Devo scaricare questo?

http://www.microsoft.com/windows/directx/default.mspx

Perchè su CodeProject io ho trovato sta cosa:
Before we can begin a .NET DirectShow application we need to create a reference to the DirectShow COM DLL. So, copy the "Interop.QuartzTypeLib.dll" DLL into your project folder and add a reference to this DLL. In Visual Studio.NET this is done by choosing Add Reference from the project menu. As next choose the "Browse..." Button of the Add reference Dialog and select the DirectShow COM DLL.
So, after the reference to the DirectShow COM DLL is created add the
following code line to your project, to make the DirectShow Interface Classes
visible:
codice:
using QuartzTypeLib;
ma io non ho il DirectShow ma ho solo un DirectShowStream 1.0.