text: /** @file patest_buffer.c
  	@ingroup test_src
  	@brief Test opening streams with different buffer sizes.
  	@author Phil Burk  http://www.softsynth.com
  */
  /*
   * $Id: patest_buffer.c 1368 2008-03-01 00:38:27Z rossb $
   *
   * This program uses the PortAudio Portable Audio Library.
   * For more information see: http://www.portaudio.com
   * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
   *
   * Permission is hereby granted, free of charge, to any person obtaining
   * a copy of this software and associated documentation files
   * (the "Software"), to deal in the Software without restriction,
   * including without limitation the rights to use, copy, modify, merge,
   * publish, distribute, sublicense, and/or sell copies of the Software,
   * and to permit persons to whom the Software is furnished to do so,
   * subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be
   * included in all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
   * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
   * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
   * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   */
  
  /*
   * The text above constitutes the entire PortAudio license; however, 
   * the PortAudio community also makes the following non-binding requests:
   *
   * Any person wishing to distribute modifications to the Software is
   * requested to send the modifications to the original developer so that
   * they can be incorporated into the canonical version. It is also 
   * requested that these non-binding requests be included along with the 
   * license above.
   */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <math.h>
  #include "portaudio.h"
  #define NUM_SECONDS   (3)
  #define SAMPLE_RATE   (44100)
  #ifndef M_PI
  #define M_PI  (3.14159265)
  #endif
  #define TABLE_SIZE   (200)
  
  #define BUFFER_TABLE  14
  long buffer_table[] = {paFramesPerBufferUnspecified,16,32,64,128,200,256,500,512,600,723,1000,1024,2345};
  
  typedef struct
  {
      short sine[TABLE_SIZE];
      int left_phase;
      int right_phase;
      unsigned int sampsToGo;
  }
  paTestData;
  PaError TestOnce( int buffersize, PaDeviceIndex );
  
  /* This routine will be called by the PortAudio engine when audio is needed.
  ** It may called at interrupt level on some machines so don't do anything
  ** that could mess up the system like calling malloc() or free().
  */
  static int patest1Callback( const void *inputBuffer, void *outputBuffer,
                              unsigned long framesPerBuffer,
                              const PaStreamCallbackTimeInfo* timeInfo,
                              PaStreamCallbackFlags statusFlags,
                              void *userData )
  {
      paTestData *data = (paTestData*)userData;
      short *out = (short*)outputBuffer;
      unsigned int i;
      int finished = 0;
      (void) inputBuffer; /* Prevent "unused variable" warnings. */
  
      if( data->sampsToGo < framesPerBuffer )
      {
          /* final buffer... */
  
          for( i=0; i<data->sampsToGo; i++ )
          {
              *out++ = data->sine[data->left_phase];  /* left */
              *out++ = data->sine[data->right_phase];  /* right */
              data->left_phase += 1;
              if( data->left_phase >= TABLE_SIZE ) data->left_phase -= TABLE_SIZE;
              data->right_phase += 3; /* higher pitch so we can distinguish left and right. */
              if( data->right_phase >= TABLE_SIZE ) data->right_phase -= TABLE_SIZE;
          }
          /* zero remainder of final buffer */
          for( ; i<framesPerBuffer; i++ )
          {
              *out++ = 0; /* left */
              *out++ = 0; /* right */
          }
  
          finished = 1;
      }
      else
      {
          for( i=0; i<framesPerBuffer; i++ )
          {
              *out++ = data->sine[data->left_phase];  /* left */
              *out++ = data->sine[data->right_phase];  /* right */
              data->left_phase += 1;
              if( data->left_phase >= TABLE_SIZE ) data->left_phase -= TABLE_SIZE;
              data->right_phase += 3; /* higher pitch so we can distinguish left and right. */
              if( data->right_phase >= TABLE_SIZE ) data->right_phase -= TABLE_SIZE;
          }
          data->sampsToGo -= framesPerBuffer;
      }
      return finished;
  }
  
  /*******************************************************************/
  int main(int argc, char **args);
  int main(int argc, char **args)
  {
      int i;
      int device = -1;
      PaError err;
      printf("Test opening streams with different buffer sizes\n");
      if( argc > 1 ) {
         device=atoi( args[1] );
         printf("Using device number %d.\n\n", device );
      } else {
         printf("Using default device.\n\n" );
      }
  
      for (i = 0 ; i < BUFFER_TABLE; i++)
      {
          printf("Buffer size %ld\n", buffer_table[i]);
          err = TestOnce(buffer_table[i], device);
          if( err < 0 ) return 0;
  
      }
      return 0;
  }
  
  
  PaError TestOnce( int buffersize, PaDeviceIndex device )
  {
      PaStreamParameters outputParameters;
      PaStream *stream;
      PaError err;
      paTestData data;
      int i;
      int totalSamps;
      /* initialise sinusoidal wavetable */
      for( i=0; i<TABLE_SIZE; i++ )
      {
          data.sine[i] = (short) (32767.0 * sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. ));
      }
      data.left_phase = data.right_phase = 0;
      data.sampsToGo = totalSamps =  NUM_SECONDS * SAMPLE_RATE; /* Play for a few seconds. */
      err = Pa_Initialize();
      if( err != paNoError ) goto error;
      
      if( device == -1 )
          outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
      else
          outputParameters.device = device ;
  
      if (outputParameters.device == paNoDevice) {
        fprintf(stderr,"Error: No default output device.\n");
        goto error;
      }
  
      outputParameters.channelCount = 2;                      /* stereo output */
      outputParameters.sampleFormat = paInt16;                /* 32 bit floating point output */
      outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
      outputParameters.hostApiSpecificStreamInfo = NULL;
      err = Pa_OpenStream(
                &stream,
                NULL,                         /* no input */
                &outputParameters,
                SAMPLE_RATE,
                buffersize,                   /* frames per buffer */
                (paClipOff | paDitherOff),
                patest1Callback,
                &data );
      if( err != paNoError ) goto error;
  
      err = Pa_StartStream( stream );
      if( err != paNoError ) goto error;
      printf("Waiting for sound to finish.\n");
      Pa_Sleep(1000*NUM_SECONDS);
      err = Pa_CloseStream( stream );
      if( err != paNoError ) goto error;
      Pa_Terminate();
      return paNoError;
  error:
      Pa_Terminate();
      fprintf( stderr, "An error occured while using the portaudio stream\n" );
      fprintf( stderr, "Error number: %d\n", err );
      fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
      fprintf( stderr, "Host Error message: %s\n", Pa_GetLastHostErrorInfo()->errorText );
      return err;
  }
  