手机视频研究系列（1）

 

在windowsmobile下进行视频采集，我采用的directshow进行实现。

我的开发环境是vs2005，用的开发语言为C++，做正儿八经的事情，我还是倾向于使用C++来做，当然用directshow可能最好用C++比较好。

我开发电脑上安装的是windowsmobile sdk 6.0。在安装好了SDK后，在c:/Program Files/Windows Mobile 6SDK/Samples/PocketPC/CPP/win32/CameraCapture/目录下有个视频采集的例子，打开就可以编译。如果编译过程中出现如下错误：

错误       1     errorLNK2001: 无法解析的外部符号IID_IMediaEvent  graphmanager.obj  

错误       2     errorLNK2001: 无法解析的外部符号PIN_CATEGORY_STILL    graphmanager.obj  

错误       3     errorLNK2001: 无法解析的外部符号CLSID_IMGSinkFilter  graphmanager.obj  

错误       4     errorLNK2001: 无法解析的外部符号PIN_CATEGORY_CAPTURE      graphmanager.obj  

错误       5     errorLNK2001: 无法解析的外部符号MEDIATYPE_Video     graphmanager.obj  

错误       6     errorLNK2001: 无法解析的外部符号MEDIASUBTYPE_Asf graphmanager.obj  

错误       7     errorLNK2001: 无法解析的外部符号DMOCATEGORY_VIDEO_ENCODER      graphmanager.obj  

错误       8     errorLNK2001: 无法解析的外部符号CLSID_DMOWrapperFilter  graphmanager.obj  

错误       9     errorLNK2001: 无法解析的外部符号CLSID_VideoCapture   graphmanager.obj  

错误       10    errorLNK2001: 无法解析的外部符号CLSID_FilterGraph      graphmanager.obj  

错误       11    errorLNK2001: 无法解析的外部符号CLSID_CaptureGraphBuilder      graphmanager.obj  

错误       12    fatalerror LNK1120: 11 个无法解析的外部命令       Windows Mobile 6Professional SDK   

不用着急，我也遇到了这样的情况，可能跟DIRECTX的安装有些关系，请调整vs2005的编译环境设置，“工具/选项/项目和解决方案/VC++目录/”，平台选windows mobile 6 professional，库文件中将“C:/Program Files/WindowsMobile 6 SDK/PocketPC/lib/ARMV4I”调整到最上面，然后编译就应该就可以编译通过了。

我的测试真机为S900，显示出来的按钮显示不正常，我对appwindow.cpp做了部分调整如下：

HRESULT CAppWindow::CreateControls( HINSTANCE hInstance ) { HRESULT hr = S_OK; WNDCLASS wndClass; ATOM classAtom; LONG lReturn; RECT rcWorkArea; // First, let's register the window class ZeroMemory( &wndClass, sizeof( wndClass )); wndClass.lpfnWndProc = CAppWindow::AppWindowProc; wndClass.hInstance = hInstance; wndClass.lpszClassName = L"Camera Recording Video Class"; classAtom = RegisterClass( &wndClass ); if( classAtom == NULL ) { ERR( HRESULT_FROM_WIN32( GetLastError() )); } // Now, create the main window SystemParametersInfo(SPI_GETWORKAREA, 0, &rcWorkArea, 0); m_hwnd = CreateWindow( L"Camera Recording Video Class", L"Main Window", WS_VISIBLE, rcWorkArea.left, rcWorkArea.top, rcWorkArea.right - rcWorkArea.left, rcWorkArea.bottom - rcWorkArea.top, NULL, NULL, hInstance, (PVOID) this ); if( m_hwnd == NULL ) { ERR( HRESULT_FROM_WIN32( GetLastError() )); } // Workaround for bug in SetWindowLong, call twice the API lReturn = SetWindowLong( m_hwnd, GWL_USERDATA, (LONG) this ); lReturn = SetWindowLong( m_hwnd, GWL_USERDATA, (LONG) this ); if( lReturn == NULL ) { ERR( HRESULT_FROM_WIN32( GetLastError() )); } // Create a "Start Capture" button and add it to the main window m_startButtonHwnd = CreateWindow( L"Button", L"Start Video Recording", WS_CHILD | WS_VISIBLE | BS_CENTER | BS_PUSHBUTTON | BS_VCENTER, 30, 10, 390, 50, m_hwnd, (HMENU) CMD_START_RECORD_VIDEO, hInstance, NULL ); if( m_startButtonHwnd == NULL ) { ERR( HRESULT_FROM_WIN32( GetLastError() )); } // Create a "Stop Capture" button and add it to the main window m_stopButtonHwnd = CreateWindow( L"Button", L"Stop Video Recording", WS_CHILD | WS_VISIBLE | BS_CENTER | BS_PUSHBUTTON | BS_VCENTER, 30, 70, 390, 50, m_hwnd, (HMENU) CMD_STOP_RECORD_VIDEO, hInstance, NULL ); if( m_startButtonHwnd == NULL ) { ERR( HRESULT_FROM_WIN32( GetLastError() )); } // The stop capture button is disabled by default EnableWindow( m_stopButtonHwnd, FALSE ); // Create the take still image button m_stillButtonHwnd = CreateWindow( L"Button", L"Take a still image", WS_CHILD | WS_VISIBLE | BS_CENTER | BS_PUSHBUTTON | BS_VCENTER, 30, 130, 390, 50, m_hwnd, (HMENU) CMD_STILL_IMAGE, hInstance, NULL ); if( m_startButtonHwnd == NULL ) { ERR( HRESULT_FROM_WIN32( GetLastError() )); } // Create the graph manager. This will control the dshow capture pipeline m_pGraphManager = new CGraphManager(); if( m_pGraphManager == NULL ) { ERR( E_OUTOFMEMORY ); } CHK( m_pGraphManager->RegisterNotificationWindow( m_hwnd )); CHK( m_pGraphManager->Init()); CHK( m_pGraphManager->BuildCaptureGraph()); Cleanup: return hr; } 

运行效果：