Use ltmfCapture to Perform a Capture and Save It as a WMV File

1. Create an instance of the ltmfCapture class. This is accomplished using the Win32 CoCreateInstance function,  as follows:

   //C Source 
   IltmfCapture* pCapture; 
   CoCreateInstance(&CLSID_ltmfCapture, NULL, CLSCTX_INPROC_SERVER,&IID_IltmfCapture,(void**) &pCapture); 
    
   //C++ Source 
   IltmfCapture* pCapture; 
   CoCreateInstance(&CLSID_ltmfCapture, NULL, CLSCTX_INPROC_SERVER,&IID_IltmfCapture, (void**) &pCapture); 

2. Define the notification window, which receives the capture status notifications:

   //C Source 
   HWND hwndNotify; 
   #define WM_CAPTURENOTIFY (WM_USER + 1000) 
   IltmfCapture_SetNotifyWindow(pCapture, (long)hwndNotify, WM_CAPTURENOTIFY); 
    
   // C++ Source 
   HWND hwndNotify; 
   #define WM_CAPTURENOTIFY (WM_USER + 1000)  
   pCapture->SetNotifyWindow((long)hwndNotify, WM_CAPTURENOTIFY); 

   The above code instructs the capture object to send WM_CAPTURENOTIFY messages to the window procedure of hwndNotify. The wParam parameter of the window message will contain the notification code.

   ✎ NOTE

   A capture can be accomplished without using a notification window, but the user would be required to poll the objects state to determine when the capture has finished.

3. Define a frame window for the video preview:

   //C Source 
   HWND  hwndFrame; 
   IltmfCapture_put_VideoWindowFrame(pCapture, (long)hwndFrame); 
    
   // C++ Source 
   HWND hwndFrame; 
   pCapture->put_VideoWindowFrame((long)hwndFrame); 

   The user is required to create the window that serves as the video frame. ltmfCapture will subclass this window, so there is no need to forward any messages to the ltmfCapture object. By default, ltmfCapture will automatically maximize the video within the frame window. The video will automatically resize when the frame window size changes.

   ✎ NOTE

   The notification window and the video frame window can be the same.

4. Set the Target file:

   //C Source 
   BSTR bstr; 
   bstr = SysAllocString(L"c:\\captured.wmv"); 
   IltmfCapture_put_Target 
    
   // C++ Source 
   BSTR bstr; 
   ::SysAllocString(L"c:\\captured.wmv"); 
   pCapture->put_TargetFile(bstr); 
   ::SysFreeString(bstr); 

5. Set the video device:

   //C Source 
   IltmfDevices* devices; 
   IltmfCapture_get_VideoDevices(pCapture, &devices); 
   IltmfDevices_put_Selection(devices, 0); 
   IltmfDevices_Release(devices); 
    
   // C++ Source 
   IltmfDevices* devices; 
   pCapture->get_VideoDevices(&devices); 
   devices->put_Selection(0); 
   devices->Release(); 

6. Set the audio device:

   //C Source 
   HIltmfDevices* devices; 
   IltmfCapture_get_AudioDevices(pCapture, &devices); 
   IltmfDevices_put_Selection(devices, 0); 
   IltmfDevices_Release(devices); 
    
   //C++ Source 
   IltmfDevices* devices; 
   pCapture->get_AudioDevices(&devices); 
   devices->put_Selection(0); 
   devices->Release(); 

7. Set the target format :

   //C Source 
   IltmfCapture_put_TargetFormat(pCapture, ltmfCapture_TargetFormat_WMV); 
    
   //C++ Source 
   pCapture->put_TargetFormat(ltmfCapture_TargetFormat_WMV); 

8. To start capturing, call the StartCapture function as follows:

   //C Source 
   IltmfCapture_StartCapture(pCapture, ltmfCapture_Mode_VideoAndAudio) 
    
   //C++ Source 
   pCapture->StartCapture(ltmfCapture_Mode_VideoAndAudio); 

9. To stop capturing, call the StopCapture function as follows:

   //C Source 
   IltmfCapture_StopCapture(pCapture); 
    
   //C++ Source 
   pCapture->StopCapture(); 

10. Release the capture object (and all active objects) when you are done.