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//------------------------------------------------------------------------------
// File: TransIP.h
//
// Desc: DirectShow base classes - defines classes from which simple
// Transform-In-Place filters may be derived.
//
// Copyright (c) 1992-2001 Microsoft Corporation. All rights reserved.
//------------------------------------------------------------------------------
//
// The difference between this and Transfrm.h is that Transfrm copies the data.
//
// It assumes the filter has one input and one output stream, and has no
// interest in memory management, interface negotiation or anything else.
//
// Derive your class from this, and supply Transform and the media type/format
// negotiation functions. Implement that class, compile and link and
// you're done.
#ifndef __TRANSIP__
#define __TRANSIP__
// ======================================================================
// This is the com object that represents a simple transform filter. It
// supports IBaseFilter, IMediaFilter and two pins through nested interfaces
// ======================================================================
class CTransInPlaceFilter;
// Several of the pin functions call filter functions to do the work,
// so you can often use the pin classes unaltered, just overriding the
// functions in CTransInPlaceFilter. If that's not enough and you want
// to derive your own pin class, override GetPin in the filter to supply
// your own pin classes to the filter.
// ==================================================
// Implements the input pin
// ==================================================
class CTransInPlaceInputPin : public CTransformInputPin{
protected: CTransInPlaceFilter * const m_pTIPFilter; // our filter
BOOL m_bReadOnly; // incoming stream is read only
public:
CTransInPlaceInputPin( TCHAR *pObjectName, CTransInPlaceFilter *pFilter, HRESULT *phr, LPCWSTR pName);
// --- IMemInputPin -----
// Provide an enumerator for media types by getting one from downstream
STDMETHODIMP EnumMediaTypes( IEnumMediaTypes **ppEnum );
// Say whether media type is acceptable.
HRESULT CheckMediaType(const CMediaType* pmt);
// Return our upstream allocator
STDMETHODIMP GetAllocator(IMemAllocator ** ppAllocator);
// get told which allocator the upstream output pin is actually
// going to use.
STDMETHODIMP NotifyAllocator(IMemAllocator * pAllocator, BOOL bReadOnly);
// Allow the filter to see what allocator we have
// N.B. This does NOT AddRef
IMemAllocator * PeekAllocator() const { return m_pAllocator; }
// Pass this on downstream if it ever gets called.
STDMETHODIMP GetAllocatorRequirements(ALLOCATOR_PROPERTIES *pProps);
HRESULT CompleteConnect(IPin *pReceivePin);
inline const BOOL ReadOnly() { return m_bReadOnly ; }
}; // CTransInPlaceInputPin
// ==================================================
// Implements the output pin
// ==================================================
class CTransInPlaceOutputPin : public CTransformOutputPin{
protected: // m_pFilter points to our CBaseFilter
CTransInPlaceFilter * const m_pTIPFilter;
public:
CTransInPlaceOutputPin( TCHAR *pObjectName, CTransInPlaceFilter *pFilter, HRESULT *phr, LPCWSTR pName);
// --- CBaseOutputPin ------------
// negotiate the allocator and its buffer size/count
// Insists on using our own allocator. (Actually the one upstream of us).
// We don't override this - instead we just agree the default
// then let the upstream filter decide for itself on reconnect
// virtual HRESULT DecideAllocator(IMemInputPin * pPin, IMemAllocator ** pAlloc);
// Provide a media type enumerator. Get it from upstream.
STDMETHODIMP EnumMediaTypes( IEnumMediaTypes **ppEnum );
// Say whether media type is acceptable.
HRESULT CheckMediaType(const CMediaType* pmt);
// This just saves the allocator being used on the output pin
// Also called by input pin's GetAllocator()
void SetAllocator(IMemAllocator * pAllocator);
IMemInputPin * ConnectedIMemInputPin() { return m_pInputPin; }
// Allow the filter to see what allocator we have
// N.B. This does NOT AddRef
IMemAllocator * PeekAllocator() const { return m_pAllocator; }
HRESULT CompleteConnect(IPin *pReceivePin);
}; // CTransInPlaceOutputPin
class AM_NOVTABLE CTransInPlaceFilter : public CTransformFilter{
public:
// map getpin/getpincount for base enum of pins to owner
// override this to return more specialised pin objects
virtual CBasePin *GetPin(int n);
public:
// Set bModifiesData == false if your derived filter does
// not modify the data samples (for instance it's just copying
// them somewhere else or looking at the timestamps).
CTransInPlaceFilter(TCHAR *, LPUNKNOWN, REFCLSID clsid, HRESULT *, bool bModifiesData = true);#ifdef UNICODE
CTransInPlaceFilter(CHAR *, LPUNKNOWN, REFCLSID clsid, HRESULT *, bool bModifiesData = true);#endif
// The following are defined to avoid undefined pure virtuals.
// Even if they are never called, they will give linkage warnings/errors
// We override EnumMediaTypes to bypass the transform class enumerator
// which would otherwise call this.
HRESULT GetMediaType(int iPosition, CMediaType *pMediaType) { DbgBreak("CTransInPlaceFilter::GetMediaType should never be called"); return E_UNEXPECTED; }
// This is called when we actually have to provide out own allocator.
HRESULT DecideBufferSize(IMemAllocator*, ALLOCATOR_PROPERTIES *);
// The functions which call this in CTransform are overridden in this
// class to call CheckInputType with the assumption that the type
// does not change. In Debug builds some calls will be made and
// we just ensure that they do not assert.
HRESULT CheckTransform(const CMediaType *mtIn, const CMediaType *mtOut) { return S_OK; };
// =================================================================
// ----- You may want to override this -----------------------------
// =================================================================
HRESULT CompleteConnect(PIN_DIRECTION dir,IPin *pReceivePin);
// chance to customize the transform process
virtual HRESULT Receive(IMediaSample *pSample);
// =================================================================
// ----- You MUST override these -----------------------------------
// =================================================================
virtual HRESULT Transform(IMediaSample *pSample) PURE;
// this goes in the factory template table to create new instances
// static CCOMObject * CreateInstance(LPUNKNOWN, HRESULT *);
#ifdef PERF
// Override to register performance measurement with a less generic string
// You should do this to avoid confusion with other filters
virtual void RegisterPerfId() {m_idTransInPlace = MSR_REGISTER(TEXT("TransInPlace"));}#endif // PERF
// implementation details
protected:
IMediaSample * CTransInPlaceFilter::Copy(IMediaSample *pSource);
#ifdef PERF
int m_idTransInPlace; // performance measuring id
#endif // PERF
bool m_bModifiesData; // Does this filter change the data?
// these hold our input and output pins
friend class CTransInPlaceInputPin; friend class CTransInPlaceOutputPin;
CTransInPlaceInputPin *InputPin() const { return (CTransInPlaceInputPin *)m_pInput; }; CTransInPlaceOutputPin *OutputPin() const { return (CTransInPlaceOutputPin *)m_pOutput; };
// Helper to see if the input and output types match
BOOL TypesMatch() { return InputPin()->CurrentMediaType() == OutputPin()->CurrentMediaType(); }
// Are the input and output allocators different?
BOOL UsingDifferentAllocators() const { return InputPin()->PeekAllocator() != OutputPin()->PeekAllocator(); }}; // CTransInPlaceFilter
#endif /* __TRANSIP__ */
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