DirectShow访问USB摄像头Demo

/************************************************************************************

功能： 打开USB摄像头

参数： index - 输入，摄像头序号

bDisplayProperties - 输入，指示是否自动弹出摄像头属性页

nWidth - 输入，宽度，输入不为0，并且在bDisplayProperties为false时有效

nHeight - 输入，高度，输入不为0，并且在bDisplayProperties为false时有效

返回： true-成功，false-失败

*************************************************************************************/

bool CCameraDS::OpenCamera(int nCamID, bool bDisplayProperties,int nWidth,int nHeight)

{

HRESULT hr = S_OK;

CoInitialize(NULL);

// Create the Filter Graph Manager.

hr = CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC,

IID_IGraphBuilder, (void **)&m_pGraph);

hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER,

IID_IBaseFilter, (LPVOID *)&m_pSampleGrabberFilter);

hr = m_pGraph->QueryInterface(IID_IMediaControl, (void **) &m_pMediaControl);

hr = m_pGraph->QueryInterface(IID_IMediaEvent, (void **) &m_pMediaEvent);

hr = CoCreateInstance(CLSID_NullRenderer, NULL, CLSCTX_INPROC_SERVER,

IID_IBaseFilter, (LPVOID*) &m_pNullFilter);

hr = m_pGraph->AddFilter(m_pNullFilter, L"NullRenderer");

hr = m_pSampleGrabberFilter->QueryInterface(IID_ISampleGrabber, (void**)&m_pSampleGrabber);

AM_MEDIA_TYPE mt;

ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));

= MEDIATYPE_Video;

= MEDIASUBTYPE_RGB24;

= FORMAT_VideoInfo;

hr = m_pSampleGrabber->SetMediaType(&mt);

MYFREEMEDIATYPE(mt);

m_pGraph->AddFilter(m_pSampleGrabberFilter, L"Grabber");

// Bind Device Filter. We know the device because the id was passed in

BindFilter(nCamID, &m_pDeviceFilter);

m_pGraph->AddFilter(m_pDeviceFilter, NULL);

CComPtr<IEnumPins> pEnum;

m_pDeviceFilter->EnumPins(&pEnum);

hr = pEnum->Reset();

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

pEnum = NULL;

m_pSampleGrabberFilter->EnumPins(&pEnum);

pEnum->Reset();

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

pEnum = NULL;

m_pSampleGrabberFilter->EnumPins(&pEnum);

pEnum->Reset();

pEnum->Skip(1);

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

pEnum = NULL;

m_pNullFilter->EnumPins(&pEnum);

pEnum->Reset();

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

//SetCrossBar();

//add by chengs 20160617

if (nWidth>0 && nHeight>0)

{

SetCaps(nWidth,nHeight);

}

if (bDisplayProperties)

{

CComPtr<ISpecifyPropertyPages> pPages;

HRESULT hr = m_pCameraOutput->QueryInterface(IID_ISpecifyPropertyPages, (void**)&pPages);

if (SUCCEEDED(hr))

{

PIN_INFO PinInfo;

m_pCameraOutput->QueryPinInfo(&PinInfo);

CAUUID caGUID;

pPages->GetPages(&caGUID);

OleCreatePropertyFrame(NULL, 0, 0,

L"Property Sheet", 1,

(IUnknown **)&(m_pCameraOutput.p),

,

,

0, 0, NULL);

CoTaskMemFree();

->Release();

}

}

hr = m_pGraph->Connect(m_pCameraOutput, m_pGrabberInput);

hr = m_pGraph->Connect(m_pGrabberOutput, m_pNullInputPin);

if (FAILED(hr))

{

switch(hr)

{

case VFW_S_NOPREVIEWPIN :

break;

case E_FAIL :

break;

case E_INVALIDARG :

break;

case E_POINTER :

break;

}

}

m_pSampleGrabber->SetBufferSamples(TRUE);

m_pSampleGrabber->SetOneShot(TRUE);

hr = m_pSampleGrabber->GetConnectedMediaType(&mt);

if(FAILED(hr))

return false;

VIDEOINFOHEADER *videoHeader;

videoHeader = reinterpret_cast<VIDEOINFOHEADER*>();

m_nWidth = videoHeader->;

m_nHeight = videoHeader->;

m_bConnected = true;

return true;

}

/************************************************************************

功能： 获取一帧视频流数据

参数：

返回： 一帧视频流数据

*************************************************************************/

unsigned char* CCameraDS::QueryFrame()

{

long evCode;

long size = 0;

m_pMediaControl->Run();

m_pMediaEvent->WaitForCompletion(5000, &evCode); //INFINITE

m_pSampleGrabber->GetCurrentBuffer(&size, NULL);

if (size == 0)

{

return NULL;

}

//if the buffer size changed

if (size != m_nBufferSize)

{

if (m_pFrame)

free(m_pFrame);

m_nBufferSize = size;

m_pFrame = (unsigned char*)malloc(m_nWidth*m_nHeight*3);

}

if (m_pFrame == NULL)

{

return NULL;

}

m_pSampleGrabber->GetCurrentBuffer(&m_nBufferSize, (long*)m_pFrame);

ImrotateVertical_RGB(m_pFrame, m_nWidth, m_nHeight);

return m_pFrame;

}