Mercurial > hg > audiostuff
comparison spandsp-0.0.6pre17/src/swept_tone.c @ 4:26cd8f1ef0b1
import spandsp-0.0.6pre17
author | Peter Meerwald <pmeerw@cosy.sbg.ac.at> |
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date | Fri, 25 Jun 2010 15:50:58 +0200 |
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3:c6c5a16ce2f2 | 4:26cd8f1ef0b1 |
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1 /* | |
2 * SpanDSP - a series of DSP components for telephony | |
3 * | |
4 * swept_tone.c - Swept tone generation | |
5 * | |
6 * Written by Steve Underwood <steveu@coppice.org> | |
7 * | |
8 * Copyright (C) 2009 Steve Underwood | |
9 * | |
10 * All rights reserved. | |
11 * | |
12 * This program is free software; you can redistribute it and/or modify | |
13 * it under the terms of the GNU General Public License version 2, as | |
14 * published by the Free Software Foundation. | |
15 * | |
16 * This program is distributed in the hope that it will be useful, | |
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
19 * GNU General Public License for more details. | |
20 * | |
21 * You should have received a copy of the GNU General Public License | |
22 * along with this program; if not, write to the Free Software | |
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
24 * | |
25 * $Id: swept_tone.c,v 1.2 2009/09/23 16:02:59 steveu Exp $ | |
26 */ | |
27 | |
28 /*! \file */ | |
29 | |
30 #if defined(HAVE_CONFIG_H) | |
31 #include "config.h" | |
32 #endif | |
33 | |
34 #include <stdlib.h> | |
35 #include <inttypes.h> | |
36 #include <string.h> | |
37 #include <stdio.h> | |
38 #if defined(HAVE_TGMATH_H) | |
39 #include <tgmath.h> | |
40 #endif | |
41 #if defined(HAVE_MATH_H) | |
42 #include <math.h> | |
43 #endif | |
44 #include "floating_fudge.h" | |
45 | |
46 #include "spandsp/telephony.h" | |
47 #include "spandsp/logging.h" | |
48 #include "spandsp/complex.h" | |
49 #include "spandsp/vector_float.h" | |
50 #include "spandsp/complex_vector_float.h" | |
51 #include "spandsp/vector_int.h" | |
52 #include "spandsp/complex_vector_int.h" | |
53 #include "spandsp/dds.h" | |
54 | |
55 #include "spandsp/swept_tone.h" | |
56 | |
57 #include "spandsp/private/logging.h" | |
58 #include "spandsp/private/swept_tone.h" | |
59 | |
60 SPAN_DECLARE(swept_tone_state_t *) swept_tone_init(swept_tone_state_t *s, float start, float end, float level, int duration, int repeating) | |
61 { | |
62 if (s == NULL) | |
63 { | |
64 if ((s = (swept_tone_state_t *) malloc(sizeof(*s))) == NULL) | |
65 return NULL; | |
66 } | |
67 memset(s, 0, sizeof(*s)); | |
68 s->current_phase_inc = | |
69 s->starting_phase_inc = dds_phase_rate(start); | |
70 s->phase_inc_step = dds_phase_rate((end - start)/(float) duration); | |
71 s->scale = dds_scaling_dbm0(level); | |
72 s->duration = duration; | |
73 s->repeating = repeating; | |
74 s->pos = 0; | |
75 s->phase = 0; | |
76 return s; | |
77 } | |
78 /*- End of function --------------------------------------------------------*/ | |
79 | |
80 SPAN_DECLARE(int) swept_tone(swept_tone_state_t *s, int16_t amp[], int max_len) | |
81 { | |
82 int i; | |
83 int len; | |
84 int chunk_len; | |
85 | |
86 for (len = 0; len < max_len; ) | |
87 { | |
88 chunk_len = max_len - len; | |
89 if (chunk_len > s->duration - s->pos) | |
90 chunk_len = s->duration - s->pos; | |
91 for (i = len; i < len + chunk_len; i++) | |
92 { | |
93 amp[i] = (dds(&s->phase, s->current_phase_inc)*s->scale) >> 15; | |
94 s->current_phase_inc += s->phase_inc_step; | |
95 } | |
96 len += chunk_len; | |
97 s->pos += chunk_len; | |
98 if (s->pos >= s->duration) | |
99 { | |
100 if (!s->repeating) | |
101 break; | |
102 s->pos = 0; | |
103 s->current_phase_inc = s->starting_phase_inc; | |
104 } | |
105 } | |
106 return len; | |
107 } | |
108 /*- End of function --------------------------------------------------------*/ | |
109 | |
110 SPAN_DECLARE(float) swept_tone_current_frequency(swept_tone_state_t *s) | |
111 { | |
112 return dds_frequency(s->current_phase_inc); | |
113 } | |
114 /*- End of function --------------------------------------------------------*/ | |
115 | |
116 SPAN_DECLARE(int) swept_tone_release(swept_tone_state_t *s) | |
117 { | |
118 return 0; | |
119 } | |
120 /*- End of function --------------------------------------------------------*/ | |
121 | |
122 SPAN_DECLARE(int) swept_tone_free(swept_tone_state_t *s) | |
123 { | |
124 free(s); | |
125 return 0; | |
126 } | |
127 /*- End of function --------------------------------------------------------*/ | |
128 /*- End of file ------------------------------------------------------------*/ |