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comparison spandsp-0.0.3/spandsp-0.0.3/src/super_tone_tx.c @ 5:f762bf195c4b

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import spandsp-0.0.3
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 16:00:21 +0200
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4:26cd8f1ef0b1 5:f762bf195c4b
1 /*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * super_tone_tx.c - Flexible telephony supervisory tone generation.
5 *
6 * Written by Steve Underwood <steveu@coppice.org>
7 *
8 * Copyright (C) 2003 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: super_tone_tx.c,v 1.15 2006/11/19 14:07:25 steveu Exp $
26 */
27
28 /*! \file */
29
30 #ifdef HAVE_CONFIG_H
31 #include "config.h"
32 #endif
33
34 #include <stdlib.h>
35 #include <string.h>
36 #include <stdio.h>
37 #include <fcntl.h>
38 #include <ctype.h>
39 #include <time.h>
40 #include <inttypes.h>
41 #if defined(HAVE_TGMATH_H)
42 #include <tgmath.h>
43 #endif
44 #if defined(HAVE_MATH_H)
45 #include <math.h>
46 #endif
47
48 #include "spandsp/telephony.h"
49 #include "spandsp/complex.h"
50 #include "spandsp/dds.h"
51 #include "spandsp/super_tone_tx.h"
52
53 super_tone_tx_step_t *super_tone_tx_make_step(super_tone_tx_step_t *s,
54 float f1,
55 float l1,
56 float f2,
57 float l2,
58 int length,
59 int cycles)
60 {
61 if (s == NULL)
62 {
63 s = (super_tone_tx_step_t *) malloc(sizeof(super_tone_tx_step_t));
64 if (s == NULL)
65 return NULL;
66 }
67 if (f1 >= 1.0)
68 {
69 s->phase_rate[0] = dds_phase_ratef(f1);
70 s->gain[0] = dds_scaling_dbm0f(l1);
71 }
72 else
73 {
74 s->phase_rate[0] = 0;
75 s->gain[0] = 0;
76 }
77 if (f2 >= 1.0)
78 {
79 s->phase_rate[1] = dds_phase_ratef(f2);
80 s->gain[1] = dds_scaling_dbm0f(l2);
81 }
82 else
83 {
84 s->phase_rate[1] = 0;
85 s->gain[1] = 0;
86 }
87 s->tone = (f1 > 0.0);
88 s->length = length*8;
89 s->cycles = cycles;
90 s->next = NULL;
91 s->nest = NULL;
92 return s;
93 }
94 /*- End of function --------------------------------------------------------*/
95
96 void super_tone_tx_free(super_tone_tx_step_t *s)
97 {
98 super_tone_tx_step_t *t;
99
100 while (s)
101 {
102 /* Follow nesting... */
103 if (s->nest)
104 super_tone_tx_free(s->nest);
105 t = s;
106 s = s->next;
107 free(t);
108 }
109 }
110 /*- End of function --------------------------------------------------------*/
111
112 super_tone_tx_state_t *super_tone_tx_init(super_tone_tx_state_t *s, super_tone_tx_step_t *tree)
113 {
114 if (tree == NULL)
115 return NULL;
116 memset(s, 0, sizeof(*s));
117 s->level = 0;
118 s->levels[0] = tree;
119 s->cycles[0] = tree->cycles;
120
121 s->current_position = 0;
122 return s;
123 }
124 /*- End of function --------------------------------------------------------*/
125
126 int super_tone_tx(super_tone_tx_state_t *s, int16_t amp[], int max_samples)
127 {
128 int samples;
129 int limit;
130 int len;
131 float xamp;
132 super_tone_tx_step_t *tree;
133
134 if (s->level < 0 || s->level > 3)
135 return 0;
136 samples = 0;
137 tree = s->levels[s->level];
138 while (tree && samples < max_samples)
139 {
140 if (tree->tone)
141 {
142 /* A period of tone. A length of zero means infinite
143 length. */
144 if (s->current_position == 0)
145 {
146 /* New step - prepare the tone generator */
147 s->phase_rate[0] = tree->phase_rate[0];
148 s->gain[0] = tree->gain[0];
149 s->phase_rate[1] = tree->phase_rate[1];
150 s->gain[1] = tree->gain[1];
151 }
152 len = tree->length - s->current_position;
153 if (tree->length == 0)
154 {
155 len = max_samples - samples;
156 /* We just need to make current position non-zero */
157 s->current_position = 1;
158 }
159 else if (len > max_samples - samples)
160 {
161 len = max_samples - samples;
162 s->current_position += len;
163 }
164 else
165 {
166 s->current_position = 0;
167 }
168 for (limit = len + samples; samples < limit; samples++)
169 {
170 xamp = 0.0;
171 if (s->phase_rate[0])
172 xamp += dds_modf(&(s->phase[0]), s->phase_rate[0], s->gain[0], 0);
173 if (s->phase_rate[1])
174 xamp += dds_modf(&(s->phase[1]), s->phase_rate[1], s->gain[1], 0);
175 amp[samples] = (int16_t) lrintf(xamp);
176 }
177 if (s->current_position)
178 return samples;
179 }
180 else if (tree->length)
181 {
182 /* A period of silence. The length must always
183 be explicitly stated. A length of zero does
184 not give infinite silence. */
185 len = tree->length - s->current_position;
186 if (len > max_samples - samples)
187 {
188 len = max_samples - samples;
189 s->current_position += len;
190 }
191 else
192 {
193 s->current_position = 0;
194 }
195 memset(amp + samples, 0, sizeof(uint16_t)*len);
196 samples += len;
197 if (s->current_position)
198 return samples;
199 }
200 /* Nesting has priority... */
201 if (tree->nest)
202 {
203 tree = tree->nest;
204 s->levels[++s->level] = tree;
205 s->cycles[s->level] = tree->cycles;
206 }
207 else
208 {
209 /* ...Next comes repeating, and finally moving forward a step. */
210 /* When repeating, note that zero cycles really means endless cycles. */
211 while (tree->cycles && --s->cycles[s->level] <= 0)
212 {
213 tree = tree->next;
214 if (tree)
215 {
216 /* A fresh new step. */
217 s->levels[s->level] = tree;
218 s->cycles[s->level] = tree->cycles;
219 break;
220 }
221 /* If we are nested we need to pop, otherwise this is the end. */
222 if (s->level <= 0)
223 {
224 /* Mark the tone as completed */
225 s->levels[0] = NULL;
226 break;
227 }
228 tree = s->levels[--s->level];
229 }
230 }
231
232 }
233 return samples;
234 }
235 /*- End of function --------------------------------------------------------*/
236 /*- End of file ------------------------------------------------------------*/

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