/*
* $Id: patest_latency.c,v 1.4 2002/03/21 00:58:45 philburk Exp $
* Hear the latency caused by big buffers.
* Play a sine wave and change frequency based on letter input.
*
* Author: Phil Burk <philburk@softsynth.com>, and Darren Gibbs
*
* 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.
*
* 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 OUTPUT_DEVICE (Pa_GetDefaultOutputDeviceID())
#define SAMPLE_RATE (44100)
#define FRAMES_PER_BUFFER (64)
#if 0
#define MIN_LATENCY_MSEC (2000)
#define NUM_BUFFERS ((MIN_LATENCY_MSEC * SAMPLE_RATE) / (FRAMES_PER_BUFFER * 1000))
#else
#define NUM_BUFFERS (0)
#endif
#define MIN_FREQ (100.0f)
#define CalcPhaseIncrement(freq) ((freq)/SAMPLE_RATE)
#ifndef M_PI
#define M_PI (3.14159265)
#endif
#define TABLE_SIZE (400)
typedef struct
{
float sine[TABLE_SIZE + 1]; // add one for guard point for interpolation
float phase_increment;
float left_phase;
float right_phase;
}
paTestData;
float LookupSine( paTestData *data, float phase );
/* Convert phase between and 1.0 to sine value
* using linear interpolation.
*/
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;
int i;
int finished = 0;
(void) outTime; /* Prevent unused variable warnings. */
(void) inputBuffer;
for( i=0; i<framesPerBuffer; i++ )
{
*out++ = LookupSine(data, data->left_phase); /* left */
*out++ = LookupSine(data, data->right_phase); /* right */
data->left_phase += data->phase_increment;
if( data->left_phase >= 1.0f ) data->left_phase -= 1.0f;
data->right_phase += (data->phase_increment * 1.5f); /* fifth above */
if( data->right_phase >= 1.0f ) data->right_phase -= 1.0f;
}
return 0;
}
/*******************************************************************/
int main(void);
int main(void)
{
PortAudioStream *stream;
PaError err;
paTestData data;
int i;
int done = 0;
printf("PortAudio Test: enter letter then hit ENTER. numBuffers = %d\n", NUM_BUFFERS );
/* initialise sinusoidal wavetable */
for( i=0; i<TABLE_SIZE; i++ )
{
data.sine[i] = 0.90f * (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
}
data.sine[TABLE_SIZE] = data.sine[0]; // set guard point
data.left_phase = data.right_phase = 0.0;
data.phase_increment = CalcPhaseIncrement(MIN_FREQ);
err = Pa_Initialize();
if( err != paNoError ) goto error;
printf("PortAudio Test: output device = %d\n", OUTPUT_DEVICE );
err = Pa_OpenStream(
&stream,
paNoDevice,
0, /* no input */
paFloat32, /* 32 bit floating point input */
NULL,
OUTPUT_DEVICE,
2, /* stereo output */
paFloat32, /* 32 bit floating point output */
NULL,
SAMPLE_RATE,
FRAMES_PER_BUFFER,
NUM_BUFFERS, /* number of buffers, if zero then use default minimum */
paClipOff|paDitherOff, /* 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;
printf("Play ASCII keyboard. Hit 'q' to stop. (Use RETURN key on Mac)\n");
fflush(stdout);
while ( !done )
{
float freq;
int index;
char c;
do
{
c = getchar();
}
while( c < ' '); /* Strip white space and control chars. */
if( c == 'q' ) done = 1;
index = c % 26;
freq = MIN_FREQ + (index * 40.0);
data.phase_increment = CalcPhaseIncrement(freq);
}
printf("Call Pa_StopStream()\n");
err = Pa_StopStream( 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;
}