[wdmaudiodev] Re: wasapi audioclientproperties

  • From: Matthew van Eerde <Matthew.van.Eerde@xxxxxxxxxxxxx>
  • To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Wed, 11 Jun 2014 20:21:23 +0000

There are two ways* to stream via DirectKS: "standard streaming" and "standard 
looped streaming".

The DirectKS sample only shows how to do "standard streaming".

Later-generation drivers tend to be WinRT miniports; portcls only advertises 
support for "standard looped streaming" on such drivers. Here's a screenshot of 
KS Studio on hdaudio.sys.

[cid:image001.png@01CF8575.CD674A00]

The DirectKS sample doesn't work on such devices. It should continue to work 
(even on Windows 7 or Windows 8) if the driver supports "standard streaming", 
though.

To be more specific:


1.       WaveRT miniports (like the inbox Microsoft HD Audio class driver 
hdaudio.sys) support only "standard looped streaming".

2.       WaveCyclic miniports support both streaming models.

3.       WavePci miniports support both streaming models.

4.       The inbox Microsoft USB Audio class driver (usbaudio.sys) supports 
only "standard streaming".

5.       The inbox Microsoft Bluetooth audio class drivers (btha2dp.sys, 
bthhfaud.sys) support only "standard streaming".

*OK, there's a little bit more than two ways. There's also audio offload, and 
KSPROPSETID_RtAudio, and other complications. But let's pretend there's only 
two for now.

PNG image

Other related posts:

  1. Home
  2. wdmaudiodev
  3. Archive
  4. 06-2014