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How to get event notifications from user application by using SysVAD?

yugeshavyugeshav Member Posts: 3

Hello all,

I am using SysVAD for creating virtual mic and speaker for my project. I need to get a event notification in processing application whenever a user application like audacity is configured with SysVAD mic. Can you please suggest me how to do it.

Thanks in advance,


  • Tim_RobertsTim_Roberts Member - All Emails Posts: 13,699

    Have you tried anything at all? You can't really expect us to start from nothing.

    You will need to be able to handle ioctls in SYSVAD, so your application has a way to get notified. That means adding an ioctl handler, and adding a way to queue pending requests. You can use inverted call, where the application sends in a couple of ioctls that remain pending in the driver until something happens. You then complete a request with an event structure.

    As for when that happens, the stream base class Init call is a likely place for a "connect" notification, and the destructor is a likely place for a "disconnect" notification.

    HOWEVER, please understand that there is no way to find out which application has opened the device. If that's what you were hoping, you need to forget about it right now. With the advent of the Audio Engine in Vista, applications no longer talk directly to audio drivers. Applications talk to the Audio Engine process, and the Audio Engine talks to the drivers. Every open you get is from the Audio Engine.

    Tim Roberts, [email protected]
    Providenza & Boekelheide, Inc.

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