audunix.h

linux下的一款播放器

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 * Source last modified: $Id: audUnix.h,v 1.2.50.1 2004/07/09 02:02:00 hubbe Exp $
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#ifndef _AUDUNIX
#define _AUDUNIX

#include "hxengin.h"
#include "hxcom.h"
#include "hxausvc.h"
#include "auderrs.h"
#include "hxaudev.h"
#include "hxaudply.h"

#if defined(_THREADED_AUDIO) && defined(_UNIX_THREADS_SUPPORTED)
#  include "unix/UnixThreads.h"
#  define LOCK(a)   if( m_bUserWantsThreads) (a)->Lock()
#  define UNLOCK(a) if( m_bUserWantsThreads) (a)->Unlock()
#else
#  define LOCK(a)   
#  define UNLOCK(a)
#endif

#define MAX_DEV_NAME 255


class CAudioOutUNIX : public CHXAudioDevice
{
  public:
    CAudioOutUNIX();
    
    //How big can device names be under UNIX?
    
    //-1 is usually considered to be no file descriptor.
    static const int NO_FILE_DESCRIPTOR;

    static const int MAX_VOLUME;
    
    // Used to indicate the current exported state of the virtual audio device.
    typedef enum audio_state
    {
        RA_AOS_CLOSED,          // Normal non-playing state
        RA_AOS_OPENING,         // Opened, before first audio buffer play b
        RA_AOS_OPEN_PAUSED,     // Opened and paused
        RA_AOS_OPEN_PLAYING,    // Opened and after first audio buffer play begins
        RA_AOS_CLOSING          // We've been told to close after audio fin
    } AUDIOSTATE;
    
    inline BOOL IsOpen() const { return (m_wState==RA_AOS_OPEN_PLAYING || m_wState==RA_AOS_OPEN_PAUSED);}
    
    // Create friend class for scheduled playback callback.
    class HXPlaybackCountCB : public IHXCallback
    {
      private:
        BOOL           m_timed;
        LONG32         m_lRefCount;
        CAudioOutUNIX* m_pAudioDeviceObject;
        
        virtual ~HXPlaybackCountCB();
        PRIVATE_DESTRUCTORS_ARE_NOT_A_CRIME
      public:
        //Ctors
        HXPlaybackCountCB(CAudioOutUNIX* object, BOOL timed = TRUE) :
            m_timed(timed),
            m_lRefCount(0),
            m_pAudioDeviceObject( object )
        {};

        //IUnkown methods
        STDMETHOD(QueryInterface)   (THIS_ REFIID riid, void** ppvObj);
        STDMETHOD_(ULONG32,AddRef)  (THIS);
        STDMETHOD_(ULONG32,Release) (THIS);
        
        //IHXCallback methods
        STDMETHOD(Func) (THIS);
    };
    friend class CAudioOutUNIX::HXPlaybackCountCB;

    //To get the last return code.
    HX_RESULT GetLastError() const { return m_wLastError; }
    
  protected:

    //--------------------------------------------------
    // NON-DEVICE SPECIFIC METHODS
    //--------------------------------------------------
    virtual ~CAudioOutUNIX();
    
    HX_RESULT _Imp_Open( const HXAudioFormat* pFormat );         //Implemented.
    HX_RESULT _Imp_Close( void );                                 //Implemented.
    HX_RESULT _Imp_Write( const HXAudioData* pAudioOutHdr );     //Implemented.
    HX_RESULT _Imp_Reset( void );                                 //Implemented.
    HX_RESULT _Imp_Drain( void );                                 //Implemented.
    HX_RESULT _Imp_SetVolume( const UINT16 uVolume );             //Implemented.
    HX_RESULT _Imp_GetCurrentTime( ULONG32& ulCurrentTime);       //Implemented.
    BOOL      _Imp_SupportsVolume( void );                        //Implemented.
    UINT16    _Imp_GetVolume( void );                             //Implemented.

    //Not used but defined in CHXAudioDevice as pure virtual.
    UINT16    _NumberOfBlocksRemainingToPlay(void);               //Implemented.
    void      _initAfterContext();                                //Implemented.

    //-------------------------------------------
    // DEVICE SPECIFIC METHODS.
    //-------------------------------------------
    virtual HX_RESULT _Imp_Seek(ULONG32 ulSeekTime); //default provided
    virtual HX_RESULT _Imp_Resume( void );           //default provided
    virtual HX_RESULT _Imp_Pause( void );            //default provided
    virtual HX_RESULT _Imp_CheckFormat( const HXAudioFormat* pFormat); //default provided.

    //Device specific methods to Pause/Resume the device. If a device can't handle
    //the pause/resume in hardware then it must return RA_AOE_NOTSUPPORTED, the
    //default. In this case we use a 'rollback' method.
    virtual HX_RESULT _Pause();                     //default provided.  
    virtual HX_RESULT _Resume();                    //default provided.  

    //Now a couple of routines to help us determine the type
    //of hardware device we are dealing with.
    
    //A method to determine if the audio devices file descriptor,
    //if it has one, should be added to the client core's select loop.
    //The default implementation is 'yes it should be added'.
    virtual BOOL _IsSelectable() const;

    //A mehtod to let us know if the hardware supports puase/resume.
    //We can use this to remove unneeded memcpys and other expensive
    //operations. The default implementation is 'No, not supported'.
    virtual BOOL _HardwarePauseSupported() const;

    //The Imp_Write method just fills up our write list. This method
    //is the one that actually sends the data to the audio device.
    ULONG32 _PushBits();

#if defined(_THREADED_AUDIO) && defined(_UNIX_THREADS_SUPPORTED)
    //-------------------------------------------------------
    // Thread support.
    //-------------------------------------------------------
    static void* AudioThread( void *thisPointer );
#endif    
    
    
    //-------------------------------------------------------
    // These Device Specific methods must be implemented 
    // by the platform specific sub-classes.
    //-------------------------------------------------------

    //What should we do if there are no file descriptors?
    virtual INT16 _Imp_GetAudioFd(void) = 0;
        
    //Device specific method to return number of bytes played.
    //default implementation is to do a low precision calculation
    //to compute an estimate. Device capable of computing this 
    //acturatly will override this method. This should never 
    //return a number greater than m_ulTotalWritten.
    virtual UINT64 _GetBytesActualyPlayed(void) const =0;

    //Device specific method to set the audio device characteristics. Sample rate,
    //bits-per-sample, etc.
    //Method *must* set member vars. m_unSampleRate, m_unNumChannels and
    //m_ulDeviceBufferSize.
    virtual HX_RESULT _SetDeviceConfig( const HXAudioFormat* pFormat ) = 0;

    //Device specific method to test whether or not the device supports the
    //given format. If the device can not be opened, or otherwise tested,
    //it should return RA_AOE_DEVBUSY.
    virtual HX_RESULT _CheckFormat( const HXAudioFormat* pFormat );//default imp just returns OK.

    //deprecated.....
    virtual HX_RESULT _CheckSampleRate( ULONG32 ulSampleRate ) = 0;

    //Device specific method to write bytes out to the audiodevice and return a
    //count of bytes written. 
    virtual HX_RESULT _WriteBytes( UCHAR* buffer, ULONG32 ulBuffLength, LONG32& lCount ) = 0;

    //Device specific methods to open/close the mixer and audio devices.
    virtual HX_RESULT _OpenAudio() = 0;
    virtual HX_RESULT _CloseAudio() = 0;
    virtual HX_RESULT _OpenMixer() = 0;
    virtual HX_RESULT _CloseMixer() = 0;

    //Device specific method to reset device and return it to a state that it 
    //can accept new sample rates, num channels, etc.
    virtual HX_RESULT _Reset() = 0;            

    //Device specific method to get/set the devices current volume.
    virtual UINT16    _GetVolume() const = 0;
    virtual HX_RESULT _SetVolume(UINT16 volume) = 0;

    //Device specific method to drain a device. This should play the remaining
    //bytes in the devices buffer and then return.
    virtual HX_RESULT _Drain() = 0;

    //Device specific method to return the amount of room available on the
    //audio device that can be written without blocking.
    virtual HX_RESULT _GetRoomOnDevice( ULONG32& ulBytes ) const = 0;

    //--------------------------------------------------
    // Other stuff.
    //--------------------------------------------------
    void      DoTimeSyncs(void);
    HX_RESULT ReschedPlaybackCheck(void);
    HXPlaybackCountCB* m_pCallback;
    
    AUDIOSTATE        m_wState;               // This is 
    BOOL              m_bMixerPresent;
    UINT16            m_wBlockSize;
    UINT64            m_ulLastNumBytes;       // Number of bytes played back since last open
    BOOL              m_bFirstWrite;          // First write
    UINT64            m_ulTotalWritten;       // Total bytes written
    Timeval*          m_pPlaybackCountCBTime;
    ULONG32           m_PendingCallbackID;    // Used for fake time sync
    BOOL              m_bCallbackPending;     // Used for fake time sync

    CHXSimpleList*    m_pWriteList;
    UINT32            m_unSampleRate;
    UINT32            m_unNumChannels;
    mutable HX_RESULT m_wLastError;           // The last error d

    //Some member vars to help keep track of data that is currently
    //in the device. We use this do a smart Pause/Resume for those
    //devices that can't do it in hardware.
    //block size is in audUNIX::m_wBlockSize

    //here is the buffer list to keep a copy of the data in the
    //device. We need to keep as many buffers, at m_wBlockSize in
    //size each, to cover the entire data space of the device.
    //CHXAudioDevice passes in chunks of size m_wBlockSize.
    //The device holds fragment_size*num_fragments as reported by
    //the device after it has had a chance to compute the frag size.
    //This occurs AFTER the other qualities like sample size, sample
    //rate have already been set.
    ULONG32 m_ulDeviceBufferSize; 
    UCHAR*  m_pRollbackBuffer;
    

#if defined(_THREADED_AUDIO) && defined(_UNIX_THREADS_SUPPORTED)
    //
    // Audio thread support
    //
    // Mutext to protect the writelist and the play state of this
    // device.
    HXMutex*  m_mtxWriteListPlayStateLock;
    HXMutex*  m_mtxDeviceStateLock;
    HXThread* m_audioThread;
    BOOL       m_bUserWantsThreads;
    ULONG32    m_ulSleepTime;
#endif    
    
  private:
    
    //protect the unintentional copy ctor.
    CAudioOutUNIX( const CAudioOutUNIX& );
};

#endif  //_AudioOutUNIX