感測器群組轉換 (相機配置檔 V2)
感測器群組轉換可能會使用類似 DMFT 的機制來發佈相機配置檔。 MF_DEVICEMFT_SENSORPROFILE_COLLECTION屬性可以透過IMFSensorTransformFactory：：GetTransformInformation 的IMFAttributes 參數發行，每個支援的感測器群組轉換 (SGT) 。
在 IMFSensorTransformFactory：：InitializeFactory 呼叫期間，將會提供 IMSensorDevice 介面的集合，SGT Factory 可能會藉由 QI-ing IMFGetService 介面的 IMFSensorDevice 介面，從可用的裝置變更可用的相機設定檔。 從這個介面，SGT Factory 可能會要求IMFSensorProfileCollection 介面。
然後，如果 SGT Factory 選擇這麼做，SGT Factory 可能會為每個 IMFSensorDevice 新增/移除/更新可用的相機配置檔。 修改過的相機配置檔只會針對包含 SGT 的感測器群組保存。 個別裝置的相機配置檔不會以新資訊修改。
感測器群組轉換範例
IFACEMETHODIMP
SampleSensorTransformFactory::InitializeFactory(
_In_ DWORD dwMaxTransformCount,
_In_ IMFCollection* sensorDevices,
_In_opt_ IMFAttributes* pAttributes
)
{
DWORD sensorDeviceCount = 0;
ComPtr<IUnknown> unknown;
if (nullptr == sensorDevices)
{
return E_INVALIDARG;
}
// For this example, the IHV/OEM added a SGT to a multi-camera
// setup. And the SGT is responsible for updating the profile
// information available from each of the physical cameras, and
// leave it's own profile as "blank". This has the net effect
// of having the SGT support any profile the physical devices
// expose.
RETURN_IF_FAILED (sensorDevices->GetElementCount(&sensorDeviceCount));
for (DWORD idx = 0; idx < sensorDeviceCount; idx++)
{
ComPtr<IMFGetService> service;
ComPtr<IMFSensorProfileCollection> profileCollection;
SENSORPROFILEID sensorProfileId;
RETURN_IF_FAILED (sensorDevices->GetElement(idx,
unknown.ReleaseAndGetAddressOf()));
RETURN_IF_FAILED (unknown.As(service.ReleaseAndGetAddressOf()));
RETURN_IF_FAILED (service->GetService(GUID_NULL,
ID_PPV_ARGS(profileCollection.ReleaseAndGetAddressOf())));
// Let's assume that for this ISP/sensor, we cannot support
// photo sequence but our reference driver published a single
// photo sequence profile whose ID is hardcoded to a static
// variable s_PhotoSequenceProfileId.
RETURN_IF_FAILED (profileCollection->RemoveProfile(&s_PhotoSequenceProfileId));
// Let's also assume this is a low cost ISP/sensor so our driver
// cannot support Video HDR (VHDR) control for high frame rate
// recording and our reference implementation published multiple
// high frame rate recording profile.
//
// Also for this combination of ISP/sensor, we cannot support
// Face Auth (IR doesn't support alternate illumination option).
// So we need to remove all Face Auth from our collection.
for (DWORD profileIdx = 0;
profileIdx < profileCollection->GetProfileCount();)
{
ComPtr<IMFSensorProfile> profile;
RETURN_IF_FAILED (profileCollection->GetProfile(profileIdx,
profile.ReleaseAndGetAddressOf()));
RETURN_IF_FAILED (profile->GetProfileId(&profileId));
if (profileId.Type == KSCAMERAPROFILE_HighFrameRate)
{
RETURN_IF_FAILED (profile->AddBlockedControl(L"VHDR"));
}
if (profileId.Type == KSCAMERAPROFILE_FaceAuth_Mode)
{
RETURN_IF_FAILED (profileCollection->RemoveProfileByIndex(profileIdx));
}
else
{
profileIdx++;
}
}
}
// Set the profile collection to the attribute store that will be returned when
// IMFSensorTransformFactory::GetTransformInformation is called.
RETURN_IF_FAILED (m_spAttributes->SetUnknown(MF_DEVICEMFT_SENSORPROFILE_COLLECTION,
spProfileCollection));
// ... Rest of the InitializeFactory logic...
}