transfrm.cpp

包裝ffmpeg中的codecs成為DirectShow中的transform filter

//------------------------------------------------------------------------------
// File: Transfrm.cpp
//
// Desc: DirectShow base classes - implements class for simple transform
//       filters such as video decompressors.
//
// Copyright (c) 1992-2002 Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------


#include <streams.h>
#include <measure.h>


// =================================================================
// Implements the CTransformFilter class
// =================================================================

CTransformFilter::CTransformFilter(TCHAR     *pName,
                                   LPUNKNOWN pUnk,
                                   REFCLSID  clsid) :
    CBaseFilter(pName,pUnk,&m_csFilter, clsid),
    m_pInput(NULL),
    m_pOutput(NULL),
    m_bEOSDelivered(FALSE),
    m_bQualityChanged(FALSE),
    m_bSampleSkipped(FALSE)
{
#ifdef PERF
    RegisterPerfId();
#endif //  PERF
}

#ifdef UNICODE
CTransformFilter::CTransformFilter(char     *pName,
                                   LPUNKNOWN pUnk,
                                   REFCLSID  clsid) :
    CBaseFilter(pName,pUnk,&m_csFilter, clsid),
    m_pInput(NULL),
    m_pOutput(NULL),
    m_bEOSDelivered(FALSE),
    m_bQualityChanged(FALSE),
    m_bSampleSkipped(FALSE)
{
#ifdef PERF
    RegisterPerfId();
#endif //  PERF
}
#endif

// destructor

CTransformFilter::~CTransformFilter()
{
    // Delete the pins

    delete m_pInput;
    delete m_pOutput;
}


// Transform place holder - should never be called
HRESULT CTransformFilter::Transform(IMediaSample * pIn, IMediaSample *pOut)
{
    UNREFERENCED_PARAMETER(pIn);
    UNREFERENCED_PARAMETER(pOut);
    DbgBreak("CTransformFilter::Transform() should never be called");
    return E_UNEXPECTED;
}


// return the number of pins we provide

int CTransformFilter::GetPinCount()
{
    return 2;
}


// return a non-addrefed CBasePin * for the user to addref if he holds onto it
// for longer than his pointer to us. We create the pins dynamically when they
// are asked for rather than in the constructor. This is because we want to
// give the derived class an oppportunity to return different pin objects

// We return the objects as and when they are needed. If either of these fails
// then we return NULL, the assumption being that the caller will realise the
// whole deal is off and destroy us - which in turn will delete everything.

CBasePin *
CTransformFilter::GetPin(int n)
{
    HRESULT hr = S_OK;

    // Create an input pin if necessary

    if (m_pInput == NULL) {

        m_pInput = new CTransformInputPin(NAME("Transform input pin"),
                                          this,              // Owner filter
                                          &hr,               // Result code
                                          L"XForm In");      // Pin name


        //  Can't fail
        ASSERT(SUCCEEDED(hr));
        if (m_pInput == NULL) {
            return NULL;
        }
        m_pOutput = (CTransformOutputPin *)
		   new CTransformOutputPin(NAME("Transform output pin"),
                                            this,            // Owner filter
                                            &hr,             // Result code
                                            L"XForm Out");   // Pin name


        // Can't fail
        ASSERT(SUCCEEDED(hr));
        if (m_pOutput == NULL) {
            delete m_pInput;
            m_pInput = NULL;
        }
    }

    // Return the appropriate pin

    if (n == 0) {
        return m_pInput;
    } else
    if (n == 1) {
        return m_pOutput;
    } else {
        return NULL;
    }
}


//
// FindPin
//
// If Id is In or Out then return the IPin* for that pin
// creating the pin if need be.  Otherwise return NULL with an error.

STDMETHODIMP CTransformFilter::FindPin(LPCWSTR Id, IPin **ppPin)
{
    CheckPointer(ppPin,E_POINTER);
    ValidateReadWritePtr(ppPin,sizeof(IPin *));

    if (0==lstrcmpW(Id,L"In")) {
        *ppPin = GetPin(0);
    } else if (0==lstrcmpW(Id,L"Out")) {
        *ppPin = GetPin(1);
    } else {
        *ppPin = NULL;
        return VFW_E_NOT_FOUND;
    }

    HRESULT hr = NOERROR;
    //  AddRef() returned pointer - but GetPin could fail if memory is low.
    if (*ppPin) {
        (*ppPin)->AddRef();
    } else {
        hr = E_OUTOFMEMORY;  // probably.  There's no pin anyway.
    }
    return hr;
}


// override these two functions if you want to inform something
// about entry to or exit from streaming state.

HRESULT
CTransformFilter::StartStreaming()
{
    return NOERROR;
}


HRESULT
CTransformFilter::StopStreaming()
{
    return NOERROR;
}


// override this to grab extra interfaces on connection

HRESULT
CTransformFilter::CheckConnect(PIN_DIRECTION dir,IPin *pPin)
{
    UNREFERENCED_PARAMETER(dir);
    UNREFERENCED_PARAMETER(pPin);
    return NOERROR;
}


// place holder to allow derived classes to release any extra interfaces

HRESULT
CTransformFilter::BreakConnect(PIN_DIRECTION dir)
{
    UNREFERENCED_PARAMETER(dir);
    return NOERROR;
}


// Let derived classes know about connection completion

HRESULT
CTransformFilter::CompleteConnect(PIN_DIRECTION direction,IPin *pReceivePin)
{
    UNREFERENCED_PARAMETER(direction);
    UNREFERENCED_PARAMETER(pReceivePin);
    return NOERROR;
}


// override this to know when the media type is really set

HRESULT
CTransformFilter::SetMediaType(PIN_DIRECTION direction,const CMediaType *pmt)
{
    UNREFERENCED_PARAMETER(direction);
    UNREFERENCED_PARAMETER(pmt);
    return NOERROR;
}


// Set up our output sample
HRESULT
CTransformFilter::InitializeOutputSample(IMediaSample *pSample, IMediaSample **ppOutSample)
{
    IMediaSample *pOutSample;

    // default - times are the same

    AM_SAMPLE2_PROPERTIES * const pProps = m_pInput->SampleProps();
    DWORD dwFlags = m_bSampleSkipped ? AM_GBF_PREVFRAMESKIPPED : 0;

    // This will prevent the image renderer from switching us to DirectDraw
    // when we can't do it without skipping frames because we're not on a
    // keyframe.  If it really has to switch us, it still will, but then we
    // will have to wait for the next keyframe
    if (!(pProps->dwSampleFlags & AM_SAMPLE_SPLICEPOINT)) {
	dwFlags |= AM_GBF_NOTASYNCPOINT;
    }

    ASSERT(m_pOutput->m_pAllocator != NULL);
    HRESULT hr = m_pOutput->m_pAllocator->GetBuffer(
             &pOutSample
             , pProps->dwSampleFlags & AM_SAMPLE_TIMEVALID ?
                   &pProps->tStart : NULL
             , pProps->dwSampleFlags & AM_SAMPLE_STOPVALID ?
                   &pProps->tStop : NULL
             , dwFlags
         );
    *ppOutSample = pOutSample;
    if (FAILED(hr)) {
        return hr;
    }

    ASSERT(pOutSample);
    IMediaSample2 *pOutSample2;
    if (SUCCEEDED(pOutSample->QueryInterface(IID_IMediaSample2,
                                             (void **)&pOutSample2))) {
        /*  Modify it */
        AM_SAMPLE2_PROPERTIES OutProps;
        EXECUTE_ASSERT(SUCCEEDED(pOutSample2->GetProperties(
            FIELD_OFFSET(AM_SAMPLE2_PROPERTIES, tStart), (PBYTE)&OutProps)
        ));
        OutProps.dwTypeSpecificFlags = pProps->dwTypeSpecificFlags;
        OutProps.dwSampleFlags =
            (OutProps.dwSampleFlags & AM_SAMPLE_TYPECHANGED) |
            (pProps->dwSampleFlags & ~AM_SAMPLE_TYPECHANGED);
        OutProps.tStart = pProps->tStart;
        OutProps.tStop  = pProps->tStop;
        OutProps.cbData = FIELD_OFFSET(AM_SAMPLE2_PROPERTIES, dwStreamId);
        hr = pOutSample2->SetProperties(
            FIELD_OFFSET(AM_SAMPLE2_PROPERTIES, dwStreamId),
            (PBYTE)&OutProps
        );
        if (pProps->dwSampleFlags & AM_SAMPLE_DATADISCONTINUITY) {
            m_bSampleSkipped = FALSE;
        }
        pOutSample2->Release();
    } else {
        if (pProps->dwSampleFlags & AM_SAMPLE_TIMEVALID) {
            pOutSample->SetTime(&pProps->tStart,
                                &pProps->tStop);
        }
        if (pProps->dwSampleFlags & AM_SAMPLE_SPLICEPOINT) {
            pOutSample->SetSyncPoint(TRUE);
        }
        if (pProps->dwSampleFlags & AM_SAMPLE_DATADISCONTINUITY) {
            pOutSample->SetDiscontinuity(TRUE);
            m_bSampleSkipped = FALSE;
        }
        // Copy the media times

        LONGLONG MediaStart, MediaEnd;
        if (pSample->GetMediaTime(&MediaStart,&MediaEnd) == NOERROR) {
            pOutSample->SetMediaTime(&MediaStart,&MediaEnd);
        }
    }
    return S_OK;
}

// override this to customize the transform process

HRESULT
CTransformFilter::Receive(IMediaSample *pSample)
{
    /*  Check for other streams and pass them on */
    AM_SAMPLE2_PROPERTIES * const pProps = m_pInput->SampleProps();
    if (pProps->dwStreamId != AM_STREAM_MEDIA) {
        return m_pOutput->m_pInputPin->Receive(pSample);
    }
    HRESULT hr;
    ASSERT(pSample);
    IMediaSample * pOutSample;

    // If no output to deliver to then no point sending us data

    ASSERT (m_pOutput != NULL) ;

    // Set up the output sample
    hr = InitializeOutputSample(pSample, &pOutSample);

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

    // Start timing the transform (if PERF is defined)
    MSR_START(m_idTransform);

    // have the derived class transform the data

    hr = Transform(pSample, pOutSample);

    // Stop the clock and log it (if PERF is defined)
    MSR_STOP(m_idTransform);

    if (FAILED(hr)) {
	DbgLog((LOG_TRACE,1,TEXT("Error from transform")));
    } else {
        // the Transform() function can return S_FALSE to indicate that the
        // sample should not be delivered; we only deliver the sample if it's
        // really S_OK (same as NOERROR, of course.)
        if (hr == NOERROR) {
    	    hr = m_pOutput->m_pInputPin->Receive(pOutSample);
            m_bSampleSkipped = FALSE;	// last thing no longer dropped
        } else {
            // S_FALSE returned from Transform is a PRIVATE agreement
            // We should return NOERROR from Receive() in this cause because returning S_FALSE
            // from Receive() means that this is the end of the stream and no more data should
            // be sent.
            if (S_FALSE == hr) {

                //  Release the sample before calling notify to avoid
                //  deadlocks if the sample holds a lock on the system
                //  such as DirectDraw buffers do
                pOutSample->Release();
                m_bSampleSkipped = TRUE;
                if (!m_bQualityChanged) {
                    NotifyEvent(EC_QUALITY_CHANGE,0,0);
                    m_bQualityChanged = TRUE;
                }
                return NOERROR;
            }
        }
    }

    // release the output buffer. If the connected pin still needs it,
    // it will have addrefed it itself.
    pOutSample->Release();

    return hr;
}


// Return S_FALSE to mean "pass the note on upstream"
// Return NOERROR (Same as S_OK)
// to mean "I've done something about it, don't pass it on"
HRESULT CTransformFilter::AlterQuality(Quality q)
{
    UNREFERENCED_PARAMETER(q);
    return S_FALSE;
}


// EndOfStream received. Default behaviour is to deliver straight
// downstream, since we have no queued data. If you overrode Receive
// and have queue data, then you need to handle this and deliver EOS after
// all queued data is sent
HRESULT
CTransformFilter::EndOfStream(void)
{
    HRESULT hr = NOERROR;
    if (m_pOutput != NULL) {
        hr = m_pOutput->DeliverEndOfStream();
    }

    return hr;
}


// enter flush state. Receives already blocked
// must override this if you have queued data or a worker thread
HRESULT
CTransformFilter::BeginFlush(void)
{
    HRESULT hr = NOERROR;
    if (m_pOutput != NULL) {
	// block receives -- done by caller (CBaseInputPin::BeginFlush)

	// discard queued data -- we have no queued data

	// free anyone blocked on receive - not possible in this filter

	// call downstream
	hr = m_pOutput->DeliverBeginFlush();
    }
    return hr;
}


// leave flush state. must override this if you have queued data
// or a worker thread
HRESULT
CTransformFilter::EndFlush(void)
{
    // sync with pushing thread -- we have no worker thread

    // ensure no more data to go downstream -- we have no queued data

    // call EndFlush on downstream pins
    ASSERT (m_pOutput != NULL);
    return m_pOutput->DeliverEndFlush();

    // caller (the input pin's method) will unblock Receives
}


// override these so that the derived filter can catch them

STDMETHODIMP
CTransformFilter::Stop()
{
    CAutoLock lck1(&m_csFilter);
    if (m_State == State_Stopped) {
        return NOERROR;
    }

    // Succeed the Stop if we are not completely connected

    ASSERT(m_pInput == NULL || m_pOutput != NULL);
    if (m_pInput == NULL || m_pInput->IsConnected() == FALSE ||
        m_pOutput->IsConnected() == FALSE) {
                m_State = State_Stopped;
                m_bEOSDelivered = FALSE;
                return NOERROR;
    }

    ASSERT(m_pInput);
    ASSERT(m_pOutput);

    // decommit the input pin before locking or we can deadlock
    m_pInput->Inactive();

    // synchronize with Receive calls

    CAutoLock lck2(&m_csReceive);
    m_pOutput->Inactive();

    // allow a class derived from CTransformFilter
    // to know about starting and stopping streaming

    HRESULT hr = StopStreaming();
    if (SUCCEEDED(hr)) {
	// complete the state transition
	m_State = State_Stopped;
	m_bEOSDelivered = FALSE;
    }
    return hr;
}


STDMETHODIMP
CTransformFilter::Pause()
{
    CAutoLock lck(&m_csFilter);
    HRESULT hr = NOERROR;

    if (m_State == State_Paused) {
        // (This space left deliberately blank)
    }

    // If we have no input pin or it isn't yet connected then when we are
    // asked to pause we deliver an end of stream to the downstream filter.
    // This makes sure that it doesn't sit there forever waiting for
    // samples which we cannot ever deliver without an input connection.

    else if (m_pInput == NULL || m_pInput->IsConnected() == FALSE) {
        if (m_pOutput && m_bEOSDelivered == FALSE) {
            m_pOutput->DeliverEndOfStream();
            m_bEOSDelivered = TRUE;
        }
        m_State = State_Paused;
    }