#ifndef STK_RTWVIN_H #define STK_RTWVIN_H #include "WvIn.h" #include "RtAudio.h" #include "Mutex.h" namespace stk { /***************************************************/ /*! \class RtWvIn \brief STK realtime audio (blocking) input class. This class provides a simplified interface to RtAudio for realtime audio input. It is a subclass of WvIn. This class makes use of RtAudio's callback functionality by creating a large ring-buffer from which data is read. This class should not be used when low-latency is desired. RtWvIn supports multi-channel data in both interleaved and non-interleaved formats. It is important to distinguish the tick() method that computes a single frame (and returns only the specified sample of a multi-channel frame) from the overloaded one that takes an StkFrames object for multi-channel and/or multi-frame data. by Perry R. Cook and Gary P. Scavone, 1995-2011. */ /***************************************************/ class RtWvIn : public WvIn { public: //! Default constructor. /*! The default \e device argument value (zero) will select the default input device on your system. The first device enumerated by the underlying audio API is specified with a value of one. The default buffer size of RT_BUFFER_SIZE is defined in Stk.h. An StkError will be thrown if an error occurs duing instantiation. */ RtWvIn( unsigned int nChannels = 1, StkFloat sampleRate = Stk::sampleRate(), int device = 0, int bufferFrames = RT_BUFFER_SIZE, int nBuffers = 20 ); //! Class destructor. ~RtWvIn(); //! Start the audio input stream. /*! The stream is started automatically, if necessary, when a tick() or tickFrame() method is called. */ void start( void ); //! Stop the audio input stream. /*! It may be necessary to use this method to avoid audio underflow problems if you wish to temporarily stop audio input. */ void stop( void ); //! Return the specified channel value of the last computed frame. /*! For multi-channel files, use the lastFrame() function to get all values from the last computed frame. If the device is stopped, the returned value is 0.0. The \c channel argument must be less than the number of channels in the audio stream (the first channel is specified by 0). However, range checking is only performed if _STK_DEBUG_ is defined during compilation, in which case an out-of-range value will trigger an StkError exception. */ StkFloat lastOut( unsigned int channel = 0 ); //! Compute a sample frame and return the specified \c channel value. /*! For multi-channel files, use the lastFrame() function to get all values from the computed frame. If the device is "stopped", it is "started". The \c channel argument must be less than the number of channels in the audio stream (the first channel is specified by 0). However, range checking is only performed if _STK_DEBUG_ is defined during compilation, in which case an out-of-range value will trigger an StkError exception. */ StkFloat tick( unsigned int channel = 0 ); //! Fill the StkFrames argument with computed frames and return the same reference. /*! If the device is "stopped", it is "started". The number of channels in the StkFrames argument must equal the number of channels specified during instantiation. However, this is only checked if _STK_DEBUG_ is defined during compilation, in which case an incompatibility will trigger an StkError exception. */ StkFrames& tick( StkFrames& frames ); // This function is not intended for general use but must be // public for access from the audio callback function. void fillBuffer( void *buffer, unsigned int nFrames ); protected: RtAudio adc_; Mutex mutex_; bool stopped_; unsigned int readIndex_; unsigned int writeIndex_; unsigned int framesFilled_; }; inline StkFloat RtWvIn :: lastOut( unsigned int channel ) { #if defined(_STK_DEBUG_) if ( channel >= data_.channels() ) { oStream_ << "RtWvIn::lastOut(): channel argument and audio stream are incompatible!"; handleError( StkError::FUNCTION_ARGUMENT ); } #endif return lastFrame_[channel]; } } // stk namespace #endif