/** @file patest1.c	@ingroup test_src	@brief Ring modulate the audio input with a sine wave for 20 seconds.	@author Ross Bencina <rossb@audiomulch.com>*//* * $Id: patest1.c 1097 2006-08-26 08:27:53Z rossb $ * * 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"#ifndef M_PI#define M_PI (3.14159265)#endif#define SAMPLE_RATE (44100)typedef struct{    float sine[100];    int phase;    int sampsToGo;}patest1data;static int patest1Callback( const void *inputBuffer, void *outputBuffer,                            unsigned long framesPerBuffer,                            const PaStreamCallbackTimeInfo* timeInfo,                            PaStreamCallbackFlags statusFlags,                            void *userData ){    patest1data *data = (patest1data*)userData;    float *in = (float*)inputBuffer;    float *out = (float*)outputBuffer;    int framesToCalc = framesPerBuffer;    unsigned long i = 0;    int finished;    if( data->sampsToGo < framesPerBuffer )    {        framesToCalc = data->sampsToGo;        finished = paComplete;    }    else    {        finished = paContinue;    }    for( ; 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<framesPerBuffer; 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;    PaStreamParameters      inputParameters, outputParameters;    const PaHostErrorInfo*  herr;    printf("patest1.c\n"); fflush(stdout);    printf("Ring modulate input for 20 seconds.\n"); fflush(stdout);        /* initialise sinusoidal wavetable */    for( i=0; i<100; i++ )        data.sine[i] = sin( ((double)i/100.) * M_PI * 2. );    data.phase = 0;    data.sampsToGo = SAMPLE_RATE * 20;        /* 20 seconds. */    /* initialise portaudio subsytem */    err = Pa_Initialize();    inputParameters.device = Pa_GetDefaultInputDevice();    /* default input device */    inputParameters.channelCount = 2;                       /* stereo input */    inputParameters.sampleFormat = paFloat32;               /* 32 bit floating point input */    inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency;    inputParameters.hostApiSpecificStreamInfo = NULL;    outputParameters.device = Pa_GetDefaultOutputDevice();  /* default output device */    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,                        &inputParameters,                        &outputParameters,                        (double)SAMPLE_RATE, /* Samplerate in Hertz. */                        512,                 /* Small buffers */                        paClipOff,           /* We won't output out of range samples so don't bother clipping them. */                        patest1Callback,                        &data );    if( err != paNoError ) goto done;    err = Pa_StartStream( stream );    if( err != paNoError ) goto done;        printf( "Press any key to end.\n" ); fflush(stdout);             getc( stdin ); /* wait for input before exiting */    err = Pa_AbortStream( stream );    if( err != paNoError ) goto done;        printf( "Waiting for stream to complete...\n" );    /* sleep until playback has finished */    while( ( err = Pa_IsStreamActive( stream ) ) == 1 ) Pa_Sleep(1000);    if( err < 0 ) goto done;    err = Pa_CloseStream( stream );    if( err != paNoError ) goto done;done:    Pa_Terminate();    if( err != paNoError )    {        fprintf( stderr, "An error occured while using portaudio\n" );        if( err == paUnanticipatedHostError )        {            fprintf( stderr, " unanticipated host error.\n");            herr = Pa_GetLastHostErrorInfo();            if (herr)            {                fprintf( stderr, " Error number: %ld\n", herr->errorCode );                if (herr->errorText)                    fprintf( stderr, " Error text: %s\n", herr->errorText );            }            else                fprintf( stderr, " Pa_GetLastHostErrorInfo() failed!\n" );        }        else        {            fprintf( stderr, " Error number: %d\n", err );            fprintf( stderr, " Error text: %s\n", Pa_GetErrorText( err ) );        }        err = 1;          /* Always return 0 or 1, but no other return codes. */    }    printf( "bye\n" );    return err;}