//------------------------------------------------------------------------------
// File: Transfrm.cpp
//
// Desc: DirectShow base classes - implements class for simple transform
// filters such as video decompressors.
//
// Copyright (c) 1992-2001 Microsoft Corporation. All rights reserved.
//------------------------------------------------------------------------------
#include "streams.h"
#include "measure.h"
// =================================================================
// Implements the CTransformFilter class
// =================================================================
CTransformFilter::CTransformFilter(__in_opt LPCTSTR pName,
__inout_opt 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(__in_opt LPCSTR pName,
__inout_opt 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, __deref_out 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, __deref_out 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;
}
// We may have an input connection but no output connection
// However, if we have an input pin we do have an output pin
else if (m_pOutput->IsConnected() == FALSE) {
m_State = State_Paused;
}
else {
if (m_State == State_Stopped) {
// allow a class derived from CTransformFilter
// to know about starting and stopping streaming
CAutoLock lck2(&m_csReceive);
hr = StartStreaming();
}
if (SUCCEEDED(hr)) {
hr = CBaseFilter::Pause();
}
}
m_bSampleSkipped = FALSE;
m_bQualityChanged = FALSE;
return hr;
}
HRESULT
CTransformFilter::NewSegment(
REFERENCE_TIME tStart,
REFERENCE_TIME tStop,
double dRate)
{
if (m_pOutput != NULL) {
return m_pOutput->DeliverNewSegment(tStart, tStop, dRate);
}
return S_OK;
}
// Check streaming status
HRESULT
CTransformInputPin::CheckStreaming()
{
ASSERT(m_pTransformFilter->m_pOutput != NULL);
if (!m_pTransformFilter->m_pOutput->IsConnected()) {
return VFW_E_NOT_CONNECTED;
} else {
// Shouldn't be able to get any data if we're not connected!
ASSERT(IsConnected());
// we're flushing
if (m_bFlushing) {
return S_FALSE;
}
// Don't process stuff in Stopped state
if (IsStopped()) {
return VFW_E_WRONG_STATE;
}
if (m_bRunTimeError) {
return VFW_E_RUNTIME_ERROR;
}
return S_OK;
}
}
// =================================================================
// Implements the CTransformInputPin class
// =================================================================
// constructor
CTransformInputPin::CTransformInputPin(
__in_opt LPCTSTR pObjectName,
__inout CTransformFilter *pTransformFilter,
__inout HRESULT * phr,
__in_opt LPCWSTR pName)
: CBaseInputPin(pObjectName, pTransformFilter, &pTransformFilter->m_csFilter, phr, pName)
{
DbgLog((LOG_TRACE,2,TEXT("CTransformInputPin::CTransformInputPin")));
m_pTransformFilter = pTransformFilter;
}
#ifdef UNICODE
CTransformInputPin::CTransformInputPin(
__in_opt LPCSTR pObjectName,
__inout CTransformFilter *pTransformFilter,
__inout HRESULT * phr,
__in_opt LPCWSTR pName)
: CBaseInputPin(pObjectName, pTransformFilter, &pTransformFilter->m_csFilter, phr, pName)
{
DbgLog((LOG_TRACE,2,TEXT("CTransformInputPin::CTransformInputPin")));
m_pTransformFilter = pTransformFilter;
}
#endif
// provides derived filter a chance to grab extra interfaces
HRESULT
CTransformInputPin::CheckConnect(IPin *pPin)
{
HRESULT hr = m_pTransformFilter->CheckConnect(PINDIR_INPUT,pPin);
if (FAILED(hr)) {
return hr;
}
return CBaseInputPin::CheckConnect(pPin);
}
// provides derived filter a chance to release it's extra interfaces
HRESULT
CTransformInputPin::BreakConnect()
{
// Can't disconnect unless stopped
ASSERT(IsStopped());
m_pTransformFilter->BreakConnect(PINDIR_INPUT);
return CBaseInputPin::BreakConnect();
}
// Let derived class know when the input pin is connected
HRESULT
CTransformInputPin::CompleteConnect(IPin *pReceivePin)
{
HRESULT hr = m_pTransformFilter->CompleteConnect(PINDIR_INPUT,pReceivePin);
if (FAILED(hr)) {
return hr;
}
return CBaseInputPin::CompleteConnect(pReceivePin);
}
// check that we can support a given media type
HRESULT
CTransformInputPin::CheckMediaType(const CMediaType* pmt)
{
// Check the input type
HRESULT hr = m_pTransformFilter->CheckInputType(pmt);
if (S_OK != hr) {
return hr;
}
// if the output pin is still connected, then we have
// to check the transform not just the input format
if ((m_pTransformFilter->m_pOutput != NULL) &&
(m_pTransformFilter->m_pOutput->IsConnected())) {
return m_pTransformFilter->CheckTransform(
pmt,
&m_pTransformFilter->m_pOutput->CurrentMediaType());
} else {
return hr;
}
}
// set the media type for this connection
HRESULT
CTransformInputPin::SetMediaType(const CMediaType* mtIn)
{
// Set the base class media type (should always succeed)
HRESULT hr = CBasePin::SetMediaType(mtIn);
if (FAILED(hr)) {
return hr;
}
// check the transform can be done (should always succeed)
ASSERT(SUCCEEDED(m_pTransformFilter->CheckInputType(mtIn)));
return m_pTransformFilter->SetMediaType(PINDIR_INPUT,mtIn);
}
// =================================================================
// Implements IMemInputPin interface
// =================================================================
// provide EndOfStream that passes straight downstream
// (there is no queued data)
STDMETHODIMP
CTransformInputPin::EndOfStream(void)
{
CAutoLock lck(&m_pTransformFilter->m_csReceive);
HRESULT hr = CheckStreaming();
if (S_OK == hr) {
hr = m_pTransformFilter->EndOfStream();
}
return hr;
}
// enter flushing state. Call default handler to block Receives, then
// pass to overridable method in filter
STDMETHODIMP
CTransformInputPin::BeginFlush(void)
{
CAutoLock lck(&m_pTransformFilter->m_csFilter);
// Are we actually doing anything?
ASSERT(m_pTransformFilter->m_pOutput != NULL);
if (!IsConnected() ||
!m_pTransformFilter->m_pOutput->IsConnected()) {
return VFW_E_NOT_CONNECTED;
}
HRESULT hr = CBaseInputPin::BeginFlush();
if (FAILED(hr)) {
return hr;
}
return m_pTransformFilter->BeginFlush();
}
// leave flushing state.
// Pass to overridable method in filter, then call base class
// to unblock receives (finally)
STDMETHODIMP
CTransformInputPin::EndFlush(void)
{
CAutoLock lck(&m_pTransformFilter->m_csFilter);
// Are we actually doing anything?
ASSERT(m_pTransformFilter->m_pOutput != NULL);
if (!IsConnected() ||
!m_pTransformFilter->m_pOutput->IsConnected()) {
return VFW_E_NOT_CONNECTED;
}
HRESULT hr = m_pTransformFilter->EndFlush();
if (FAILED(hr)) {
return hr;
}
return CBaseInputPin::EndFlush();
}
// here's the next block of data from the stream.
// AddRef it yourself if you need to hold it beyond the end
// of this call.
HRESULT
CTransformInputPin::Receive(IMediaSample * pSample)
{
HRESULT hr;
CAutoLock lck(&m_pTransformFilter->m_csReceive);
ASSERT(pSample);
// check all is well with the base class
hr = CBaseInputPin::Receive(pSample);
if (S_OK == hr) {
hr = m_pTransformFilter->Receive(pSample);
}
return hr;
}
// override to pass downstream
STDMETHODIMP
CTransformInputPin::NewSegment(
REFERENCE_TIME tStart,
REFERENCE_TIME tStop,
double dRate)
{
// Save the values in the pin
CBasePin::NewSegment(tStart, tStop, dRate);
return m_pTransformFilter->NewSegment(tStart, tStop, dRate);
}
// =================================================================
// Implements the CTransformOutputPin class
// =================================================================
// constructor
CTransformOutputPin::CTransformOutputPin(
__in_opt LPCTSTR pObjectName,
__inout CTransformFilter *pTransformFilter,
__inout HRESULT * phr,
__in_opt LPCWSTR pPinName)
: CBaseOutputPin(pObjectName, pTransformFilter, &pTransformFilter->m_csFilter, phr, pPinName),
m_pPosition(NULL)
{
DbgLog((LOG_TRACE,2,TEXT("CTransformOutputPin::CTransformOutputPin")));
m_pTransformFilter = pTransformFilter;
}
#ifdef UNICODE
CTransformOutputPin::CTransformOutputPin(
__in_opt LPCSTR pObjectName,
__inout CTransformFilter *pTransformFilter,
__inout HRESULT * phr,
__in_opt LPCWSTR pPinName)
: CBaseOutputPin(pObjectName, pTransformFilter, &pTransformFilter->m_csFilter, phr, pPinName),
m_pPosition(NULL)
{
DbgLog((LOG_TRACE,2,TEXT("CTransformOutputPin::CTransformOutputPin")));
m_pTransformFilter = pTransformFilter;
}
#endif
// destructor
CTransformOutputPin::~CTransformOutputPin()
{
DbgLog((LOG_TRACE,2,TEXT("CTransformOutputPin::~CTransformOutputPin")));
if (m_pPosition) m_pPosition->Release();
}
// overriden to expose IMediaPosition and IMediaSeeking control interfaces
STDMETHODIMP
CTransformOutputPin::NonDelegatingQueryInterface(REFIID riid, __deref_out void **ppv)
{
CheckPointer(ppv,E_POINTER);
ValidateReadWritePtr(ppv,sizeof(PVOID));
*ppv = NULL;
if (riid == IID_IMediaPosition || riid == IID_IMediaSeeking) {
// we should have an input pin by now
ASSERT(m_pTransformFilter->m_pInput != NULL);
if (m_pPosition == NULL) {
HRESULT hr = CreatePosPassThru(
GetOwner(),
FALSE,
(IPin *)m_pTransformFilter->m_pInput,
&m_pPosition);
if (FAILED(hr)) {
return hr;
}
}
return m_pPosition->QueryInterface(riid, ppv);
} else {
return CBaseOutputPin::NonDelegatingQueryInterface(riid, ppv);
}
}
// provides derived filter a chance to grab extra interfaces
HRESULT
CTransformOutputPin::CheckConnect(IPin *pPin)
{
// we should have an input connection first
ASSERT(m_pTransformFilter->m_pInput != NULL);
if ((m_pTransformFilter->m_pInput->IsConnected() == FALSE)) {
return E_UNEXPECTED;
}
HRESULT hr = m_pTransformFilter->CheckConnect(PINDIR_OUTPUT,pPin);
if (FAILED(hr)) {
return hr;
}
return CBaseOutputPin::CheckConnect(pPin);
}
// provides derived filter a chance to release it's extra interfaces
HRESULT
CTransformOutputPin::BreakConnect()
{
// Can't disconnect unless stopped
ASSERT(IsStopped());
m_pTransformFilter->BreakConnect(PINDIR_OUTPUT);
return CBaseOutputPin::BreakConnect();
}
// Let derived class know when the output pin is connected
HRESULT
CTransformOutputPin::CompleteConnect(IPin *pReceivePin)
{
HRESULT hr = m_pTransformFilter->CompleteConnect(PINDIR_OUTPUT,pReceivePin);
if (FAILED(hr)) {
return hr;
}
return CBaseOutputPin::CompleteConnect(pReceivePin);
}
// check a given transform - must have selected input type first
HRESULT
CTransformOutputPin::CheckMediaType(const CMediaType* pmtOut)
{
// must have selected input first
ASSERT(m_pTransformFilter->m_pInput != NULL);
if ((m_pTransformFilter->m_pInput->IsConnected() == FALSE)) {
return E_INVALIDARG;
}
return m_pTransformFilter->CheckTransform(
&m_pTransformFilter->m_pInput->CurrentMediaType(),
pmtOut);
}
// called after we have agreed a media type to actually set it in which case
// we run the CheckTransform function to get the output format type again
HRESULT
CTransformOutputPin::SetMediaType(const CMediaType* pmtOut)
{
HRESULT hr = NOERROR;
ASSERT(m_pTransformFilter->m_pInput != NULL);
ASSERT(m_pTransformFilter->m_pInput->CurrentMediaType().IsValid());
// Set the base class media type (should always succeed)
hr = CBasePin::SetMediaType(pmtOut);
if (FAILED(hr)) {
return hr;
}
#ifdef _DEBUG
if (FAILED(m_pTransformFilter->CheckTransform(&m_pTransformFilter->
m_pInput->CurrentMediaType(),pmtOut))) {
DbgLog((LOG_ERROR,0,TEXT("*** This filter is accepting an output media type")));
DbgLog((LOG_ERROR,0,TEXT(" that it can't currently transform to. I hope")));
DbgLog((LOG_ERROR,0,TEXT(" it's smart enough to reconnect its input.")));
}
#endif
return m_pTransformFilter->SetMediaType(PINDIR_OUTPUT,pmtOut);
}
// pass the buffer size decision through to the main transform class
HRESULT
CTransformOutputPin::DecideBufferSize(
IMemAllocator * pAllocator,
__inout ALLOCATOR_PROPERTIES* pProp)
{
return m_pTransformFilter->DecideBufferSize(pAllocator, pProp);
}
// return a specific media type indexed by iPosition
HRESULT
CTransformOutputPin::GetMediaType(
int iPosition,
__inout CMediaType *pMediaType)
{
ASSERT(m_pTransformFilter->m_pInput != NULL);
// We don't have any media types if our input is not connected
if (m_pTransformFilter->m_pInput->IsConnected()) {
return m_pTransformFilter->GetMediaType(iPosition,pMediaType);
} else {
return VFW_S_NO_MORE_ITEMS;
}
}
// Override this if you can do something constructive to act on the
// quality message. Consider passing it upstream as well
// Pass the quality mesage on upstream.
STDMETHODIMP
CTransformOutputPin::Notify(IBaseFilter * pSender, Quality q)
{
UNREFERENCED_PARAMETER(pSender);
ValidateReadPtr(pSender,sizeof(IBaseFilter));
// First see if we want to handle this ourselves
HRESULT hr = m_pTransformFilter->AlterQuality(q);
if (hr!=S_FALSE) {
return hr; // either S_OK or a failure
}
// S_FALSE means we pass the message on.
// Find the quality sink for our input pin and send it there
ASSERT(m_pTransformFilter->m_pInput != NULL);
return m_pTransformFilter->m_pInput->PassNotify(q);
} // Notify
// the following removes a very large number of level 4 warnings from the microsoft
// compiler output, which are not useful at all in this case.
#pragma warning(disable:4514)
↑ V522 There might be dereferencing of a potential null pointer 'm_pOutput'.
↑ V572 It is odd that the object which was created using 'new' operator is immediately cast to another type.