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Ok, what the heck IS the windows audio service (audiosrv) anyway?

Ok, what the heck IS the windows audio service (audiosrv) anyway?

  • Comments 12

This morning, Dmitry asked what the heck was the audio service for anyway.

That's actually a really good question.

For Windows XP, the most common use for the audiosrv service is that if the audiosrv service didn't exist, applications that linked with winmm.dll would also get setupapi.dll in their address space.  This is a bad thing, since setupapi is relatively large, and for 99% of the apps that use winmm.dll (usually to call PlaySound), they don't need it until they actually start playing sounds (which is often never). 

As a part of this, audiosrv monitors for plug and play notifications (again, so the app doesn't have to) and allows the application to respond to plug and play changes without having to burn a thread (and a window pump) just to detect when the user plugs in their USB speakers.  All that work's done in audiosrv.

There's a bunch of other stuff, related to global audio digital signal processing that audiosrv manages, and some stuff to manage user audio preferences, but offloading the PnP functionality is the "big one".  Before Windows XP, this functionality was actually a part of csrss.exe (the windows client/server runtime subsystem), but in Windows XP it was broken out into its own service.

For Longhorn, Audiosrv will be doing a lot more, but unfortunately, I can't talk about that :(  Sorry. 

I really do want to be able to talk about the stuff we're doing, but unfortunately none of it's been announced yet, and since none of its been announced yet...

Edit: Corrected title.  Also added a little more about longhorn.

  • Here's my guess for the new audiosrv stuff in Longhorn: built-in speech recognition that's integrated with the new input stuff (you know, ink and all) so that it can be integrated really well in new Avalon applications and still decently well in legacy applications.

    Do I get a prize? :)
  • Nope, sorry Stephane.

    Speach goes through the speach recognition engine, but has very little to do with audiosrv (except as a client of audio capture).
  • Does the audio service also serve a similar purpose to the Arts and other sound servers on Linux, mixing the sound from different applications?
  • In Windows XP, mixing etc is done by the kmixer.sys driver, since the main audio engine for XP is in the kernel.

  • wtf are all these services anyway? Is there comprehensive documentation on all of these somewhere besides the 1 sentence description that gets cut off by the edit control/listview?
  • Google is your friend:
    http://www.google.com/search?sourceid=navclient&ie=UTF-8&q=list+of+windows+services

    The 6th entry is:
    http://www.theeldergeek.com/services_guide.htm

    The 8th or so entry is:
    http://www.microsoft.com/windows2000/techinfo/howitworks/management/w2kservices.asp

  • The 6th entry tells you a 1 sentence description. The 8th entry is very lightweight but it's better than nothing.
  • The most comprehensive list of windows services is at BlackViper.com. He not only tells you what each one does, but which one you really need for various system uses.
    http://www.blackviper.com/WinXP/servicecfg.htm

    A hint on the audio stuff coming in Longhorn comes from Paul Thurrott's aero prototype screenshots.
    http://www.winsupersite.com/images/showcase/lh-winhec-02.png

    You have already mentioned the per-application volume controls.

    http://blogs.msdn.com/larryosterman/archive/2004/07/14/183175.aspx#183230

    So there must be something else to it.
    Looks really cool anyway.
  • The thing is that what's going to be in audiosrv is also under flux - we've been having a lot of active discussions about this in the past week or so.
  • I would like to see a per application volume setting in the next Windows OS. Maybe that's the new secret audiosrv feature planned for Longhorn?
  • A few months back my sound card suddenly stopped working! Initially I thought it
    was a problem with my sound card. So I got a new sound card and installed the
    driver for it. But the problem persisted. After much fiddling around with my
    system, I discovered that the windows service AudioSrv is not started on my
    system. And when I try to start the service manually by issuing command:
    "net start AudioSrv"
    I get the following error message:
    The service is not responding to the control function.
    More help is available by typing NET HELPMSG 2186.

    My question is what is wrong with this service ? How can I start the service. If
    that part of the system is broken, how can I fix it. Any help appreciated.
    Thanx.
  • A few months back my sound card suddenly stopped working! Initially I thought it
    was a problem with my sound card. So I got a new sound card and installed the
    driver for it. But the problem persisted. After much fiddling around with my
    system, I discovered that the windows service AudioSrv is not started on my
    system. And when I try to start the service manually by issuing command:
    "net start AudioSrv"
    I get the following error message:
    The service is not responding to the control function.
    More help is available by typing NET HELPMSG 2186.

    My question is what is wrong with this service ? How can I start the service. If
    that part of the system is broken, how can I fix it. Any help appreciated.
    Thanx.
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