Adding Windows Media Support to the ltmmPlay Object for C

The following code demonstrates how to add Windows Media support to the ltmmPlay Object.

#include "ltmm.h"
#include "assert.h"

HINSTANCE g_hInstance;  // application instance handle
IltmmPlay* g_pPlay;  // play object's interface pointer

extern "C"
{
   // declare the windows media certificate creation function
   HRESULT STDMETHODCALLTYPE WMCreateCertificate( IUnknown** pUnkCert ); 
};

// link the stub library
#pragma comment(lib, "wmstub.lib")


int APIENTRY WinMain(HINSTANCE hInstance, 
                     HINSTANCE /*hPrevInstance*/, 
                     LPSTR     /*lpCmdLine*/, 
                     int       /*nCmdShow*/) 
{
   HRESULT hr; 
   IUnknown* punkCert; 
   
   g_hInstance = hInstance; 

   // initialize COM library
   hr = CoInitialize(NULL); 
   if(FAILED(hr)) 
      goto error; 
   
   // create the play object
   hr = CoCreateInstance(CLSID_ltmmPlay, NULL, CLSCTX_INPROC_SERVER, IID_IltmmPlay, (void**) &g_pPlay); 
   if(FAILED(hr)) 
      goto error; 
   
   // create windows media certificate   
   hr = WMCreateCertificate(&punkCert); 
   if(SUCCEEDED(hr)) 
   {
      // assign the certificate to the play object
      g_pPlay->put_WMCertificate(punkCert); 
      punkCert->Release();
   }   
   
#ifdef _DEBUG
   {
      // verify assignment
      g_pPlay->get_WMCertificate(&punkCert); 
      assert(punkCert != NULL); 
      if(punkCert) 
         punkCert->Release();
   }
#endif

//   TODO: place additional code here

error: 
   // cleanup

   if(g_pPlay) 
      g_pPlay->Release();

   CoUninitialize();
   
   return 0; 
}