Use ltmmCapture to Perform Simple Still Image Capture

  1. To begin simple still image capturing, create an instance of the ltmmCapture class. This is accomplished using the Win32 CoCreateInstance function as follows:

C Source 

IltmmCapture* pCapture;   
CoCreateInstance(&CLSID_ltmmCapture, NULL, CLSCTX_INPROC_SERVER, &IID_IltmmCapture, (void**) &pCapture);

C++ Source 

IltmmCapture* pCapture;    
CoCreateInstance(CLSID_ltmmCapture, NULL, CLSCTX_INPROC_SERVER, IID_IltmmCapture, (void**) &pCapture);

  1. Define the video devices to be used as the capture source. The ltmmCapture object contains video device collection objects. The first video device can be selected for capture by calling the device collection's put_Selection function:

C Source 

IltmmDevices* pDevices;   
// get an interface into video devices collection   
IltmmCapture_get_VideoDevices(pCapture, &pDevices);    
// select the first video device   
IltmmDevices_put_Selection (pDevices, 0);   
// release collection   
IUnknown_Release(pDevices);

C++ Source 

IltmmDevices* pDevices;    
// get an interface into video devices collection   
pCapture->get_VideoDevices(&pDevices);   
// select device   
pDevices->put_Selection(0);   
// release collection   
pDevices->Release();

  1. Define the target or output file, as demonstrated with the following code:

C Source 

BSTR bstr;    
// create a string containing the target file path   
bstr = SysAllocString(L"c:\\target.mpg");    
// assign the target file path to the capture object   
IltmmCapture_put_TargetFile (pCapture, bstr);    
// free the string   
SysFreeString(bstr);

C++ Source 

BSTR bstr;    
// create a string containing the target file path   
bstr = SysAllocString(L"c:\\target.mpg");    
// assign the target file path to the capture object   
pCapture->put_TargetFile (bstr);    
// free the string   
SysFreeString(bstr);

  1. Start capturing still image data. This is accomplished with the following code:

C Source 

IltmmCapture_StartCapture (pCapture, ltmmCapture_Mode_Still);

C++ Source 

pCapture->StartCapture (ltmmCapture_Mode_Still);

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LEADTOOLS Multimedia C API Help
Introduction
Version History
Getting Started
Copyright Notice
Directories
Multimedia Files You Must Include With Your Application (Redistributables)
Frequently Asked Questions
LEADTOOLS Multimedia Features
Add-on Modules
Programming with LEADTOOLS Multimedia
Appendix
LEADTOOLS Licensing