aboutsummaryrefslogtreecommitdiffstats
path: root/codecs/codec_a_mu.c
blob: b9c1c4938f35531033881ad6b75fa247124c3157 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief codec_a_mu.c - translate between alaw and ulaw directly
 *
 * \ingroup codecs
 */

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include <fcntl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "asterisk/lock.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/translate.h"
#include "asterisk/channel.h"
#include "asterisk/alaw.h"
#include "asterisk/ulaw.h"
#include "asterisk/utils.h"

#define BUFFER_SAMPLES   8000	/* size for the translation buffers */

static unsigned char mu2a[256];
static unsigned char a2mu[256];

/* Sample frame data (Mu data is okay) */

#include "ulaw_slin_ex.h"

/*! \brief convert frame data and store into the buffer */
static int alawtoulaw_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
	int x = f->samples;
	unsigned char *src = f->data;
	unsigned char *dst = (unsigned char *)pvt->outbuf + pvt->samples;

	pvt->samples += x;
	pvt->datalen += x;

	while (x--)
		*dst++ = a2mu[*src++];

	return 0;
}

/*! \brief convert frame data and store into the buffer */
static int ulawtoalaw_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
	int x = f->samples;
	unsigned char *src = f->data;
	unsigned char *dst = (unsigned char *)pvt->outbuf + pvt->samples;

	pvt->samples += x;
	pvt->datalen += x;

	while (x--)
		*dst++ = mu2a[*src++];

	return 0;
}

/*
 * alawToLin_Sample. Just random data, somehow...
 */
static struct ast_frame *alawtoulaw_sample(void)
{
	static struct ast_frame f;
	f.frametype = AST_FRAME_VOICE;
	f.subclass = AST_FORMAT_ALAW;
	f.datalen = sizeof(ulaw_slin_ex);
	f.samples = sizeof(ulaw_slin_ex);
	f.mallocd = 0;
	f.offset = 0;
	f.src = __PRETTY_FUNCTION__;
	f.data = ulaw_slin_ex; /* XXX what ? */
	return &f;
}

static struct ast_frame *ulawtoalaw_sample(void)
{
	static struct ast_frame f;
	f.frametype = AST_FRAME_VOICE;
	f.subclass = AST_FORMAT_ULAW;
	f.datalen = sizeof(ulaw_slin_ex);
	f.samples = sizeof(ulaw_slin_ex);
	f.mallocd = 0;
	f.offset = 0;
	f.src = __PRETTY_FUNCTION__;
	f.data = ulaw_slin_ex;
	return &f;
}

static struct ast_translator alawtoulaw = {
	.name = "alawtoulaw",
	.srcfmt = AST_FORMAT_ALAW,
	.dstfmt = AST_FORMAT_ULAW,
	.framein = alawtoulaw_framein,
	.sample = alawtoulaw_sample,
	.buffer_samples = BUFFER_SAMPLES,
	.buf_size = BUFFER_SAMPLES,
};

static struct ast_translator ulawtoalaw = {
	.name = "ulawtoalaw",
	.srcfmt = AST_FORMAT_ULAW,
	.dstfmt = AST_FORMAT_ALAW,
	.framein = ulawtoalaw_framein,
	.sample = ulawtoalaw_sample,
	.buffer_samples = BUFFER_SAMPLES,
	.buf_size = BUFFER_SAMPLES,
};

/*! \brief standard module glue */

static int unload_module(void)
{
	int res;

	res = ast_unregister_translator(&ulawtoalaw);
	res |= ast_unregister_translator(&alawtoulaw);

	return res;
}

static int load_module(void)
{
	int res;
	int x;

	for (x=0;x<256;x++) {
		mu2a[x] = AST_LIN2A(AST_MULAW(x));
		a2mu[x] = AST_LIN2MU(AST_ALAW(x));
	}
	res = ast_register_translator(&alawtoulaw);
	if (!res)
		res = ast_register_translator(&ulawtoalaw);
	else
		ast_unregister_translator(&alawtoulaw);

	return res;
}

AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "A-law and Mulaw direct Coder/Decoder");