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comparison spandsp-0.0.6pre17/src/silence_gen.c @ 4:26cd8f1ef0b1

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import spandsp-0.0.6pre17
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 15:50:58 +0200
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3:c6c5a16ce2f2 4:26cd8f1ef0b1
1 /*
2 * SpanDSP - a series of DSP components for telephony
3 *
4 * silence_gen.c - A silence generator, for inserting timed silences.
5 *
6 * Written by Steve Underwood <steveu@coppice.org>
7 *
8 * Copyright (C) 2006 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 Lesser General Public License version 2.1,
14 * as 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 Lesser General Public License for more details.
20 *
21 * You should have received a copy of the GNU Lesser General Public
22 * License along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 *
25 * $Id: silence_gen.c,v 1.23 2009/09/04 14:38:46 steveu Exp $
26 */
27
28 /*! \file */
29
30 #if defined(HAVE_CONFIG_H)
31 #include "config.h"
32 #endif
33
34 #include <inttypes.h>
35 #include <stdlib.h>
36 #include <stdio.h>
37 #include <fcntl.h>
38 #include <string.h>
39 #if defined(HAVE_TGMATH_H)
40 #include <tgmath.h>
41 #endif
42 #if defined(HAVE_MATH_H)
43 #include <math.h>
44 #endif
45 #include "floating_fudge.h"
46 #include <assert.h>
47 #include <limits.h>
48
49 #include "spandsp/telephony.h"
50 #include "spandsp/logging.h"
51 #include "spandsp/async.h"
52 #include "spandsp/silence_gen.h"
53
54 #include "spandsp/private/silence_gen.h"
55
56 SPAN_DECLARE_NONSTD(int) silence_gen(silence_gen_state_t *s, int16_t *amp, int max_len)
57 {
58 if (s->remaining_samples != INT_MAX)
59 {
60 if (max_len >= s->remaining_samples)
61 {
62 max_len = s->remaining_samples;
63 if (max_len && s->status_handler)
64 s->status_handler(s->status_user_data, SIG_STATUS_SHUTDOWN_COMPLETE);
65 }
66 s->remaining_samples -= max_len;
67 }
68 if (INT_MAX - s->total_samples >= max_len)
69 s->total_samples += max_len;
70 memset(amp, 0, max_len*sizeof(int16_t));
71 return max_len;
72 }
73 /*- End of function --------------------------------------------------------*/
74
75 SPAN_DECLARE(void) silence_gen_always(silence_gen_state_t *s)
76 {
77 s->remaining_samples = INT_MAX;
78 }
79 /*- End of function --------------------------------------------------------*/
80
81 SPAN_DECLARE(void) silence_gen_set(silence_gen_state_t *s, int silent_samples)
82 {
83 s->remaining_samples = silent_samples;
84 s->total_samples = 0;
85 }
86 /*- End of function --------------------------------------------------------*/
87
88 SPAN_DECLARE(void) silence_gen_alter(silence_gen_state_t *s, int silent_samples)
89 {
90 /* Block negative silences */
91 if (silent_samples < 0)
92 {
93 if (-silent_samples > s->remaining_samples)
94 silent_samples = -s->remaining_samples;
95 }
96 s->remaining_samples += silent_samples;
97 s->total_samples += silent_samples;
98 }
99 /*- End of function --------------------------------------------------------*/
100
101 SPAN_DECLARE(int) silence_gen_remainder(silence_gen_state_t *s)
102 {
103 return s->remaining_samples;
104 }
105 /*- End of function --------------------------------------------------------*/
106
107 SPAN_DECLARE(int) silence_gen_generated(silence_gen_state_t *s)
108 {
109 return s->total_samples;
110 }
111 /*- End of function --------------------------------------------------------*/
112
113 SPAN_DECLARE(void) silence_gen_status_handler(silence_gen_state_t *s, modem_tx_status_func_t handler, void *user_data)
114 {
115 s->status_handler = handler;
116 s->status_user_data = user_data;
117 }
118 /*- End of function --------------------------------------------------------*/
119
120 SPAN_DECLARE(silence_gen_state_t *) silence_gen_init(silence_gen_state_t *s, int silent_samples)
121 {
122 if (s == NULL)
123 {
124 if ((s = (silence_gen_state_t *) malloc(sizeof(*s))) == NULL)
125 return NULL;
126 }
127 memset(s, 0, sizeof(*s));
128 s->remaining_samples = silent_samples;
129 return s;
130 }
131 /*- End of function --------------------------------------------------------*/
132
133 SPAN_DECLARE(int) silence_gen_release(silence_gen_state_t *s)
134 {
135 return 0;
136 }
137 /*- End of function --------------------------------------------------------*/
138
139 SPAN_DECLARE(int) silence_gen_free(silence_gen_state_t *s)
140 {
141 if (s)
142 free(s);
143 return 0;
144 }
145 /*- End of function --------------------------------------------------------*/
146
147 /* The following dummy routines, to absorb data, don't really have a proper home,
148 so they have been put here. */
149
150 SPAN_DECLARE_NONSTD(int) span_dummy_rx(void *user_data, const int16_t amp[], int len)
151 {
152 return 0;
153 }
154 /*- End of function --------------------------------------------------------*/
155
156 SPAN_DECLARE(int) span_dummy_mod(void *user_data, int16_t amp[], int len)
157 {
158 return len;
159 }
160 /*- End of function --------------------------------------------------------*/
161
162 SPAN_DECLARE_NONSTD(int) span_dummy_rx_fillin(void *user_data, int len)
163 {
164 return 0;
165 }
166 /*- End of function --------------------------------------------------------*/
167 /*- End of file ------------------------------------------------------------*/

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