[wdmaudiodev] Problem with capturing for single sample rate device in XP

  • From: KS <wakeup1504@xxxxxxxxx>
  • To: wdmaudiodev@xxxxxxxxxxxxx
  • Date: Thu, 15 Mar 2007 23:22:24 +0800

Hi,

I'm trying to do an AVStream based driver for a single sample rate device.
in XP  I'm currently seeing some issue with capturing when the recording
stream is set to a different sample rate from my device. My device only
support 16kHz 16bits mono for recording. When I use Sound Recorder to record
a 16kHz 16 bits mono stream, all was well. However, when I tried to record
at other sample rates (8kHz 16bits mono, 48kHz 16 bits mono etc), somehow
the application is interpreting 10 seconds worth of data as 5 seconds, which
result in all my recording sound like being play at a fast forward rate.

It seems that this time issue (10 second recording become 5 seconds data to
sound recorder), will happen as long as the sample rate chosen for the
recording stream is not the same as my device rate (i.e. any rate other than
16kHz). Does any know what might be wrong? I'm suspecting some issue with
one of the KSProperty calls, but is not sure about what to look at.

I've also check that the stream that was created on my AVStream driver is
always 16kHz 16bits mono, which is what I support.

Thanks for any advice.

KS

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