asterisk/codecs/codec_ulaw.c

195 lines
4.2 KiB
C

/*
* 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_ulaw.c - translate between signed linear and ulaw
*
* \ingroup codecs
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/translate.h"
#include "asterisk/ulaw.h"
#include "asterisk/utils.h"
#define BUFFER_SAMPLES 8096 /* size for the translation buffers */
/* Sample frame data */
#include "asterisk/slin.h"
#include "ex_ulaw.h"
/*! \brief convert and store samples in outbuf */
static int ulawtolin_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 */
/* convert and copy in outbuf */
while (i--)
*dst++ = AST_MULAW(*src++);
return 0;
}
/*! \brief convert and store samples in outbuf */
static int lintoulaw_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_LIN2MU(*src++);
return 0;
}
/*!
* \brief The complete translator for ulawToLin.
*/
static struct ast_translator ulawtolin = {
.name = "ulawtolin",
.src_codec = {
.name = "ulaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "slin",
.framein = ulawtolin_framein,
.sample = ulaw_sample,
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES * 2,
};
static struct ast_translator testlawtolin = {
.name = "testlawtolin",
.src_codec = {
.name = "testlaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "slin",
.framein = ulawtolin_framein,
.sample = ulaw_sample,
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES * 2,
};
/*!
* \brief The complete translator for LinToulaw.
*/
static struct ast_translator lintoulaw = {
.name = "lintoulaw",
.src_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "ulaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "ulaw",
.framein = lintoulaw_framein,
.sample = slin8_sample,
.buf_size = BUFFER_SAMPLES,
.buffer_samples = BUFFER_SAMPLES,
};
static struct ast_translator lintotestlaw = {
.name = "lintotestlaw",
.src_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "testlaw",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "testlaw",
.framein = lintoulaw_framein,
.sample = slin8_sample,
.buf_size = BUFFER_SAMPLES,
.buffer_samples = BUFFER_SAMPLES,
};
static int unload_module(void)
{
int res;
res = ast_unregister_translator(&lintoulaw);
res |= ast_unregister_translator(&ulawtolin);
res |= ast_unregister_translator(&testlawtolin);
res |= ast_unregister_translator(&lintotestlaw);
return res;
}
static int load_module(void)
{
int res;
res = ast_register_translator(&ulawtolin);
res |= ast_register_translator(&lintoulaw);
res |= ast_register_translator(&lintotestlaw);
res |= ast_register_translator(&testlawtolin);
if (res) {
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "mu-Law Coder/Decoder",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
);