使用directshow代替opencv的vfw的源代码

本文提供了使用directshow代替opencv的vfw 的源代码,与转化为iplimage格式的算法.
实验中发现opencv的cvCaptureFromCAM 使用的是vfw,采用消息机制,速度较慢,测试发现fps只有 9-12左右,太慢了.  发现经过使用directshow后速度提升到60帧/s.在opencv group上了解到这是一个普遍问题,也许有人做过转换,却没有完整的例子与代码.在此贴出.对希望提高opencv视频分析速度的有所帮助.

http://hardy.gigcities.com/Directshow_Opencv.rar 下载代码

用法如下:
static ARFrameGrabber frameGrabber;
IplImage ds_frame;
frameGrabber.Init(0, true);
frameGrabber.SetFlippedImage(true);
for(;;)
    {
       IplImage *frame =0;
 frameGrabber.GrabByteFrame();
 BYTE *myBuffer = frameGrabber.GetByteBuffer();

 int width = frameGrabber.GetWidth();
 int height = frameGrabber.GetHeight();  
 int stride  = (width * sizeof( RGBTRIPLE ) + 3) & -4;

 cvInitImageHeader( &ds_frame, cvSize(width, height), 8, 3,IPL_ORIGIN_BL, 4 );
 ds_frame.widthStep = stride;   
 cvSetData( &ds_frame, myBuffer, stride ); 
 frame = &ds_frame;

        /* 视频分析部分 */
     
   }

以下是directshow源文件,加入工程可用.

// ARFrameGrabber.h: interface for the ARFrameGrabber class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_ARFRAMEGRABBER_H__C5553937_4BAB_4FEF_B4A6_1693AB0C99E3__INCLUDED_)
#define AFX_ARFRAMEGRABBER_H__C5553937_4BAB_4FEF_B4A6_1693AB0C99E3__INCLUDED_

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

//#include <AR/config.h>

#define WIN32_LEAN_AND_MEAN
#include <windows.h>
#include <dshow.h>
//#include <streams.h>
#include <atlbase.h>
#include <qedit.h>

class SmartString
{
public:
 SmartString():str(NULL) {}

 SmartString(char* pStr):str(NULL)
 {
  if (pStr)
  {
   int size = int(strlen(pStr));
   str = new char[size+1];
   strcpy(str, pStr);
  }
 }

 SmartString(SmartString& sStr)
 {
  SetString(sStr.GetBuffer());
 }

 ~SmartString()
 {
  if (str)
   delete[] str;
 }

 SmartString& operator =(char* pStr)
 {
  SetString(pStr);
  return *this;
 }

 SmartString& operator =(SmartString& sStr)
 {
  SetString(sStr.GetBuffer());
  return *this;
 }

 char* GetBuffer() {return str;}

protected:
 void SetString(char *pStr)
 {
  if (str)
   delete[] str;

  if (!pStr)
  {
   str = NULL;
  }
  else
  {
   int size = int(strlen(pStr));
   str = new char[size + 1];
   strcpy(str, pStr);
  }

 }

 char* str;
};

class DeviceInfo
{
public:
 DeviceInfo():next(NULL), deviceId(-1)
 {
 }
 ~DeviceInfo()
 {
  if (next)
   delete next;
 }

 SmartString friendlyName;
 int   deviceId; 
 DeviceInfo* next;
};

class  ARFrameGrabber 
{
public:
 ARFrameGrabber();
 virtual ~ARFrameGrabber();

 void Init(int deviceId, bool displayProperties = true);
 void BindFilter(int deviceId, IBaseFilter **pFilter);
 void GrabFrame(long* size, long** pBuffer);
 void GrabFrame();
 void Grab32BitFrame();
 void GrabByteFrame();
 void SetCrossBar();
 

 long  GetBufferSize() {return bufferSize;}
 long* GetBuffer() {return pBuffer;}
 BYTE* GetByteBuffer() {return pBYTEbuffer;}
 
 void SetFlippedImage(bool flag) {flipImage = flag;}

 void DisplayProperties();
 void EnumDevices(DeviceInfo *head);
    int GetWidth();
    int GetHeight();