Directshow 擷取圖片問題題--請大大幫我解答

發表時間：2005-12-01 11:57:51

IP:210.201.xxx.xxx 未訂閱

以下是小弟的程式,可以看到預覽的的畫面可是儲存的檔案temp.bmp無法開啟...用小畫家開啟會顯示"無法辨識的格式" 探討的原因有可能是圖片並沒有寫入檔案當中..只有產生了檔案(檔案大小150K) hr = CoCreateInstance (CLSID_FilterGraph, NULL, CLSCTX_INPROC, IID_IGraphBuilder, (void **) &m_pGraph); if (FAILED(hr)) return hr; // Create the capture graph builder hr = CoCreateInstance (CLSID_CaptureGraphBuilder2 , NULL, CLSCTX_INPROC, IID_ICaptureGraphBuilder2, (void **) &m_pCapture); if (FAILED(hr)) return hr; // pGrabber.CoCreateInstance( CLSID_SampleGrabber ); // Create the Sample Grabber. IBaseFilter *pGrabberF = NULL; hr = CoCreateInstance(CLSID_SampleGrabber, NULL, CLSCTX_INPROC_SERVER, IID_IBaseFilter, (void**)&pGrabberF); if (FAILED(hr)) return hr; // Obtain interfaces for media control and Video Window hr = m_pGraph->QueryInterface(IID_IMediaControl,(LPVOID *) &m_pMC); if (FAILED(hr)) return hr; hr = m_pGraph->QueryInterface(IID_IVideoWindow, (LPVOID *) &m_pVW); hr = m_pVW->put_AutoShow(OAFALSE); hr = m_pGraph->QueryInterface(IID_IMediaEvent, (LPVOID *) &m_pME); if (FAILED(hr)) return hr; ISampleGrabber *pGrabber; pGrabberF->QueryInterface(IID_ISampleGrabber, (void**)&pGrabber); hr = m_pME->SetNotifyWindow((OAHWND)(m_hWnd), WM_GRAPHNOTIFY, 0); hr = m_pCapture->SetFiltergraph(m_pGraph); IMoniker *pMoniker = NULL; ICreateDevEnum *pDevEnum = 0; IEnumMoniker *pClassEnum = NULL; ULONG cFetched; hr = CoCreateInstance (CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC,IID_ICreateDevEnum, (void **) &pDevEnum); hr = pDevEnum->CreateClassEnumerator (CLSID_VideoInputDeviceCategory, &pClassEnum, 0); if (hr==S_OK) //發現TV Card { pClassEnum->Next (1, &pMoniker, &cFetched); hr = pMoniker->BindToObject(0,0,IID_IBaseFilter, (void**)&pVcap); if (FAILED(hr)) return hr; pClassEnum = NULL; hr = m_pGraph->AddFilter(pVcap, L"Video Capture"); hr = m_pGraph->AddFilter(pGrabberF, L"Sample Grabber"); hr = m_pCapture->RenderStream (&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video,pVcap, NULL, NULL); hr = m_pCapture->FindInterface(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video, pVcap,IID_IAMTVTuner, (void **)&pIAMTVTuner) hr = m_pCapture->FindInterface(&LOOK_UPSTREAM_ONLY, NULL, pVcap,IID_IAMCrossbar, (void**)&pIAMCrossbar); RECT rc; ::GetClientRect(m_hWnd, &rc); 設定可視 m_pVW->put_Owner((OAHWND) m_hWnd); m_pVW->put_WindowStyle(WS_CHILD | WS_CLIPCHILDREN); m_pVW->SetWindowPosition(0, 0, rc.right , rc.bottom ); hr = m_pVW->put_Visible(OATRUE); pIAMCrossbar->Route(1,1); IsCreate=1; //m_pMC->Run(); ShowMessage("OPEN_OCX_TV CARD ok!"); //Sleep(500); //取得當前所連接媒體的類型 // AM_MEDIA_TYPE mt; ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE)); mt.majortype = MEDIATYPE_Video; mt.subtype = MEDIASUBTYPE_RGB24; hr = pGrabber->SetMediaType(&mt); //CComPtr pSource; hr = pGrabber->GetConnectedMediaType(&mt); // Examine the format block. VIDEOINFOHEADER *pVih; if ((mt.formattype == FORMAT_VideoInfo) && (mt.cbFormat >= sizeof(VIDEOINFOHEADER)) && (mt.pbFormat != NULL) ) { pVih = (VIDEOINFOHEADER*)mt.pbFormat; } else { // Wrong format. Free the format block and return an error. } // Do buffer the samples as they pass through // hr = pGrabber->SetBufferSamples(TRUE); m_pMC->Run(); Sleep(5000); //long EvCode = 0; //hr = m_pME->WaitForCompletion(INFINITE, &EvCode); long cbBuffer = 0; //hr = pGrabber->GetCurrentBuffer(&cbBuffer, NULL); BYTE *pBuffer = new BYTE[cbBuffer]; //hr = pGrabber->GetCurrentBuffer(&cbBuffer, (long*)pBuffer); m_pMC->Stop(); //Create a file to hold the bitmap HANDLE hf = CreateFile(m_szFileName, GENERIC_WRITE, FILE_SHARE_READ, NULL,CREATE_ALWAYS, NULL, NULL ); if( hf == INVALID_HANDLE_VALUE ) { return 0; } //Write out the file header // BITMAPFILEHEADER bfh; memset(&bfh, 0, sizeof(bfh)); bfh.bfSize = sizeof( bfh ) cbBuffer sizeof( BITMAPINFOHEADER ); bfh.bfOffBits = sizeof( BITMAPINFOHEADER ) sizeof( BITMAPFILEHEADER ); DWORD dwWritten = 0; WriteFile( hf, &bfh, sizeof( bfh ), &dwWritten, NULL ); //Write the bitmap format // BITMAPINFOHEADER bih; bih.biSize = sizeof(bih); bih.biWidth = pVih->bmiHeader.biWidth; bih.biHeight = pVih->bmiHeader.biHeight; bih.biPlanes = pVih->bmiHeader.biPlanes; bih.biBitCount = pVih->bmiHeader.biBitCount; WriteFile( hf, &bfh, sizeof( bfh ), &dwWritten, NULL ); //Write the bitmap bits // //dwWritten = 0; WriteFile( hf, pBuffer, cbBuffer, &dwWritten, NULL ); CloseHandle( hf ); }