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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_a_mu.c - translate between alaw and ulaw directly
*
* \ingroup codecs
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/translate.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 */
#include "ex_ulaw.h"
#include "ex_alaw.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.ptr;
unsigned char *dst = pvt->outbuf.uc + 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.ptr;
unsigned char *dst = pvt->outbuf.uc + pvt->samples;
pvt->samples += x;
pvt->datalen += x;
while (x--)
*dst++ = mu2a[*src++];
return 0;
}
static struct ast_translator alawtoulaw = {
.name = "alawtoulaw",
.src_codec = {
.name = "alaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "ulaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "ulaw",
.framein = alawtoulaw_framein,
.sample = alaw_sample,
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES,
};
static struct ast_translator ulawtoalaw = {
.name = "ulawtoalaw",
.src_codec = {
.name = "ulaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "alaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "alaw",
.framein = ulawtoalaw_framein,
.sample = ulaw_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);
res |= ast_register_translator(&ulawtoalaw);
if (res) {
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO_STANDARD(ASTERISK_GPL_KEY, "A-law and Mulaw direct Coder/Decoder");
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