The Net: Ultimate Internet Guide/WWLCD1.ISO/mac/SiteBldr/AMOVIE/SDK/_SETUP/COMMON.Z/source.h

C/C++ Source or Header | 1996-04-01 | 5.4 KB | 163 lines

//==========================================================================;
//
//  THIS CODE AND INFORMATION IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY
//  KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
//  IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A PARTICULAR
//  PURPOSE.
//
//  Copyright (c) 1992 - 1996  Microsoft Corporation.  All Rights Reserved.
//
//--------------------------------------------------------------------------;

// Classes to simplify creation of ActiveX source filters that support
// continuous generation of data. It provides no support for IMediaControl
// or IMediaPosition
//
// Derive your source filter from CSource.
// During construction either:
//    Create some CSourceStream objects to manage your pins
//    Provide the user with a means of doing so eg, an IPersistFile interface.
//
// CSource provides:
//    IFilter interface management
//    IMediaFilter interface management, via CBaseFilter
//    Pin counting for CBaseFilter
//
// Derive a class from CSourceStream to manage your output pin types
//  Implement GetMediaType/1 to return the type you support. If you support multiple
//   types then overide GetMediaType/3, CheckMediaType and GetMediaTypeCount.
//  Implement Fillbuffer() to put data into one buffer.
//
// CSourceStream provides:
//    IPin management via CBaseOutputPin
//    Worker thread management

#ifndef __CSOURCE__
#define __CSOURCE__

class CSourceStream;  // The class that will handle each pin


//
// CSource
//
// Override construction to provide a means of creating
// CSourceStream derived objects - ie a way of creating pins.
class CSource : public CBaseFilter {
public:

    CSource(TCHAR *pName, LPUNKNOWN lpunk, CLSID clsid, HRESULT *phr);
    ~CSource();

    int       GetPinCount(void);
    CBasePin *GetPin(int n);

    STDMETHODIMP FindPin(LPCWSTR Id, IPin **ppPin);

    int FindPinNumber(IPin *iPin);

    // -- Utilities --

    CCritSec*    pStateLock(void) { return &m_cStateLock; }    // provide our critical section

    HRESULT     AddPin(CSourceStream *);
    HRESULT     RemovePin(CSourceStream *);

protected:

    int             m_iPins;       // The number of pins on this filter. Updated by CSourceStream
                          // constructors & destructors.
    CSourceStream **m_paStreams;   // the pins on this filter.

    CCritSec m_cStateLock;    // Lock this to serialize function accesses to the filter state

};


//
// CSourceStream
//
// Use this class to manage a stream of data that comes from a
// pin.
// Uses a worker thread to put data on the pin.
class CSourceStream : public CThread, public CBaseOutputPin {
public:

    CSourceStream(TCHAR *pObjectName,
                  HRESULT *phr,
                  CSource *pms,
                  LPCWSTR pName);

    virtual ~CSourceStream(void);  // virtual destructor ensures derived class destructors are called too.

protected:

    CSource *m_pFilter;    // The parent of this stream

    // should it be a STDMETHODIMP???
    STDMETHODIMP QueryId(LPWSTR *Id);

    // *
    // * Data Source
    // *
    // * The following three functions: FillBuffer, OnThreadCreate/Destroy, are
    // * called from within the ThreadProc. They are used in the creation of
    // * the media samples this pin will provide
    // *

    // Override this to provide the worker thread a means
    // of processing a buffer
    virtual HRESULT FillBuffer(IMediaSample *pSamp) PURE;

    // Called as the thread is created/destroyed - use to perform
    // jobs such as start/stop streaming mode
    // If OnThreadCreate returns an error the thread will exit.
    virtual HRESULT OnThreadCreate(void) {return NOERROR;};
    virtual HRESULT OnThreadDestroy(void) {return NOERROR;};
    virtual HRESULT OnThreadStartPlay(void) {return NOERROR;};

    // *
    // * Worker Thread
    // *

    HRESULT Active(void);    // Starts up the worker thread
    HRESULT Inactive(void);  // Exits the worker thread.

public:
    // thread commands
    enum Command {CMD_INIT, CMD_PAUSE, CMD_RUN, CMD_STOP, CMD_EXIT};
    HRESULT Init(void) { return CallWorker(CMD_INIT); }
    HRESULT Exit(void) { return CallWorker(CMD_EXIT); }
    HRESULT Run(void) { return CallWorker(CMD_RUN); }
    HRESULT Pause(void) { return CallWorker(CMD_PAUSE); }
    HRESULT Stop(void) { return CallWorker(CMD_STOP); }

protected:
    Command GetRequest(void) { return (Command) CThread::GetRequest(); }
    BOOL    CheckRequest(Command *pCom) { return CThread::CheckRequest( (DWORD *) pCom); }

    // override these if you want to add thread commands
    virtual DWORD ThreadProc(void);          // the thread function

    virtual HRESULT DoBufferProcessingLoop(void);    // the loop executed whilst running


    // *
    // * AM_MEDIA_TYPE support
    // *

    // If you support more than one media type then override these 2 functions
    virtual HRESULT CheckMediaType(const CMediaType *pMediaType);
    virtual HRESULT GetMediaType(int iPosition, CMediaType *pMediaType);  // List pos. 0-n

    // If you support only one type then override this fn.
    // This will only be called by the default implementations
    // of CheckMediaType and GetMediaType(int, CMediaType*)
    // You must override this fn. or the above 2!
    virtual HRESULT GetMediaType(CMediaType *pMediaType) {return E_UNEXPECTED;}

};

#endif // __CSOURCE__