RtAudio.h

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/************************************************************************/
/************************************************************************/

#ifndef __RTAUDIO_H
#define __RTAUDIO_H

#define RTAUDIO_VERSION "5.2.0"

#if defined _WIN32 || defined __CYGWIN__
  #if defined(RTAUDIO_EXPORT)
    #define RTAUDIO_DLL_PUBLIC __declspec(dllexport)
  #else
    #define RTAUDIO_DLL_PUBLIC
  #endif
#else
  #if __GNUC__ >= 4
    #define RTAUDIO_DLL_PUBLIC __attribute__( (visibility( "default" )) )
  #else
    #define RTAUDIO_DLL_PUBLIC
  #endif
#endif

#include <string>
#include <vector>
#include <stdexcept>
#include <iostream>

typedef unsigned long RtAudioFormat;
static const RtAudioFormat RTAUDIO_SINT8 = 0x1;    // 8-bit signed integer.
static const RtAudioFormat RTAUDIO_SINT16 = 0x2;   // 16-bit signed integer.
static const RtAudioFormat RTAUDIO_SINT24 = 0x4;   // 24-bit signed integer.
static const RtAudioFormat RTAUDIO_SINT32 = 0x8;   // 32-bit signed integer.
static const RtAudioFormat RTAUDIO_FLOAT32 = 0x10; // Normalized between plus/minus 1.0.
static const RtAudioFormat RTAUDIO_FLOAT64 = 0x20; // Normalized between plus/minus 1.0.

typedef unsigned int RtAudioStreamFlags;
static const RtAudioStreamFlags RTAUDIO_NONINTERLEAVED = 0x1;    // Use non-interleaved buffers (default = interleaved).
static const RtAudioStreamFlags RTAUDIO_MINIMIZE_LATENCY = 0x2;  // Attempt to set stream parameters for lowest possible latency.
static const RtAudioStreamFlags RTAUDIO_HOG_DEVICE = 0x4;        // Attempt grab device and prevent use by others.
static const RtAudioStreamFlags RTAUDIO_SCHEDULE_REALTIME = 0x8; // Try to select realtime scheduling for callback thread.
static const RtAudioStreamFlags RTAUDIO_ALSA_USE_DEFAULT = 0x10; // Use the "default" PCM device (ALSA only).
static const RtAudioStreamFlags RTAUDIO_JACK_DONT_CONNECT = 0x20; // Do not automatically connect ports (JACK only).

typedef unsigned int RtAudioStreamStatus;
static const RtAudioStreamStatus RTAUDIO_INPUT_OVERFLOW = 0x1;    // Input data was discarded because of an overflow condition at the driver.
static const RtAudioStreamStatus RTAUDIO_OUTPUT_UNDERFLOW = 0x2;  // The output buffer ran low, likely causing a gap in the output sound.


typedef int (*RtAudioCallback)( void *outputBuffer, void *inputBuffer,
                                unsigned int nFrames,
                                double streamTime,
                                RtAudioStreamStatus status,
                                void *userData );

/************************************************************************/
/************************************************************************/

class RTAUDIO_DLL_PUBLIC RtAudioError : public std::runtime_error
{
 public:
  enum Type {
    WARNING,           
    DEBUG_WARNING,     
    UNSPECIFIED,       
    NO_DEVICES_FOUND,  
    INVALID_DEVICE,    
    MEMORY_ERROR,      
    INVALID_PARAMETER, 
    INVALID_USE,       
    DRIVER_ERROR,      
    SYSTEM_ERROR,      
    THREAD_ERROR       
  };

  RtAudioError( const std::string& message,
                Type type = RtAudioError::UNSPECIFIED )
    : std::runtime_error(message), type_(type) {}

  virtual void printMessage( void ) const
    { std::cerr << '\n' << what() << "\n\n"; }

  virtual const Type& getType(void) const { return type_; }

  virtual const std::string getMessage(void) const
    { return std::string(what()); }

 protected:
  Type type_;
};


typedef void (*RtAudioErrorCallback)( RtAudioError::Type type, const std::string &errorText );

// **************************************************************** //
//
// RtAudio class declaration.
//
// RtAudio is a "controller" used to select an available audio i/o
// interface.  It presents a common API for the user to call but all
// functionality is implemented by the class RtApi and its
// subclasses.  RtAudio creates an instance of an RtApi subclass
// based on the user's API choice.  If no choice is made, RtAudio
// attempts to make a "logical" API selection.
//
// **************************************************************** //

class RtApi;

class RTAUDIO_DLL_PUBLIC RtAudio
{
 public:

  enum Api {
    UNSPECIFIED,    
    LINUX_ALSA,     
    LINUX_PULSE,    
    LINUX_OSS,      
    UNIX_JACK,      
    MACOSX_CORE,    
    WINDOWS_WASAPI, 
    WINDOWS_ASIO,   
    WINDOWS_DS,     
    RTAUDIO_DUMMY,  
    NUM_APIS        
  };

  struct DeviceInfo {
    bool probed;                  
    std::string name;             
    unsigned int outputChannels{};  
    unsigned int inputChannels{};   
    unsigned int duplexChannels{};  
    bool isDefaultOutput{false};         
    bool isDefaultInput{false};          
    std::vector<unsigned int> sampleRates; 
    unsigned int preferredSampleRate{}; 
    RtAudioFormat nativeFormats{};  
  };

  struct StreamParameters {
    unsigned int deviceId{};     
    unsigned int nChannels{};    
    unsigned int firstChannel{}; 
  };


  struct StreamOptions {
    RtAudioStreamFlags flags{};      
    unsigned int numberOfBuffers{};  
    std::string streamName;        
    int priority{};                  
  };

  static std::string getVersion( void );


  static void getCompiledApi( std::vector<RtAudio::Api> &apis );


  static std::string getApiName( RtAudio::Api api );


  static std::string getApiDisplayName( RtAudio::Api api );


  static RtAudio::Api getCompiledApiByName( const std::string &name );


  RtAudio( RtAudio::Api api=UNSPECIFIED );


  ~RtAudio();

  RtAudio::Api getCurrentApi( void );


  unsigned int getDeviceCount( void );


  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );


  unsigned int getDefaultOutputDevice( void );


  unsigned int getDefaultInputDevice( void );


  void openStream( RtAudio::StreamParameters *outputParameters,
                   RtAudio::StreamParameters *inputParameters,
                   RtAudioFormat format, unsigned int sampleRate,
                   unsigned int *bufferFrames, RtAudioCallback callback,
                   void *userData = NULL, RtAudio::StreamOptions *options = NULL, RtAudioErrorCallback errorCallback = NULL );


  void closeStream( void );


  void startStream( void );


  void stopStream( void );


  void abortStream( void );

  bool isStreamOpen( void ) const;

  bool isStreamRunning( void ) const;


  double getStreamTime( void );


  void setStreamTime( double time );


  long getStreamLatency( void );


  unsigned int getStreamSampleRate( void );

  void showWarnings( bool value = true );

 protected:

  void openRtApi( RtAudio::Api api );
  RtApi *rtapi_;
};

// Operating system dependent thread functionality.
#if defined(_WIN32) || defined(__CYGWIN__)

  #ifndef NOMINMAX
    #define NOMINMAX
  #endif
  #include <windows.h>
  #include <process.h>
  #include <stdint.h>

  typedef uintptr_t ThreadHandle;
  typedef CRITICAL_SECTION StreamMutex;

#else

  // Using pthread library for various flavors of unix.
  #include <pthread.h>

  typedef pthread_t ThreadHandle;
  typedef pthread_mutex_t StreamMutex;

#endif

// Setup for "dummy" behavior if no apis specified.
#if !(defined(__WINDOWS_DS__) || defined(__WINDOWS_ASIO__) || defined(__WINDOWS_WASAPI__) \
      || defined(__LINUX_ALSA__) || defined(__LINUX_PULSE__) || defined(__UNIX_JACK__) \
      || defined(__LINUX_OSS__) || defined(__MACOSX_CORE__))

  #define __RTAUDIO_DUMMY__

#endif

// This global structure type is used to pass callback information
// between the private RtAudio stream structure and global callback
// handling functions.
struct CallbackInfo {
  void *object{};    // Used as a "this" pointer.
  ThreadHandle thread{};
  void *callback{};
  void *userData{};
  void *errorCallback{};
  void *apiInfo{};   // void pointer for API specific callback information
  bool isRunning{false};
  bool doRealtime{false};
  int priority{};
};

// **************************************************************** //
//
// RtApi class declaration.
//
// Subclasses of RtApi contain all API- and OS-specific code necessary
// to fully implement the RtAudio API.
//
// Note that RtApi is an abstract base class and cannot be
// explicitly instantiated.  The class RtAudio will create an
// instance of an RtApi subclass (RtApiOss, RtApiAlsa,
// RtApiJack, RtApiCore, RtApiDs, or RtApiAsio).
//
// **************************************************************** //

#pragma pack(push, 1)
class S24 {

 protected:
  unsigned char c3[3];

 public:
  S24() {}

  S24& operator = ( const int& i ) {
    c3[0] = (unsigned char)(i & 0x000000ff);
    c3[1] = (unsigned char)((i & 0x0000ff00) >> 8);
    c3[2] = (unsigned char)((i & 0x00ff0000) >> 16);
    return *this;
  }

  S24( const double& d ) { *this = (int) d; }
  S24( const float& f ) { *this = (int) f; }
  S24( const signed short& s ) { *this = (int) s; }
  S24( const char& c ) { *this = (int) c; }

  int asInt() {
    int i = c3[0] | (c3[1] << 8) | (c3[2] << 16);
    if (i & 0x800000) i |= ~0xffffff;
    return i;
  }
};
#pragma pack(pop)

#if defined( HAVE_GETTIMEOFDAY )
  #include <sys/time.h>
#endif

#include <sstream>

class RTAUDIO_DLL_PUBLIC RtApi
{
public:

  RtApi();
  virtual ~RtApi();
  virtual RtAudio::Api getCurrentApi( void ) = 0;
  virtual unsigned int getDeviceCount( void ) = 0;
  virtual RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) = 0;
  virtual unsigned int getDefaultInputDevice( void );
  virtual unsigned int getDefaultOutputDevice( void );
  void openStream( RtAudio::StreamParameters *outputParameters,
                   RtAudio::StreamParameters *inputParameters,
                   RtAudioFormat format, unsigned int sampleRate,
                   unsigned int *bufferFrames, RtAudioCallback callback,
                   void *userData, RtAudio::StreamOptions *options,
                   RtAudioErrorCallback errorCallback );
  virtual void closeStream( void );
  virtual void startStream( void ) = 0;
  virtual void stopStream( void ) = 0;
  virtual void abortStream( void ) = 0;
  long getStreamLatency( void );
  unsigned int getStreamSampleRate( void );
  virtual double getStreamTime( void );
  virtual void setStreamTime( double time );
  bool isStreamOpen( void ) const { return stream_.state != STREAM_CLOSED; }
  bool isStreamRunning( void ) const { return stream_.state == STREAM_RUNNING; }
  void showWarnings( bool value ) { showWarnings_ = value; }


protected:

  static const unsigned int MAX_SAMPLE_RATES;
  static const unsigned int SAMPLE_RATES[];

  enum { FAILURE, SUCCESS };

  enum StreamState {
    STREAM_STOPPED,
    STREAM_STOPPING,
    STREAM_RUNNING,
    STREAM_CLOSED = -50
  };

  enum StreamMode {
    OUTPUT,
    INPUT,
    DUPLEX,
    UNINITIALIZED = -75
  };

  // A protected structure used for buffer conversion.
  struct ConvertInfo {
    int channels;
    int inJump, outJump;
    RtAudioFormat inFormat, outFormat;
    std::vector<int> inOffset;
    std::vector<int> outOffset;
  };

  // A protected structure for audio streams.
  struct RtApiStream {
    unsigned int device[2];    // Playback and record, respectively.
    void *apiHandle;           // void pointer for API specific stream handle information
    StreamMode mode;           // OUTPUT, INPUT, or DUPLEX.
    StreamState state;         // STOPPED, RUNNING, or CLOSED
    char *userBuffer[2];       // Playback and record, respectively.
    char *deviceBuffer;
    bool doConvertBuffer[2];   // Playback and record, respectively.
    bool userInterleaved;
    bool deviceInterleaved[2]; // Playback and record, respectively.
    bool doByteSwap[2];        // Playback and record, respectively.
    unsigned int sampleRate;
    unsigned int bufferSize;
    unsigned int nBuffers;
    unsigned int nUserChannels[2];    // Playback and record, respectively.
    unsigned int nDeviceChannels[2];  // Playback and record channels, respectively.
    unsigned int channelOffset[2];    // Playback and record, respectively.
    unsigned long latency[2];         // Playback and record, respectively.
    RtAudioFormat userFormat;
    RtAudioFormat deviceFormat[2];    // Playback and record, respectively.
    StreamMutex mutex;
    CallbackInfo callbackInfo;
    ConvertInfo convertInfo[2];
    double streamTime;         // Number of elapsed seconds since the stream started.

#if defined(HAVE_GETTIMEOFDAY)
    struct timeval lastTickTimestamp;
#endif

    RtApiStream()
      :apiHandle(0), deviceBuffer(0) { device[0] = 11111; device[1] = 11111; }
  };

  typedef S24 Int24;
  typedef signed short Int16;
  typedef signed int Int32;
  typedef float Float32;
  typedef double Float64;

  std::ostringstream errorStream_;
  std::string errorText_;
  bool showWarnings_;
  RtApiStream stream_;
  bool firstErrorOccurred_;

  virtual bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                                unsigned int firstChannel, unsigned int sampleRate,
                                RtAudioFormat format, unsigned int *bufferSize,
                                RtAudio::StreamOptions *options );

  void tickStreamTime( void );

  void clearStreamInfo();

  void verifyStream( void );

  void error( RtAudioError::Type type );

  void convertBuffer( char *outBuffer, char *inBuffer, ConvertInfo &info );

  void byteSwapBuffer( char *buffer, unsigned int samples, RtAudioFormat format );

  unsigned int formatBytes( RtAudioFormat format );

  void setConvertInfo( StreamMode mode, unsigned int firstChannel );
};

// **************************************************************** //
//
// Inline RtAudio definitions.
//
// **************************************************************** //

inline RtAudio::Api RtAudio :: getCurrentApi( void ) { return rtapi_->getCurrentApi(); }
inline unsigned int RtAudio :: getDeviceCount( void ) { return rtapi_->getDeviceCount(); }
inline RtAudio::DeviceInfo RtAudio :: getDeviceInfo( unsigned int device ) { return rtapi_->getDeviceInfo( device ); }
inline unsigned int RtAudio :: getDefaultInputDevice( void ) { return rtapi_->getDefaultInputDevice(); }
inline unsigned int RtAudio :: getDefaultOutputDevice( void ) { return rtapi_->getDefaultOutputDevice(); }
inline void RtAudio :: closeStream( void ) { return rtapi_->closeStream(); }
inline void RtAudio :: startStream( void ) { return rtapi_->startStream(); }
inline void RtAudio :: stopStream( void )  { return rtapi_->stopStream(); }
inline void RtAudio :: abortStream( void ) { return rtapi_->abortStream(); }
inline bool RtAudio :: isStreamOpen( void ) const { return rtapi_->isStreamOpen(); }
inline bool RtAudio :: isStreamRunning( void ) const { return rtapi_->isStreamRunning(); }
inline long RtAudio :: getStreamLatency( void ) { return rtapi_->getStreamLatency(); }
inline unsigned int RtAudio :: getStreamSampleRate( void ) { return rtapi_->getStreamSampleRate(); }
inline double RtAudio :: getStreamTime( void ) { return rtapi_->getStreamTime(); }
inline void RtAudio :: setStreamTime( double time ) { return rtapi_->setStreamTime( time ); }
inline void RtAudio :: showWarnings( bool value ) { rtapi_->showWarnings( value ); }

// RtApi Subclass prototypes.

#if defined(__MACOSX_CORE__)

#include <CoreAudio/AudioHardware.h>

class RtApiCore: public RtApi
{
public:

  RtApiCore();
  ~RtApiCore();
  RtAudio::Api getCurrentApi( void ) override { return RtAudio::MACOSX_CORE; }
  unsigned int getDeviceCount( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  unsigned int getDefaultOutputDevice( void ) override;
  unsigned int getDefaultInputDevice( void ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  bool callbackEvent( AudioDeviceID deviceId,
                      const AudioBufferList *inBufferList,
                      const AudioBufferList *outBufferList );

  private:

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;
  static const char* getErrorCode( OSStatus code );
};

#endif

#if defined(__UNIX_JACK__)

class RtApiJack: public RtApi
{
public:

  RtApiJack();
  ~RtApiJack();
  RtAudio::Api getCurrentApi( void ) override { return RtAudio::UNIX_JACK; }
  unsigned int getDeviceCount( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  bool callbackEvent( unsigned long nframes );

  private:

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;

  bool shouldAutoconnect_;
};

#endif

#if defined(__WINDOWS_ASIO__)

class RtApiAsio: public RtApi
{
public:

  RtApiAsio();
  ~RtApiAsio();
  RtAudio::Api getCurrentApi( void ) override { return RtAudio::WINDOWS_ASIO; }
  unsigned int getDeviceCount( void ) override;
  unsigned int getDefaultOutputDevice( void ) override;
  unsigned int getDefaultInputDevice( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  bool callbackEvent( long bufferIndex );

  private:

  std::vector<RtAudio::DeviceInfo> devices_;
  void saveDeviceInfo( void );
  bool coInitialized_;
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;
};

#endif

#if defined(__WINDOWS_DS__)

class RtApiDs: public RtApi
{
public:

  RtApiDs();
  ~RtApiDs();
  RtAudio::Api getCurrentApi( void ) override { return RtAudio::WINDOWS_DS; }
  unsigned int getDeviceCount( void ) override;
  unsigned int getDefaultOutputDevice( void ) override;
  unsigned int getDefaultInputDevice( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  void callbackEvent( void );

  private:

  bool coInitialized_;
  bool buffersRolling;
  long duplexPrerollBytes;
  std::vector<struct DsDevice> dsDevices;
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;
};

#endif

#if defined(__WINDOWS_WASAPI__)

struct IMMDeviceEnumerator;

class RtApiWasapi : public RtApi
{
public:
  RtApiWasapi();
  virtual ~RtApiWasapi();

  RtAudio::Api getCurrentApi( void ) override { return RtAudio::WINDOWS_WASAPI; }
  unsigned int getDeviceCount( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

private:
  bool coInitialized_;
  IMMDeviceEnumerator* deviceEnumerator_;

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int* bufferSize,
                        RtAudio::StreamOptions* options ) override;

  static DWORD WINAPI runWasapiThread( void* wasapiPtr );
  static DWORD WINAPI stopWasapiThread( void* wasapiPtr );
  static DWORD WINAPI abortWasapiThread( void* wasapiPtr );
  void wasapiThread();
};

#endif

#if defined(__LINUX_ALSA__)

class RtApiAlsa: public RtApi
{
public:

  RtApiAlsa();
  ~RtApiAlsa();
  RtAudio::Api getCurrentApi() override { return RtAudio::LINUX_ALSA; }
  unsigned int getDeviceCount( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  void callbackEvent( void );

  private:

  std::vector<RtAudio::DeviceInfo> devices_;
  void saveDeviceInfo( void );
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;
};

#endif

#if defined(__LINUX_PULSE__)

class RtApiPulse: public RtApi
{
public:
  ~RtApiPulse();
  RtAudio::Api getCurrentApi() override { return RtAudio::LINUX_PULSE; }
  unsigned int getDeviceCount( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  void callbackEvent( void );

  private:

  void collectDeviceInfo( void );
  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels,
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;
};

#endif

#if defined(__LINUX_OSS__)

class RtApiOss: public RtApi
{
public:

  RtApiOss();
  ~RtApiOss();
  RtAudio::Api getCurrentApi() override { return RtAudio::LINUX_OSS; }
  unsigned int getDeviceCount( void ) override;
  RtAudio::DeviceInfo getDeviceInfo( unsigned int device ) override;
  void closeStream( void ) override;
  void startStream( void ) override;
  void stopStream( void ) override;
  void abortStream( void ) override;

  // This function is intended for internal use only.  It must be
  // public because it is called by the internal callback handler,
  // which is not a member of RtAudio.  External use of this function
  // will most likely produce highly undesirable results!
  void callbackEvent( void );

  private:

  bool probeDeviceOpen( unsigned int device, StreamMode mode, unsigned int channels, 
                        unsigned int firstChannel, unsigned int sampleRate,
                        RtAudioFormat format, unsigned int *bufferSize,
                        RtAudio::StreamOptions *options ) override;
};

#endif

#if defined(__RTAUDIO_DUMMY__)

class RtApiDummy: public RtApi
{
public:

  RtApiDummy() { errorText_ = "RtApiDummy: This class provides no functionality."; error( RtAudioError::WARNING ); }
  RtAudio::Api getCurrentApi( void ) override { return RtAudio::RTAUDIO_DUMMY; }
  unsigned int getDeviceCount( void ) override { return 0; }
  RtAudio::DeviceInfo getDeviceInfo( unsigned int /*device*/ ) override { RtAudio::DeviceInfo info; return info; }
  void closeStream( void ) override {}
  void startStream( void ) override {}
  void stopStream( void ) override {}
  void abortStream( void ) override {}

  private:

  bool probeDeviceOpen( unsigned int /*device*/, StreamMode /*mode*/, unsigned int /*channels*/, 
                        unsigned int /*firstChannel*/, unsigned int /*sampleRate*/,
                        RtAudioFormat /*format*/, unsigned int * /*bufferSize*/,
                        RtAudio::StreamOptions * /*options*/ ) override { return false; }
};

#endif

#endif

// Indentation settings for Vim and Emacs
//
// Local Variables:
// c-basic-offset: 2
// indent-tabs-mode: nil
// End:
//
// vim: et sts=2 sw=2