[wdmaudiodev] Re: AVStream minidriver Capture stream fails WASAPI Exclusive-mode Stream
- From: "Mike Kemp" <mjk@xxxxxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Thu, 29 May 2014 08:34:46 +0100
Hi Matthew
Can you just clarify why there is a size ambiguity with the WAVE_FORMAT_PCM?
This is for background interest and I don't have the documentation to hand, but
I'd appreciate knowing what the issue is for future reference...
Thanks,
Mike
----- Original Message -----
From: Matthew van Eerde
To: wdmaudiodev@xxxxxxxxxxxxx
Sent: Wednesday, May 28, 2014 12:11 AM
Subject: [wdmaudiodev] Re: AVStream minidriver Capture stream fails WASAPI
Exclusive-mode Stream
It is an error (due to container size ambiguity) to specify wFormatTag =
WAVE_FORMAT_PCM with wBitsPerSample = 24. Try:
Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE
Format.wBitsPerSample = 24
Format.cbSize = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX)
SubFormat = KSDATAFORMAT_SUBTYPE_PCM
Samples.wValidBitsPerSample = 24
dwChannelMask = KSAUDIO_SPEAKER_STEREO
This doesn't explain your current predicament, though.
After streaming once in shared mode, what is PKEY_AudioEngine_DeviceFormat?
You can query that by running this tool:
http://blogs.msdn.com/b/matthew_van_eerde/archive/2011/06/13/how-to-enumerate-audio-endpoint-immdevice-properties-on-your-system.aspx
How (if at all) does this value differ from the format you're trying to use
in exclusive mode?
When you do the IAudioClient::IsFormatSupported(AUDCLNT_SHAREMODE_EXCLUSIVE,
.) call which fails, do you see any property requests in your driver?
Of particular interest are KSPROPERTY_PIN_DATAINTERSECTION, which calls into
your IMiniport::DataRangeIntersection method, KSPROPERTY_PIN_PROPOSEDATAFORMAT,
and KSPROPERTY_PIN_PROPOSEDATAFORMAT2.
Other related posts:
