C++ PropVariantInit函数代码示例

//-------------------------------------------------------------------------
// Description:
//
//  GetCurrentEffectsSetting
//      Gets the current aggregate effects-enable setting
//
// Parameters:
//
//  properties - Property store holding configurable effects settings
//
//  pkeyEnable - VT_UI4 property holding an enable/disable setting
//
//  processingMode - Audio processing mode
//
// Return values:
//  LONG - true if the effect is enabled
//
// Remarks:
//  The routine considers the value of the specified property, the well known
//  master PKEY_AudioEndpoint_Disable_SysFx property, and the specified
//  processing mode.If the processing mode is RAW then the effect is off. If
//  PKEY_AudioEndpoint_Disable_SysFx is non-zero then the effect is off.
//
LONG GetCurrentEffectsSetting(IPropertyStore* properties, PROPERTYKEY pkeyEnable, GUID processingMode)
{
    HRESULT hr;
    BOOL enabled;
    PROPVARIANT var;

    PropVariantInit(&var);

    // Get the state of whether channel swap MFX is enabled or not. 

    // Check the master disable property defined by Windows
    hr = properties->GetValue(PKEY_AudioEndpoint_Disable_SysFx, &var);
    enabled = (SUCCEEDED(hr)) && !((var.vt == VT_UI4) && (var.ulVal != 0));

    PropVariantClear(&var);

    // Check the APO's enable property, defined by this APO.
    hr = properties->GetValue(pkeyEnable, &var);
    enabled = enabled && ((SUCCEEDED(hr)) && ((var.vt == VT_UI4) && (var.ulVal != 0)));

    PropVariantClear(&var);

    enabled = enabled && !IsEqualGUID(processingMode, AUDIO_SIGNALPROCESSINGMODE_RAW);

    return (LONG)enabled;
}

HRESULT FakeDevice::GetObjectIDsFromPersistentUniqueIDs(
            ACCESS_SCOPE                          Scope,
    _In_    IPortableDevicePropVariantCollection* pPersistentIDs,
    _In_    IPortableDevicePropVariantCollection* pObjectIDs)
{
    HRESULT hr      = S_OK;
    DWORD   dwCount = 0;

    if ((pPersistentIDs == NULL) ||
        (pObjectIDs     == NULL))
    {
        hr = E_POINTER;
        CHECK_HR(hr, ("Cannot have NULL parameter"));
        return hr;
    }

    // Iterate through the persistent ID list and add the equivalent object ID for each element.
    hr = pPersistentIDs->GetCount(&dwCount);
    CHECK_HR(hr, "Failed to get count from persistent ID collection");

    if (hr == S_OK)
    {
        PROPVARIANT pvPersistentID = {0};

        for(DWORD dwIndex = 0; dwIndex < dwCount; dwIndex++)
        {
            PropVariantInit(&pvPersistentID);

            hr = pPersistentIDs->GetAt(dwIndex, &pvPersistentID);
            CHECK_HR(hr, "Failed to get persistent ID at index %d", dwIndex);

            if (hr == S_OK)
            {
                hr = m_DeviceContent.GetObjectIDByPersistentID(Scope, pvPersistentID.pwszVal, pObjectIDs);
                CHECK_HR(hr, "Failed to get object ID from persistent unique ID '%ws'", pvPersistentID.pwszVal);
            }

            if (hr == HRESULT_FROM_WIN32(ERROR_NOT_FOUND))
            {
                PROPVARIANT pvEmptyObjectID = {0};
                pvEmptyObjectID.vt = VT_LPWSTR;
                pvEmptyObjectID.pwszVal = L"";

                // Insert empty string when object cannot be found
                hr = pObjectIDs->Add(&pvEmptyObjectID);
                CHECK_HR(hr, "Failed to set empty string for persistent unique ID '%ws' when object cannot be found", pvPersistentID.pwszVal);
            }

            PropVariantClear(&pvPersistentID);

            if(FAILED(hr))
            {
                break;
            }
        }
    }

    return hr;
}

static HRESULT LoadUnknownMetadata(IStream *input, const GUID *preferred_vendor,
    DWORD persist_options, MetadataItem **items, DWORD *item_count)
{
    HRESULT hr;
    MetadataItem *result;
    STATSTG stat;
    BYTE *data;
    ULONG bytesread;

    TRACE("\n");

    hr = IStream_Stat(input, &stat, STATFLAG_NONAME);
    if (FAILED(hr))
        return hr;

    data = HeapAlloc(GetProcessHeap(), 0, stat.cbSize.QuadPart);
    if (!data) return E_OUTOFMEMORY;

    hr = IStream_Read(input, data, stat.cbSize.QuadPart, &bytesread);
    if (bytesread != stat.cbSize.QuadPart) hr = E_FAIL;
    if (hr != S_OK)
    {
        HeapFree(GetProcessHeap(), 0, data);
        return hr;
    }

    result = HeapAlloc(GetProcessHeap(), 0, sizeof(MetadataItem));
    if (!result)
    {
        HeapFree(GetProcessHeap(), 0, data);
        return E_OUTOFMEMORY;
    }

    PropVariantInit(&result[0].schema);
    PropVariantInit(&result[0].id);
    PropVariantInit(&result[0].value);

    result[0].value.vt = VT_BLOB;
    result[0].value.u.blob.cbSize = bytesread;
    result[0].value.u.blob.pBlobData = data;

    *items = result;
    *item_count = 1;

    return S_OK;
}

//
//  Retrieves the device friendly name for a particular device in a device collection.
//
LPWSTR GetDeviceName(IMMDeviceCollection *DeviceCollection, UINT DeviceIndex)
{
    IMMDevice *device;
    LPWSTR deviceId;
    HRESULT hr;

    hr = DeviceCollection->Item(DeviceIndex, &device);
    if (FAILED(hr))
    {
        printf("Unable to get device %d: %x\n", DeviceIndex, hr);
        return NULL;
    }
    hr = device->GetId(&deviceId);
    if (FAILED(hr))
    {
        printf("Unable to get device %d id: %x\n", DeviceIndex, hr);
        return NULL;
    }

    IPropertyStore *propertyStore;
    hr = device->OpenPropertyStore(STGM_READ, &propertyStore);
    SafeRelease(&device);
    if (FAILED(hr))
    {
        printf("Unable to open device %d property store: %x\n", DeviceIndex, hr);
        return NULL;
    }

    PROPVARIANT friendlyName;
    PropVariantInit(&friendlyName);
    hr = propertyStore->GetValue(PKEY_Device_FriendlyName, &friendlyName);
    SafeRelease(&propertyStore);

    if (FAILED(hr))
    {
        printf("Unable to retrieve friendly name for device %d : %x\n", DeviceIndex, hr);
        return NULL;
    }

    wchar_t deviceName[128];
    hr = StringCbPrintf(deviceName, sizeof(deviceName), L"%s (%s)", friendlyName.vt != VT_LPWSTR ? L"Unknown" : friendlyName.pwszVal, deviceId);
    if (FAILED(hr))
    {
        printf("Unable to format friendly name for device %d : %x\n", DeviceIndex, hr);
        return NULL;
    }

    PropVariantClear(&friendlyName);
    CoTaskMemFree(deviceId);

    wchar_t *returnValue = _wcsdup(deviceName);
    if (returnValue == NULL)
    {
        printf("Unable to allocate buffer for return\n");
        return NULL;
    }
    return returnValue;
}

// ----------------------------------------------------------------------------
//
AudioVolumeController* AudioVolumeController::createVolumeController( )
{
    HRESULT hr;
    IMMDeviceEnumerator *pEnumerator = NULL;
    IMMDevice *pDefaultDevice = NULL;
    IAudioEndpointVolume *endpointVolume = NULL;
    LPWSTR pstrDefaultId = NULL;
    IPropertyStore *pProperties = NULL;

    try {
        hr = CoCreateInstance(
               CLSID_MMDeviceEnumerator, NULL,
               CLSCTX_ALL, IID_IMMDeviceEnumerator,
               (void**)&pEnumerator);
        AUDIO_VOLUME_ASSERT( hr, "Cannot create COM device enumerator instance" );

        // Get the default audio endpoint (if we don't get one its not an error)
        hr = pEnumerator->GetDefaultAudioEndpoint( eRender, eConsole, &pDefaultDevice );
        AUDIO_VOLUME_ASSERT( hr, "Cannot get default audio render device" );

        hr = pDefaultDevice->OpenPropertyStore( STGM_READ, &pProperties );
        AUDIO_VOLUME_ASSERT( hr, "Cannot open IMMDevice property store" );

        PROPVARIANT varName;
        // Initialize container for property value.
        PropVariantInit(&varName);

        // Get the endpoint's friendly-name property.
        hr = pProperties->GetValue( PKEY_Device_DeviceDesc , &varName);
        AUDIO_VOLUME_ASSERT( hr, "Cannot open IMMDevice name property" );

        CString render_name = CW2A( varName.pwszVal );

        DMXStudio::log_status( "Default audio render device '%s'", render_name );

        PropVariantClear(&varName);

        hr = pDefaultDevice->Activate( IID_IAudioEndpointVolume, CLSCTX_INPROC_SERVER, NULL, (LPVOID *)&endpointVolume );
        AUDIO_VOLUME_ASSERT( hr, "Cannot activate default render device" );

        SAFE_RELEASE( pDefaultDevice );
        SAFE_RELEASE( pProperties );
        SAFE_RELEASE( pEnumerator );

        CoTaskMemFree( pstrDefaultId );

        return new AudioVolumeController( endpointVolume, render_name );
    }
    catch ( ... ) {
        CoTaskMemFree( pstrDefaultId );

        SAFE_RELEASE( pDefaultDevice );
        SAFE_RELEASE( pProperties );
        SAFE_RELEASE( pEnumerator );

        throw;
    }
}

HRESULT CSwapAPOLFX::Initialize(UINT32 cbDataSize, BYTE* pbyData)
{
    HRESULT                         hr = S_OK;
    PROPVARIANT                     var;

    IF_TRUE_ACTION_JUMP( ((NULL == pbyData) && (0 != cbDataSize)), hr = E_INVALIDARG, Exit);
    IF_TRUE_ACTION_JUMP( ((NULL != pbyData) && (0 == cbDataSize)), hr = E_POINTER, Exit);
    IF_TRUE_ACTION_JUMP( (cbDataSize != sizeof(APOInitSystemEffects) ), hr = E_INVALIDARG, Exit);

    APOInitSystemEffects* papoSysFxInit = (APOInitSystemEffects*)pbyData;

    //
    //  Store locally for later reference
    //
    m_spAPOSystemEffectsProperties = papoSysFxInit->pAPOSystemEffectsProperties;

    //
    //  Get the current value
    //
    PropVariantInit(&var);

    if (m_spAPOSystemEffectsProperties != NULL)
    {
        // Get the state of whether channel swap LFX is enabled or not
        hr = m_spAPOSystemEffectsProperties->GetValue(PKEY_Endpoint_Enable_Channel_Swap_LFX, &var);

        if (SUCCEEDED(hr) && (var.vt == VT_UI4))
        {
            if (var.ulVal == 0L)
            {
                m_fEnableSwapLFX = FALSE;
            }
            else
            {
                m_fEnableSwapLFX = TRUE;
            }
        }
        else
        {
            PropVariantClear(&var);
        }
    }

    //
    //  Register for notification of registry updates
    //
    hr = m_spEnumerator.CoCreateInstance(__uuidof(MMDeviceEnumerator));
    IF_FAILED_JUMP(hr, Exit);

    hr = m_spEnumerator->RegisterEndpointNotificationCallback(this);
    IF_FAILED_JUMP(hr, Exit);

     m_bIsInitialized = true;


Exit:
    return hr;
}

///////////////////////////////////////////////////////////////////////////
//
// Function:
//      EnumDevice
//
// Description:
//      Enumerate audio device and return the device information.
//
//  Parameters:
//      eDataFlow: eRender for render device, eCapture for capture device
//      uNumElements: Size of audio device info structure array.
//      pDevicInfo: device info structure array. Caller is responsible to allocate and free
//                  memory. The array size is specified by uNumElements.
//
// Return:
//      S_OK if successful
//
///////////////////////////////////////////////////////////////////////////////
HRESULT EnumDevice(EDataFlow eDataFlow, UINT uNumElements, AUDIO_DEVICE_INFO *pDevicInfo)
{
    HRESULT hResult = S_OK;
    WCHAR* pszDeviceId = NULL;
    PROPVARIANT value;
    UINT index, dwCount;
    bool IsMicArrayDevice;

    CComPtr<IMMDeviceEnumerator> spEnumerator;
    CComPtr<IMMDeviceCollection> spEndpoints;    

    hResult = spEnumerator.CoCreateInstance(__uuidof(MMDeviceEnumerator));
    IF_FAILED_JUMP(hResult, Exit);

    hResult = spEnumerator->EnumAudioEndpoints(eDataFlow, DEVICE_STATE_ACTIVE, &spEndpoints);
    IF_FAILED_JUMP(hResult, Exit);

    hResult = spEndpoints->GetCount(&dwCount);
    IF_FAILED_JUMP(hResult, Exit);

    if (dwCount != uNumElements)
        return E_INVALIDARG;

    ZeroMemory(pDevicInfo, sizeof(AUDIO_DEVICE_INFO)*uNumElements);
    
    for (index = 0; index < dwCount; index++)
    {
        CComPtr<IMMDevice> spDevice;
        CComPtr<IPropertyStore> spProperties;

        PropVariantInit(&value);

        hResult = spEndpoints->Item(index, &spDevice);
        IF_FAILED_JUMP(hResult, Exit);
         
        hResult = spDevice->GetId(&pszDeviceId);
        IF_FAILED_JUMP(hResult, Exit);

        hResult = spDevice->OpenPropertyStore(STGM_READ, &spProperties);
        IF_FAILED_JUMP(hResult, Exit);

        hResult = spProperties->GetValue(PKEY_Device_FriendlyName, &value);
        IF_FAILED_JUMP(hResult, Exit);

        EndpointIsMicArray(spDevice, IsMicArrayDevice);

        StringCchCopy(pDevicInfo[index].szDeviceID, MAX_STR_LEN-1, pszDeviceId);
        StringCchCopy(pDevicInfo[index].szDeviceName, MAX_STR_LEN-1, value.pwszVal);
        pDevicInfo[index].bIsMicArrayDevice = IsMicArrayDevice;
        
        PropVariantClear(&value);
        CoTaskMemFree(pszDeviceId);
        pszDeviceId = NULL;
    }

Exit:
    return hResult;
}

std::string CAESinkDirectSound::GetDefaultDevice()
{
  IMMDeviceEnumerator* pEnumerator = NULL;
  IMMDevice*           pDevice = NULL;
  IPropertyStore*      pProperty = NULL;
  HRESULT              hr;
  PROPVARIANT          varName;
  std::string          strDevName = "default";

  hr = CoCreateInstance(CLSID_MMDeviceEnumerator, NULL, CLSCTX_ALL, IID_IMMDeviceEnumerator, (void**)&pEnumerator);
  if (FAILED(hr))
  {
    CLog::Log(LOGERROR, __FUNCTION__": Could not allocate WASAPI device enumerator. CoCreateInstance error code: %s", WASAPIErrToStr(hr));
    goto failed;
  }

  hr = pEnumerator->GetDefaultAudioEndpoint(eRender, eMultimedia, &pDevice);
  if (FAILED(hr))
  {
    CLog::Log(LOGERROR, __FUNCTION__": Retrieval of audio endpoint enumeration failed.");
    goto failed;
  }

  hr = pDevice->OpenPropertyStore(STGM_READ, &pProperty);
  if (FAILED(hr))
  {
    CLog::Log(LOGERROR, __FUNCTION__": Retrieval of DirectSound endpoint properties failed.");
    goto failed;
  }

  PropVariantInit(&varName);
  hr = pProperty->GetValue(PKEY_AudioEndpoint_FormFactor, &varName);
  if (FAILED(hr))
  {
    CLog::Log(LOGERROR, __FUNCTION__": Retrieval of DirectSound endpoint form factor failed.");
    goto failed;
  }
  AEDeviceType aeDeviceType = winEndpoints[(EndpointFormFactor)varName.uiVal].aeDeviceType;
  PropVariantClear(&varName);

  hr = pProperty->GetValue(PKEY_AudioEndpoint_GUID, &varName);
  if (FAILED(hr))
  {
    CLog::Log(LOGERROR, __FUNCTION__": Retrieval of DirectSound endpoint GUID failed.");    
    goto failed;
  }

  strDevName = localWideToUtf(varName.pwszVal);
  PropVariantClear(&varName);

failed:

  SAFE_RELEASE(pProperty);
  SAFE_RELEASE(pDevice);
  SAFE_RELEASE(pEnumerator);

  return strDevName;
}

STDMETHODIMP tTVPPlayerCallback::Invoke( IMFAsyncResult *pAsyncResult ) {
	HRESULT hr;
	MediaEventType met = MESessionClosed;
	CComPtr<IMFMediaEvent> pMediaEvent;
	if( SUCCEEDED(hr = owner_->GetMediaSession()->EndGetEvent( pAsyncResult, &pMediaEvent )) ) {
		if( SUCCEEDED(hr = pMediaEvent->GetType(&met)) ) {
			PROPVARIANT pvValue;
			PropVariantInit(&pvValue);
			switch( met ) {
			case MESessionClosed:
				owner_->OnMediaItemCleared();
				break;
			case MESessionPaused:
				owner_->OnPause();
				break;
			case MESessionEnded:
				owner_->OnPlayBackEnded();
				break;
			case MESessionNotifyPresentationTime:
				break;
			case MESessionRateChanged:
				if( SUCCEEDED(pMediaEvent->GetValue( &pvValue )) ) {
					double value;
					if( FAILED(PropVariantToDouble(pvValue,&value)) ) {
						value = 1.0;
					}
					owner_->OnRateSet(value);
				} else {
					owner_->OnRateSet(1.0);
				}
				break;
			case MESessionScrubSampleComplete:
				break;
			case MESessionStarted:
				owner_->OnPlay();
				break;
			case MESessionStopped:
				owner_->OnStop();
				break;
			case MESessionStreamSinkFormatChanged:
				break;
			case MESessionTopologiesCleared:
				break;
			case MESessionTopologySet:
				break;
			case MESessionTopologyStatus: {
				UINT32 status = MF_TOPOSTATUS_INVALID;
				pMediaEvent->GetUINT32( MF_EVENT_TOPOLOGY_STATUS, &status );
				owner_->OnTopologyStatus(status);
				break;
				}
			}
			PropVariantClear(&pvValue);
		}
		owner_->GetMediaSession()->BeginGetEvent( this, NULL );
	}
	return S_OK;
}

void CWordBinaryMetadataDiscoveryWorker::DiscoverSummaryInformation(REFFMTID iidPropsertySet) 
{
	bool bNotFound;
	OpenPropertySet(iidPropsertySet, bNotFound);
	if(bNotFound)
	{
		ClosePropertySet();
		return;
	}

	if(NULL == m_pPropertyStg)
		throw Workshare::Exception(_T("NULL pointer encountered (m_pPropertyStg)"));

	IEnumSTATPROPSTG *pEnumProp;
	
	HRESULT hRes = m_pPropertyStg->Enum(&pEnumProp);
	if(FAILED(hRes))
	{
		ClosePropertySet();
		HandlePropertyError(_T(__FUNCTION__), _T("Enumerate user-defined properties failed"), hRes);
		return;
	}

	STATPROPSTG PropertyInformation;
	ZeroMemory(&PropertyInformation, sizeof(STATPROPSTG));
	PROPSPEC propSpec;
	PROPVARIANT propVar;

	SetCodePageProperty();

	while(S_OK == pEnumProp->Next(1, &PropertyInformation, NULL))
	{
		PropVariantInit(&propVar);
		// Build a PROPSPEC for this property.
		ZeroMemory(&propSpec, sizeof(PROPSPEC));
		propSpec.ulKind = PRSPEC_PROPID;
		propSpec.propid = PropertyInformation.propid;

		// Read this property.
		hRes = m_pPropertyStg->ReadMultiple(1, &propSpec, &propVar);
		if(SUCCEEDED(hRes))
		{
			if (FMTID_SummaryInformation == iidPropsertySet)
				AddBuiltInPropertyForSummary(propVar, PropertyInformation.propid);
			else if (FMTID_DocSummaryInformation == iidPropsertySet)
				AddBuiltInPropertyForDocSummary(propVar, PropertyInformation.propid);
		}
		else
		{
			CStdString sErr;
			sErr.Format(_T("Failed to read property id: %d, error code: %d"), propSpec.propid, hRes);
			LOG_WS_ERROR(sErr);
		}
	}
	pEnumProp->Release();
	ClosePropertySet();
}

/**
 *  This method is called when we receive a WPD_COMMAND_CAPABILITIES_GET_SUPPORTED_FORMATS
 *  command.  This message is sent when the client needs to know the possible formats supported
 *  by the specified content type (e.g. for image objects, the driver may choose to support JPEG and BMP files).
 *
 *  The parameters sent to us are:
 *  - WPD_PROPERTY_CAPABILITIES_CONTENT_TYPE - a GUID value containing the content type
 *    whose formats the caller is interested in.  If the value is WPD_CONTENT_TYPE_ALL, then the driver
 *    must return a list of all formats supported by the device.
 *
 *  The driver should:
 *  - Return an IPortableDevicePropVariantCollection (of type VT_CLSID) in
 *      WPD_PROPERTY_CAPABILITIES_FORMATS, indicating the formats supported by the
 *      specified content type.
 *      If there are no formats supported by the specified content type, the driver should return an
 *      empty collection.
 */
HRESULT WpdCapabilities::OnGetSupportedFormats(
    _In_ IPortableDeviceValues*  pParams,
    _In_ IPortableDeviceValues*  pResults)
{
    HRESULT hr              = S_OK;
    GUID    guidContentType = GUID_NULL;
    CComPtr<IPortableDevicePropVariantCollection> pFormats;

    // First get ALL parameters for this command.  If we cannot get ALL parameters
    // then E_INVALIDARG should be returned and no further processing should occur.

    // Get the content type whose supported formats have been requested
    if (hr == S_OK)
    {
        hr = pParams->GetGuidValue(WPD_PROPERTY_CAPABILITIES_CONTENT_TYPE, &guidContentType);
        CHECK_HR(hr, "Missing value for WPD_PROPERTY_CAPABILITIES_CONTENT_TYPE");
    }

    // CoCreate a collection to store the supported formats.
    if (hr == S_OK)
    {
        hr = CoCreateInstance(CLSID_PortableDevicePropVariantCollection,
                              NULL,
                              CLSCTX_INPROC_SERVER,
                              IID_IPortableDevicePropVariantCollection,
                              (VOID**) &pFormats);
        CHECK_HR(hr, "Failed to CoCreate CLSID_PortableDevicePropVariantCollection");
    }

    // Add the supported formats for the specified content type to the collection.
    if (hr == S_OK)
    {
        PROPVARIANT pv = {0};
        PropVariantInit(&pv);
        // Don't call PropVariantClear, since we did not allocate the memory for these GUIDs

        if ((guidContentType   == WPD_CONTENT_TYPE_DOCUMENT) ||
            ((guidContentType  == WPD_CONTENT_TYPE_ALL)))
        {
            // Add WPD_OBJECT_FORMAT_TEXT to the supported formats collection
            pv.vt    = VT_CLSID;
            pv.puuid = (CLSID*)&WPD_OBJECT_FORMAT_TEXT;
            hr = pFormats->Add(&pv);
            CHECK_HR(hr, "Failed to add WPD_OBJECT_FORMAT_TEXT");
        }
    }

    // Set the WPD_PROPERTY_CAPABILITIES_FORMATS value in the results.
    if (hr == S_OK)
    {
        hr = pResults->SetIUnknownValue(WPD_PROPERTY_CAPABILITIES_FORMATS, pFormats);
        CHECK_HR(hr, "Failed to set WPD_PROPERTY_CAPABILITIES_FORMATS");
    }

    return hr;
}

//! Retrieves the value associated with pkey, if it exists.
QVariant ShellNodeInfo::propertyValue(const PROPERTYKEY &pkey)
{
    QVariant ret;
    PROPVARIANT var;
    PropVariantInit(&var);
    if (d->item->GetProperty(pkey, &var) == S_OK)
        ret = util::fromPROPVARIANT(var);
    PropVariantClear(&var);
    return ret;
}

void MFDecoderSourceReader::reset()
{
    if (!m_sourceReader)
        return;
    PROPVARIANT vPos;
    PropVariantInit(&vPos);
    vPos.vt = VT_I8;
    vPos.uhVal.QuadPart = 0;
    m_sourceReader->SetCurrentPosition(GUID_NULL, vPos);
}

//nog werk nodig! met de union!!
PROPVARIANT ConvertJavaToPropVariant(JNIEnv* env, jobject jobjPropVariant)
{
	//variabelen
	jclass cls;
	jmethodID mid;
	PROPVARIANT pv;
	jstring jsValue;
	LPWSTR wszBuffer;
	LPWSTR wszValue;
	jobject jobjObjectValue;


	//methode implementatie
	PropVariantInit(&pv);
	cls = env->FindClass("jmtp/PropVariant");
	//printf("convert 1\n");
	mid = env->GetMethodID(cls, "getVt", "()I");
	pv.vt = static_cast<VARTYPE>(env->CallIntMethod(jobjPropVariant, mid));
	//printf("convert 2\n");
	int strLength;
	switch(pv.vt)
	{
		case VT_LPWSTR:
			//printf("convert 3\n");
			mid = env->GetMethodID(cls, "getValue", "()Ljava/lang/Object;");
			jsValue = (jstring)env->CallObjectMethod(jobjPropVariant, mid);
			strLength = env->GetStringLength(jsValue);
			//printf("convert3.4:%d\n", strLength);
			wszBuffer = ConvertJavaStringToWCHAR(env, jsValue); //(WCHAR*)env->GetStringChars(jsValue, NULL);
			wszValue = new WCHAR[strLength+1];
			if (wszValue == NULL) {
				//printf("conver tproblem null\n");
			}
			for (int i = 0; i < strLength; i++) {
				wszValue[i] = wszBuffer[i];
			}
			wszValue[strLength] = 0;
			//wcscpy_s(wszValue, strLength, wszBuffer);
			//wprintf(L"convert3.5:%s\n", wszBuffer);
			//wprintf(L"convert3.6:%s\n", wszValue);
			delete wszBuffer;
			pv.pwszVal = wszValue;
			//wprintf(L"convert4:%s\n", pv.pwszVal);
			break;
		case VT_BOOL:
			mid = env->GetMethodID(cls, "getValue", "()Ljava/lang/Object;");
			jobjObjectValue = env->CallObjectMethod(jobjPropVariant, mid);
			mid = env->GetMethodID(env->FindClass("java/lang/Boolean"), "booleanValue", "()Z");
			pv.boolVal = env->CallBooleanMethod(jobjObjectValue, mid);
			break;
	}
	//andere types worden momenteel niet ondersteunt
	
	return pv;
}

void CMFCamCapture::runSession()
{
    PROPVARIANT var;
    PropVariantInit(&var);
    
    HRESULT hr = S_OK;
    CHECK_HR(hr = m_spSession->Start(&GUID_NULL, &var));

done:
    PropVariantClear(&var);
}