rtaudio/tests/playsaw.cpp

/******************************************/
/*
  playsaw.cpp
  by Gary P. Scavone, 2006

  This program will output sawtooth waveforms
  of different frequencies on each channel.
*/
/******************************************/

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

/*
typedef signed long  MY_TYPE;
#define FORMAT RTAUDIO_SINT24
#define SCALE  2147483647.0

typedef char  MY_TYPE;
#define FORMAT RTAUDIO_SINT8
#define SCALE  127.0
*/

typedef signed short  MY_TYPE;
#define FORMAT RTAUDIO_SINT16
#define SCALE  32767.0

/*
typedef signed long  MY_TYPE;
#define FORMAT RTAUDIO_SINT32
#define SCALE  2147483647.0

typedef float  MY_TYPE;
#define FORMAT RTAUDIO_FLOAT32
#define SCALE  1.0

typedef double  MY_TYPE;
#define FORMAT RTAUDIO_FLOAT64
#define SCALE  1.0
*/

#define BASE_RATE 0.005
#define TIME   1.0

void usage( void ) {
  // Error function in case of incorrect command-line
  // argument specifications
  std::cout << "\nuseage: playsaw N fs <device> <channelOffset>\n";
  std::cout << "    where N = number of channels,\n";
  std::cout << "    fs = the sample rate,\n";
  std::cout << "    device = optional device to use (default = 0),\n";
  std::cout << "    and channelOffset = an optional channel offset on the device (default = 0).\n\n";
  exit( 0 );
}

unsigned int channels;
RtAudio::StreamOptions options;

//#define USE_INTERLEAVED
#if defined( USE_INTERLEAVED )

// Interleaved buffers
int saw( void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames,
         double streamTime, RtAudioStreamStatus status, void *data )
{
  unsigned int i, j;
  extern unsigned int channels;
  MY_TYPE *buffer = (MY_TYPE *) outputBuffer;
  double *lastValues = (double *) data;

  if ( status )
    std::cout << "Stream underflow detected!" << std::endl;

  for ( i=0; i<nBufferFrames; i++ ) {
    for ( j=0; j<channels; j++ ) {
      *buffer++ = (MY_TYPE) (lastValues[j] * SCALE);
      lastValues[j] += BASE_RATE * (j+1+(j*0.1));
      if ( lastValues[j] >= 1.0 ) lastValues[j] -= 2.0;
    }
  }

  return 0;
}

#else // Use non-interleaved buffers

int saw( void *outputBuffer, void *inputBuffer, unsigned int nBufferFrames,
         double streamTime, RtAudioStreamStatus status, void *data )
{
  unsigned int i, j;
  extern unsigned int channels;
  MY_TYPE *buffer = (MY_TYPE *) outputBuffer;
  double *lastValues = (double *) data;

  if ( status )
    std::cout << "Stream underflow detected!" << std::endl;

  double increment;
  for ( j=0; j<channels; j++ ) {
    increment = BASE_RATE * (j+1+(j*0.1));
    for ( i=0; i<nBufferFrames; i++ ) {
      *buffer++ = (MY_TYPE) (lastValues[j] * SCALE);
      lastValues[j] += increment;
      if ( lastValues[j] >= 1.0 ) lastValues[j] -= 2.0;
    }
  }

  return 0;
}
#endif

int main( int argc, char *argv[] )
{
  unsigned int bufferFrames, fs, device = 0, offset = 0;

  // minimal command-line checking
  if (argc < 3 || argc > 5 ) usage();

  RtAudio dac;
  if ( dac.getDeviceCount() < 1 ) {
    std::cout << "\nNo audio devices found!\n";
    exit( 1 );
  }

  channels = (unsigned int) atoi( argv[1] );
  fs = (unsigned int) atoi( argv[2] );
  if ( argc > 3 )
    device = (unsigned int) atoi( argv[3] );
  if ( argc > 4 )
    offset = (unsigned int) atoi( argv[4] );

  double *data = (double *) calloc( channels, sizeof( double ) );

  // Let RtAudio print messages to stderr.
  dac.showWarnings( true );

  // Set our stream parameters for output only.
  bufferFrames = 256;
  RtAudio::StreamParameters oParams;
  oParams.deviceId = device;
  oParams.nChannels = channels;
  oParams.firstChannel = offset;

  options.flags |= RTAUDIO_HOG_DEVICE;
  options.flags |= RTAUDIO_SCHEDULE_REALTIME;
#if !defined( USE_INTERLEAVED )
  options.flags |= RTAUDIO_NONINTERLEAVED;
#endif
  try {
    dac.openStream( &oParams, NULL, FORMAT, fs, &bufferFrames, &saw, (void *)data, &options );
    dac.startStream();
  }
  catch ( RtError& e ) {
    e.printMessage();
    goto cleanup;
  }

  char input;
  //std::cout << "Stream latency = " << dac.getStreamLatency() << "\n" << std::endl;
  std::cout << "\nPlaying ... press <enter> to quit (buffer size = " << bufferFrames << ").\n";
  std::cin.get( input );

  try {
    // Stop the stream
    dac.stopStream();
  }
  catch ( RtError& e ) {
    e.printMessage();
  }

 cleanup:
  if ( dac.isStreamOpen() ) dac.closeStream();
  free( data );

  return 0;
}