使用DirectShow打开摄像头 MFC编程

    之前使用OpenCV 自带的函数打开摄像头，在Win7下无法使用的朋友可以参考一下这篇文章。使用DirectShow可以实现打开多个摄像头。首先从网上下载三个文件：DirectShow、CameraDS.cpp、CameraDS.h其中DirectShow是一个文件夹，没必要下载安装程序，DirectShow里面包含了lib文件与Include头文件。接下来是配置DirectShow，新建一个MFC工程，然后在文件一栏添加CameraDS.cpp与CameraDS.h到工程里，还要在工程的.cpp文件哪里添加DirectShow的头文件。比如

//以下fordirectshow#include "camerads.h" #include <stdio.h> #include <stdarg.h> #include <time.h>

       接下来就可以着手写打开摄像通头的程序了。以下是相关代码：

 

// 行人检测Dlg.cpp : implementation file
//

#include "stdafx.h"
#include "行人检测.h"
#include "行人检测Dlg.h"

#include <cv.h>
#include <cxcore.h>
#include <highgui.h>

//以下fordirectshow
#include "camerads.h" 
#include <stdio.h> 
#include <stdarg.h> 
#include <time.h> 

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About

class CAboutDlg : public CDialog
{
public:
	CAboutDlg();

// Dialog Data
	//{{AFX_DATA(CAboutDlg)
	enum { IDD = IDD_ABOUTBOX };
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CAboutDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);    // DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	//{{AFX_MSG(CAboutDlg)
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD)
{
	//{{AFX_DATA_INIT(CAboutDlg)
	//}}AFX_DATA_INIT
}

void CAboutDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAboutDlg)
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAboutDlg, CDialog)
	//{{AFX_MSG_MAP(CAboutDlg)
		// No message handlers
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyDlg dialog

CMyDlg::CMyDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CMyDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CMyDlg)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CMyDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CMyDlg)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CMyDlg, CDialog)
	//{{AFX_MSG_MAP(CMyDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_FILE_OPEN, OnFileOpen)
	ON_WM_TIMER()
	ON_WM_CANCELMODE()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CMyDlg message handlers

BOOL CMyDlg::OnInitDialog()
{
	CDialog::OnInitDialog();

	// Add "About..." menu item to system menu.

	// IDM_ABOUTBOX must be in the system command range.
	ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
	ASSERT(IDM_ABOUTBOX < 0xF000);

	CMenu* pSysMenu = GetSystemMenu(FALSE);
	if (pSysMenu != NULL)
	{
		CString strAboutMenu;
		strAboutMenu.LoadString(IDS_ABOUTBOX);
		if (!strAboutMenu.IsEmpty())
		{
			pSysMenu->AppendMenu(MF_SEPARATOR);
			pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
		}
	}

	// Set the icon for this dialog.  The framework does this automatically
	//  when the application's main window is not a dialog
	SetIcon(m_hIcon, TRUE);			// Set big icon
	SetIcon(m_hIcon, FALSE);		// Set small icon
	// TODO: Add extra initialization here
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CMyDlg::OnSysCommand(UINT nID, LPARAM lParam)
{
	if ((nID & 0xFFF0) == IDM_ABOUTBOX)
	{
		CAboutDlg dlgAbout;
		dlgAbout.DoModal();
	}
	else
	{
		CDialog::OnSysCommand(nID, lParam);
	}
}

// If you add a minimize button to your dialog, you will need the code below
//  to draw the icon.  For MFC applications using the document/view model,
//  this is automatically done for you by the framework.

void CMyDlg::OnPaint() 
{
	if (IsIconic())
	{
		CPaintDC dc(this); // device context for painting

		SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0);

		// Center icon in client rectangle
		int cxIcon = GetSystemMetrics(SM_CXICON);
		int cyIcon = GetSystemMetrics(SM_CYICON);
		CRect rect;
		GetClientRect(&rect);
		int x = (rect.Width() - cxIcon + 1) / 2;
		int y = (rect.Height() - cyIcon + 1) / 2;

		// Draw the icon
		dc.DrawIcon(x, y, m_hIcon);
	}
	else
	{
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CMyDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}



void CMyDlg::OnFileOpen() 
{
	// TODO: Add your control notification handler code here
//打开摄像头，指定摄像头0开始，参数2指示是否自动弹出摄像头属性页。 
 if(!camera.OpenCamera(0)) //false不弹出属性窗，用代码制定宽和高 
{ 
fprintf(stderr, "Can not open camera 0.\n");//不成功，if(!0)，执行代码 
//return -1; 
} 
    SetTimer(1,40,NULL);                //每隔一段时间读出一帧视频图像	
}

void CMyDlg::OnTimer(UINT nIDEvent) 
{
	// TODO: Add your message handler code here and/or call default
	pFrame = camera.QueryFrame();  //抓取一帧
	ShowPicture(IDC_srcp, pFrame);   //显示图像
	CDialog::OnTimer(nIDEvent);

}

void CMyDlg::ShowPicture(int nID, IplImage *Image)   //显示图像函数
{
    	CDC *pDC = GetDlgItem(nID)->GetDC();//根据ID获得窗口指针再获取与该窗口关联的上下文指针	
	    HDC hdc= pDC->GetSafeHdc();                      // 获取设备上下文句柄
	    CRect rect;											// 矩形类
	    GetDlgItem(nID)->GetClientRect(&rect); //	获取box1客户区
	    CvvImage cimg;										//
	    cimg.CopyOf(Image,1);		  //参数1代表通道数，故此ShowPicture(int nID, IplImage *Image)函数只能显示单通道图像						
	    cimg.DrawToHDC(hdc,&rect);							//输出图像
	    ReleaseDC( pDC );
	    cimg.Destroy();										//销毁
}

void CMyDlg::OnCancelMode() 
{
	CDialog::OnCancelMode();

	// TODO: Add your message handler code here
	
}


void CMyDlg::OnOK() 
{
	// TODO: Add extra validation here
	camera.CloseCamera(); 
	CDialog::OnOK();
}

头文件

// 行人检测Dlg.h : header file
//
#include "cv.h"
#include "highgui.h"

#include "camerads.h" 

#if !defined(AFX_DLG_H__A2371946_D45A_470D_A282_28670F9555E9__INCLUDED_)
#define AFX_DLG_H__A2371946_D45A_470D_A282_28670F9555E9__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

/////////////////////////////////////////////////////////////////////////////
// CMyDlg dialog

class CMyDlg : public CDialog
{
// Construction
public:
	void ShowPicture(int nID, IplImage *Image);
    CCameraDS camera;
    //声明IplImage指针
   IplImage* pFrame ;

	CMyDlg(CWnd* pParent = NULL);	// standard constructor

// Dialog Data
	//{{AFX_DATA(CMyDlg)
	enum { IDD = IDD_MY_DIALOG };
		// NOTE: the ClassWizard will add data members here
	//}}AFX_DATA

	// ClassWizard generated virtual function overrides
	//{{AFX_VIRTUAL(CMyDlg)
	protected:
	virtual void DoDataExchange(CDataExchange* pDX);	// DDX/DDV support
	//}}AFX_VIRTUAL

// Implementation
protected:
	HICON m_hIcon;

	// Generated message map functions
	//{{AFX_MSG(CMyDlg)
	virtual BOOL OnInitDialog();
	afx_msg void OnSysCommand(UINT nID, LPARAM lParam);
	afx_msg void OnPaint();
	afx_msg HCURSOR OnQueryDragIcon();
	afx_msg void OnFileOpen();
	afx_msg void OnTimer(UINT nIDEvent);
	afx_msg void OnCancelMode();
	virtual void OnOK();
	//}}AFX_MSG
	DECLARE_MESSAGE_MAP()
};

//{{AFX_INSERT_LOCATION}}
// Microsoft Visual C++ will insert additional declarations immediately before the previous line.

#endif // !defined(AFX_DLG_H__A2371946_D45A_470D_A282_28670F9555E9__INCLUDED_)