playing media sources sequentially and help with Sequencer Source sample

Hi,

I am trying to write a application that will play video files one after the other without any delays. I have tried following the code in the Sequencer Source sample, however the function hr = GetCollectionObject(pSourceNodes, 0, &pNode); called in HRESULT CPlaylist::GetDurationFromTopology(IMFTopology* pTopology, LONGLONG* phnsDuration) is missing in the sample. Anyone know what the function GetCollectionObject should be?

Any other samples or examples of playing media sequentially?

I am just starting to learn about the Media Foundation, if you know of any good books or articles on it, please let me know also.

Thanks