win音视频--Dshow视频采集显示

         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;
}

环境：vs2008 + win7 + directx90