PortAudio: pa_fuzz.c Source File

PortAudio 2.0

- Main Page
- Related Pages
- Modules
- Data Structures
- Files

- File List
- Globals

pa_fuzz.c
Go to the documentation of this file.
1
6 /*
7 * $Id: pa_fuzz.c 1752 2011-09-08 03:21:55Z philburk $
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 }