Part iii chapter introducing directshowstdapi cocreateinstance refclsid rclsid

296 Part III
Chapter 13: Introducing DirectShow

STDAPI CoCreateInstance(
REFCLSID rclsid,
LPUNKNOWN pUnkOuter,
DWORD dwClsContext,
REFIID riid,
LPVOID *ppv
);

LPVOID *ppv: Address where the specified interface is to be returned.

HRESULT InitDirectShow (HWND hWnd)
{
HRESULT hr = CoInitialize(NULL);
if (SUCCEEDED(hr))
{
hr = CoCreateInstance(CLSID_FilterGraph, NULL,
CLSCTX_INPROC_SERVER, IID_IGraphBuilder, (void **)&pGraph); }
return hr;
}

hr = pGraph->QueryInterface(IID_IMediaControl, (void **)&pControl); }
return hr;
}

13.5 The Event Mechanism