[wdmaudiodev] AVStream mixer problems on XP

  • From: Harry Graham <harry_graham@xxxxxxxxxx>
  • To: "'wdmaudiodev@xxxxxxxxxxxxx'" <wdmaudiodev@xxxxxxxxxxxxx>
  • Date: Thu, 5 Jun 2003 12:08:10 -0700

I have created two AVStream filters, one for record, and the second for
playback, each containing its' own mixer topology described by Node and
Connections descriptors. SndVol32 displays the mixer lines and controls
correctly on W2K (DirectX9), but fails to display correctly on XP (also
For the record filter, all the relevant controls are displayed, but all the
volume controls are disabled.
For the playback filter, the result is pretty much nonsense.  Lines are
displayed that don't exist (CD and Unknown pin), and none of the analog
lines (there are 4 of them) input to the summer are displayed.
I have examined the sysaudio filters(KSCATEGORY_AUDIO_DEVICE) with KsStudio,
and don't see any reason why SndVol32 fails to work on XP.  The sysaudio
filters are slightly different on XP, due to the addition of DRM, AEC, etc.,
but the analog lines are identical in both XP and W2K.
Does anyone know what could cause XP to behave so differently from W2K?

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