DirectShow中的Playcap的那個範例 |
答題得分者是:ikk
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GN00291313
一般會員 發表:5 回覆:5 積分:2 註冊:2009-04-14 發送簡訊給我 |
請問DirectShow中的Playcap的那個範例,它影像的串流在哪邊? 因為我想把影像在buffer中做處理,請各位大大指教一下,謝謝><.....
[code cpp] //--------------------------------------------------------------------------- __fastcall TForm1::TForm1(TComponent* Owner) : TForm(Owner) { g_dwGraphRegister=0; g_pVW = NULL; g_pMC = NULL; g_pME = NULL; g_pGraph = NULL; g_pCapture = NULL; g_psCurrent = Stopped; if(FAILED(CoInitializeEx(NULL, COINIT_APARTMENTTHREADED))) //Initialize COM { Msg(TEXT("CoInitialize Failed!\r\n")); Application->Terminate(); return; } if(FAILED(CaptureVideo())) { Application->Terminate(); return; } } //--------------------------------------------------------------------------- __fastcall TForm1::~TForm1() { CloseInterfaces(); CoUninitialize(); // Release COM } //--------------------------------------------------------------------------- void __fastcall TForm1::WndProc(Messages::TMessage &Message) { switch(Message.Msg) { case WM_GRAPHNOTIFY: HandleGraphEvent(); break; case WM_SIZE: ResizeVideoWindow(); break; case WM_WINDOWPOSCHANGED: ChangePreviewState(!(IsIconic(Handle))); break; case WM_CLOSE: // Hide the main window while the graph is destroyed ShowWindow(Handle, SW_HIDE); CloseInterfaces(); // Stop capturing and release interfaces break; case WM_DESTROY: PostQuitMessage(0); Message.Result = 0; return; } // Pass this message to the video window for notification of system changes if (g_pVW) g_pVW->NotifyOwnerMessage((LONG_PTR)Handle, Message.Msg, Message.WParam, Message.LParam); TForm::WndProc(Message); } //--------------------------------------------------------------------------- void TForm1::Msg(TCHAR *szFormat, ...) { TCHAR szBuffer[1024]; // Large buffer for long filenames or URLs const size_t NUMCHARS = sizeof(szBuffer) / sizeof(szBuffer[0]); const int LASTCHAR = NUMCHARS - 1; // Format the input string va_list pArgs; va_start(pArgs, szFormat); // Use a bounded buffer size to prevent buffer overruns. Limit count to // character size minus one to allow for a NULL terminating character. _vsntprintf(szBuffer, NUMCHARS - 1, szFormat, pArgs); va_end(pArgs); // Ensure that the formatted string is NULL-terminated szBuffer[LASTCHAR] = TEXT('\0'); MessageBox(NULL, szBuffer, TEXT("PlayCap Message"), MB_OK | MB_ICONERROR); } //--------------------------------------------------------------------------- #ifdef REGISTER_FILTERGRAPH // { // //--------------------------------------------------------------------------- // Removes a filter graph from the Running Object Table void TForm1::RemoveGraphFromRot(DWORD pdwRegister) { IRunningObjectTable *pROT; if (SUCCEEDED(GetRunningObjectTable(0, &pROT))) { pROT->Revoke(pdwRegister); pROT->Release(); } } //--------------------------------------------------------------------------- HRESULT TForm1::AddGraphToRot(IUnknown *pUnkGraph, DWORD *pdwRegister) { IMoniker * pMoniker; IRunningObjectTable *pROT; WCHAR wsz[128]; HRESULT hr; if (!pUnkGraph || !pdwRegister) return E_POINTER; if (FAILED(GetRunningObjectTable(0, &pROT))) return E_FAIL; wsprintfW(wsz, L"FilterGraph x pid x\0", (DWORD_PTR)pUnkGraph, GetCurrentProcessId()); hr = CreateItemMoniker(L"!", wsz, &pMoniker); if (SUCCEEDED(hr)) { // Use the ROTFLAGS_REGISTRATIONKEEPSALIVE to ensure a strong reference // to the object. Using this flag will cause the object to remain // registered until it is explicitly revoked with the Revoke() method. // // Not using this flag means that if GraphEdit remotely connects // to this graph and then GraphEdit exits, this object registration // will be deleted, causing future attempts by GraphEdit to fail until // this application is restarted or until the graph is registered again. hr = pROT->Register(ROTFLAGS_REGISTRATIONKEEPSALIVE, pUnkGraph, pMoniker, pdwRegister); pMoniker->Release(); } pROT->Release(); return hr; } //--------------------------------------------------------------------------- #endif // } // //--------------------------------------------------------------------------- HRESULT TForm1::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)Handle, WM_GRAPHNOTIFY, 0); return hr; } //--------------------------------------------------------------------------- void TForm1::CloseInterfaces(void) { // Stop previewing data if (g_pMC) g_pMC->StopWhenReady(); g_psCurrent = Stopped; // Stop receiving events if (g_pME) g_pME->SetNotifyWindow(NULL, WM_GRAPHNOTIFY, 0); // Relinquish ownership (IMPORTANT!) of the video window. // Failing to call put_Owner can lead to assert failures within // the video renderer, as it still assumes that it has a valid // parent window. if(g_pVW) { g_pVW->put_Visible(OAFALSE); g_pVW->put_Owner(NULL); } #ifdef REGISTER_FILTERGRAPH // Remove filter graph from the running object table if (g_dwGraphRegister) RemoveGraphFromRot(g_dwGraphRegister); #endif // Release DirectShow interfaces SAFE_RELEASE(g_pMC); SAFE_RELEASE(g_pME); SAFE_RELEASE(g_pVW); SAFE_RELEASE(g_pGraph); SAFE_RELEASE(g_pCapture); } //--------------------------------------------------------------------------- HRESULT TForm1::FindCaptureDevice(IBaseFilter ** ppSrcFilter) { HRESULT hr; IBaseFilter * pSrc = NULL; CComPtr ULONG cFetched; if (!ppSrcFilter) return E_POINTER; // Create the system device enumerator CComPtr 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 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) { MessageBox(Handle,TEXT("No video capture device was detected.\r\n\r\n") TEXT("This sample requires a video capture device, such as a USB WebCam,\r\n") TEXT("to be installed and working properly. The sample will now close."), TEXT("No Video Capture Hardware"), MB_OK | MB_ICONINFORMATION); return E_FAIL; } // Use the first video capture device on the device list. // Note that if the Next() call succeeds but there are no monikers, // it will return S_FALSE (which is not a failure). Therefore, we // 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; } //--------------------------------------------------------------------------- void TForm1::ResizeVideoWindow(void) { // Resize the video preview window to match owner window size if (g_pVW) { RECT rc; // Make the preview video fill our window ::GetClientRect(Handle, &rc); g_pVW->SetWindowPosition(0, 0, rc.right, rc.bottom); } } //--------------------------------------------------------------------------- HRESULT TForm1::SetupVideoWindow(void) { HRESULT hr; // Set the video window to be a child of the main window hr = g_pVW->put_Owner((OAHWND)Handle); 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; } //--------------------------------------------------------------------------- HRESULT TForm1::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 the capture filter to the graph! hr=0x%x\r\n\r\n") TEXT("If you have a working video capture device, please make sure\r\n") TEXT("that it is connected and is not being used by another application.\r\n\r\n") TEXT("The sample will now close."), 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 (&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, pSrcFilter, NULL, NULL); if (FAILED(hr)) { Msg(TEXT("Couldn't render the video capture stream. hr=0x%x\r\n") TEXT("The capture device may already be in use by another application.\r\n\r\n") TEXT("The sample will now close."), 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; } #ifdef REGISTER_FILTERGRAPH // Add our graph to the running object table, which will allow // the GraphEdit application to "spy" on our graph 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 TForm1::ChangePreviewState(int nShow) { HRESULT hr=S_OK; // If the media control interface isn't ready, don't call it if (!g_pMC) return S_OK; if (nShow) { if (g_psCurrent != Running) { // Start previewing video data hr = g_pMC->Run(); g_psCurrent = Running; } } else { // Stop previewing video data hr = g_pMC->StopWhenReady(); g_psCurrent = Stopped; } return hr; } //--------------------------------------------------------------------------- HRESULT TForm1::HandleGraphEvent(void) { LONG evCode, evParam1, evParam2; HRESULT hr=S_OK; if (!g_pME) return E_POINTER; 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; } //--------------------------------------------------------------------------- [/code] |
ikk
尊榮會員 發表:4 回覆:413 積分:768 註冊:2003-06-30 發送簡訊給我 |
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