Step1:enumerate the supported capture video modes

Hi,
I created win32 Project Visual c++,then I added DeckLinkAPI.idl to My Project As it described in SDK Documentation (Section 2.1 "Using the DeckLink API in a project").

When I readed (Section 2.4.1 "Capture") I found that An application performing a standard streaming capture operation should perform the
following steps:

step1:
If desired, enumerate the supported capture video modes by calling
IDeckLinkInput::GetDisplayModeIterator. For each reported capture mode,
call IDeckLinkInput::DoesSupportVideoMode to check if the combination of the video
mode and pixel format is supported.

How Can I Use IDeckLinkInput and how can I call IDeckLinkInput::GetDisplayModeIterator?

My Example Code is

#include <afxwin.h> // MFC core and standard components
#include <afxext.h> // MFC extensions




class CMyFrame : public CFrameWnd {
public:
CMyFrame() {
Create(NULL, _T("MFC Application Tutorial")); // WS_VISIBLE | WS_OVERLAPPED
}
};


class CExample : public CWinApp {
BOOL InitInstance() {

CMyFrame *Frame = new CMyFrame(); m_pMainWnd = Frame;

Frame->ShowWindow(SW_NORMAL);
Frame->UpdateWindow();

return TRUE;
}
};

CExample theApp;

thank You,,,,