SpinSimpleGUI_DirectShow.cpp

SpinSimpleGUI_DirectShow.cpp is written based off Microsoft's DirectShow sample playcap application.

SpinSimpleGUI_DirectShow.cpp is written based off Microsoft's DirectShow sample playcap application. This example demonstrates how to connect to Teledyne's DirectShow video capture source filter, setup camera settings through the IID_IPtGreyDevice interface, and renders and previews video capture data.

Also check out the NodeMapInfo example if you haven't already. NodeMapInfo demonstrates how to retrieve node map information and explores retrieving information from all major node types on the camera. The various node type include string, integer, float, boolean, command, enumeration, category, and value types. Only enumeration and integer type retrieval are covered in this example.

Please make sure Microsoft Windows SDK 7.1 is installed prior to building this example. Windows SDK 7.1 is the last version shipped with a set of DirectShow samples, and the DirectShow BaseClasses. DirectShow runtime is now a part of the operating system so no DirectShow redistributables are required.

Microsoft Windows SDK 7.1 can be found here: https://www.microsoft.com/en-us/download/details.aspx?id=8279

Note: You may run into problems installing Windows SDK 7.1 if you have a newer version of Visual Studio C++ 2010 Redistributable installed. To resolve the issue, you must uninstall all versions of the Visual C++ 2010 Redistributable before installing the Windows 7 SDK.

Reference: https://support.microsoft.com/en-us/topic/windows-sdk-fails-to-install-with-return-code-5100-56c17a69-4b37-77a6-aee5-9fd35ac534c4

//=============================================================================
// Copyright (c) 2001-2024 FLIR Systems, Inc. All Rights Reserved.
//
// This software is the confidential and proprietary information of FLIR
// Integrated Imaging Solutions, Inc. ("Confidential Information"). You
// shall not disclose such Confidential Information and shall use it only in
// accordance with the terms of the license agreement you entered into
// with FLIR Integrated Imaging Solutions, Inc. (FLIR).
//
// FLIR MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF THE
// SOFTWARE, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
// PURPOSE, OR NON-INFRINGEMENT. FLIR SHALL NOT BE LIABLE FOR ANY DAMAGES
// SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING
// THIS SOFTWARE OR ITS DERIVATIVES.
//=============================================================================
 
#ifndef _WIN32_WINNT        // Allow use of features specific to Windows XP or later.
#define _WIN32_WINNT 0x0501 // Change this to the appropriate value to target other versions of Windows.
#endif
 
#include <iostream>
#include <dshow.h>
 
#include "resource.h"
#include "comdef.h"
#include "SpinSimpleGUI_DirectShow.h"
#include "SpinnakerDirectShow.h"
 
//
// Global data
//
HWND ghApp = 0;
DWORD g_dwGraphRegister = 0;
 
IVideoWindow* g_pVW = nullptr;
IMediaControl* g_pMC = nullptr;
IMediaEventEx* g_pME = nullptr;
IGraphBuilder* g_pGraph = nullptr;
ICaptureGraphBuilder2* g_pCapture = nullptr;
PLAYSTATE g_psCurrent = Stopped;
 
HRESULT CaptureVideo()
{
    HRESULT hr;
    IBaseFilter* pSrcFilter = nullptr;
 
    // Get DirectShow interfaces
    hr = GetInterfaces();
    if (FAILED(hr))
    {
        MsgError(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))
    {
        MsgError(TEXT("Failed to set capture filter graph!  hr=0x%x"), hr);
        return hr;
    }
 
    // Use the system device enumerator and class enumerator to find
    // a Teledyne video capture/preview device.
    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))
    {
        MsgError(
            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;
    }
 
    // Setup Teledyne camera
    hr = SetupCamera(pSrcFilter);
    if (FAILED(hr))
    {
        // Don't display a message because FindCaptureDevice will handle it
        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, nullptr, nullptr);
    if (FAILED(hr))
    {
        MsgError(
            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))
    {
        MsgError(TEXT("Couldn't initialize video window!  hr=0x%x"), hr);
        return hr;
    }
 
    // Start previewing video data
    hr = g_pMC->Run();
    if (FAILED(hr))
    {
        MsgError(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 = S_OK;
    IBaseFilter* pSrc = nullptr;
    IMoniker* pMoniker = nullptr;
    ICreateDevEnum* pDevEnum = nullptr;
    IEnumMoniker* pClassEnum = nullptr;
 
    if (!ppSrcFilter)
    {
        return E_POINTER;
    }
 
    // Create the system device enumerator
    hr = CoCreateInstance(CLSID_SystemDeviceEnum, nullptr, CLSCTX_INPROC, IID_ICreateDevEnum, (void**)&pDevEnum);
    if (FAILED(hr))
    {
        MsgError(TEXT("Couldn't create system enumerator!  hr=0x%x"), hr);
    }
 
    // Create an enumerator for the video capture devices
    if (SUCCEEDED(hr))
    {
        hr = pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory, &pClassEnum, 0);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't create class enumerator!  hr=0x%x"), hr);
        }
    }
 
    if (SUCCEEDED(hr))
    {
        // If there are no enumerators for the requested type, then
        // CreateClassEnumerator will succeed, but pClassEnum will be nullptr.
        if (pClassEnum == nullptr)
        {
            MessageBox(
                ghApp,
                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);
            hr = E_FAIL;
        }
    }
 
    // Enumerate Teledyne device
    // 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 (SUCCEEDED(hr))
    {
        while (pClassEnum->Next(1, &pMoniker, nullptr) == S_OK)
        {
            IPropertyBag* pPropBag = nullptr;
            hr = pMoniker->BindToStorage(0, 0, IID_IPropertyBag, (void**)(&pPropBag));
 
            if (FAILED(hr))
            {
                SAFE_RELEASE(pMoniker);
                continue; // Skip this one, maybe the next one will work.
            }
 
            // Find the description or friendly name.
            VARIANT varName;
            VariantInit(&varName);
 
            hr = pPropBag->Read(L"FriendlyName", &varName, 0);
            if (SUCCEEDED(hr))
            {
                if (wcscmp(varName.bstrVal, L"PtGrey Camera") == 0)
                {
                    hr = pMoniker->BindToObject(0, 0, IID_IBaseFilter, (void**)&pSrc);
                    if (FAILED(hr))
                    {
                        _com_error err(hr);
                        LPCTSTR errMsg = err.ErrorMessage();
                        MsgError(TEXT("Couldn't bind moniker to filter object! %s"), err.ErrorMessage());
                    }
 
                    SAFE_RELEASE(pPropBag);
                    SAFE_RELEASE(pMoniker);
                    VariantClear(&varName);
                    break;
                }
 
                VariantClear(&varName);
            }
 
            SAFE_RELEASE(pPropBag);
            SAFE_RELEASE(pMoniker);
        }
    }
 
    // Copy the found filter pointer to the output parameter.
    if (SUCCEEDED(hr) && pSrc)
    {
        *ppSrcFilter = pSrc;
        (*ppSrcFilter)->AddRef();
    }
 
    if (!pSrc)
    {
        MessageBox(
            ghApp,
            TEXT("Unable to detect Spinnaker video capture source.\r\n\r\n") TEXT("Please\r\n")
                TEXT(" 1. Ensure DirectShow was chosen as a component during\r\n") TEXT("     installation\r\n")
                    TEXT(" 2. Run DirectShowRegister_v140_[x32 or x64].bat from \r\n")
                        TEXT("     <InstallDirectory>\\Spinnaker\\src\\DirectShowScriptFiles"),
            TEXT("Spinnaker DirectShow Source Not Found"),
            MB_OK | MB_ICONINFORMATION);
        hr = E_FAIL;
    }
 
    SAFE_RELEASE(pSrc);
    SAFE_RELEASE(pDevEnum);
    SAFE_RELEASE(pClassEnum);
 
    return hr;
}
 
HRESULT GetInterfaces(void)
{
    HRESULT hr;
 
    // Create the filter graph
    hr = CoCreateInstance(CLSID_FilterGraph, nullptr, CLSCTX_INPROC, IID_IGraphBuilder, (void**)&g_pGraph);
    if (FAILED(hr))
    {
        return hr;
    }
 
    // Create the capture graph builder
    hr = CoCreateInstance(
        CLSID_CaptureGraphBuilder2, nullptr, 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_IMediaEventEx, (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;
}
 
void 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);
    }
 
    // Release DirectShow interfaces
    SAFE_RELEASE(g_pMC);
    SAFE_RELEASE(g_pME);
    SAFE_RELEASE(g_pVW);
    SAFE_RELEASE(g_pGraph);
    SAFE_RELEASE(g_pCapture);
}
 
HRESULT SetupCamera(IBaseFilter* pSrcFilter)
{
    //
    // Get a pointer to the IPtGreyDevice interface
    //
    ISpinnakerInterface* pProps = nullptr;
    HRESULT hr = pSrcFilter->QueryInterface(IID_ISpinnakerInterface, reinterpret_cast<void**>(&pProps));
    if (FAILED(hr))
    {
        MsgError(TEXT("Couldn't Query the Capture Interface!  hr=0x%x"), hr);
        return E_FAIL;
    }
 
    //
    // Get a pointer to the PtGreyDevice
    //
    ISpinDevice* pDevice = pProps->GetDevice();
    if (pDevice == nullptr)
    {
        MsgError(TEXT("Couldn't Query the Capture Device!"));
        return E_FAIL;
    }
 
    try
    {
        //
        // Query basic device information
        //
        char model[MAX_LENGTH];
        char sensor[MAX_LENGTH];
        char serial[MAX_LENGTH];
 
        unsigned int numDevices = 0;
        hr = pDevice->GetNumCameras(&numDevices);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't query number of devices!"));
            return hr;
        }
 
        unsigned int selectedDeviceIndex = 0;
        hr = pDevice->GetSelectedCameraIndex(&selectedDeviceIndex);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't query currently selected camera index!"));
            return hr;
        }
 
        hr = pDevice->GetCameraInfo(selectedDeviceIndex, model, sensor, serial, MAX_LENGTH);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't query camera information!"));
            return hr;
        }
 
        //
        // Query list of supported nodes
        //
        std::vector<std::string> nodes;
 
        size_t numNodes = 0;
        hr = pDevice->NodeMapGetNumNodes(&numNodes);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't query number of available nodes!"));
            return hr;
        }
 
        for (unsigned int index = 0; index < numNodes; index++)
        {
            char nodeName[MAX_LENGTH];
            hr = pDevice->NodeMapGetNodeAtIndex(index, nodeName, MAX_LENGTH);
            if (SUCCEEDED(hr))
            {
                nodes.push_back(nodeName);
            }
        }
 
        //
        // Query image settings
        //
        char pixelValue[MAX_LENGTH];
        int64_t widthValue = 0;
        int64_t heightValue = 0;
 
        //
        // Query and set PixelFormat enumeration node
        //
        std::string nodeName = "PixelFormat";
        bool isAvailable = false;
        hr = pDevice->NodeIsAvailable(nodeName.c_str(), &isAvailable);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't check whether PixelFormat is available!"));
            return hr;
        }
 
        bool isReadable = false;
        hr = pDevice->NodeIsReadable(nodeName.c_str(), &isReadable);
        if (FAILED(hr))
        {
            MsgError(TEXT("Couldn't check whether PixelFormat is readable!"));
            return hr;
        }
 
        if (isReadable)
        {
            // Get list of available entries
            size_t numEntries = 0;
            hr = pDevice->EnumerationGetNumEntries(nodeName.c_str(), &numEntries);
            if (FAILED(hr))
            {
                MsgError(TEXT("Couldn't query number of enumeration entries for PixelFormat!"));
                return hr;
            }
 
            std::vector<std::string> enumEntries;
            for (unsigned int index = 0; index < numNodes; index++)
            {
                char enumEntryName[MAX_LENGTH];
                hr = pDevice->EnumerationGetEntryAtIndex(nodeName.c_str(), index, enumEntryName, MAX_LENGTH);
                if (SUCCEEDED(hr))
                {
                    enumEntries.push_back(enumEntryName);
                }
            }
 
            // Check if entry exist and set to mono8
            bool isWritable = false;
            hr = pDevice->NodeIsWritable(nodeName.c_str(), &isWritable);
            if (FAILED(hr))
            {
                MsgError(TEXT("Couldn't check whether PixelFormat is writable!"));
                return hr;
            }
 
            bool entryExist = false;
            hr = pDevice->EnumerationEntryExists(nodeName.c_str(), "Mono8", &entryExist);
            if (FAILED(hr))
            {
                MsgError(TEXT("Couldn't check whether Mono8 entry is available for PixelFormat!"));
                return hr;
            }
 
            if (entryExist && isWritable)
            {
                pDevice->EnumerationSetEntry(nodeName.c_str(), "Mono8");
            }
 
            // Get current enumeration entry
            hr = pDevice->EnumerationGetEntry(nodeName.c_str(), pixelValue, MAX_LENGTH);
            if (FAILED(hr))
            {
                MsgError(TEXT("Couldn't get current values for PixelFormat!"));
                return hr;
            }
        }
 
        //
        // Query and read Width integer node
        //
        nodeName = "Width";
        isAvailable = false;
        pDevice->NodeIsAvailable(nodeName.c_str(), &isAvailable);
        isReadable = false;
        pDevice->NodeIsReadable(nodeName.c_str(), &isReadable);
        if (isReadable)
        {
            pDevice->IntegerGetValue(nodeName.c_str(), &widthValue);
        }
 
        //
        // Query and read Height integer node
        //
        nodeName = "Height";
        isAvailable = false;
        pDevice->NodeIsAvailable(nodeName.c_str(), &isAvailable);
        isReadable = false;
        pDevice->NodeIsReadable(nodeName.c_str(), &isReadable);
        if (isReadable)
        {
            pDevice->IntegerGetValue(nodeName.c_str(), &heightValue);
        }
 
        //
        // Display camera information
        //
        std::wstringstream infoString;
        infoString << L"Number of cameras found: " << numDevices << std::endl
                   << L"Selected Index : " << selectedDeviceIndex << std::endl
                   << L"Camera Model : " << model << std::endl
                   << L"Camera Sensor : " << sensor << std::endl
                   << L"Camera Serial : " << serial << std::endl
                   << L"Number of nodes: " << nodes.size() << std::endl
                   << L"Current Pixel Format: " << pixelValue << std::endl
                   << L"Width : " << widthValue << std::endl
                   << L"Height : " << heightValue << std::endl;
        MsgInfo(TEXT("%s"), infoString.str().c_str());
    }
    catch (Spinnaker::Exception& se)
    {
        std::basic_ostringstream<TCHAR> ex;
        ex << se.what();
        MsgError(TEXT("Unexpected exception: %s\n\r"), ex.str().c_str());
    }
 
    SAFE_RELEASE(pProps);
 
    return S_OK;
}
 
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;
}
 
void 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(ghApp, &rc);
        g_pVW->SetWindowPosition(0, 0, rc.right, rc.bottom);
    }
}
 
HRESULT 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;
}
 
void MsgError(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 nullptr terminating character.
    (void)StringCchVPrintf(szBuffer, NUMCHARS - 1, szFormat, pArgs);
    va_end(pArgs);
 
    // Ensure that the formatted string is nullptr-terminated
    szBuffer[LASTCHAR] = TEXT('\0');
 
    MessageBox(nullptr, szBuffer, TEXT("SpinSimpleGUI_DirectShow Error"), MB_OK | MB_ICONERROR);
}
 
void MsgInfo(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 nullptr terminating character.
    (void)StringCchVPrintf(szBuffer, NUMCHARS - 1, szFormat, pArgs);
    va_end(pArgs);
 
    // Ensure that the formatted string is nullptr-terminated
    szBuffer[LASTCHAR] = TEXT('\0');
 
    MessageBox(nullptr, szBuffer, TEXT("SpinSimpleGUI_DirectShow Info"), MB_OK | MB_ICONINFORMATION);
}
 
HRESULT HandleGraphEvent(void)
{
    LONG evCode;
    LONG_PTR evParam1, evParam2;
    HRESULT hr = S_OK;
 
    if (!g_pME)
    {
        return E_POINTER;
    }
 
    while (SUCCEEDED(g_pME->GetEvent(&evCode, &evParam1, &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;
}
 
LRESULT CALLBACK WndMainProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
    switch (message)
    {
    case WM_CREATE:
    {
        HINSTANCE hInstance = reinterpret_cast<LPCREATESTRUCT>(lParam)->hInstance;
        HICON hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_ICON1));
        if (hIcon != nullptr)
        {
            SendMessage(hwnd, WM_SETICON, ICON_BIG, reinterpret_cast<LPARAM>(hIcon));
        }
        break;
    }
    case WM_GRAPHNOTIFY:
        HandleGraphEvent();
        break;
 
    case WM_SIZE:
        ResizeVideoWindow();
        break;
 
    case WM_WINDOWPOSCHANGED:
        ChangePreviewState(!(IsIconic(hwnd)));
        break;
 
    case WM_CLOSE:
        // Hide the main window while the graph is destroyed
        ShowWindow(ghApp, SW_HIDE);
        CloseInterfaces(); // Stop capturing and release interfaces
        break;
 
    case WM_DESTROY:
        PostQuitMessage(0);
        return 0;
    }
 
    // Pass this message to the video window for notification of system changes
    if (g_pVW)
    {
        g_pVW->NotifyOwnerMessage((LONG_PTR)hwnd, message, wParam, lParam);
    }
 
    return DefWindowProc(hwnd, message, wParam, lParam);
}
 
int PASCAL WinMain(HINSTANCE hInstance, HINSTANCE hInstP, LPSTR lpCmdLine, int nCmdShow)
{
    MSG msg = {0};
    WNDCLASS wc;
 
    // Initialize COM
    if (FAILED(CoInitializeEx(nullptr, COINIT_APARTMENTTHREADED)))
    {
        MsgError(TEXT("CoInitialize Failed!\r\n"));
        exit(1);
    }
 
    // Register the window class
    ZeroMemory(&wc, sizeof wc);
    wc.lpfnWndProc = WndMainProc;
    wc.hInstance = hInstance;
    wc.lpszClassName = CLASSNAME;
    wc.lpszMenuName = nullptr;
    wc.hbrBackground = (HBRUSH)GetStockObject(BLACK_BRUSH);
    wc.hCursor = LoadCursor(nullptr, IDC_ARROW);
    wc.hIcon = nullptr;
    if (!RegisterClass(&wc))
    {
        MsgError(TEXT("RegisterClass Failed! Error=0x%x\r\n"), GetLastError());
        CoUninitialize();
        exit(1);
    }
 
    // Create the main window.  The WS_CLIPCHILDREN style is required.
    ghApp = CreateWindow(
        CLASSNAME,
        APPLICATIONNAME,
        WS_OVERLAPPEDWINDOW | WS_CAPTION | WS_CLIPCHILDREN,
        CW_USEDEFAULT,
        CW_USEDEFAULT,
        DEFAULT_VIDEO_WIDTH,
        DEFAULT_VIDEO_HEIGHT,
        0,
        0,
        hInstance,
        0);
 
    if (ghApp)
    {
        HRESULT hr;
 
        // Create DirectShow graph and start capturing video
        hr = CaptureVideo();
        if (FAILED(hr))
        {
            CloseInterfaces();
            DestroyWindow(ghApp);
        }
        else
        {
            // Don't display the main window until the DirectShow
            // preview graph has been created.  Once video data is
            // being received and processed, the window will appear
            // and immediately have useful video data to display.
            // Otherwise, it will be black until video data arrives.
            ShowWindow(ghApp, nCmdShow);
        }
 
        // Main message loop
        while (GetMessage(&msg, nullptr, 0, 0))
        {
            TranslateMessage(&msg);
            DispatchMessage(&msg);
        }
    }
 
    // Release COM
    CoUninitialize();
 
    return (int)msg.wParam;
}