一个粗糙的显示小程序,完成了窗口的创建,com的初始化及dshow视频的显示。dshow的文章虽说不少,但不适合入门,从小到大,有能运行的程序然后慢慢的完善,就是入门。一个入门的小程序,希望像我一样的同学门,找到希望,找到dshow音视频开发的大门。先贴出来文章,然后整理。
#include "stdafx.h" #include <DShow.h> #include <Guiddef.h> #include <strmif.h> #define CHECK_HR(s) if (FAILED(s)) {return 1;} #define SAFE_RELEASE(p) do { if ((p)) { (p)->Release(); (p) = NULL; } } while(0) LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam); #pragma comment(lib, "Dxguid.lib") #pragma comment(lib, "Strmiids.lib") int WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow) { WNDCLASSEX wcex; wcex.cbSize = sizeof(WNDCLASSEX); wcex.style = CS_HREDRAW | CS_VREDRAW; wcex.lpfnWndProc = WndProc; wcex.cbClsExtra = 0; wcex.cbWndExtra = 0; wcex.hInstance = hInstance; wcex.hIcon = LoadIcon(hInstance, MAKEINTRESOURCE(IDI_APPLICATION)); wcex.hCursor = LoadCursor(NULL, IDC_ARROW); wcex.hbrBackground = (HBRUSH)(COLOR_WINDOW+1); wcex.lpszMenuName = NULL; wcex.lpszClassName = _T("aaaaa"); wcex.hIconSm = LoadIcon(wcex.hInstance, MAKEINTRESOURCE(IDI_APPLICATION)); if (!RegisterClassEx(&wcex)) { MessageBox(NULL, _T("Call to RegisterClassEx failed!"),_T("Win32 Guided Tour"), NULL); return 1; } IGraphBuilder *m_pGraph; ICaptureGraphBuilder2 *m_pBuild; IBaseFilter *m_pSrc; IMediaControl *m_pMediaControl; IVideoWindow *m_pVidWin; CoInitialize(NULL); int nRes = 0; HRESULT hr =CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void**)&m_pGraph); CHECK_HR(1); hr = CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL,CLSCTX_INPROC_SERVER, IID_ICaptureGraphBuilder2, (void**)&m_pBuild); CHECK_HR(2); hr = m_pBuild->SetFiltergraph(m_pGraph); CHECK_HR(3); hr = m_pGraph->QueryInterface(IID_IVideoWindow, (void **)&m_pVidWin); CHECK_HR(4); ICreateDevEnum *pDevEnum=NULL; IEnumMoniker *pClsEnum=NULL; IMoniker *pMoniker = NULL; //创建设备枚举COM对象 hr = CoCreateInstance(CLSID_SystemDeviceEnum,NULL,CLSCTX_INPROC,IID_ICreateDevEnum,(void **)&pDevEnum); CHECK_HR(5); //创建视频采集设备枚举COM对象 hr = pDevEnum->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,&pClsEnum,0); CHECK_HR(6); int i = 0; while(i <= 0) { hr = pClsEnum->Next(1,&pMoniker,NULL); ++i; } CHECK_HR(7); hr = pMoniker->BindToObject(0,0,IID_IBaseFilter,(void **)&m_pSrc); CHECK_HR(8); SAFE_RELEASE(pMoniker); SAFE_RELEASE(pClsEnum); SAFE_RELEASE(pDevEnum); //将设备添加到管理器graph hr = m_pGraph->AddFilter(m_pSrc, L"Video Capture"); CHECK_HR(9); hr=m_pBuild->RenderStream(&PIN_CATEGORY_PREVIEW,&MEDIATYPE_Video,m_pSrc,NULL,NULL); CHECK_HR(10); HWND m_hWnd = ::CreateWindowA("STATIC","ds_video_preview",WS_POPUP,100,100,500,500,NULL,NULL,NULL,NULL); ShowWindow(m_hWnd, nCmdShow); UpdateWindow(m_hWnd); if (m_hWnd == NULL) { nRes = 11; } m_pVidWin->put_Owner((OAHWND)m_hWnd); m_pVidWin->SetWindowPosition(100, 100, 500, 500); m_pVidWin->put_WindowStyle(WS_CHILD | WS_CLIPSIBLINGS); hr = m_pGraph->QueryInterface(IID_IMediaControl, (void **)&m_pMediaControl); CHECK_HR(12); hr = m_pMediaControl->Run(); MSG msg; while (GetMessage(&msg, NULL, 0, 0)) { TranslateMessage(&msg); DispatchMessage(&msg); } return (int) msg.wParam; } LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam) { PAINTSTRUCT ps; HDC hdc; TCHAR greeting[] = _T("Hello, World!"); switch (message) { case WM_PAINT: hdc = BeginPaint(hWnd, &ps); TextOut(hdc,5, 5,greeting, _tcslen(greeting)); EndPaint(hWnd, &ps); break; case WM_DESTROY: PostQuitMessage(0); break; default: return DefWindowProc(hWnd, message, wParam, lParam); break; } return 0; }