/* * $Id: pa_fuzz.c,v 1.3 2003/03/02 08:01:40 dmazzoni Exp $ * pa_fuzz.c * Distort input like a fuzz boz. * * Author: Phil Burk  http://www.softsynth.com * * 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"/*** Note that many of the older ISA sound cards on PCs do NOT support** full duplex audio (simultaneous record and playback).** And some only support full duplex at lower sample rates.*/#define SAMPLE_RATE         (44100)#define PA_SAMPLE_TYPE      paFloat32#define FRAMES_PER_BUFFER   (64)typedef float SAMPLE;float CubicAmplifier( float input );static int fuzzCallback( void *inputBuffer, void *outputBuffer,                         unsigned long framesPerBuffer,                         PaTimestamp outTime, void *userData );/* Non-linear amplifier with soft distortion curve. */float CubicAmplifier( float input ){    float output, temp;    if( input < 0.0 )    {        temp = input + 1.0f;        output = (temp * temp * temp) - 1.0f;    }    else    {        temp = input - 1.0f;        output = (temp * temp * temp) + 1.0f;    }    return output;}#define FUZZ(x) CubicAmplifier(CubicAmplifier(CubicAmplifier(CubicAmplifier(x))))static int gNumNoInputs = 0;/* This routine will be called by the PortAudio engine when audio is needed.** It may be 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 fuzzCallback( void *inputBuffer, void *outputBuffer,                         unsigned long framesPerBuffer,                         PaTimestamp outTime, void *userData ){    SAMPLE *out = (SAMPLE*)outputBuffer;    SAMPLE *in = (SAMPLE*)inputBuffer;    unsigned int i;    (void) outTime; /* Prevent unused variable warnings. */    (void) userData;    if( inputBuffer == NULL )    {        for( i=0; i<framesPerBuffer; i++ )        {            *out++ = 0;  /* left - silent */            *out++ = 0;  /* right - silent */        }        gNumNoInputs += 1;    }    else    {        for( i=0; i<framesPerBuffer; i++ )        {            *out++ = FUZZ(*in++);  /* left - distorted */            *out++ = *in++;          /* right - clean */        }    }    return 0;}/*******************************************************************/int main(void);int main(void){    PortAudioStream *stream;    PaError err;    err = Pa_Initialize();    if( err != paNoError ) goto error;    err = Pa_OpenStream(              &stream,              Pa_GetDefaultInputDeviceID(), /* default output device */              2,               /* stereo input */              PA_SAMPLE_TYPE,              NULL,              Pa_GetDefaultOutputDeviceID(), /* default output device */              2,               /* stereo output */              PA_SAMPLE_TYPE,              NULL,              SAMPLE_RATE,              FRAMES_PER_BUFFER,              0,             /* number of buffers, if zero then use default minimum */              0, // paClipOff,     /* we won't output out of range samples so don't bother clipping them */              fuzzCallback,              NULL );    if( err != paNoError ) goto error;    err = Pa_StartStream( stream );    if( err != paNoError ) goto error;    printf("Hit ENTER to stop program.\n");    fflush(stdout);    getchar();    err = Pa_CloseStream( stream );    if( err != paNoError ) goto error;    printf("Finished. gNumNoInputs = %d\n", gNumNoInputs );    Pa_Terminate();    return 0;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 -1;}