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/*
* 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_alaw.c - translate between signed linear and alaw
*
* \ingroup codecs
*/
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/translate.h"
#include "asterisk/alaw.h"
#include "asterisk/utils.h"
#define BUFFER_SAMPLES 8096 /* size for the translation buffers */
/* Sample frame data */
#include "asterisk/slin.h"
#include "ex_alaw.h"
/*! \brief decode frame into lin and fill output buffer. */
static int alawtolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
int i = f->samples;
unsigned char *src = f->data.ptr;
int16_t *dst = pvt->outbuf.i16 + pvt->samples;
pvt->samples += i;
pvt->datalen += i * 2; /* 2 bytes/sample */
while (i--)
*dst++ = AST_ALAW(*src++);
return 0;
}
/*! \brief convert and store input samples in output buffer */
static int lintoalaw_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
int i = f->samples;
char *dst = pvt->outbuf.c + pvt->samples;
int16_t *src = f->data.ptr;
pvt->samples += i;
pvt->datalen += i; /* 1 byte/sample */
while (i--)
*dst++ = AST_LIN2A(*src++);
return 0;
}
static struct ast_translator alawtolin = {
.name = "alawtolin",
.srcfmt = AST_FORMAT_ALAW,
.dstfmt = AST_FORMAT_SLINEAR,
.framein = alawtolin_framein,
.sample = alaw_sample,
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES * 2,
.plc_samples = 160,
};
static struct ast_translator lintoalaw = {
"lintoalaw",
.srcfmt = AST_FORMAT_SLINEAR,
.dstfmt = AST_FORMAT_ALAW,
.framein = lintoalaw_framein,
.sample = slin8_sample,
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES,
};
static int parse_config(int reload)
{
struct ast_variable *var;
struct ast_flags config_flags = { reload ? CONFIG_FLAG_FILEUNCHANGED : 0 };
struct ast_config *cfg = ast_config_load("codecs.conf", config_flags);
if (cfg == CONFIG_STATUS_FILEMISSING || cfg == CONFIG_STATUS_FILEUNCHANGED || cfg == CONFIG_STATUS_FILEINVALID)
return 0;
for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
if (!strcasecmp(var->name, "genericplc")) {
alawtolin.useplc = ast_true(var->value) ? 1 : 0;
ast_verb(3, "codec_alaw: %susing generic PLC\n", alawtolin.useplc ? "" : "not ");
}
}
ast_config_destroy(cfg);
return 0;
}
/*! \brief standard module stuff */
static int reload(void)
{
if (parse_config(1))
return AST_MODULE_LOAD_DECLINE;
return AST_MODULE_LOAD_SUCCESS;
}
static int unload_module(void)
{
int res;
res = ast_unregister_translator(&lintoalaw);
res |= ast_unregister_translator(&alawtolin);
return res;
}
static int load_module(void)
{
int res;
if (parse_config(0))
return AST_MODULE_LOAD_DECLINE;
res = ast_register_translator(&alawtolin);
if (!res)
res = ast_register_translator(&lintoalaw);
else
ast_unregister_translator(&alawtolin);
if (res)
return AST_MODULE_LOAD_FAILURE;
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "A-law Coder/Decoder",
.load = load_module,
.unload = unload_module,
.reload = reload,
);
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