[wdmaudiodev] Re: Is there a way to list all supported format of an audio device

  • From: Matthew van Eerde <Matthew.van.Eerde@xxxxxxxxxxxxx>
  • To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Sat, 17 Aug 2013 00:40:27 +0000

Desktop apps can still play audio to that device. It just won’t be offloaded.

Windows Store apps can play audio to the device. Under certain circumstances, 
the audio will be offloaded; and under other circumstances, it won’t be. It 
depends on the kind of audio the app is playing and what other audio is playing.

The Windows Audio Session API sample shows how to explicitly play offloaded 
audio from a Windows Store app using WASAPI:

Windows 8.0: 
http://code.msdn.microsoft.com/windowsapps/Windows-Audio-Session-ea894455
Windows 8.1: 
http://code.msdn.microsoft.com/windowsapps/Windows-Audio-Session-22dcab6b

If you play via the <audio> or MediaEngine APIs, and your app satisfies certain 
criteria, and your audio is tagged correctly, and offload resources are 
available, your audio will be automatically offloaded for you with no special 
code needed.

You can tell whether/how much audio is being offloaded by querying 
KSPROPERTY_PIN_GLOBALCINSTANCES on the offload pin. Each pin instance is an 
offloaded stream.

From: wdmaudiodev-bounce@xxxxxxxxxxxxx 
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Jeff Pages
Sent: Friday, August 16, 2013 5:29 PM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Is there a way to list all supported format of an 
audio device

>Also note that Classic Win32 applications cannot use adapters that are capable 
>of processing hardware-offloaded audio.

Gosh, does that literally mean that such an adapter that is “capable of 
processing hardware-offloaded audio” (note capable, not necessarily actually 
doing it) cannot be used at all, in any way, shape or form, by a Win32 app?

Jeff

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