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Question: Topologies RRS feed

  • Question

  • I maybe confusing alot of things, but my initial impression is that eventhough very badly explained in the current MF documentation Topology in MF architecture would be replacement for DirectShow graph.

    If so:

    Is it planned by MSFT to create something like GraphEdit, but now for Topologies?

    Is it possible? If not, why?

    DirectShow API has an "intelligent" way of connecting input/output pins as well as rendering Media Sources, based on availabe DirectShow components present on the system. I don't see in MFs Topology section anything about such "intelligent" topology constructor/connector. Would there be any? If not, what the advantage?

    What current MFTs are already supported? There DMO equivalents. There CLSIDs...

     

     

    Friday, May 19, 2006 7:03 AM

Answers

  • Yes, the topology in Media Foundation is a similar concept to the graph in DirectShow.

    I agree that graphedt sure is a handy tool.  In version 1 of Media Foundation, our SDK unfortunately won't include a graphedt-like application.  It certainly is possible to write such a tool; we just haven't done it (yet).

    Media Foundation does provide some intelligent topology-building.  Take a look at the IMFMediaSession::SetTopology method.  By default, you can pass it a "partial" topology, in which you have specified only the source nodes (corresponding to streams from your IMFMediaSource) and the output nodes (corresponding to renderer streams).  The Media Session passes this partial topology to a Topology Loader, which has the necessary intelligence to take care of inserting the necessary decoders, etc. to give you a fully-resolved topology.

    In Windows Vista, there will be MFTs for WMA and WMV decoding and encoding, plus a couple others as well (resample, resize, etc).

    Hope this helps... good luck trying out Media Foundation!

    Friday, May 19, 2006 11:25 PM