Windows Media Foundation How to use IMFMediaSink::AddStreamSink - c++

Question

I am implementing sample application using Windows Media Foundation.
I have created one example application as described in below link:
https://msdn.microsoft.com/en-us/library/windows/desktop/ms703190(v=vs.85).aspx
In the above example I have added two video streams using MFCreateAggregateSource.
In the EVR renderer I am able to hear audio of both the videos but I am not able to see only one reference stream video or which is first loaded.
As per the below link,
https://msdn.microsoft.com/en-us/library/windows/desktop/aa965265(v=vs.85).aspx
The EVR media sink initially has one stream sink, which corresponds to the reference stream. To add new stream sinks, call IMFMediaSink::AddStreamSink.
In my application I am using MFCreateVideoRendererActivate.
How can I use IMFMediaSink::AddStreamSink to add streams to my EVR.
So that I can see two video stream playing in one renderer.
** Update **
I have modified below example code and added code to add video
HRESULT CreateMediaSinkActivate(
IMFStreamDescriptor *pSourceSD, // Pointer to the stream descriptor.
DWORD iStream,
HWND hVideoWindow, // Handle to the video clipping window.
IMFActivate **ppActivate
)
{
IMFMediaTypeHandler *pHandler = NULL;
IMFActivate *pActivate = NULL;
// Get the media type handler for the stream.
HRESULT hr = pSourceSD->GetMediaTypeHandler(&pHandler);
if (FAILED(hr))
{
goto done;
}
// Get the major media type.
GUID guidMajorType;
hr = pHandler->GetMajorType(&guidMajorType);
if (FAILED(hr))
{
goto done;
}
// Create an IMFActivate object for the renderer, based on the media type.
if (MFMediaType_Audio == guidMajorType)
{
// Create the audio renderer.
hr = MFCreateAudioRendererActivate(&pActivate);
}
else if (MFMediaType_Video == guidMajorType) // Added this else if case
{
// Create the video renderer.
hr = MFCreateVideoRendererActivate(hVideoWindow, &pActivate);
IMFMediaSink* pVideoSink = NULL;
HRESULT hrMS = pActivate->ActivateObject(IID_IMFMediaSink, (void**)&pVideoSink);
if (SUCCEEDED(hrMS))
{
IMFStreamSink* pStreamSink = NULL;
hrMS = pVideoSink->AddStreamSink(iStream, NULL, &pStreamSink);
if (SUCCEEDED(hrMS))
{
DWORD dwID=10;
hrMS = pStreamSink->GetIdentifier(&dwID);
if (SUCCEEDED(hrMS))
{
printf("\n%d", dwID);
SafeRelease(&pStreamSink);
}
}
}
}
else
{
// Unknown stream type.
hr = E_FAIL;
// Optionally, you could deselect this stream instead of failing.
}
if (FAILED(hr))
{
goto done;
}
// Return IMFActivate pointer to caller.
*ppActivate = pActivate;
(*ppActivate)->AddRef();
done:
SafeRelease(&pHandler);
SafeRelease(&pActivate);
return hr;
}
But problem is that I am not able to see two video stream in the video window.