How To Implement Extended Camera Control Properties
The camera driver should implement extended camera control properties as individual property sets—that is, each property should be implemented as a single property set. The following example code can be used as a starting point for implementing these properties.
Note Because an extended property’s data size can be of arbitrary length, query the user-mode stack for the size of the data by passing a null buffer. A two-step process is needed: first the driver returns the required length, as shown in the example code, then the user-mode stack requests a proper buffer for the property data.
Driver implementation
DEFINE_KSPROPERTY_TABLE(SocSimFilterFocusPropertyItems)
{
DEFINE_KSPROPERTY_ITEM(
0,
CCaptureFilter::FocusRectHandler,
sizeof(KSPROPERTY),
0,
CCaptureFilter::FocusRectHandler,
NULL, 0, NULL, NULL, 0
)
};
DEFINE_KSPROPERTY_TABLE(SocSimFilterVideoStabPropertyItems)
{
DEFINE_KSPROPERTY_ITEM(
0,
CCaptureFilter::VideoStabilizationModeHandler,
sizeof(KSPROPERTY),
0,
CCaptureFilter::VideoStabilizationModeHandler,
NULL, 0, NULL, NULL, 0
)
};
DEFINE_KSPROPERTY_TABLE(SocSimFilterFlashPropertyItems)
{
DEFINE_KSPROPERTY_ITEM(
0,
CCaptureFilter::FlashHandler,
sizeof(KSPROPERTY),
0,
CCaptureFilter::FlashHandler,
NULL, 0, NULL, NULL, 0
)
};
DEFINE_KSPROPERTY_SET_TABLE(SocSimFilterPropertySets)
{
DEFINE_KSPROPERTY_SET(
&PROPSETID_VIDCAP_CAMERACONTROL_REGION_OF_INTEREST,
SIZEOF_ARRAY(SocSimFilterFocusPropertyItems),
SocSimFilterFocusPropertyItems,
0,
NULL),
DEFINE_KSPROPERTY_SET(
&PROPSETID_VIDCAP_CAMERACONTROL_FLASH,
SIZEOF_ARRAY(SocSimFilterFlashPropertyItems),
SocSimFilterFlashPropertyItems,
0,
NULL),
DEFINE_KSPROPERTY_SET(
&PROPSETID_VIDCAP_CAMERACONTROL_VIDEO_STABILIZATION,
SIZEOF_ARRAY(SocSimFilterVideoStabPropertyItems),
SocSimFilterVideoStabPropertyItems,
0,
NULL)
};
NTSTATUS
CCaptureFilter::FlashHandler(
__in PIRP Irp,
__in PKSPROPERTY Property,
__inout PVOID pData
)
{
PAGED_CODE();
NTSTATUS Status = STATUS_SUCCESS;
NT_ASSERT(Irp);
NT_ASSERT(Property);
CCaptureFilter* pFilter = reinterpret_cast <CCaptureFilter*>(KsGetFilterFromIrp(Irp)->Context);
PIO_STACK_LOCATION pIrpStack = IoGetCurrentIrpStackLocation(Irp);
ULONG ulOutputBufferLength = pIrpStack->Parameters.DeviceIoControl.OutputBufferLength;
ULONG InputBufferLength = pIrpStack->Parameters.DeviceIoControl.InputBufferLength;
if (Property->Flags & KSPROPERTY_TYPE_SET)
{
if (ulOutputBufferLength == 0)
{
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S);
Status = STATUS_BUFFER_OVERFLOW;
}
else if (ulOutputBufferLength < sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S))
{
Status = STATUS_BUFFER_TOO_SMALL;
}
else if (pData && ulOutputBufferLength >= sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S))
{
PKSPROPERTY_CAMERACONTROL_FLASH_S pFlash = (PKSPROPERTY_CAMERACONTROL_FLASH_S)pData;
pFilter->m_Flash = pFlash->Flash;
pFilter->m_FlashCapabilites = pFlash->Capabilities;
Status = STATUS_SUCCESS;
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S);
}
else
{
Status = STATUS_INVALID_PARAMETER;
}
}
else if (Property->Flags & KSPROPERTY_TYPE_GET)
{
if (ulOutputBufferLength == 0)
{
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S);
Status = STATUS_BUFFER_OVERFLOW;
}
else if (ulOutputBufferLength < sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S))
{
Status = STATUS_BUFFER_TOO_SMALL;
}
else if (pData && ulOutputBufferLength >= sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S))
{
PKSPROPERTY_CAMERACONTROL_FLASH_S pFlash = (PKSPROPERTY_CAMERACONTROL_FLASH_S)pData;
pFlash->Flash = pFilter->m_Flash;
pFlash->Capabilities = pFilter->m_FlashCapabilites;
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_FLASH_S);
Status = STATUS_SUCCESS;
}
else
{
Status = STATUS_INVALID_PARAMETER;
}
}
return Status;
}
NTSTATUS
CCaptureFilter::VideoStabilizationModeHandler(
__in PIRP Irp,
__in PKSPROPERTY Property,
__inout PVOID pData
)
{
PAGED_CODE();
NTSTATUS Status = STATUS_SUCCESS;
NT_ASSERT(Irp);
NT_ASSERT(Property);
CCaptureFilter* pFilter = reinterpret_cast <CCaptureFilter*>(KsGetFilterFromIrp(Irp)->Context);
PIO_STACK_LOCATION pIrpStack = IoGetCurrentIrpStackLocation(Irp);
ULONG ulOutputBufferLength = pIrpStack->Parameters.DeviceIoControl.OutputBufferLength;
ULONG InputBufferLength = pIrpStack->Parameters.DeviceIoControl.InputBufferLength;
if (Property->Flags & KSPROPERTY_TYPE_SET)
{
if (ulOutputBufferLength == 0)
{
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S);
Status = STATUS_BUFFER_OVERFLOW;
}
else if (ulOutputBufferLength < sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S))
{
Status = STATUS_BUFFER_TOO_SMALL;
}
else if (pData && ulOutputBufferLength >= sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S))
{
PKSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S pVideoStab = (PKSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S)pData;
pFilter->m_VideoStabMode = pVideoStab->VideoStabilizationMode;
pFilter->m_VideoStabCapabilites = pVideoStab->Capabilities;
Status = STATUS_SUCCESS;
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S);
}
else
{
Status = STATUS_INVALID_PARAMETER;
}
}
else if (Property->Flags & KSPROPERTY_TYPE_GET)
{
if (ulOutputBufferLength == 0)
{
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S);
Status = STATUS_BUFFER_OVERFLOW;
}
else if (ulOutputBufferLength < sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S))
{
Status = STATUS_BUFFER_TOO_SMALL;
}
else if (pData && ulOutputBufferLength >= sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S))
{
PKSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S pVideoStab = (PKSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S)pData;
pVideoStab->VideoStabilizationMode = pFilter->m_VideoStabMode;
pVideoStab->Capabilities = pFilter->m_VideoStabCapabilites;
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_VIDEOSTABILIZATION_MODE_S);
Status = STATUS_SUCCESS;
}
else
{
Status = STATUS_INVALID_PARAMETER;
}
}
return Status;
}
NTSTATUS
CCaptureFilter::FocusRectHandler(
__in PIRP Irp,
__in PKSPROPERTY Property,
__inout PVOID pData
)
{
PAGED_CODE();
NTSTATUS Status = STATUS_SUCCESS;
NT_ASSERT(Irp);
NT_ASSERT(Property);
CCaptureFilter* pFilter = reinterpret_cast <CCaptureFilter*>(KsGetFilterFromIrp(Irp)->Context);
PIO_STACK_LOCATION pIrpStack = IoGetCurrentIrpStackLocation(Irp);
ULONG ulOutputBufferLength = pIrpStack->Parameters.DeviceIoControl.OutputBufferLength;
ULONG InputBufferLength = pIrpStack->Parameters.DeviceIoControl.InputBufferLength;
if (Property->Flags & KSPROPERTY_TYPE_SET)
{
if (ulOutputBufferLength == 0)
{
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S);
Status = STATUS_BUFFER_OVERFLOW;
}
else if (ulOutputBufferLength < sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S))
{
Status = STATUS_BUFFER_TOO_SMALL;
}
else if (pData && ulOutputBufferLength >= sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S))
{
PKSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S pFocusRect = (PKSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S)pData;
pFilter->m_FocusRect.left = pFocusRect->FocusRect.left;
pFilter->m_FocusRect.top = pFocusRect->FocusRect.top;
pFilter->m_FocusRect.right = pFocusRect->FocusRect.right;
pFilter->m_FocusRect.bottom = pFocusRect->FocusRect.bottom;
pFilter->m_AutoFocusLock = pFocusRect->AutoFocusLock;
pFilter->m_AutoExposureLock = pFocusRect->AutoExposureLock;
pFilter->m_AutoWhitebalanceLock = pFocusRect->AutoWhitebalanceLock;
Status = STATUS_SUCCESS;
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S);
}
else
{
Status = STATUS_INVALID_PARAMETER;
}
}
else if (Property->Flags & KSPROPERTY_TYPE_GET)
{
if (ulOutputBufferLength == 0)
{
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S);
Status = STATUS_BUFFER_OVERFLOW;
}
else if (ulOutputBufferLength < sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S))
{
Status = STATUS_BUFFER_TOO_SMALL;
}
else if (pData && ulOutputBufferLength >= sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S))
{
PKSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S pFocusRect = (PKSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S)pData;
pFocusRect->FocusRect.left = pFilter->m_FocusRect.left;
pFocusRect->FocusRect.top = pFilter->m_FocusRect.top;
pFocusRect->FocusRect.right = pFilter->m_FocusRect.right;
pFocusRect->FocusRect.bottom = pFilter->m_FocusRect.bottom;
pFocusRect->AutoFocusLock = pFilter->m_AutoFocusLock;
pFocusRect->AutoExposureLock = pFilter->m_AutoExposureLock;
pFocusRect->AutoWhitebalanceLock = pFilter->m_AutoWhitebalanceLock;
Irp->IoStatus.Information = sizeof(KSPROPERTY_CAMERACONTROL_REGION_OF_INTEREST_S);
Status = STATUS_SUCCESS;
}
else
{
Status = STATUS_INVALID_PARAMETER;
}
}
return Status;
}
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