0x80004005);
private const int E_NOINTERFACE = unchecked((int)0x80004002);
private bool _fSafeForScripting = true;
private bool _fSafeForInitializing = true;
public int GetInterfaceSafetyOptions(ref Guid riid, ref int pdwSupportedOptions, ref int pdwEnabledOptions)
{
int Rslt = E_FAIL;
string strGUID = riid.ToString("B");
pdwSupportedOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER | INTERFACESAFE_FOR_UNTRUSTED_DATA;
switch (strGUID)
{
case _IID_IDispatch:
case _IID_IDispatchEx:
Rslt = S_OK;
pdwEnabledOptions = 0;
if (_fSafeForScripting == true)
pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_CALLER;
break;
case _IID_IPersistStorage:
case _IID_IPersistStream:
case _IID_IPersistPropertyBag:
Rslt = S_OK;
pdwEnabledOptions = 0;
if (_fSafeForInitializing == true)
pdwEnabledOptions = INTERFACESAFE_FOR_UNTRUSTED_DATA;
break;
default:
Rslt = E_NOINTERFACE;
break;
}
return Rslt;
}
public int SetInterfaceSafetyOptions(ref Guid riid, int dwOptionSetMask, int dwEnabledOptions)
{
int Rslt = E_FAIL;
string strGUID = riid.ToString("B");
switch (strGUID)
{
case _IID_IDispatch:
case _IID_IDispatchEx:
if (((dwEnabledOptions & dwOptionSetMask) == INTERFACESAFE_FOR_UNTRUSTED_CALLER) && (_fSafeForScripting == true))
Rslt = S_OK;
break;
case _IID_IPersistStorage:
case _IID_IPersistStream:
case _IID_IPersistPropertyBag:
if (((dwEnabledOptions & dwOptionSetMask) == INTERFACESAFE_FOR_UNTRUSTED_DATA) && (_fSafeForInitializing == true))
Rslt = S_OK;
break;
default:
Rslt = E_NOINTERFACE;
break;
}
return Rslt;
}
#endregion
}
View Code
用于测试的HTML页面代码：
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title></title>
<meta charset="utf-8" />
<script>
//初始化 设置USB控件大小和显示
var array = new Array();
window.onload = function () {
var USBCamera = document.getElementById("USBCamera");
USBCamera.Stop(); //停止视频
array = JSON.parse(document.getElementById("USBCamera").GetResolution());//获取USB分辨率
/*
判断获取数据是否成功（USB连接是否正常）
大于1为成功，摄像头基本有多个分辨率
也可以判断返回值中index是否为负数
获取到的分辨率最大的为第一个下标为：0
*/
if (array.length > 1) {
//分辨率下标 宽 高
var index = 0, width = 0, height = 0;
for (var i = 0; i < array.length; i++) {
var size = array[i].Capabilities.FrameSize;
if (size.Width > width && size.Height > height) {
index = i;
width = size.Width;
height = size.Height;
}
}
//此处我获取分辨率的最大值赋值，实际可以更改
USBCamera.FormSize(width, height, "宋体", 9, "", 10000);//初始化
USBCamera.Start(index);//打开摄像头
} else {
if (array[0].index == -1) { //-1未连接
USBCamera.FromSize(400, 400, "宋体", 9, "摄像头未连接", 10000);
} if (array[0].index == -2) { //-2 获取是发生错误
USBCamera.FromSize(400, 400, "宋体", 9, "摄像头连接有异常，请联系管理人员！", 10000);
}
}
}
//关闭时执行Stop
window.BeforeUnloadEvent = function () {
document.getElementById("USBCamera").Stop();
}
//测试连接
function TestConnection() {
alert(document.getElementById("USBCamera").Connection());
}
//打开摄像头
function StartCamera() {
document.getElementById("USBCamera").Start(0);
}
//关闭摄像头
function StopCamera() {
document.getElementById("USBCamera").Stop();
}
//获取截图
function GetScreenshots() {
var imgInfo = document.getElementById("USBCamera").GetScreenshots();
if (imgInfo.result) {
document.getElementById("DisplayScreenshots").src = "data:image/jpg;base64," + imgInfo.message;
} else {
alert("截图获取失败");
}
}
//获取分辨率
function GetResolution() {
console.log(document.getElementById("USBCamera").GetResolution());
}
</script>
</head>
<body>
<div>
<button onclick="TestConnection()">测试连接</button>
<button onclick="StartCamera()">打开摄像头</button>
<button onclick="StopCamera()">关闭摄像头</button>
<button onclick="GetScreenshots()">获取截图</button>
<button onclick="GetResolution()">获取分辨率</button>
</div>
<hr />
<h3>截图显示</h3>
<img style="width:300px;height:300px;" id="DisplayScreenshots" />
<div style="float:right;width:70%">
<object id="USBCamera" classid="clsid:887FC3C3-A970-4A36-92EF-D4EB31541C40">
<div class="alert alert-danger">视频控件载入失败！如未安装，请<a href="InstallationPackage/Setup1.msi">下载安装</a>。</div>
</object>
</div>
</body>
</html>
View Code
实现的效果图：
结语
VS使用的2015社区版，社区版。。。有点尴尬所以打包使用的 Visual Studio Installer
一回生二回熟，第一次写这个满脸蒙蔽。
不过这次稍微整理了一下，改动了一点，后续准备找个人脸识别的开源接口融合进来。
下面给个下载地址，可以直接调试，需要注意使用IE，由于没有加证书，IE需要设置。
工具>Internet选项
>安全>加入受信任的站点>
>自定义级别>ActiveX控件和插件>ActivexX控件自动提示>启用
>对未标记为可安全执行的脚本的ActivexX控件初始化并执行脚本>启用
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