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/** @file patest_leftright.c
@ingroup test_src
@brief Play different tone sine waves that
alternate between left and right channel.
The low tone should be on the left channel.
@author Ross Bencina <rossb@audiomulch.com>
@author Phil Burk <philburk@softsynth.com>
*/
/*
* $Id$
*
* 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 <math.h>
#include "portaudio.h"
#define NUM_SECONDS (8)
#define SAMPLE_RATE (44100)
#define FRAMES_PER_BUFFER (512)
#ifndef M_PI
#define M_PI (3.14159265)
#endif
#define TABLE_SIZE (200)
#define BALANCE_DELTA (0.001)
typedef struct
{
float sine[TABLE_SIZE];
int left_phase;
int right_phase;
float targetBalance; // 0.0 = left, 1.0 = right
float currentBalance;
} paTestData;
/* 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( const void *inputBuffer,
void *outputBuffer,
unsigned long framesPerBuffer,
const PaStreamCallbackTimeInfo* timeInfo,
PaStreamCallbackFlags statusFlags,
void *userData )
{
paTestData *data = (paTestData*)userData;
float *out = (float*)outputBuffer;
unsigned long i;
int finished = 0;
/* Prevent unused variable warnings. */
(void) inputBuffer;
for( i=0; i<framesPerBuffer; i++ )
{
// Smoothly pan between left and right.
if( data->currentBalance < data->targetBalance )
{
data->currentBalance += BALANCE_DELTA;
}
else if( data->currentBalance > data->targetBalance )
{
data->currentBalance -= BALANCE_DELTA;
}
// Apply left/right balance.
*out++ = data->sine[data->left_phase] * (1.0f - data->currentBalance); /* left */
*out++ = data->sine[data->right_phase] * data->currentBalance; /* 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;
}
return finished;
}
/*******************************************************************/
int main(void);
int main(void)
{
PaStream *stream;
PaStreamParameters outputParameters;
PaError err;
paTestData data;
int i;
printf("Play different tone sine waves that alternate between left and right channel.\n");
printf("The low tone should be on the left channel.\n");
/* initialise sinusoidal wavetable */
for( i=0; i<TABLE_SIZE; i++ )
{
data.sine[i] = (float) sin( ((double)i/(double)TABLE_SIZE) * M_PI * 2. );
}
data.left_phase = data.right_phase = 0;
data.currentBalance = 0.0;
data.targetBalance = 0.0;
err = Pa_Initialize();
if( err != paNoError ) goto error;
outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
if (outputParameters.device == paNoDevice) {
fprintf(stderr,"Error: No default output device.\n");
goto error;
}
outputParameters.channelCount = 2; /* stereo output */
outputParameters.sampleFormat = paFloat32; /* 32 bit floating point output */
outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
outputParameters.hostApiSpecificStreamInfo = NULL;
err = Pa_OpenStream( &stream,
NULL, /* No input. */
&outputParameters, /* As above. */
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;
printf("Play for several seconds.\n");
for( i=0; i<4; i++ )
{
printf("Hear low sound on left side.\n");
data.targetBalance = 0.01;
Pa_Sleep( 1000 );
printf("Hear high sound on right side.\n");
data.targetBalance = 0.99;
Pa_Sleep( 1000 );
}
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 occurred 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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