set resolution with direct show

void VC::SetResolution(IBaseFilter* pSrcFilter, int Width, int Height) {IAMStreamConfig *pConfig = NULL;g_pCapture->FindInterface(&PIN_CATEGORY_CAPTURE,&MEDIATYPE_Video, pSrcFilter, IID_IAMStreamConfig, (void**)&pConfig);int resolutions, size;VIDEO_STREAM_CONFIG_CAPS caps;pConfig->GetNumberOfCapabilities(&resolutions, &size);for (int i = 0; i < resolutions; i++){AM_MEDIA_TYPE *mediaType;if (pConfig->GetStreamCaps(i, &mediaType, reinterpret_cast<BYTE*>(&caps)) == S_OK){int maxWidth = caps.MaxOutputSize.cx;int maxHeigth = caps.MaxOutputSize.cy;if (maxWidth == Width && maxHeigth == Height){VIDEOINFOHEADER *info = reinterpret_cast<VIDEOINFOHEADER*>(mediaType->pbFormat);info->bmiHeader.biWidth = maxWidth;info->bmiHeader.biHeight = maxHeigth;info->bmiHeader.biSizeImage = DIBSIZE(info->bmiHeader);HRESULT hr = pConfig->SetFormat(mediaType);MyDeleteMediaType(mediaType);break;}MyDeleteMediaType(mediaType);}}SAFE_RELEASE(pConfig);}

void VC::MyDeleteMediaType(AM_MEDIA_TYPE *pmt){if (pmt != NULL){// See FreeMediaType for the implementation.MyFreeMediaType(*pmt);        CoTaskMemFree(pmt);    }}void VC::MyFreeMediaType(AM_MEDIA_TYPE& mt){if (mt.cbFormat != 0)    {        CoTaskMemFree((PVOID)mt.pbFormat);        mt.cbFormat = 0;        mt.pbFormat = NULL;    }    if (mt.pUnk != NULL)    {        // Unecessary because pUnk should not be used, but safest.        mt.pUnk->Release();        mt.pUnk = NULL;    }}

To implement it -

int VC::Begin(HWND hWnd, HWND prvWindow, IBaseFilter* pSrcFilter){HRESULT hr;// Get DirectShow interfaces    hr = GetInterfaces(hWnd);    if (FAILED(hr)) {return -1;    }// Attach the filter graph to the capture graph    hr = g_pCapture->SetFiltergraph(g_pGraph);    if (FAILED(hr)) {return -2;    }/*hr = FindCaptureDevice(&pSrcFilter);    if (FAILED(hr)) {// Don't display a message because FindCaptureDevice will handle itreturn hr;    }*/SetResolution(pSrcFilter, 1280, 720);// Add Capture filter to our graph.    hr = g_pGraph->AddFilter(pSrcFilter, L"Video Capture");    if(FAILED(hr)) {pSrcFilter->Release();        return -4;    }SetResolution(pSrcFilter, 1280, 720);hr = sgAddSampleGrabber(g_pGraph);    if (FAILED(hr)) {return -5;    }hr = sgSetSampleGrabberMediaType();    /*AM_MEDIA_TYPE mt;IAMStreamConfig *pSC=NULL; //HRESULT hr;        ZeroMemory(&mt, sizeof(AM_MEDIA_TYPE));hr = g_pCapture->FindInterface(&PIN_CATEGORY_PREVIEW, 0 , pSrcFilter, IID_IAMStreamConfig,(void **)&pSC); if(FAILED(hr)) {AfxMessageBox(L"FAIL");return hr;}        mt.majortype = MEDIATYPE_Video;        mt.subtype = MEDIASUBTYPE_RGB24;//VIDEOINFOHEADER *pVih = (VIDEOINFOHEADER *)mt.pbFormat;        //gChannels = pVih->bmiHeader.biBitCount / 8;        pVih->bmiHeader.biWidth = 1280;        pVih->bmiHeader.biHeight = 720;         mt.pbFormat = (unsigned char *) pVih; pSC->SetFormat(&mt);         hr = pGrabber->SetMediaType(&mt);        if (FAILED(hr)) {                return hr;        }        hr = pGrabber->SetOneShot(FALSE);        hr = pGrabber->SetBufferSamples(TRUE);*///if (FAILED(hr)) {return -6;    }//IBaseFilter* pGrabber2 = sgGetSampleGrabber();// Render the preview pin on the video capture filter    // Use this instead of g_pGraph->RenderFilehr = g_pCapture->RenderStream(&PIN_CATEGORY_PREVIEW, &MEDIATYPE_Video, pSrcFilter, pGrabberFilter/*NULL*/, NULL);if (FAILED(hr)) {pSrcFilter->Release();        return -7;    }hr = sgGetSampleGrabberMediaType();// 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(prvWindow);    if (FAILED(hr)) {             return -8;    }return 0;}