MyAudio.cpp

//
// MyAudio.cpp
// stkExample
//
// Created by Jorge Herrera on 2011-10-26.
//
// ------------------
// Class to abstract audio stream
// IMPORTANT: it will quit the app if it can't setup or start!!!


#include "MyAudio.h"
#include <iostream>
#include <cstdlib>

// constructor
MyAudio::MyAudio( unsigned int nChann, float sr, unsigned int buffSize, RtAudioFormat format )
{
  m_audio = NULL;
  m_numChannels = nChann;
  m_sampleRate = sr;
  m_bufferSize = buffSize;
  m_format = format;
}

// destructor
MyAudio::~MyAudio()
{
  if( m_audio )
  {
    stop();
    delete m_audio;
  }
}

// RtAudio configuration
void MyAudio::setup( RtAudioCallback callback, void * userData )
{
  if( !callback )
  {
    std::cerr << "No callback provided!" << std::endl;
    exit(1);
  }

  try
  {
    m_audio = new RtAudio();
  }
  catch( RtError & err ) {
    err.printMessage();
    exit(1);
  }

  if( m_audio->getDeviceCount() < 1 )
  {
    // nopes
    std::cout << "no audio devices found!" << std::endl;
    exit(1);
  }

  // let RtAudio print messages to stderr.
  m_audio->showWarnings( true );

  // set input and output parameters
  RtAudio::StreamParameters iParams, oParams;
  iParams.deviceId = m_audio->getDefaultInputDevice();
  iParams.nChannels = m_numChannels;
  iParams.firstChannel = 0;
  oParams.deviceId = m_audio->getDefaultOutputDevice();
  oParams.nChannels = m_numChannels;
  oParams.firstChannel = 0;

  // set the callback and start stream
  try
  {
    m_audio->openStream( &oParams,
        &iParams,
        m_format,
        m_sampleRate,
        &m_bufferSize,
        callback,
        userData);

    std::cerr << "Buffer size defined by RtAudio: " << m_bufferSize << std::endl;
  }
  catch( RtError & err )
  {
    err.printMessage();
    exit(1);
  }

}

// start audio stream
void MyAudio::start()
{
  try
  {
    m_audio->startStream();
    // test RtAudio functionality for reporting latency.
    std::cout << "stream latency: " << m_audio->getStreamLatency() << " frames" << std::endl;
  }
  catch( RtError & err )
  {
    err.printMessage();
    exit(1);
  }
}

// stop audio stream
void MyAudio::stop()
{
  if( m_audio )
  {
    if ( m_audio->isStreamRunning() ) m_audio->stopStream();
    if ( m_audio->isStreamOpen() ) m_audio->closeStream();
  }
}