amfilter.h

mediastreamer2是开源的网络传输媒体流的库

//------------------------------------------------------------------------------
// File: AMFilter.h
//
// Desc: DirectShow base classes - efines class hierarchy for streams
//       architecture.
//
// Copyright (c) Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------


#ifndef __FILTER__
#define __FILTER__

/* The following classes are declared in this header: */

class CBaseMediaFilter;     // IMediaFilter support
class CBaseFilter;          // IBaseFilter,IMediaFilter support
class CBasePin;             // Abstract base class for IPin interface
class CEnumPins;            // Enumerate input and output pins
class CEnumMediaTypes;      // Enumerate the pin's preferred formats
class CBaseOutputPin;       // Adds data provider member functions
class CBaseInputPin;        // Implements IMemInputPin interface
class CMediaSample;         // Basic transport unit for IMemInputPin
class CBaseAllocator;       // General list guff for most allocators
class CMemAllocator;        // Implements memory buffer allocation


//=====================================================================
//=====================================================================
//
// QueryFilterInfo and QueryPinInfo AddRef the interface pointers
// they return.  You can use the macro below to release the interface.
//
//=====================================================================
//=====================================================================

#define QueryFilterInfoReleaseGraph(fi) if ((fi).pGraph) (fi).pGraph->Release();

#define QueryPinInfoReleaseFilter(pi) if ((pi).pFilter) (pi).pFilter->Release();

//=====================================================================
//=====================================================================
// Defines CBaseMediaFilter
//
// Abstract base class implementing IMediaFilter.
//
// Typically you will derive your filter from CBaseFilter rather than
// this,  unless you are implementing an object such as a plug-in
// distributor that needs to support IMediaFilter but not IBaseFilter.
//
// Note that IMediaFilter is derived from IPersist to allow query of
// class id.
//=====================================================================
//=====================================================================

class AM_NOVTABLE CBaseMediaFilter : public CUnknown,
                                     public IMediaFilter
{

protected:

    FILTER_STATE    m_State;            // current state: running, paused
    IReferenceClock *m_pClock;          // this filter's reference clock
    // note: all filters in a filter graph use the same clock

    // offset from stream time to reference time
    CRefTime        m_tStart;

    CLSID	    m_clsid;            // This filters clsid
                                        // used for serialization
    CCritSec        *m_pLock;           // Object we use for locking

public:

    CBaseMediaFilter(
        const TCHAR     *pName,
        LPUNKNOWN pUnk,
        CCritSec  *pLock,
	REFCLSID   clsid);

    virtual ~CBaseMediaFilter();

    DECLARE_IUNKNOWN

    // override this to say what interfaces we support where
    STDMETHODIMP NonDelegatingQueryInterface(REFIID riid, void ** ppv);

    //
    // --- IPersist method ---
    //

    STDMETHODIMP GetClassID(CLSID *pClsID);

    // --- IMediaFilter methods ---

    STDMETHODIMP GetState(DWORD dwMSecs, FILTER_STATE *State);

    STDMETHODIMP SetSyncSource(IReferenceClock *pClock);

    STDMETHODIMP GetSyncSource(IReferenceClock **pClock);

    // default implementation of Stop and Pause just record the
    // state. Override to activate or de-activate your filter.
    // Note that Run when called from Stopped state will call Pause
    // to ensure activation, so if you are a source or transform
    // you will probably not need to override Run.
    STDMETHODIMP Stop();
    STDMETHODIMP Pause();


    // the start parameter is the difference to be added to the
    // sample's stream time to get the reference time for
    // its presentation
    STDMETHODIMP Run(REFERENCE_TIME tStart);

    // --- helper methods ---

    // return the current stream time - ie find out what
    // stream time should be appearing now
    virtual HRESULT StreamTime(CRefTime& rtStream);

    // Is the filter currently active? (running or paused)
    BOOL IsActive() {
        CAutoLock cObjectLock(m_pLock);
        return ((m_State == State_Paused) || (m_State == State_Running));
    };
};

//=====================================================================
//=====================================================================
// Defines CBaseFilter
//
// An abstract class providing basic IBaseFilter support for pin
// enumeration and filter information reading.
//
// We cannot derive from CBaseMediaFilter since methods in IMediaFilter
// are also in IBaseFilter and would be ambiguous. Since much of the code
// assumes that they derive from a class that has m_State and other state
// directly available, we duplicate code from CBaseMediaFilter rather than
// having a member variable.
//
// Derive your filter from this, or from a derived object such as
// CTransformFilter.
//=====================================================================
//=====================================================================


class AM_NOVTABLE CBaseFilter : public CUnknown,        // Handles an IUnknown
                    public IBaseFilter,     // The Filter Interface
                    public IAMovieSetup     // For un/registration
{

friend class CBasePin;

protected:
    FILTER_STATE    m_State;            // current state: running, paused
    IReferenceClock *m_pClock;          // this graph's ref clock
    CRefTime        m_tStart;           // offset from stream time to reference time
    CLSID	    m_clsid;            // This filters clsid
                                        // used for serialization
    CCritSec        *m_pLock;           // Object we use for locking

    WCHAR           *m_pName;           // Full filter name
    IFilterGraph    *m_pGraph;          // Graph we belong to
    IMediaEventSink *m_pSink;           // Called with notify events
    LONG            m_PinVersion;       // Current pin version

public:

    CBaseFilter(
        const TCHAR *pName,     // Object description
        LPUNKNOWN pUnk,         // IUnknown of delegating object
        CCritSec  *pLock,       // Object who maintains lock
	REFCLSID   clsid);      // The clsid to be used to serialize this filter

    CBaseFilter(
        TCHAR     *pName,       // Object description
        LPUNKNOWN pUnk,         // IUnknown of delegating object
        CCritSec  *pLock,       // Object who maintains lock
	REFCLSID   clsid,       // The clsid to be used to serialize this filter
        HRESULT   *phr);        // General OLE return code
#ifdef UNICODE
    CBaseFilter(
        const CHAR *pName,     // Object description
        LPUNKNOWN pUnk,         // IUnknown of delegating object
        CCritSec  *pLock,       // Object who maintains lock
	REFCLSID   clsid);      // The clsid to be used to serialize this filter

    CBaseFilter(
        CHAR     *pName,       // Object description
        LPUNKNOWN pUnk,         // IUnknown of delegating object
        CCritSec  *pLock,       // Object who maintains lock
	REFCLSID   clsid,       // The clsid to be used to serialize this filter
        HRESULT   *phr);        // General OLE return code
#endif
    ~CBaseFilter();

    DECLARE_IUNKNOWN

    // override this to say what interfaces we support where
    STDMETHODIMP NonDelegatingQueryInterface(REFIID riid, void ** ppv);
#ifdef DEBUG
    STDMETHODIMP_(ULONG) NonDelegatingRelease();
#endif

    //
    // --- IPersist method ---
    //

    STDMETHODIMP GetClassID(CLSID *pClsID);

    // --- IMediaFilter methods ---

    STDMETHODIMP GetState(DWORD dwMSecs, FILTER_STATE *State);

    STDMETHODIMP SetSyncSource(IReferenceClock *pClock);

    STDMETHODIMP GetSyncSource(IReferenceClock **pClock);


    // override Stop and Pause so we can activate the pins.
    // Note that Run will call Pause first if activation needed.
    // Override these if you want to activate your filter rather than
    // your pins.
    STDMETHODIMP Stop();
    STDMETHODIMP Pause();

    // the start parameter is the difference to be added to the
    // sample's stream time to get the reference time for
    // its presentation
    STDMETHODIMP Run(REFERENCE_TIME tStart);

    // --- helper methods ---

    // return the current stream time - ie find out what
    // stream time should be appearing now
    virtual HRESULT StreamTime(CRefTime& rtStream);

    // Is the filter currently active?
    BOOL IsActive() {
        CAutoLock cObjectLock(m_pLock);
        return ((m_State == State_Paused) || (m_State == State_Running));
    };

    // Is this filter stopped (without locking)
    BOOL IsStopped() {
        return (m_State == State_Stopped);
    };

    //
    // --- IBaseFilter methods ---
    //

    // pin enumerator
    STDMETHODIMP EnumPins(
                    IEnumPins ** ppEnum);


    // default behaviour of FindPin assumes pin ids are their names
    STDMETHODIMP FindPin(
        LPCWSTR Id,
        IPin ** ppPin
    );

    STDMETHODIMP QueryFilterInfo(
                    FILTER_INFO * pInfo);

    STDMETHODIMP JoinFilterGraph(
                    IFilterGraph * pGraph,
                    LPCWSTR pName);

    // return a Vendor information string. Optional - may return E_NOTIMPL.
    // memory returned should be freed using CoTaskMemFree
    // default implementation returns E_NOTIMPL
    STDMETHODIMP QueryVendorInfo(
                    LPWSTR* pVendorInfo
            );

    // --- helper methods ---

    // send an event notification to the filter graph if we know about it.
    // returns S_OK if delivered, S_FALSE if the filter graph does not sink
    // events, or an error otherwise.
    HRESULT NotifyEvent(
        long EventCode,
        LONG_PTR EventParam1,
        LONG_PTR EventParam2);

    // return the filter graph we belong to
    IFilterGraph *GetFilterGraph() {
        return m_pGraph;
    }

    // Request reconnect
    // pPin is the pin to reconnect
    // pmt is the type to reconnect with - can be NULL
    // Calls ReconnectEx on the filter graph
    HRESULT ReconnectPin(IPin *pPin, AM_MEDIA_TYPE const *pmt);

    // find out the current pin version (used by enumerators)
    virtual LONG GetPinVersion();
    void IncrementPinVersion();

    // you need to supply these to access the pins from the enumerator
    // and for default Stop and Pause/Run activation.
    virtual int GetPinCount() PURE;
    virtual CBasePin *GetPin(int n) PURE;

    // --- IAMovieSetup methods ---

    STDMETHODIMP Register();    // ask filter to register itself
    STDMETHODIMP Unregister();  // and unregister itself

    // --- setup helper methods ---
    // (override to return filters setup data)

    virtual LPAMOVIESETUP_FILTER GetSetupData(){ return NULL; }

};


//=====================================================================
//=====================================================================
// Defines CBasePin
//
// Abstract class that supports the basics of IPin
//=====================================================================
//=====================================================================

class  AM_NOVTABLE CBasePin : public CUnknown, public IPin, public IQualityControl
{

protected:

    WCHAR *         m_pName;		        // This pin's name
    IPin            *m_Connected;               // Pin we have connected to
    PIN_DIRECTION   m_dir;                      // Direction of this pin
    CCritSec        *m_pLock;                   // Object we use for locking
    bool            m_bRunTimeError;            // Run time error generated
    bool            m_bCanReconnectWhenActive;  // OK to reconnect when active
    bool            m_bTryMyTypesFirst;         // When connecting enumerate
                                                // this pin's types first
    CBaseFilter    *m_pFilter;                  // Filter we were created by
    IQualityControl *m_pQSink;                  // Target for Quality messages
    LONG            m_TypeVersion;              // Holds current type version
    CMediaType      m_mt;                       // Media type of connection

    CRefTime        m_tStart;                   // time from NewSegment call
    CRefTime        m_tStop;                    // time from NewSegment
    double          m_dRate;                    // rate from NewSegment

#ifdef DEBUG
    LONG            m_cRef;                     // Ref count tracing
#endif

    // displays pin connection information

#ifdef DEBUG
    void DisplayPinInfo(IPin *pReceivePin);
    void DisplayTypeInfo(IPin *pPin, const CMediaType *pmt);
#else
    void DisplayPinInfo(IPin *pReceivePin) {};
    void DisplayTypeInfo(IPin *pPin, const CMediaType *pmt) {};
#endif

    // used to agree a media type for a pin connection

    // given a specific media type, attempt a connection (includes
    // checking that the type is acceptable to this pin)
    HRESULT
    AttemptConnection(
        IPin* pReceivePin,      // connect to this pin
        const CMediaType* pmt   // using this type
    );

    // try all the media types in this enumerator - for each that
    // we accept, try to connect using ReceiveConnection.
    HRESULT TryMediaTypes(
                        IPin *pReceivePin,      // connect to this pin
                        const CMediaType *pmt,        // proposed type from Connect
                        IEnumMediaTypes *pEnum);    // try this enumerator

    // establish a connection with a suitable mediatype. Needs to
    // propose a media type if the pmt pointer is null or partially
    // specified - use TryMediaTypes on both our and then the other pin's
    // enumerator until we find one that works.
    HRESULT AgreeMediaType(
                        IPin *pReceivePin,      // connect to this pin
                        const CMediaType *pmt);       // proposed type from Connect

public:

    CBasePin(
        TCHAR *pObjectName,         // Object description
        CBaseFilter *pFilter,       // Owning filter who knows about pins
        CCritSec *pLock,            // Object who implements the lock
        HRESULT *phr,               // General OLE return code