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/*
$Id: patest1.c,v 1.1.1.1 2002/01/22 00:52:33 phil Exp $
patest1.c
Ring modulate the audio input with a sine wave for 20 seconds
using the Portable Audio api
Author: Ross Bencina <rossb@audiomulch.com>
Modifications:
April 5th, 2001 - PLB - Check for NULL inputBuffer.
*/
#include <stdio.h>
#include <math.h>
#include "portaudio.h"
#ifndef M_PI
#define M_PI (3.14159265)
#endif
typedef struct
{
float sine[100];
int phase;
int sampsToGo;
}
patest1data;
static int patest1Callback( void *inputBuffer, void *outputBuffer,
unsigned long bufferFrames,
PaTimestamp outTime, void *userData )
{
patest1data *data = (patest1data*)userData;
float *in = (float*)inputBuffer;
float *out = (float*)outputBuffer;
int framesToCalc = bufferFrames;
unsigned long i;
int finished = 0;
/* Check to see if any input data is available. */
if(inputBuffer == NULL) return 0;
if( data->sampsToGo < bufferFrames )
{
framesToCalc = data->sampsToGo;
finished = 1;
}
for( i=0; i<framesToCalc; i++ )
{
*out++ = *in++ * data->sine[data->phase]; /* left */
*out++ = *in++ * data->sine[data->phase++]; /* right */
if( data->phase >= 100 )
data->phase = 0;
}
data->sampsToGo -= framesToCalc;
/* zero remainder of final buffer if not already done */
for( ; i<bufferFrames; i++ )
{
*out++ = 0; /* left */
*out++ = 0; /* right */
}
return finished;
}
int main(int argc, char* argv[]);
int main(int argc, char* argv[])
{
PaStream *stream;
PaError err;
patest1data data;
int i;
int inputDevice = Pa_GetDefaultInputDeviceID();
int outputDevice = Pa_GetDefaultOutputDeviceID();
/* initialise sinusoidal wavetable */
for( i=0; i<100; i++ )
data.sine[i] = sin( ((double)i/100.) * M_PI * 2. );
data.phase = 0;
data.sampsToGo = 44100 * 20; // 20 seconds
/* initialise portaudio subsytem */
Pa_Initialize();
err = Pa_OpenStream(
&stream,
inputDevice,
2, /* stereo input */
paFloat32, /* 32 bit floating point input */
NULL,
outputDevice,
2, /* stereo output */
paFloat32, /* 32 bit floating point output */
NULL,
44100.,
512, /* small buffers */
0, /* let PA determine number of buffers */
paClipOff, /* we won't output out of range samples so don't bother clipping them */
patest1Callback,
&data );
if( err == paNoError )
{
err = Pa_StartStream( stream );
printf( "Press any key to end.\n" );
getc( stdin ); //wait for input before exiting
Pa_AbortStream( stream );
printf( "Waiting for stream to complete...\n" );
while( Pa_StreamActive( stream ) )
Pa_Sleep(1000); /* sleep until playback has finished */
err = Pa_CloseStream( stream );
}
else
{
fprintf( stderr, "An error occured while opening the portaudio stream\n" );
if( err == paHostError )
fprintf( stderr, "Host error number: %d\n", Pa_GetHostError() );
else
fprintf( stderr, "Error number: %d\n", err );
}
Pa_Terminate();
printf( "bye\n" );
return 0;
}
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