Capturing frames from webcam using DirectShow.NET

If your main concern is "access webcam" and not "access webcam with DirectShow", then I would have a look at the AForge.NET-Framework. I tried it with DirectShow once just to find out that I could do the same thing with multiple video sources in less time with less code.

Here is some sample code: Access to USB cameras and video files using DirectShow

you could build one yourself. If you look into the windows sdk 7.0~ folders you can go to samples > multimedia > directshow > and there should be a filters folder that shows you how to make generic filters and do w/e you want