/* $Id: patest1.c,v 1.1.1.1 2003-05-09 16:03:56 ggeiger 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, PaTime 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_GetDefaultInputDevice(); int outputDevice = Pa_GetDefaultOutputDevice(); /* 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_IsStreamActive( 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 ); fprintf( stderr, "Error text: %s\n", Pa_GetErrorText( err ) ); } } Pa_Terminate(); printf( "bye\n" ); return 0; }