pa_fuzz.c (6399B)
1 /** @file pa_fuzz.c 2 @ingroup examples_src 3 @brief Distort input like a fuzz box. 4 @author Phil Burk http://www.softsynth.com 5 */ 6 /* 7 * $Id$ 8 * 9 * This program uses the PortAudio Portable Audio Library. 10 * For more information see: http://www.portaudio.com 11 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk 12 * 13 * Permission is hereby granted, free of charge, to any person obtaining 14 * a copy of this software and associated documentation files 15 * (the "Software"), to deal in the Software without restriction, 16 * including without limitation the rights to use, copy, modify, merge, 17 * publish, distribute, sublicense, and/or sell copies of the Software, 18 * and to permit persons to whom the Software is furnished to do so, 19 * subject to the following conditions: 20 * 21 * The above copyright notice and this permission notice shall be 22 * included in all copies or substantial portions of the Software. 23 * 24 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 25 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 26 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 27 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 28 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 29 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 30 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 31 */ 32 33 /* 34 * The text above constitutes the entire PortAudio license; however, 35 * the PortAudio community also makes the following non-binding requests: 36 * 37 * Any person wishing to distribute modifications to the Software is 38 * requested to send the modifications to the original developer so that 39 * they can be incorporated into the canonical version. It is also 40 * requested that these non-binding requests be included along with the 41 * license above. 42 */ 43 44 #include <stdio.h> 45 #include <math.h> 46 #include "portaudio.h" 47 /* 48 ** Note that many of the older ISA sound cards on PCs do NOT support 49 ** full duplex audio (simultaneous record and playback). 50 ** And some only support full duplex at lower sample rates. 51 */ 52 #define SAMPLE_RATE (44100) 53 #define PA_SAMPLE_TYPE paFloat32 54 #define FRAMES_PER_BUFFER (64) 55 56 typedef float SAMPLE; 57 58 float CubicAmplifier( float input ); 59 static int fuzzCallback( const void *inputBuffer, void *outputBuffer, 60 unsigned long framesPerBuffer, 61 const PaStreamCallbackTimeInfo* timeInfo, 62 PaStreamCallbackFlags statusFlags, 63 void *userData ); 64 65 /* Non-linear amplifier with soft distortion curve. */ 66 float CubicAmplifier( float input ) 67 { 68 float output, temp; 69 if( input < 0.0 ) 70 { 71 temp = input + 1.0f; 72 output = (temp * temp * temp) - 1.0f; 73 } 74 else 75 { 76 temp = input - 1.0f; 77 output = (temp * temp * temp) + 1.0f; 78 } 79 80 return output; 81 } 82 #define FUZZ(x) CubicAmplifier(CubicAmplifier(CubicAmplifier(CubicAmplifier(x)))) 83 84 static int gNumNoInputs = 0; 85 /* This routine will be called by the PortAudio engine when audio is needed. 86 ** It may be called at interrupt level on some machines so don't do anything 87 ** that could mess up the system like calling malloc() or free(). 88 */ 89 static int fuzzCallback( const void *inputBuffer, void *outputBuffer, 90 unsigned long framesPerBuffer, 91 const PaStreamCallbackTimeInfo* timeInfo, 92 PaStreamCallbackFlags statusFlags, 93 void *userData ) 94 { 95 SAMPLE *out = (SAMPLE*)outputBuffer; 96 const SAMPLE *in = (const SAMPLE*)inputBuffer; 97 unsigned int i; 98 (void) timeInfo; /* Prevent unused variable warnings. */ 99 (void) statusFlags; 100 (void) userData; 101 102 if( inputBuffer == NULL ) 103 { 104 for( i=0; i<framesPerBuffer; i++ ) 105 { 106 *out++ = 0; /* left - silent */ 107 *out++ = 0; /* right - silent */ 108 } 109 gNumNoInputs += 1; 110 } 111 else 112 { 113 for( i=0; i<framesPerBuffer; i++ ) 114 { 115 *out++ = FUZZ(*in++); /* left - distorted */ 116 *out++ = *in++; /* right - clean */ 117 } 118 } 119 120 return paContinue; 121 } 122 123 /*******************************************************************/ 124 int main(void); 125 int main(void) 126 { 127 PaStreamParameters inputParameters, outputParameters; 128 PaStream *stream; 129 PaError err; 130 131 err = Pa_Initialize(); 132 if( err != paNoError ) goto error; 133 134 inputParameters.device = Pa_GetDefaultInputDevice(); /* default input device */ 135 if (inputParameters.device == paNoDevice) { 136 fprintf(stderr,"Error: No default input device.\n"); 137 goto error; 138 } 139 inputParameters.channelCount = 2; /* stereo input */ 140 inputParameters.sampleFormat = PA_SAMPLE_TYPE; 141 inputParameters.suggestedLatency = Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency; 142 inputParameters.hostApiSpecificStreamInfo = NULL; 143 144 outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ 145 if (outputParameters.device == paNoDevice) { 146 fprintf(stderr,"Error: No default output device.\n"); 147 goto error; 148 } 149 outputParameters.channelCount = 2; /* stereo output */ 150 outputParameters.sampleFormat = PA_SAMPLE_TYPE; 151 outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency; 152 outputParameters.hostApiSpecificStreamInfo = NULL; 153 154 err = Pa_OpenStream( 155 &stream, 156 &inputParameters, 157 &outputParameters, 158 SAMPLE_RATE, 159 FRAMES_PER_BUFFER, 160 0, /* paClipOff, */ /* we won't output out of range samples so don't bother clipping them */ 161 fuzzCallback, 162 NULL ); 163 if( err != paNoError ) goto error; 164 165 err = Pa_StartStream( stream ); 166 if( err != paNoError ) goto error; 167 168 printf("Hit ENTER to stop program.\n"); 169 getchar(); 170 err = Pa_CloseStream( stream ); 171 if( err != paNoError ) goto error; 172 173 printf("Finished. gNumNoInputs = %d\n", gNumNoInputs ); 174 Pa_Terminate(); 175 return 0; 176 177 error: 178 Pa_Terminate(); 179 fprintf( stderr, "An error occured while using the portaudio stream\n" ); 180 fprintf( stderr, "Error number: %d\n", err ); 181 fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) ); 182 return -1; 183 }