1 /*
2 * $Id: test_w_saw.c,v 1.3 2006/06/10 21:30:55 dmazzoni Exp $
3 * test_w_saw.c
4 * Generate stereo sawtooth waveforms.
5 *
6 * Author: Phil Burk, http://www.softsynth.com
7 *
8 * This program uses PABLIO, the Portable Audio Blocking I/O Library.
9 * PABLIO is built on top of PortAudio, the Portable Audio Library.
10 *
11 * For more information see: http://www.audiomulch.com/portaudio/
12 * Copyright (c) 1999-2000 Ross Bencina and Phil Burk
13 *
14 * Permission is hereby granted, free of charge, to any person obtaining
15 * a copy of this software and associated documentation files
16 * (the "Software"), to deal in the Software without restriction,
17 * including without limitation the rights to use, copy, modify, merge,
18 * publish, distribute, sublicense, and/or sell copies of the Software,
19 * and to permit persons to whom the Software is furnished to do so,
20 * subject to the following conditions:
21 *
22 * The above copyright notice and this permission notice shall be
23 * included in all copies or substantial portions of the Software.
24 *
25 * Any person wishing to distribute modifications to the Software is
26 * requested to send the modifications to the original developer so that
27 * they can be incorporated into the canonical version.
28 *
29 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
30 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
31 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
32 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
33 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
34 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
35 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
36 *
37 */
38
39 #include <stdio.h>
40 #include <stdlib.h>
41 #include <math.h>
42 #include "pablio.h"
43 #include <string.h>
44
45 #define SAMPLE_RATE (44100)
46 #define NUM_SECONDS (6)
47 #define SAMPLES_PER_FRAME (2)
48
49 #define FREQUENCY (220.0f)
50 #define PHASE_INCREMENT (2.0f * FREQUENCY / SAMPLE_RATE)
51 #define FRAMES_PER_BLOCK (100)
52
53 float samples[FRAMES_PER_BLOCK][SAMPLES_PER_FRAME];
54 float phases[SAMPLES_PER_FRAME];
55
56 /*******************************************************************/
57 int main(void);
main(void)58 int main(void)
59 {
60 int i,j;
61 PaError err;
62 PABLIO_Stream *aOutStream;
63
64 printf("Generate sawtooth waves using PABLIO.\n");
65 fflush(stdout);
66
67 /* Open simplified blocking I/O layer on top of PortAudio. */
68 err = OpenAudioStream( &aOutStream, SAMPLE_RATE, paFloat32,
69 (PABLIO_WRITE | PABLIO_STEREO) );
70 if( err != paNoError ) goto error;
71
72 /* Initialize oscillator phases. */
73 phases[0] = 0.0;
74 phases[1] = 0.0;
75
76 for( i=0; i<(NUM_SECONDS * SAMPLE_RATE); i += FRAMES_PER_BLOCK )
77 {
78 /* Generate sawtooth waveforms in a block for efficiency. */
79 for( j=0; j<FRAMES_PER_BLOCK; j++ )
80 {
81 /* Generate a sawtooth wave by incrementing a variable. */
82 phases[0] += PHASE_INCREMENT;
83 /* The signal range is -1.0 to +1.0 so wrap around if we go over. */
84 if( phases[0] > 1.0f ) phases[0] -= 2.0f;
85 samples[j][0] = phases[0];
86
87 /* On the second channel, generate a sawtooth wave a fifth higher. */
88 phases[1] += PHASE_INCREMENT * (3.0f / 2.0f);
89 if( phases[1] > 1.0f ) phases[1] -= 2.0f;
90 samples[j][1] = phases[1];
91 }
92
93 /* Write samples to output. */
94 WriteAudioStream( aOutStream, samples, FRAMES_PER_BLOCK );
95 }
96
97 CloseAudioStream( aOutStream );
98
99 printf("Sawtooth sound test complete.\n" );
100 fflush(stdout);
101 return 0;
102
103 error:
104 fprintf( stderr, "An error occured while using PABLIO\n" );
105 fprintf( stderr, "Error number: %d\n", err );
106 fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
107 return -1;
108 }
109