[wdmaudiodev] Re: Dynamic format negotiation on Windows 7
- From: K93157 <k93157@xxxxxxxxx>
- To: wdmaudiodev@xxxxxxxxxxxxx
- Date: Wed, 10 Feb 2010 17:11:20 -0800 (PST)
Hi Cheng.
Thank you very much for very useful information. I have implemented the below
changes. Now I am able to send event (GenerateEventList) successfully and also
supporting PCPROPERTY_ITEM_FLAG_GET.
Audio Stack seems to call my driver's handler with
KSPROPERTY_PIN_PROPOSEDDATAFORMAT and Get option. My driver is returning new
capabilities (new sample rate and bits per sample). However windows is still
using old sample rate and bits per sample and control panel still shows old
sample rate, bits as the default values
I am at loss on what is going on.
Please let me know if I am missing anything
Kishore
----- Original Message ----
From: Cheng-mean Liu (SOCCER) <soccerl@xxxxxxxxxxxxx>
To: "wdmaudiodev@xxxxxxxxxxxxx" <wdmaudiodev@xxxxxxxxxxxxx>
Sent: Wed, February 10, 2010 10:57:11 AM
Subject: [wdmaudiodev] Re: Dynamic format negotiation on Windows 7
Hi Uwe:
The new PCPROPERTY_ITEM_FLAG_GET was also added into Win7 for the drivers to
propose preferred device format to be set as default. As part of the whitepaper
I mentioned earlier, here is the section related to this.
".., but the old format was not removed automatically." I am not seeing this
behavior in the implementation in our HD Audio Class driver, could you double
check to see if the old format is not one of supported formats reported after
the dynamic format is triggered.
Thanks
Cheng-mean
KSProperty:Updated KSPROPERTY_PIN_PROPOSEDDATAFORMAT Property
This is a KS property that has been supported since Vista. However in Vista,
only the PCPROPERTY_ITEM_FLAG_SET flag was supported for querying whether a
format is supported by a driver. In Windows 7, Support for the
PCPROPERTY_ITEM_FLAG_GET request type was added to
KSPROPERTY_PIN_PROPOSEDDATAFORMAT in Windows 7. for drivers to report their
preference for the default device format settings of their devices. The
Windows 7 audio stack will sends KSPROPERTY_PIN_PROPOSEDDATAFORMAT with the
PCPROPERTY_ITEM_FLAG_GET flag set to query a driver for its preferred device
default format.
KSPROPERTY_PIN_PROPOSEDDATAFORMAT This is a KS property that has been supported
since Vista. However in Vista, only the PCPROPERTY_ITEM_FLAG_SET flag was
supported for querying whether a particular format is supported by a driver.
KSPROPERTY_PIN_PROPOSEDDATAFORMATThis is a property on the Wave filter pin.
For more details, please see the KSPROPERTY_PIN_PROPOSEDDATAFORMAT reference
page on MSDN.
The following sample code shows how you can update your miniport driver code to
handle the PCPROPERTY_ITEM_FLAG_GET flag.
http://msdn.microsoft.com/en-us/library/ms808355.aspx
Sample code:
NTSTATUS CMiniportHelper::PropertyHandlerPinProposeFormat(__inout
PPCPROPERTY_REQUEST _pPropReq)
{
...
//
// command basic support handling
//
if (_pPropReq->Verb & KSPROPERTY_TYPE_BASICSUPPORT)
{
// Validate buffer size
if (!_pPropReq->ValueSize)
{
// ValueSize buffer too small
_pPropReq->ValueSize = sizeof(ULONG);
SET_STATUS_AND_JUMP(STATUS_BUFFER_OVERFLOW, exit);
}
else if (_pPropReq->ValueSize < sizeof (ULONG))
{
SET_STATUS_AND_JUMP(STATUS_BUFFER_TOO_SMALL,exit);
}
else
{
// we have at least a ulong to work with so fill in access flags
ULONG *accessFlags = static_cast<ULONG*>(_pPropReq->Value);
*accessFlags = KSPROPERTY_TYPE_BASICSUPPORT | KSPROPERTY_TYPE_SET |
KSPROPERTY_TYPE_GET;
_pPropReq->ValueSize = sizeof(ULONG);
SET_STATUS_AND_JUMP(STATUS_SUCCESS, exit);
}
}
else if (_pPropReq->Verb & KSPROPERTY_TYPE_SET)
{
ULONG cbMinSize = sizeof(KSDATAFORMAT_WAVEFORMATEX);
...
KSDATAFORMAT_WAVEFORMATEX *pKsFormat =
(KSDATAFORMAT_WAVEFORMATEX*)_pPropReq->Value;
...
// replace with your own format checking routine here.
status = pDataPin->IsFormatSupported(&pKsFormat->WaveFormatEx);
..
}
else if (_pPropReq->Verb & KSPROPERTY_TYPE_GET)
{
ULONG cbMinSize = sizeof(KSDATAFORMAT) + sizeof(WAVEFORMATEXTENSIBLE);
...
// Fill in the KSDATAFORMAT
KSDATAFORMAT *pKsFormat = static_cast<KSDATAFORMAT*>(_pPropReq->Value);
pKsFormat->FormatSize = sizeof(KSDATAFORMAT) + sizeof(WAVEFORMATEXTENSIBLE);
pKsFormat->Flags = 0;
pKsFormat->Reserved = 0;
pKsFormat->SampleSize = 0;
pKsFormat->MajorFormat = KSDATAFORMAT_TYPE_AUDIO;
pKsFormat->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
pKsFormat->Specifier = KSDATAFORMAT_SPECIFIER_WAVEFORMATEX;
// Fill in the Waveformat Extensible with preferred format parameters
WAVEFORMATEXTENSIBLE *pWfx =
reinterpret_cast<WAVEFORMATEXTENSIBLE*>(pKsFormat + 1);
pWfx->Format.wFormatTag = WAVE_FORMAT_EXTENSIBLE;
pWfx->Format.nChannels = static_cast<WORD>(numChannels);
pWfx->Format.nSamplesPerSec = sampleRate;
pWfx->Format.nBlockAlign = static_cast<WORD>(numChannels * (containerSize /
8));
pWfx->Format.nAvgBytesPerSec = sampleRate * pWfx->Format.nBlockAlign;
pWfx->Format.wBitsPerSample = static_cast<WORD>(containerSize);
pWfx->Format.cbSize = sizeof(WAVEFORMATEXTENSIBLE) - sizeof(WAVEFORMATEX);
pWfx->SubFormat = KSDATAFORMAT_SUBTYPE_PCM;
pWfx->Samples.wValidBitsPerSample = static_cast<WORD>(bitDepth);
pWfx->dwChannelMask = channelMask;
}
else
{
...
}
...
exit:
return status;
}
-----Original Message-----
From: wdmaudiodev-bounce@xxxxxxxxxxxxx
[mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of uwekirst
Sent: Wednesday, February 10, 2010 10:47 AM
To: wdmaudiodev@xxxxxxxxxxxxx
Subject: [wdmaudiodev] Re: Dynamic format negotiation on Windows 7
Hi Chen-mean Liu,
I have also tried to implement dynamic Format changes to my driver (it's
wavecyclic though).
I wasn't 100% sucessful.
The basic issue was that after changing the format, the new format
appeared in the ms win7 audio control panel, but the old format was not
removed automatically.
The old one was still selected.
If I tried to test the two formats (old and new) it turned out that the
old one does not work, but the new one works as expected.
Because there seem to be still user interaction necessary (changing the
selection from old to new format) I feel that this feature is not usefull.
Any ideas what am I missing?
Thanks,
/Uwe
Cheng-mean Liu (SOCCER) schrieb:
> Hi Kishore:
>
> This is a whitepaper on " Windows 7 Changes Related to Audio Drivers", it
>has a section called "Dynamic Format Change Support", that has instructions on
>how to do it.
> This whitepaper is in the final stage of getting published to WHDC site.
>
> Here is the information I cut from the current state of this paper. Let me
> know if you have any question in implementing this feature.
>
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