USB摄像头采集图像(DirectShow)

摄像头除了可以捕获视频流还可以捕获单张静止的图片，静止的图片质量比流的质量要高。支持输出静态图片的摄像头一般要提供一个静态图片PIN，这个PIN的种类是PIN_CATEGORY_STILL。

捕捉静态图片常用的filter是Sample Graber filter，它的用法参考手册。然后将捕捉filter的静态PIN连接到Sample Grabber，再将Sample Grabber连接到Null Render filter，连接Null Render只是为了给Sample Grabber 的输出PIN上连接点东西。其结构图如下所示：

 

                                           Capture Device --------------->  SampleGraber ---------------------> Null  Render

为了实现上图所示的流图，需要分别实现其Filter，然后将各个Filter加入Graph，最后将他们连接起来，就实现整个流程。

1.Capture Device 作为采集设备构建Filter，采用如下代码

//将设备id为deviceId的设备绑定到指定的pFilter

bool UsbCamera::BindFilter(int deviceId, IBaseFilter **pFilter)

{

         if (deviceId < 0)

                   return false;

         CComPtr<ICreateDevEnum> pCreateDevEnum;

         HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER,

                   IID_ICreateDevEnum, (void**)&pCreateDevEnum);

         if (hr != NOERROR)

                   return false;

         CComPtr<IEnumMoniker> pEm;

         hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,

                   &pEm, 0);

         if (hr != NOERROR)

                   return false;

         pEm->Reset();

         ULONG cFetched;

         IMoniker *pM;

         int index = 0;

         while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK, index <= deviceId)

         {

                   IPropertyBag *pBag;

                   hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void **)&pBag);

                   if(SUCCEEDED(hr))

                   {

                            VARIANT var;

                            var.vt = VT_BSTR;

                            hr = pBag->Read(L"FriendlyName", &var, NULL);

                            if (hr == NOERROR)

                            {

                                     if (index == deviceId)

                                     {

                                               pM->BindToObject(0, 0, IID_IBaseFilter, (void**)pFilter);

                                     }

                                     SysFreeString(var.bstrVal);

                            }

                            pBag->Release();

                   }

                   pM->Release();

                   index++;

         }

         return true;

}

2.Sample Graber Filter的实现

加入Sample Graber Filter是为了设置媒体的类型

IBaseFilter* pSampleGrabberFilter;

hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,

                   IID_IBaseFilter, (LPVOID *)&pSampleGrabberFilter);

ISampleGrabber*  pSampleGrabber;

hr = pSampleGrabberFilter->QueryInterface(IID_ISampleGrabber, (void**)&pSampleGrabber);

//设置媒体类型

AM_MEDIA_TYPE   mt;

ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));

mt.majortype  = MEDIATYPE_Video;

if (mode == "MEDIASUBTYPE_RGB24" )

{

         mt.subtype = MEDIASUBTYPE_RGB24;

         bytePP     = 3.0;

}

else if (mode == "MEDIASUBTYPE_YUY2" )

{

         mt.subtype = MEDIASUBTYPE_YUY2;

         bytePP     = 2.0;

}

mt.formattype = FORMAT_VideoInfo;

hr = pSampleGrabber->SetMediaType(&mt);

3.Null Render Filter的实现

IBaseFilter* pNullFilter;

hr = CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER,

                   IID_IBaseFilter, (LPVOID*) &pNullFilter);

4．将各个Filter加入Graph

IGraphBuilder* pGraph;

hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC,

                   IID_IGraphBuilder, (void **)&pGraph);

pGraph->AddFilter(pDeviceFilter, NULL);

pGraph->AddFilter(pSampleGrabberFilter, L"Grabber");

pGraph->AddFilter(pNullFilter, L"NullRenderer");

5.对于有的采集设备可能有多个输入和输出的PIN，我们需选择一个通路，通过SetCrossBar设备;

//对于有多个输入和输出的设备，需选择一个通路，另外设置媒体类型;

void UsbCamera::SetCrossBar(int fr, int iiw, int iih,string mode)

{

         IAMCrossbar *pXBar1             = NULL;

         IAMStreamConfig*      pVSC      = NULL;

         HRESULT hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL,

                   CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2,

                   (void **)&pBuilder);

         if (SUCCEEDED(hr))

                   hr = pBuilder->SetFiltergraph(pGraph);

         hr = pBuilder->FindInterface(&LOOK_UPSTREAM_ONLY, NULL,

                   pDeviceFilter,IID_IAMCrossbar, (void**)&pXBar1);

         if (SUCCEEDED(hr))

         {

                   long OutputPinCount;

                   long InputPinCount;

                   long PinIndexRelated;

                   long PhysicalType;

                   long inPort = 0;

                   long outPort = 0;

                   pXBar1->get_PinCounts(&OutputPinCount,&InputPinCount);

                   for(int i =0;i<InputPinCount;i++)

                   {

                            pXBar1->get_CrossbarPinInfo(TRUE,i,&PinIndexRelated,&PhysicalType);

                            if(PhysConn_Video_Composite==PhysicalType)

                            {

                                     inPort = i;

                                     break;

                            }

                   }

                   for(int i =0;i<OutputPinCount;i++)

                   {

                            pXBar1->get_CrossbarPinInfo(FALSE,i,&PinIndexRelated,&PhysicalType);

                            if(PhysConn_Video_VideoDecoder==PhysicalType)

                            {

                                     outPort = i;

                                     break;

                            }

                   }

                   if(S_OK==pXBar1->CanRoute(outPort,inPort))

                   {

                            pXBar1->Route(outPort,inPort);

                   }

                   pXBar1->Release();          

         }

         //设置媒体类型;

         hr = pBuilder->FindInterface( &PIN_CATEGORY_CAPTURE,0,pDeviceFilter,

                   IID_IAMStreamConfig,(void**)&pVSC );

         AM_MEDIA_TYPE *pmt;

         if( SUCCEEDED(hr) )

         {

                   hr = pVSC->GetFormat(&pmt);

                   if (hr == NOERROR)

                   {

                            if (pmt->formattype == FORMAT_VideoInfo )

                            {

                                     VIDEOINFOHEADER *pvi = (VIDEOINFOHEADER*) pmt->pbFormat;

                                     if (mode == "MEDIASUBTYPE_RGB24" )

                                               pmt->subtype = MEDIASUBTYPE_RGB24;

                                     else if (mode == "MEDIASUBTYPE_YUY2" )

                                               pmt->subtype = MEDIASUBTYPE_YUY2;

                                     pvi->AvgTimePerFrame = (LONGLONG)( 10000000 / fr );

                                     pvi->bmiHeader.biWidth  = iiw;

                                     pvi->bmiHeader.biHeight = iih;

                                     pvi->bmiHeader.biSizeImage = DIBSIZE(pvi->bmiHeader);

                                     hr = pVSC->SetFormat(pmt);

                            }

                            FreeMediaType(*pmt);

                   }

                   SAFE_RELEASE( pVSC );

         }

}

6.将各filter连接起来

Ipin* pCameraOutput;

Ipin* pGrabberInput;

Ipin* pGrabberOutput;

Ipin* pNullInputPin;

CComPtr<IEnumPins> pEnum;

pDeviceFilter->EnumPins(&pEnum);

hr = pEnum->Reset();

hr = pEnum->Next(1, &pCameraOutput, NULL);

pEnum = NULL;

pSampleGrabberFilter->EnumPins(&pEnum);

pEnum->Reset();

hr = pEnum->Next(1, &pGrabberInput, NULL);

pEnum = NULL;

pSampleGrabberFilter->EnumPins(&pEnum);

pEnum->Reset();

pEnum->Skip(1);

hr = pEnum->Next(1, &pGrabberOutput, NULL);

pEnum = NULL;

pNullFilter->EnumPins(&pEnum);

pEnum->Reset();

hr = pEnum->Next(1, &pNullInputPin, NULL);

//连接Pin;

hr = pGraph->Connect(pCameraOutput, pGrabberInput);

hr = pGraph->Connect(pGrabberOutput, pNullInputPin);

7.运行

pSampleGrabber->SetBufferSamples(TRUE); // true for wait frame done call back 不再另外开辟单帧缓冲区

pSampleGrabber->SetOneShot(TRUE); // FALSE=截图后继续运行graph,TRUE=STOP RUN GRAPH

hr = pSampleGrabber->GetConnectedMediaType( &mt );

VIDEOINFOHEADER *videoHeader;

assert(mt.formattype == FORMAT_VideoInfo);

videoHeader = reinterpret_cast<VIDEOINFOHEADER*>(mt.pbFormat);

width  = videoHeader->bmiHeader.biWidth;

height = videoHeader->bmiHeader.biHeight;

FreeMediaType(mt);

pMediaControl->Run();

 

 

 

8.原代码

 

//==================================ImageBuffer.h================================================================

#ifndef _imagebuffer_h_
#define _imagebuffer_h_

class ImageBuffer
{
public:
 enum {
  FORMAT_YUV444=0,
  FORMAT_YUV422,
  FORMAT_YUV411,
  FORMAT_RGB,
  FORMAT_MONO,
  FORMAT_MONO16,
  FORMAT_UYV
 };    

 int width;             
 int height;             
 int format;            
 int size;               
 unsigned char* buffer;  

 ImageBuffer::ImageBuffer()
 {

 }
 ImageBuffer::ImageBuffer(int width, int height, int format,
  unsigned char* buffer, int size)
  : width(width), height(height), format(format), buffer(buffer), size(size)
 {

 }

 //static void convert(const ImageBuffer& src, ImageBuffer& dst) throw (RobotsException); 

};

#endif

 

//==================================ImageSource.h================================================================

#ifndef _imagesource_h_
#define _imagesource_h_

#include "ImageBuffer.h"

class ImageSource
{
public:
 virtual ImageBuffer getImage() =0;
 virtual int getWidth() const=0;
 virtual int getHeight() const=0;
};
#endif

 

//==================================UsbCamera.h================================================================

#ifndef USBCAMER_H_INCLUDE
#define USBCAMER_H_INCLUDE

#include <windows.h>
#include <dshow.h>
#include <atlbase.h>
#include <qedit.h>
#include <string>
#include "ImageSource.h"

 

#define WIN32_LEAN_AND_MEAN

#ifndef SAFE_RELEASE
#define SAFE_RELEASE( x ) \
 if ( NULL != x ) \
{ \
 x->Release( ); \
 x = NULL; \
}
#endif

using namespace std;
class UsbCamera : public ImageSource
{
public:
 UsbCamera();
 virtual ~UsbCamera();

 virtual ImageBuffer getImage();
 virtual int   getWidth() const;
 virtual int   getHeight() const;

 static UsbCamera* getCamera(  int port = 0, int framerate = 30, int width = 320,
  int height = 240, string mode = "" );
 static void   destroyUsbCamera();

 void    Init( int deviceId, bool displayProperties = false, int framerate = 30,int iw = 320, int ih = 240, string mode = "" );
 void    DisplayFilterProperties();

 bool    BindFilter(int deviceId, IBaseFilter **pFilter);
 void    SetCrossBar( int fr = 30, int iiw = 320, int iih = 240, string mode = "" );
 HRESULT    GrabByteFrame();
 long    GetBufferSize()  { return bufferSize; }
 long*    GetBuffer()   { return pBuffer;    }
 BYTE*    GetByteBuffer()  { return pBYTEbuffer;}

public:
 bool        bisValid;

protected:
 IGraphBuilder*   pGraph;
 IBaseFilter*   pDeviceFilter;
 IMediaControl*   pMediaControl;
 IBaseFilter*   pSampleGrabberFilter;
 ISampleGrabber*   pSampleGrabber;
 IPin*     pGrabberInput;
 IPin*     pGrabberOutput;
 IPin*     pCameraOutput;
 IMediaEvent*   pMediaEvent;
 IBaseFilter*   pNullFilter;
 IPin*     pNullInputPin;
 ICaptureGraphBuilder2*  pBuilder;

 static UsbCamera*  m_camera;
 ImageBuffer    imagebuf;

 double                  bytePP;
private:
 void     ErrMsg(LPTSTR szFormat,...);
 void     FreeMediaType(AM_MEDIA_TYPE& mt);

 long  bufferSize;
 long*  pBuffer;
 BYTE*  pBYTEbuffer;
 bool  connected;
 int   width;
 int   height;

 ImageBuffer m_buffer;
 bool  bnotify;
 string     format_mode; 

};

#endif

 

//==================================UsbCamera.cpp================================================================

#include "StdAfx.h"
#include <assert.h>
#include "UsbCamera.h"

#ifndef USE_YUV422_FORMAT
#define USE_YUV422_FORMAT 0
#endif

#ifndef USE_RGB24_FORMAT
#define USE_RGB24_FORMAT  1
#endif

#ifndef SEND_WORK_STATE
#define SEND_WORK_STATE  0
#endif

UsbCamera* UsbCamera::m_camera = NULL;

UsbCamera::UsbCamera():bisValid(false),pBuffer(NULL),pBYTEbuffer(NULL),bufferSize(0),bytePP(2.0),
 connected(false),bnotify(false),width(0),height(0)
{
 if (FAILED(CoInitialize(NULL)))
 {
  return;
 }
 pGraph     = NULL;
 pDeviceFilter   = NULL;
 pMediaControl   = NULL;
 pSampleGrabberFilter = NULL;
 pSampleGrabber   = NULL;
 pGrabberInput   = NULL;
 pGrabberOutput   = NULL;
 pCameraOutput   = NULL;
 pMediaEvent    = NULL;
 pNullFilter    = NULL;
 pNullInputPin   = NULL;
 pBuilder    = NULL;

}

UsbCamera::~UsbCamera()
{
 if( connected )
 {
  if (pMediaControl )
  {
   pMediaControl->Stop();
  }
  SAFE_RELEASE(pGraph);
  SAFE_RELEASE(pDeviceFilter);
  SAFE_RELEASE(pMediaControl);
  SAFE_RELEASE(pSampleGrabberFilter);
  SAFE_RELEASE(pSampleGrabber);
  SAFE_RELEASE(pGrabberInput);
  SAFE_RELEASE(pGrabberOutput);
  SAFE_RELEASE(pCameraOutput);
  SAFE_RELEASE(pMediaEvent);
  SAFE_RELEASE(pNullFilter);
  SAFE_RELEASE(pNullInputPin);
  SAFE_RELEASE(pBuilder);
  CoUninitialize();
 }
 if( pBuffer )
  delete[] pBuffer;
 if( pBYTEbuffer )
  delete[] pBYTEbuffer;
}

void UsbCamera::Init(int deviceId, bool displayProperties,
 int framerate, int iw , int ih, string mode )
{
 HRESULT hr = S_OK;
 format_mode = mode;
 // Create the Filter Graph Manager.
 hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC,
  IID_IGraphBuilder, (void **)&pGraph);

 hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,
  IID_IBaseFilter, (LPVOID *)&pSampleGrabberFilter);

 hr = pGraph->QueryInterface(IID_IMediaControl, (void **) &pMediaControl);
 hr = pGraph->QueryInterface(IID_IMediaEvent, (void **) &pMediaEvent);

 hr = CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER,
  IID_IBaseFilter, (LPVOID*) &pNullFilter);

 hr = pGraph->AddFilter(pNullFilter, L"NullRenderer");

 hr = pSampleGrabberFilter->QueryInterface(IID_ISampleGrabber, (void**)&pSampleGrabber);

 AM_MEDIA_TYPE   mt;
 ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));
 mt.majortype  = MEDIATYPE_Video;

 if (mode == "MEDIASUBTYPE_RGB24" )
 {
  mt.subtype = MEDIASUBTYPE_RGB24;
  bytePP     = 3.0;
 }
 else if (mode == "MEDIASUBTYPE_YUY2" )
 {
  mt.subtype = MEDIASUBTYPE_YUY2;
  bytePP     = 2.0;
 }

 mt.formattype = FORMAT_VideoInfo;
 hr = pSampleGrabber->SetMediaType(&mt);

 pGraph->AddFilter(pSampleGrabberFilter, L"Grabber");

 // Bind Device Filter. We know the device because the id was passed in
 if(!BindFilter(deviceId, &pDeviceFilter))
 {
  ErrMsg(TEXT("未找到USB摄像头!\n请检查设备后重试!"));
  exit(0);
  return;
 }

 pGraph->AddFilter(pDeviceFilter, NULL);

 CComPtr<IEnumPins> pEnum;
 pDeviceFilter->EnumPins(&pEnum);
 hr = pEnum->Reset();
 hr = pEnum->Next(1, &pCameraOutput, NULL);
 pEnum = NULL;
 pSampleGrabberFilter->EnumPins(&pEnum);
 pEnum->Reset();
 hr = pEnum->Next(1, &pGrabberInput, NULL);
 pEnum = NULL;
 pSampleGrabberFilter->EnumPins(&pEnum);
 pEnum->Reset();
 pEnum->Skip(1);
 hr = pEnum->Next(1, &pGrabberOutput, NULL);
 pEnum = NULL;
 pNullFilter->EnumPins(&pEnum);
 pEnum->Reset();
 hr = pEnum->Next(1, &pNullInputPin, NULL);

 SetCrossBar(framerate,iw,ih,mode);

 if (displayProperties)
 {
  CComPtr<ISpecifyPropertyPages> pPages;

  HRESULT hr = pCameraOutput->QueryInterface(IID_ISpecifyPropertyPages, (void**)&pPages);
  if (SUCCEEDED(hr))
  {
   PIN_INFO PinInfo;
   pCameraOutput->QueryPinInfo(&PinInfo);
   CAUUID caGUID;
   pPages->GetPages(&caGUID);
   OleCreatePropertyFrame( NULL,0, 0,L"Property Sheet",1,
    (IUnknown **)&(pCameraOutput),
    caGUID.cElems, caGUID.pElems,
    0,0,NULL );
   CoTaskMemFree(caGUID.pElems);
   PinInfo.pFilter->Release();
  }
 }

 hr = pGraph->Connect(pCameraOutput, pGrabberInput);
 hr = pGraph->Connect(pGrabberOutput, pNullInputPin);

 pSampleGrabber->SetBufferSamples(TRUE); // true for wait frame done call back 不再另外开辟单帧缓冲区
 pSampleGrabber->SetOneShot(TRUE); // FALSE=截图后继续运行graph,TRUE=STOP RUN GRAPH

 hr = pSampleGrabber->GetConnectedMediaType( &mt );
 VIDEOINFOHEADER *videoHeader;
 assert(mt.formattype == FORMAT_VideoInfo);
 videoHeader = reinterpret_cast<VIDEOINFOHEADER*>(mt.pbFormat);
 width  = videoHeader->bmiHeader.biWidth;
 height = videoHeader->bmiHeader.biHeight;
 FreeMediaType(mt);

 pMediaControl->Run();
 connected = true;
}

//将设备id为deviceId的设备 绑定到指定的pFilter
bool UsbCamera::BindFilter(int deviceId, IBaseFilter **pFilter)
{
 if (deviceId < 0)
  return false;
 CComPtr<ICreateDevEnum> pCreateDevEnum;
 HRESULT hr = CoCreateInstance(CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER,
  IID_ICreateDevEnum, (void**)&pCreateDevEnum);
 if (hr != NOERROR)
  return false;

 CComPtr<IEnumMoniker> pEm;
 hr = pCreateDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,
  &pEm, 0);
 if (hr != NOERROR)
  return false;

 pEm->Reset();
 ULONG cFetched;
 IMoniker *pM;
 int index = 0;
 while(hr = pEm->Next(1, &pM, &cFetched), hr==S_OK, index <= deviceId)
 {
  IPropertyBag *pBag;
  hr = pM->BindToStorage(0, 0, IID_IPropertyBag, (void **)&pBag);
  if(SUCCEEDED(hr))
  {
   VARIANT var;
   var.vt = VT_BSTR;
   hr = pBag->Read(L"FriendlyName", &var, NULL);
   if (hr == NOERROR)
   {
    if (index == deviceId)
    {
     pM->BindToObject(0, 0, IID_IBaseFilter, (void**)pFilter);
    }
    SysFreeString(var.bstrVal);
   }
   pBag->Release();
  }
  pM->Release();
  index++;
 }
 return true;
}

//对于有多个输入和输出的设备，需选择一个通路，另外设置媒体类型;
void UsbCamera::SetCrossBar(int fr, int iiw, int iih,string mode)
{
 IAMCrossbar *pXBar1             = NULL;
 IAMStreamConfig*      pVSC      = NULL;

 HRESULT hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL,
  CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2,
  (void **)&pBuilder);

 if (SUCCEEDED(hr))
  hr = pBuilder->SetFiltergraph(pGraph);

 hr = pBuilder->FindInterface(&LOOK_UPSTREAM_ONLY, NULL,
  pDeviceFilter,IID_IAMCrossbar, (void**)&pXBar1);

 if (SUCCEEDED(hr))
 {
  long OutputPinCount;
  long InputPinCount;
  long PinIndexRelated;
  long PhysicalType;
  long inPort = 0;
  long outPort = 0;

  pXBar1->get_PinCounts(&OutputPinCount,&InputPinCount);
  for(int i =0;i<InputPinCount;i++)
  {
   pXBar1->get_CrossbarPinInfo(TRUE,i,&PinIndexRelated,&PhysicalType);
   if(PhysConn_Video_Composite==PhysicalType)
   {
    inPort = i;
    break;
   }
  }
  for(int i =0;i<OutputPinCount;i++)
  {
   pXBar1->get_CrossbarPinInfo(FALSE,i,&PinIndexRelated,&PhysicalType);
   if(PhysConn_Video_VideoDecoder==PhysicalType)
   {
    outPort = i;
    break;
   }
  }

  if(S_OK==pXBar1->CanRoute(outPort,inPort))
  {
   pXBar1->Route(outPort,inPort);
  }
  pXBar1->Release();  
 }

 //设置媒体类型;
 hr = pBuilder->FindInterface( &PIN_CATEGORY_CAPTURE,0,pDeviceFilter,
  IID_IAMStreamConfig,(void**)&pVSC );

 AM_MEDIA_TYPE *pmt;
 if( SUCCEEDED(hr) )
 {
  hr = pVSC->GetFormat(&pmt);

  if (hr == NOERROR)
  {
   if (pmt->formattype == FORMAT_VideoInfo )
   {
    VIDEOINFOHEADER *pvi = (VIDEOINFOHEADER*) pmt->pbFormat;
    if (mode == "MEDIASUBTYPE_RGB24" )
     pmt->subtype = MEDIASUBTYPE_RGB24;
    else if (mode == "MEDIASUBTYPE_YUY2" )
     pmt->subtype = MEDIASUBTYPE_YUY2;

    pvi->AvgTimePerFrame = (LONGLONG)( 10000000 / fr );
    pvi->bmiHeader.biWidth  = iiw;
    pvi->bmiHeader.biHeight = iih;
    pvi->bmiHeader.biSizeImage = DIBSIZE(pvi->bmiHeader);
    hr = pVSC->SetFormat(pmt);
   }
   FreeMediaType(*pmt);
  }
  SAFE_RELEASE( pVSC );
 }
}

HRESULT UsbCamera::GrabByteFrame()
{
 HRESULT hr;
 long    size = 0;
 long evCode;

 hr = pMediaEvent->WaitForCompletion(10e4, &evCode); // INFINITE

#if SEND_WORK_STATE
 if( evCode == EC_COMPLETE )
  pMediaControl->Pause();
 else if( FAILED(hr) || evCode <= 0 )
 {
  if( !bnotify )
  {
   bnotify = true;
   bisValid = false;
   return E_FAIL;
  }
 }
#endif

 pSampleGrabber->GetCurrentBuffer(&size, NULL);

 // use YUV422 format
#if USE_YUV422_FORMAT
 // if buffer is not the same size as before, create a new one
 if( size != bufferSize )
 {
  if( pBuffer )
   delete[] pBuffer;
  bufferSize = size;
  pBuffer = new long[bufferSize];
  if( pBYTEbuffer )
   delete[] pBYTEbuffer;

  pBYTEbuffer = new BYTE[bufferSize*2];
  memset(pBYTEbuffer,0,sizeof(BYTE)*bufferSize*2);
 }

 pSampleGrabber->GetCurrentBuffer(&size, pBuffer);

 const BYTE* pSrc = (BYTE*) pBuffer;
 const BYTE* pSrcEnd = pSrc + (width*height*2);
 BYTE* pDest = pBYTEbuffer;

 while (pSrc < pSrcEnd)
 {
  for (register int i =0; i< width; i++)
  {
   BYTE temp = *(pSrc++);
   BYTE temp2 = *(pSrc++);
   *(pDest++) = temp2;
   *(pDest++) = temp;
  }

 } 
#endif

#if USE_RGB24_FORMAT
 // use RGB format
 if (size != bufferSize)
 {
  if (pBuffer)
   delete[] pBuffer;
  bufferSize = size;
  pBuffer = new long[bufferSize];
  if(pBYTEbuffer)
   delete[] pBYTEbuffer;
  pBYTEbuffer = new BYTE[bufferSize*3];
 }

 pSampleGrabber->GetCurrentBuffer(&size, pBuffer);

 BYTE* pDest = pBYTEbuffer;
 BYTE *pBYTETemp = pBYTEbuffer;
 const BYTE* pSrc = (BYTE*) pBuffer;

 const ULONG remainder = ((width*3+3) & ~3) - width*3;

 for (register unsigned int i = 0; i < height; i++ )
 {
  pDest = pBYTETemp + (height-i) * width * 3;
  for (register unsigned int j = 0; j < width; j++ )
  {
   const BYTE blue = *(pSrc++);
   const BYTE green = *(pSrc++);
   const BYTE red = *(pSrc++);

   *(pDest++) = red;
   *(pDest++) = green;
   *(pDest++) = blue;
   pDest += remainder;
  }
 }
#endif

 return S_OK;
}

ImageBuffer UsbCamera::getImage()
{
 HRESULT hr = S_OK;
 hr = GrabByteFrame();

 if(FAILED(hr))
  ErrMsg(TEXT("UsbCamera disconnect!"));

 const BYTE* pSrc = GetByteBuffer();

#if USE_YUV422_FORMAT
 m_buffer = ImageBuffer( width,height,ImageBuffer::FORMAT_YUV422,
  (unsigned char*)pSrc,(int)(width*height*2.));
#endif

#if USE_RGB24_FORMAT
 m_buffer = ImageBuffer( width,height,ImageBuffer::FORMAT_RGB,
  (unsigned char*)pSrc,(int)(width*height*3.));
#endif

 pMediaControl->Run();

 return m_buffer;
}

UsbCamera* UsbCamera::getCamera(int port, int framerate /* = 30 */, int width /* = 320 */,
 int height /* = 240  */,string mode)
{
 if (m_camera == NULL)
 {
  m_camera = new UsbCamera();
  m_camera->Init(port,false,framerate,width,height,mode);
  m_camera->bisValid = true;
 }
 return m_camera;
}

void UsbCamera::destroyUsbCamera()
{
 if (m_camera)
 {
  delete m_camera;
  m_camera = NULL;
 }
}

void UsbCamera::FreeMediaType(AM_MEDIA_TYPE& mt)
{
 if (mt.cbFormat != 0)
 {
  CoTaskMemFree((PVOID)mt.pbFormat);
  mt.cbFormat = 0;
  mt.pbFormat = NULL;
 }
 if (mt.pUnk != NULL)
 {
  mt.pUnk->Release();
  mt.pUnk = NULL;
 }
}

int UsbCamera::getWidth() const
{
 return width;
}

int UsbCamera::getHeight() const
{
 return height;
}

void UsbCamera::ErrMsg(LPTSTR szFormat,...)
{
 static TCHAR szBuffer[2048]={0};
 const size_t NUMCHARS = sizeof(szBuffer) / sizeof(szBuffer[0]);
 const int LASTCHAR = NUMCHARS - 1;
 va_list pArgs;
 va_start(pArgs, szFormat);
 _vsntprintf(szBuffer, NUMCHARS - 1, szFormat, pArgs);
 va_end(pArgs);

 szBuffer[LASTCHAR] = TEXT('\0');
 ///MessageBox(NULL, szBuffer, "UsbCamera Error",
 // MB_OK | MB_ICONEXCLAMATION | MB_TASKMODAL);
}

void UsbCamera::DisplayFilterProperties()
{
 ISpecifyPropertyPages* pProp;

 HRESULT hr = pDeviceFilter->QueryInterface(IID_ISpecifyPropertyPages, (void**)&pProp);
 if (SUCCEEDED(hr))
 {
  FILTER_INFO FilterInfo;
  hr = pDeviceFilter->QueryFilterInfo(&FilterInfo);
  IUnknown* pFilterUnk;
  pDeviceFilter->QueryInterface(IID_IUnknown,(void**)&pFilterUnk);

  CAUUID caGUID;
  pProp->GetPages(&caGUID);
  pProp->Release();
  OleCreatePropertyFrame(
   NULL,
   0,
   0,
   FilterInfo.achName,
   1,
   &pFilterUnk,
   caGUID.cElems,
   caGUID.pElems,
   0,
   0,
   NULL);
  pFilterUnk->Release();
  FilterInfo.pGraph->Release();
  CoTaskMemFree(caGUID.pElems);
 }

}

//==========================================main.cpp===========================================

 

#include "UsbCamera.h"

int main(int argc, char** argv)
{
 
 cvNamedWindow( "Motion", 1 );
 UsbCamera* pCamera = UsbCamera::getCamera(0,30,480,240,"MEDIASUBTYPE_RGB24");
 if(NULL == pCamera)
 {
  return 0;
 }
 ImageBuffer buffer = pCamera->getImage();
 IplImage* pImage = cvCreateImage(cvSize(buffer.width,buffer.height),8,3);
 for(;;)
 {
  
  buffer = pCamera->getImage();
  for(int i=0;i<pImage->height;i++)
  {
   uchar* data=(uchar*)pImage->imageData + pImage->widthStep * i;
   for(int j=0;j<pImage->width;j++)
   {
    data[3*j] = buffer.buffer[3*(i*buffer.width+j)+2];
    data[3*j+1] = buffer.buffer[3*(i*buffer.width+j)+1];
    data[3*j+2] = buffer.buffer[3*(i*buffer.width+j)+0];
   }
  }
  cvShowImage( "Motion", pImage );

  if( cvWaitKey(10) >= 0 )
   break;
 }
 return 0;
}