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RtAudio.h

Go to the documentation of this file.

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

// RtAudio: Version 4.0

#ifndef __RTAUDIO_H
#define __RTAUDIO_H

#include <string>
#include <vector>
#include "RtError.h"

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;   // Lower 3 bytes of 32-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.

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 );


// **************************************************************** //
//
// 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
{
 public:

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

  struct DeviceInfo {
    bool probed;                  
    std::string name;             
    unsigned int outputChannels;  
    unsigned int inputChannels;   
    unsigned int duplexChannels;  
    bool isDefaultOutput;         
    bool isDefaultInput;          
    std::vector<unsigned int> sampleRates; 
    RtAudioFormat nativeFormats;  
    // Default constructor.
    DeviceInfo()
      :probed(false), outputChannels(0), inputChannels(0), duplexChannels(0),
       isDefaultOutput(false), isDefaultInput(false), nativeFormats(0) {}
  };

  struct StreamParameters {
    unsigned int deviceId;     
    unsigned int nChannels;    
    unsigned int firstChannel; 
    // Default constructor.
    StreamParameters()
      : deviceId(0), nChannels(0), firstChannel(0) {}
  };


  struct StreamOptions {
    RtAudioStreamFlags flags;      
    unsigned int numberOfBuffers;  
    std::string streamName;        
    // Default constructor.
    StreamOptions()
      : flags(0), numberOfBuffers(0) {}
  };


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


  RtAudio( RtAudio::Api api=UNSPECIFIED ) throw();


  ~RtAudio() throw();

  RtAudio::Api getCurrentApi( void ) throw();


  unsigned int getDeviceCount( void ) throw();


  RtAudio::DeviceInfo getDeviceInfo( unsigned int device );


  unsigned int getDefaultOutputDevice( void ) throw();


  unsigned int getDefaultInputDevice( void ) throw();


  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 );


  void closeStream( void ) throw();


  void startStream( void );


  void stopStream( void );


  void abortStream( void );

  bool isStreamOpen( void ) throw();

  bool isStreamRunning( void ) throw();


  double getStreamTime( void );


  long getStreamLatency( void );

  void showWarnings( bool value = true ) throw();

 protected:

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

// Operating system dependent thread functionality.
#if defined(__WINDOWS_DS__) || defined(__WINDOWS_ASIO__)
  #include <windows.h>
  #include <process.h>

  typedef unsigned long ThreadHandle;
  typedef CRITICAL_SECTION StreamMutex;

#elif defined(__LINUX_ALSA__) || defined(__UNIX_JACK__) || defined(__LINUX_OSS__) || defined(__MACOSX_CORE__)
  // Using pthread library for various flavors of unix.
  #include <pthread.h>

  typedef pthread_t ThreadHandle;
  typedef pthread_mutex_t StreamMutex;

#else // Setup for "dummy" behavior

  #define __RTAUDIO_DUMMY__
  typedef int ThreadHandle;
  typedef int StreamMutex;

#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 *apiInfo;   // void pointer for API specific callback information
  bool isRunning;

  // Default constructor.
  CallbackInfo()
    :object(0), callback(0), userData(0), apiInfo(0), isRunning(false) {}
};

// **************************************************************** //
//
// 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, RtApiAl, RtApiDs, or RtApiAsio).
//
// **************************************************************** //

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

#include <sstream>

class 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 );
  virtual void closeStream( void );
  virtual void startStream( void ) = 0;
  virtual void stopStream( void ) = 0;
  virtual void abortStream( void ) = 0;
  long getStreamLatency( void );
  virtual double getStreamTime( void );
  bool isStreamOpen( void ) { return stream_.state != STREAM_CLOSED; };
  bool isStreamRunning( void ) { 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_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) {}
  };

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

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

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

  // 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 undesireable 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 );
  static const char* getErrorCode( OSStatus code );
};

#endif

#if defined(__UNIX_JACK__)

class RtApiJack: public RtApi
{
public:

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

  // 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 undesireable 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 );
};

#endif

#if defined(__WINDOWS_ASIO__)

class RtApiAsio: public RtApi
{
public:

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

  // 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 undesireable results!
  bool callbackEvent( long bufferIndex );

  private:

  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 );
};

#endif

#if defined(__WINDOWS_DS__)

class RtApiDs: public RtApi
{
public:

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

  // 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 undesireable results!
  void callbackEvent( void );

  private:

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

#endif

#if defined(__LINUX_ALSA__)

class RtApiAlsa: public RtApi
{
public:

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

  // 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 undesireable 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 );
};

#endif

#if defined(__LINUX_OSS__)

class RtApiOss: public RtApi
{
public:

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

  // 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 undesireable 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 );
};

#endif

#if defined(__RTAUDIO_DUMMY__)

class RtApiDummy: public RtApi
{
public:

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

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©2001-2007 Gary P. Scavone, McGill University. All Rights Reserved. Maintained by Gary P. Scavone.