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/*
* $Id: patest_maxsines.c,v 1.1.1.1 2003-05-09 16:03:56 ggeiger Exp $
* patest_maxsines.c
* How many sine waves can we calculate and play in less than 80% CPU Load.
*
* Authors:
* Ross Bencina <rossb@audiomulch.com>
* Phil Burk <philburk@softsynth.com>
*
* This program uses the PortAudio Portable Audio Library.
* For more information see: http://www.audiomulch.com/portaudio/
* 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.
*
* 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.
*
* 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.
*
*/
#include <stdio.h>
#include <math.h>
#include "portaudio.h"
#define MAX_SINES (500)
#define MAX_USAGE (0.8)
#define SAMPLE_RATE (44100)
#define FREQ_TO_PHASE_INC(freq) (freq/(float)SAMPLE_RATE)
#define MIN_PHASE_INC FREQ_TO_PHASE_INC(200.0f)
#define MAX_PHASE_INC (MIN_PHASE_INC * (1 << 5))
#define FRAMES_PER_BUFFER (512)
#ifndef M_PI
#define M_PI (3.14159265)
#endif
#define TWOPI (M_PI * 2.0)
#define TABLE_SIZE (512)
typedef struct paTestData
{
int numSines;
float sine[TABLE_SIZE + 1]; /* add one for guard point for interpolation */
float phases[MAX_SINES];
}
paTestData;
/* Convert phase between and 1.0 to sine value
* using linear interpolation.
*/
float LookupSine( paTestData *data, float phase );
float LookupSine( paTestData *data, float phase )
{
float fIndex = phase*TABLE_SIZE;
int index = (int) fIndex;
float fract = fIndex - index;
float lo = data->sine[index];
float hi = data->sine[index+1];
float val = lo + fract*(hi-lo);
return val;
}
/* 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 patestCallback( void *inputBuffer, void *outputBuffer,
unsigned long framesPerBuffer,
PaTimestamp outTime, void *userData )
{
paTestData *data = (paTestData*)userData;
float *out = (float*)outputBuffer;
float outSample;
float scaler;
int numForScale;
unsigned long i;
int j;
int finished = 0;
(void) outTime; /* Prevent unused variable warnings. */
(void) inputBuffer;
/* Detemine amplitude scaling factor */
numForScale = data->numSines;
if( numForScale < 8 ) numForScale = 8; /* prevent pops at beginning */
scaler = 1.0f / numForScale;
for( i=0; i<framesPerBuffer; i++ )
{
float output = 0.0;
float phaseInc = MIN_PHASE_INC;
float phase;
for( j=0; j<data->numSines; j++ )
{
/* Advance phase of next oscillator. */
phase = data->phases[j];
phase += phaseInc;
if( phase >= 1.0 ) phase -= 1.0;
output += LookupSine(data, phase);
data->phases[j] = phase;
phaseInc *= 1.02f;
if( phaseInc > MAX_PHASE_INC ) phaseInc = MIN_PHASE_INC;
}
outSample = (float) (output * scaler);
*out++ = outSample; /* Left */
*out++ = outSample; /* Right */
}
return finished;
}
/*******************************************************************/
int main(void);
int main(void)
{
int i;
PaStream *stream;
PaError err;
paTestData data = {0};
double load;
printf("PortAudio Test: output sine wave. SR = %d, BufSize = %d\n", SAMPLE_RATE, FRAMES_PER_BUFFER);
/* initialise sinusoidal wavetable */
for( i=0; i<TABLE_SIZE; i++ )
{
data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
}
data.sine[TABLE_SIZE] = data.sine[0]; /* set guard point */
err = Pa_Initialize();
if( err != paNoError ) goto error;
err = Pa_OpenStream(
&stream,
paNoDevice,
0, /* no input */
paFloat32,
0, /* default latency */
NULL,
Pa_GetDefaultOutputDevice(), /* default output device */
2, /* stereo output */
paFloat32, /* 32 bit floating point output */
0, /* default latency */
NULL,
SAMPLE_RATE,
FRAMES_PER_BUFFER,
paClipOff, /* we won't output out of range samples so don't bother clipping them */
patestCallback,
&data );
if( err != paNoError ) goto error;
err = Pa_StartStream( stream );
if( err != paNoError ) goto error;
/* Play an increasing number of sine waves until we hit MAX_USAGE */
do
{
data.numSines++;
Pa_Sleep( 200 );
load = Pa_GetStreamCpuLoad( stream );
printf("numSines = %d, CPU load = %f\n", data.numSines, load );
fflush( stdout );
}
while( (load < MAX_USAGE) && (data.numSines < MAX_SINES) );
err = Pa_StopStream( stream );
if( err != paNoError ) goto error;
err = Pa_CloseStream( stream );
if( err != paNoError ) goto error;
Pa_Terminate();
printf("Test finished.\n");
return err;
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 ) );
return err;
}
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