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请教:
我是找 DX 自己带的一个源码(摄像头扑获)，编译后，是可以看到预览的
但是，我不知道怎么把每一帧图象变成像素载入数组
源代码为：
#define REGISTER_FILTERGRAPH
HWND ghApp=0;
DWORD g_dwGraphRegister=0;
IVideoWindow * g_pVW = NULL;
IMediaControl * g_pMC = NULL;
IMediaEventEx * g_pME = NULL;
IGraphBuilder * g_pGraph = NULL;
ICaptureGraphBuilder2 * g_pCapture = NULL;
PLAYSTATE g_psCurrent = Stopped;
HRESULT CaptureVideo()
{
HRESULT hr;
IBaseFilter *pSrcFilter=NULL;
// Get DirectShow interfaces
hr = GetInterfaces();
if (FAILED(hr))
{
Msg(TEXT("Failed to get video interfaces! hr=0x%x"), hr);
return hr;
}
// Attach the filter graph to the capture graph
hr = g_pCapture->SetFiltergraph(g_pGraph);
if (FAILED(hr))
{
Msg(TEXT("Failed to set capture filter graph! hr=0x%x"), hr);
return hr;
}
// Use the system device enumerator and class enumerator to find
// a video capture/preview device, such as a desktop USB video camera.
hr = FindCaptureDevice(&pSrcFilter);
if (FAILED(hr))
{
// Don't display a message because FindCaptureDevice will handle it
return hr;
}
// Add Capture filter to our graph.
hr = g_pGraph->AddFilter(pSrcFilter, L"Video Capture");
if (FAILED(hr))
{
Msg(TEXT("Couldn't add capture filter to graph! hr=0x%x"), hr);
pSrcFilter->Release();
return hr;
}
// Render the preview pin on the video capture filter
// Use this instead of g_pGraph->RenderFile
hr = g_pCapture->RenderStream (& IN_CATEGORY_PREVIEW, &MEDIATYPE_Video,
pSrcFilter, NULL, NULL);
if (FAILED(hr))
{
Msg(TEXT("Couldn't render capture stream. ")
TEXT("The device may already be in use.\r\n\r\nhr=0x%x"), hr);
pSrcFilter->Release();
return hr;
}
// Now that the filter has been added to the graph and we have
// rendered its stream, we can release this reference to the filter.
pSrcFilter->Release();
// Set video window style and position
hr = SetupVideoWindow();
if (FAILED(hr))
{
Msg(TEXT("Couldn't initialize video window! hr=0x%x"), hr);
return hr;
}
// Add our graph to the running object table, which will allow
// the GraphEdit application to "spy" on our graph
#ifdef REGISTER_FILTERGRAPH
hr = AddGraphToRot(g_pGraph, &g_dwGraphRegister);
if (FAILED(hr))
{
Msg(TEXT("Failed to register filter graph with ROT! hr=0x%x"), hr);
g_dwGraphRegister = 0;
}
#endif
// Start previewing video data
hr = g_pMC->Run();
if (FAILED(hr))
{
Msg(TEXT("Couldn't run the graph! hr=0x%x"), hr);
return hr;
}
// Remember current state
g_psCurrent = Running;
return S_OK;
}
HRESULT FindCaptureDevice(IBaseFilter ** ppSrcFilter)
{
HRESULT hr;
IBaseFilter * pSrc = NULL;
CComPtr <IMoniker> pMoniker =NULL;
ULONG cFetched;
// Create the system device enumerator
CComPtr <ICreateDevEnum> pDevEnum =NULL;
hr = CoCreateInstance (CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC,
IID_ICreateDevEnum, (void ** ) &pDevEnum);
if (FAILED(hr))
{
Msg(TEXT("Couldn't create system enumerator! hr=0x%x"), hr);
return hr;
}
// Create an enumerator for the video capture devices
CComPtr <IEnumMoniker> pClassEnum = NULL;
hr = pDevEnum->CreateClassEnumerator (CLSID_VideoInputDeviceCategory, &pClassEnum, 0);
if (FAILED(hr))
{
Msg(TEXT("Couldn't create class enumerator! hr=0x%x"), hr);
return hr;
}
// If there are no enumerators for the requested type, then
// CreateClassEnumerator will succeed, but pClassEnum will be NULL.
if (pClassEnum == NULL)
{
return E_FAIL;
}
// check that the return code is S_OK instead of using SUCCEEDED() macro.
if (S_OK == (pClassEnum->Next (1, &pMoniker, &cFetched)))
{
// Bind Moniker to a filter object
hr = pMoniker->BindToObject(0,0,IID_IBaseFilter, (void**)&pSrc);
if (FAILED(hr))
{
Msg(TEXT("Couldn't bind moniker to filter object! hr=0x%x"), hr);
return hr;
}
}
else
{
Msg(TEXT("Unable to access video capture device!"));
return E_FAIL;
}
// Copy the found filter pointer to the output parameter.
// Do NOT Release() the reference, since it will still be used
// by the calling function.
*ppSrcFilter = pSrc;
return hr;
}
HRESULT GetInterfaces(void)
{
HRESULT hr;
// Create the filter graph
hr = CoCreateInstance (CLSID_FilterGraph, NULL, CLSCTX_INPROC,
IID_IGraphBuilder, (void **) &g_pGraph);
if (FAILED(hr))
return hr;
// Create the capture graph builder
hr = CoCreateInstance (CLSID_CaptureGraphBuilder2 , NULL, CLSCTX_INPROC,
IID_ICaptureGraphBuilder2, (void **) &g_pCapture);
if (FAILED(hr))
return hr;
// Obtain interfaces for media control and Video Window
hr = g_pGraph->QueryInterface(IID_IMediaControl,(LPVOID *) &g_pMC);
if (FAILED(hr))
return hr;
hr = g_pGraph->QueryInterface(IID_IVideoWindow, (LPVOID *) &g_pVW);
if (FAILED(hr))
return hr;
hr = g_pGraph->QueryInterface(IID_IMediaEvent, (LPVOID *) &g_pME);
if (FAILED(hr))
return hr;
// Set the window handle used to process graph events
hr = g_pME->SetNotifyWindow((OAHWND)ghApp, WM_GRAPHNOTIFY, 0);
return hr;
}
HRESULT SetupVideoWindow(void)
{
HRESULT hr;
// Set the video window to be a child of the main window
hr = g_pVW->put_Owner((OAHWND)ghApp);
if (FAILED(hr))
return hr;
// Set video window style
hr = g_pVW->put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN);
if (FAILED(hr))
return hr;
// Use helper function to position video window in client rect
// of main application window
ResizeVideoWindow();
// Make the video window visible, now that it is properly positioned
hr = g_pVW->put_Visible(OATRUE);
if (FAILED(hr))
return hr;
return hr;
}
#ifdef REGISTER_FILTERGRAPH
HRESULT AddGraphToRot(IUnknown *pUnkGraph, DWORD *pdwRegister)
{
IMoniker * pMoniker;
IRunningObjectTable *pROT;
WCHAR wsz[128];
HRESULT hr;
if (FAILED(GetRunningObjectTable(0, &pROT))) {
return E_FAIL;
}
wsprintfW(wsz, L"FilterGraph %08x pid %08x", (DWORD_PTR)pUnkGraph,
GetCurrentProcessId());
hr = CreateItemMoniker(L"!", wsz, &pMoniker);
if (SUCCEEDED(hr)) {
hr = pROT->Register(0, pUnkGraph, pMoniker, pdwRegister);
pMoniker->Release();
}
pROT->Release();
return hr;
}
void RemoveGraphFromRot(DWORD pdwRegister)
{
IRunningObjectTable *pROT;
if (SUCCEEDED(GetRunningObjectTable(0, &pROT))) {
pROT->Revoke(pdwRegister);
pROT->Release();
}
}
#endif
HRESULT HandleGraphEvent(void)
{
LONG evCode, evParam1, evParam2;
HRESULT hr=S_OK;
while(SUCCEEDED(g_pME->GetEvent(&evCode, (LONG_PTR *) &evParam1,
(LONG_PTR *) &evParam2, 0)))
{
//
// Free event parameters to prevent memory leaks associated with
// event parameter data. While this application is not interested
// in the received events, applications should always process them.
//
hr = g_pME->FreeEventParams(evCode, evParam1, evParam2);
// Insert event processing code here, if desired
}
return hr;
}
各位大哥，我还要加什么程序，才能取到每一帧像素.
非常感谢！
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发表于 2008-8-19 09:18:00
