src/filters/BaseClasses/source.h

   1 //------------------------------------------------------------------------------
   2 // File: Source.h
   3 //
   4 // Desc: DirectShow base classes - defines classes to simplify creation of
   5 //       ActiveX source filters that support continuous generation of data.
   6 //       No support is provided for IMediaControl or IMediaPosition.
   7 //
   8 // Copyright (c) 1992-2002 Microsoft Corporation.  All rights reserved.
   9 //------------------------------------------------------------------------------
  10
  11
  12 //
  13 // Derive your source filter from CSource.
  14 // During construction either:
  15 //    Create some CSourceStream objects to manage your pins
  16 //    Provide the user with a means of doing so eg, an IPersistFile interface.
  17 //
  18 // CSource provides:
  19 //    IBaseFilter interface management
  20 //    IMediaFilter interface management, via CBaseFilter
  21 //    Pin counting for CBaseFilter
  22 //
  23 // Derive a class from CSourceStream to manage your output pin types
  24 //  Implement GetMediaType/1 to return the type you support. If you support multiple
  25 //   types then overide GetMediaType/3, CheckMediaType and GetMediaTypeCount.
  26 //  Implement Fillbuffer() to put data into one buffer.
  27 //
  28 // CSourceStream provides:
  29 //    IPin management via CBaseOutputPin
  30 //    Worker thread management
  31
  32 #ifndef __CSOURCE__
  33 #define __CSOURCE__
  34
  35 class CSourceStream;  // The class that will handle each pin
  36
  37
  38 //
  39 // CSource
  40 //
  41 // Override construction to provide a means of creating
  42 // CSourceStream derived objects - ie a way of creating pins.
  43 class CSource : public CBaseFilter {
  44 public:
  45
  46     CSource(TCHAR *pName, LPUNKNOWN lpunk, CLSID clsid, HRESULT *phr);
  47     CSource(TCHAR *pName, LPUNKNOWN lpunk, CLSID clsid);
  48 #ifdef UNICODE
  49     CSource(CHAR *pName, LPUNKNOWN lpunk, CLSID clsid, HRESULT *phr);
  50     CSource(CHAR *pName, LPUNKNOWN lpunk, CLSID clsid);
  51 #endif
  52     ~CSource();
  53
  54     int       GetPinCount(void);
  55     CBasePin *GetPin(int n);
  56
  57     // -- Utilities --
  58
  59     CCritSec*   pStateLock(void) { return &m_cStateLock; }      // provide our critical section
  60
  61     HRESULT     AddPin(CSourceStream *);
  62     HRESULT     RemovePin(CSourceStream *);
  63
  64     STDMETHODIMP FindPin(
  65         LPCWSTR Id,
  66         IPin ** ppPin
  67     );
  68
  69     int FindPinNumber(IPin *iPin);
  70
  71 protected:
  72
  73     int             m_iPins;       // The number of pins on this filter. Updated by CSourceStream
  74                                    // constructors & destructors.
  75     CSourceStream **m_paStreams;   // the pins on this filter.
  76
  77     CCritSec m_cStateLock;      // Lock this to serialize function accesses to the filter state
  78
  79 };
  80
  81
  82 //
  83 // CSourceStream
  84 //
  85 // Use this class to manage a stream of data that comes from a
  86 // pin.
  87 // Uses a worker thread to put data on the pin.
  88 class CSourceStream : public CAMThread, public CBaseOutputPin {
  89 public:
  90
  91     CSourceStream(TCHAR *pObjectName,
  92                   HRESULT *phr,
  93                   CSource *pms,
  94                   LPCWSTR pName);
  95 #ifdef UNICODE
  96     CSourceStream(CHAR *pObjectName,
  97                   HRESULT *phr,
  98                   CSource *pms,
  99                   LPCWSTR pName);
 100 #endif
 101     virtual ~CSourceStream(void);  // virtual destructor ensures derived class destructors are called too.
 102
 103 protected:
 104
 105     CSource *m_pFilter; // The parent of this stream
 106
 107     // *
 108     // * Data Source
 109     // *
 110     // * The following three functions: FillBuffer, OnThreadCreate/Destroy, are
 111     // * called from within the ThreadProc. They are used in the creation of
 112     // * the media samples this pin will provide
 113     // *
 114
 115     // Override this to provide the worker thread a means
 116     // of processing a buffer
 117     virtual HRESULT FillBuffer(IMediaSample *pSamp) PURE;
 118
 119     // Called as the thread is created/destroyed - use to perform
 120     // jobs such as start/stop streaming mode
 121     // If OnThreadCreate returns an error the thread will exit.
 122     virtual HRESULT OnThreadCreate(void) {return NOERROR;};
 123     virtual HRESULT OnThreadDestroy(void) {return NOERROR;};
 124     virtual HRESULT OnThreadStartPlay(void) {return NOERROR;};
 125
 126     // *
 127     // * Worker Thread
 128     // *
 129
 130     HRESULT Active(void);    // Starts up the worker thread
 131     HRESULT Inactive(void);  // Exits the worker thread.
 132
 133 public:
 134     // thread commands
 135     enum Command {CMD_INIT, CMD_PAUSE, CMD_RUN, CMD_STOP, CMD_EXIT};
 136     HRESULT Init(void) { return CallWorker(CMD_INIT); }
 137     HRESULT Exit(void) { return CallWorker(CMD_EXIT); }
 138     HRESULT Run(void) { return CallWorker(CMD_RUN); }
 139     HRESULT Pause(void) { return CallWorker(CMD_PAUSE); }
 140     HRESULT Stop(void) { return CallWorker(CMD_STOP); }
 141
 142 protected:
 143     Command GetRequest(void) { return (Command) CAMThread::GetRequest(); }
 144     BOOL    CheckRequest(Command *pCom) { return CAMThread::CheckRequest( (DWORD *) pCom); }
 145
 146     // override these if you want to add thread commands
 147     virtual DWORD ThreadProc(void);             // the thread function
 148
 149     virtual HRESULT DoBufferProcessingLoop(void);    // the loop executed whilst running
 150
 151
 152     // *
 153     // * AM_MEDIA_TYPE support
 154     // *
 155
 156     // If you support more than one media type then override these 2 functions
 157     virtual HRESULT CheckMediaType(const CMediaType *pMediaType);
 158     virtual HRESULT GetMediaType(int iPosition, CMediaType *pMediaType);  // List pos. 0-n
 159
 160     // If you support only one type then override this fn.
 161     // This will only be called by the default implementations
 162     // of CheckMediaType and GetMediaType(int, CMediaType*)
 163     // You must override this fn. or the above 2!
 164     virtual HRESULT GetMediaType(CMediaType *pMediaType) {return E_UNEXPECTED;}
 165
 166     STDMETHODIMP QueryId(
 167         LPWSTR * Id
 168     );
 169 };
 170
 171 #endif // __CSOURCE__
 172