[wdmaudiodev] Exposing more than 8 channels on Windows 7

  • From: Neetu Sand <neetu.freelist@xxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Fri, 6 Jan 2012 19:26:50 +0530

Hi All,

I have a query regarding publishing 16 channels on a speaker device. I
specify channel count as 16 while specifying the datarange in pin factory.
In handler for KSPROPERTY_PIN_PROPOSEDATAFORMAT, I handle condition for 16
channels but the problem is that the handler for
KSPROPERTY_PIN_PROPOSEDATAFORMAT is never called with 16 channels. It is
called within the channel count range of 1-8. DataRangeIntersection is
never called.

Also I notice that for some devices "Advance" tab on Sound and Audio
control panel shows "Channel, Bit Depth and Sample Rate" while for others,
it just shows "Bit Depth and Sample rate". However for later case speaker
configuration is enabled but for the earlier case "configure" button on
Sound And audio control panel is disabled. What change in driver code leads
to this behavior of Sound and Audio Control Panel? I tried removing
KSPROPERTY_AUDIO_CHANNEL_CONFIG from my code but I still see "Configure"
button enabled for my device.

I am not sure what change in driver would let Sound and Audio CPL detect 16
channels for my device. Any help is appreciated.

Cheers,
Neetu

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