DirectShow samples lived under (SDK samples root)\DirectShow\ in the Windows 7.1 SDK, but the Windows 8 SDK does not have the files neither in C:\Program Files (x86)\Windows Kits\8.0 nor C:\Program Files (x86)\Microsoft SDKs\Windows. The samples are also not for download at http://code.msdn.microsoft.com/windowsapps
Microsoft now has a github repo with the old samples: https://github.com/Microsoft/Windows-classic-samples/tree/master/Samples/Win7Samples/multimedia/directshow/baseclasses