minwave.cpp

在微软例子下实现的虚拟声卡,实现了各种接口,是学习的一个好例子

        else
        {
            m_pStream[streamIndex] = stream;
        }

        *OutStream = PMINIPORTWAVECYCLICSTREAM(stream);
        (*OutStream)->AddRef();
        
        *OutDmaChannel = PDMACHANNEL(stream);
        (*OutDmaChannel)->AddRef();

        *OutServiceGroup = m_ServiceGroup;
        (*OutServiceGroup)->AddRef();

        // The stream, the DMA channel, and the service group have
        // references now for the caller.  The caller expects these
        // references to be there.
    }

    // This is our private reference to the stream.  The caller has
    // its own, so we can release in any case.
    //
    if (stream)
    {
        stream->Release();
    }
    
    return ntStatus;
} // NewStream

//=============================================================================
STDMETHODIMP_(NTSTATUS)
CMiniportWaveCyclic::NonDelegatingQueryInterface
( 
    IN  REFIID  Interface,
    OUT PVOID * Object 
)
/*++

Routine Description:

  QueryInterface

Arguments:

  Interface - GUID

  Object - interface pointer to be returned.

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    ASSERT(Object);

    if (IsEqualGUIDAligned(Interface, IID_IUnknown))
    {
        *Object = PVOID(PUNKNOWN(PMINIPORTWAVECYCLIC(this)));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IMiniport))
    {
        *Object = PVOID(PMINIPORT(this));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IMiniportWaveCyclic))
    {
        *Object = PVOID(PMINIPORTWAVECYCLIC(this));
    }
    else
    {
        *Object = NULL;
    }

    if (*Object)
    {
        // We reference the interface for the caller.

        PUNKNOWN(*Object)->AddRef();
        return STATUS_SUCCESS;
    }

    return STATUS_INVALID_PARAMETER;
} // NonDelegatingQueryInterface

//=============================================================================
NTSTATUS                            
CMiniportWaveCyclic::PropertyHandlerGeneric
(
    IN  PPCPROPERTY_REQUEST     PropertyRequest
)
/*++

Routine Description:

  Handles all properties for this miniport.

Arguments:

  PropertyRequest - property request structure

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    ASSERT(PropertyRequest);
    ASSERT(PropertyRequest->PropertyItem);

    NTSTATUS    ntStatus = STATUS_INVALID_DEVICE_REQUEST;

    switch (PropertyRequest->PropertyItem->Id)
    {
        case KSPROPERTY_AUDIO_SAMPLING_RATE:
            ntStatus = PropertyHandlerSamplingRate(PropertyRequest);
            break;
    
        default:
            ntStatus = 
                CMiniportWaveCyclicMSVAD::PropertyHandlerGeneric
                (
                    PropertyRequest
                );
    }

    return ntStatus;
} // PropertyHandlerGeneric

//=============================================================================
NTSTATUS                    
CMiniportWaveCyclic::PropertyHandlerSamplingRate
(
    IN  PPCPROPERTY_REQUEST     PropertyRequest
)
{
    NTSTATUS                    ntStatus = STATUS_INVALID_DEVICE_REQUEST;

    DPF_ENTER(("[CMiniportWaveCyclic::PropertyHandlerSamplingRate]"));

    if (PropertyRequest->Verb & KSPROPERTY_TYPE_GET)
    {
        ntStatus = ValidatePropertyParams(PropertyRequest, sizeof(LONG), 0);
        if (NT_SUCCESS(ntStatus))
        {
            *(PULONG(PropertyRequest->Value)) = m_SamplingFrequency;
            PropertyRequest->ValueSize = sizeof(LONG);
        }
    }
    else if (PropertyRequest->Verb & KSPROPERTY_TYPE_SET)
    {
        ntStatus = ValidatePropertyParams(PropertyRequest, sizeof(LONG), 0);
        if (NT_SUCCESS(ntStatus))
        {
            ULONG ulSamplingRate = *(PULONG(PropertyRequest->Value));

            // Check if the sample rate is available.
            //
            if (ulSamplingRate >= m_MinSampleRatePcm && 
                ulSamplingRate <= m_MaxSampleRatePcm)
            {
                m_SamplingFrequency = ulSamplingRate;
            }
            else
            {
                DPF(D_TERSE, ("[SampleRate not supported]"));
                ntStatus = STATUS_INVALID_PARAMETER;
            }
        }
    }
    else if (PropertyRequest->Verb & KSPROPERTY_TYPE_BASICSUPPORT)
    {
        ntStatus = 
            PropertyHandler_BasicSupport
            (
                PropertyRequest, 
                KSPROPERTY_TYPE_ALL,
                VT_I4
            );
    }

    return ntStatus;
} // PropertyHandlerSamplingRate

//=============================================================================
// CMiniportWaveStreamCyclicSimple
//=============================================================================

//=============================================================================
CMiniportWaveCyclicStream::~CMiniportWaveCyclicStream
( 
    void 
)
/*++

Routine Description:

  Destructor for wavecyclicstream 

Arguments:

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    DPF_ENTER(("[CMiniportWaveCyclicStream::~CMiniportWaveCyclicStream]"));

    // Tell the Miniport that the slot is freed now.
    //
    if (NULL != m_pMiniportLocal)
    {
        if (m_fCapture)
        {
            m_pMiniportLocal->m_fCaptureAllocated = FALSE;
        }
        else
        {
            for (ULONG i = 0; i < m_pMiniportLocal->m_MaxInputStreams; i++)
            {
                if (this == m_pMiniportLocal->m_pStream[i])
                {
                    m_pMiniportLocal->m_pStream[i] = NULL;
                    break;
                }
            }
        }
    }
} // ~CMiniportWaveCyclicStream

//=============================================================================
NTSTATUS
CMiniportWaveCyclicStream::Init
( 
    IN PCMiniportWaveCyclic         Miniport_,
    IN ULONG                        Pin_,
    IN BOOLEAN                      Capture_,
    IN PKSDATAFORMAT                DataFormat_
)
/*++

Routine Description:

  Initializes the stream object. Allocate a DMA buffer, timer and DPC

Arguments:

  Miniport_ -

  Pin_ -

  Capture_ -

  DataFormat -

  DmaChannel_ -

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    m_pMiniportLocal = Miniport_;

    return 
        CMiniportWaveCyclicStreamMSVAD::Init
        (
            Miniport_,
            Pin_,
            Capture_,
            DataFormat_
        );
} // Init

//=============================================================================
STDMETHODIMP_(NTSTATUS)
CMiniportWaveCyclicStream::NonDelegatingQueryInterface
( 
    IN  REFIID  Interface,
    OUT PVOID * Object 
)
/*++

Routine Description:

  QueryInterface

Arguments:

  Interface - GUID

  Object - interface pointer to be returned

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    ASSERT(Object);

    if (IsEqualGUIDAligned(Interface, IID_IUnknown))
    {
        *Object = PVOID(PUNKNOWN(PMINIPORTWAVECYCLICSTREAM(this)));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IMiniportWaveCyclicStream))
    {
        *Object = PVOID(PMINIPORTWAVECYCLICSTREAM(this));
    }
    else if (IsEqualGUIDAligned(Interface, IID_IDmaChannel))
    {
        *Object = PVOID(PDMACHANNEL(this));
    }
    else
    {
        *Object = NULL;
    }

    if (*Object)
    {
        PUNKNOWN(*Object)->AddRef();
        return STATUS_SUCCESS;
    }

    return STATUS_INVALID_PARAMETER;
} // NonDelegatingQueryInterface
#pragma code_seg()

#pragma code_seg("PAGE")
//=============================================================================
NTSTATUS
PropertyHandler_Wave
( 
    IN  PPCPROPERTY_REQUEST     PropertyRequest 
)
/*++

Routine Description:

  Redirects property request to miniport object

Arguments:

  PropertyRequest - 

Return Value:

  NT status code.

--*/
{
    PAGED_CODE();

    ASSERT(PropertyRequest);

    DPF_ENTER(("[PropertyHandler_Wave]"));

    return ((PCMiniportWaveCyclic)
        (PropertyRequest->MajorTarget))->PropertyHandlerGeneric
        (
            PropertyRequest
        );
} // PropertyHandler_Wave
#pragma code_seg()