Tag Archives: aggregation

DirectShow Filter Graph Spy

Inspired by a post on DirectShow Development Forum, it is sometimes useful to find out how certain application is using DirectShow to capture live video and/or audio, or play certain file etc. Filter graph topology, details about media types on the pins, used interfaces and call order. There is quite an easy step for the developer to spy over running filter graphs system wide by connecting Component Object Model (COM) “Treat As” feature with filter graph remoting through Running Object Table and connecting to remote process graphs using GraphEdit utility.

Who could imagine Windows Media Player to build such a filter graph for a video and audio Windows Media file? SRS Wow DMO, equalizer, analyzer and stuff?

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How To: Wrap an existing DirectShow filter with a private video source filter (COM aggregation)

See beginning in microsoft.public.win32.programmer.directx.video newsgroup.

This sample is demonstrating COM aggregation to embed an existing filter an re-expose it as a new filter having inner filter pre-initialized.

The Visual Studio C++.NET 2008 projects contains a DirectShow filter class that registers itself under Video Capture Sources category and embeds File Source (Async) Filter inside initialized to stream clock.avi file from Windows directory.

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