[wdmaudiodev] How to implement the SupportHandler for KSPROPERTY_AUDIO_VOLUMELEVEL?
- From: "Ydcao" <ydcao@xxxxxxxxxxx>
- To: <wdmaudiodev@xxxxxxxxxxxxx>
- Date: Mon, 11 May 2009 19:21:51 +0800
Hi,
I failed to implement Volume Control for my USB Microphone driver under
Windows Vista.
I implemented the Volume Control Support following the post "
//www.freelists.org/post/wdmaudiodev/AVStream-Mixer-Problems,15 "
It is not work. Under KSStudio, the Nodes/KSNODETYPE_VOLUME/Description
will be empty.
Take reference the USBAUDIO behavior and WDK. I have changed the code
compare to John's.
1. Add buffer size detection by compare the address of Request and
Data. ---- I do not know if it is right or not.
2. Set the pIrp->IoStatus.Information. In WDK, the Information
field should return the size of the buffer.
Compare with my driver with usbaudio.sys that loaded for UAC compatible
devices, here is the difference.
1. The system will call the handler
(usbaudio!PropertyGetOldDbBasicSupport) twice.
a. The first time, set pIrp->IoStatus.Information = 0x28; //
sizeof(KSPROPERTY_DESCRIPTION)
b. The second time, set the pIrp->IoStatus.Information = 0x28;//
sizeof(VOLUMELEVELSUPPORT) ;
2. For my driver, system only call my handle once. And the buffer
for me is sizeof (KSPROPERTY_DESCRIPTION).
I don't know what I can do now. Any help is appreciated.
Here is the code:
//--------Code here----------------------------------
typedef struct _VOLUME_LEVEL_SUPPORT {
KSPROPERTY_DESCRIPTION PropDesc;
KSPROPERTY_MEMBERSHEADER Members;
KSPROPERTY_STEPPING_LONG Range;
} VOLUMELEVELSUPPORT, *PVOLUMELEVELSUPPORT;
NTSTATUS SupportVolumeLevel(IN PIRP pIrp, IN PKSIDENTIFIER Request, IN
OUT PVOID Data)
{
LONG cbFullProperty = sizeof(KSPROPERTY_DESCRIPTION) +
sizeof(KSPROPERTY_MEMBERSHEADER) +
sizeof(KSPROPERTY_STEPPING_LONG);
if(!(Request->Flags&KSPROPERTY_TYPE_BASICSUPPORT))
return STATUS_INVALID_PARAMETER;
KSPROPERTY_DESCRIPTION PropDesc;
PropDesc.AccessFlags = KSPROPERTY_TYPE_BASICSUPPORT |
KSPROPERTY_TYPE_GET |
KSPROPERTY_TYPE_SET;
PropDesc.DescriptionSize = sizeof(KSPROPERTY_DESCRIPTION) +
sizeof(KSPROPERTY_MEMBERSHEADER) +
sizeof(KSPROPERTY_STEPPING_LONG);
PropDesc.PropTypeSet.Set = KSPROPTYPESETID_General;
PropDesc.PropTypeSet.Id = VT_I4;
PropDesc.PropTypeSet.Flags = 0;
PropDesc.MembersListCount = 1;
KSPROPERTY_MEMBERSHEADER Members;
Members.MembersFlags = KSPROPERTY_MEMBER_STEPPEDRANGES;
Members.MembersSize = sizeof(KSPROPERTY_STEPPING_LONG);
Members.MembersCount = 1;
Members.Flags =
KSPROPERTY_MEMBER_FLAG_BASICSUPPORT_UNIFORM;//KSPROPERTY_MEMBER_FLAG_BAS
ICSUPPORT_MULTICHANNEL; //
KSPROPERTY_STEPPING_LONG Range;
Range.SteppingDelta = 1;
Range.Bounds.SignedMinimum = -32767;
Range.Bounds.SignedMaximum = 32767;
VolumeSupport.PropDesc = PropDesc;
VolumeSupport.Members = Members;
VolumeSupport.Range = Range;
LONG ltemp0 = 0, ltemp1 = 0, lBufLength = 0;
ltemp0 = (LONG) Request;
ltemp1 = (LONG) Data;
lBufLength = ltemp0-ltemp1;
if( lBufLength < cbFullProperty) //Detect the buffer length.
{
pIrp->IoStatus.Information = 0;
if(lBufLength >= sizeof(KSPROPERTY_DESCRIPTION))
{ //System always call this.
*((PKSPROPERTY_DESCRIPTION) Data) = PropDesc;
pIrp->IoStatus.Information =
sizeof(KSPROPERTY_DESCRIPTION);
return STATUS_SUCCESS;
}
return STATUS_BUFFER_TOO_SMALL;
}
else
{ //Never get called.
*((PVOLUMELEVELSUPPORT) Data) = VolumeSupport;
pIrp->IoStatus.Information = cbFullProperty;
return STATUS_SUCCESS;
}
}
//--------End of code--------------------------------
Thank you
Hunter
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