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StartRecordToCustomSinkAsync not calling IMFMediaSinkPreroll

    Question

  • I have a custom MediaSink that I am invoking via MediaCapture.StartRecordToCustomSinkAsync. My media sink implements IMFMediaSinkPreroll and supplies MEDIASINK_CAN_PREROLL in GetCharacteristics. However, IMFMediaSinkPreroll.NotifyPreroll is never called and the media sink is used in exactly the same way as if I hadn't implemented IMFMediaSinkPreroll.

    According to the docs, anyone calling a mediasink should look for the IMFMediaSinkPreroll interface and use it if it exists. Can someone please confirm that MediaCapture.StartRecordToCustomSinkAsync ignores the IMFMediaSinkPreroll interface?

    Thanks, Tim

    Wednesday, July 2, 2014 6:58 PM

Answers

  • Hello Tim,

    You are seeing the expected behavior. You will never see preroll on a live media source.

    I hope this helps,

    James


    Windows SDK Technologies - Microsoft Developer Services - http://blogs.msdn.com/mediasdkstuff/

    Wednesday, July 2, 2014 9:33 PM
    Moderator

All replies

  • I'll ask our media guru to check this out.

    Matt Small - Microsoft Escalation Engineer - Forum Moderator
    If my reply answers your question, please mark this post as answered.

    NOTE: If I ask for code, please provide something that I can drop directly into a project and run (including XAML), or an actual application project. I'm trying to help a lot of people, so I don't have time to figure out weird snippets with undefined objects and unknown namespaces.

    Wednesday, July 2, 2014 7:39 PM
    Moderator
  • Hello Tim,

    You are seeing the expected behavior. You will never see preroll on a live media source.

    I hope this helps,

    James


    Windows SDK Technologies - Microsoft Developer Services - http://blogs.msdn.com/mediasdkstuff/

    Wednesday, July 2, 2014 9:33 PM
    Moderator
  • Thanks exactly what I needed to know. Thank James!
    Wednesday, July 2, 2014 9:48 PM