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asterisk/codecs/codec_ulaw.c

429 lines
8.5 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
*/
#include <fcntl.h>
#include <netinet/in.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "asterisk.h"
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
#include "asterisk/lock.h"
#include "asterisk/logger.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/options.h"
#include "asterisk/translate.h"
#include "asterisk/channel.h"
#include "asterisk/ulaw.h"
#include "asterisk/utils.h"
#define BUFFER_SIZE 8096 /* size for the translation buffers */
AST_MUTEX_DEFINE_STATIC(localuser_lock);
static int localusecnt = 0;
static char *tdesc = "Mu-law Coder/Decoder";
static int useplc = 0;
/* Sample frame data */
#include "slin_ulaw_ex.h"
#include "ulaw_slin_ex.h"
/*!
* \brief Private workspace for translating signed linear signals to ulaw.
*/
struct ulaw_encoder_pvt
{
struct ast_frame f;
char offset[AST_FRIENDLY_OFFSET]; /*!< Space to build offset */
unsigned char outbuf[BUFFER_SIZE]; /*!< Encoded ulaw, two nibbles to a word */
int tail;
};
/*!
* \brief Private workspace for translating ulaw signals to signed linear.
*/
struct ulaw_decoder_pvt
{
struct ast_frame f;
char offset[AST_FRIENDLY_OFFSET]; /* Space to build offset */
short outbuf[BUFFER_SIZE]; /* Decoded signed linear values */
int tail;
plc_state_t plc;
};
/*!
* \brief ulawToLin_New
* Create a new instance of ulaw_decoder_pvt.
*
* Results:
* Returns a pointer to the new instance.
*
* Side effects:
* None.
*/
static struct ast_translator_pvt *ulawtolin_new(void)
{
struct ulaw_decoder_pvt *tmp;
if ((tmp = ast_calloc(1, sizeof(*tmp)))) {
tmp->tail = 0;
plc_init(&tmp->plc);
localusecnt++;
ast_update_use_count();
}
return (struct ast_translator_pvt *)tmp;
}
/*!
* \brief LinToulaw_New
* Create a new instance of ulaw_encoder_pvt.
*
* Results:
* Returns a pointer to the new instance.
*
* Side effects:
* None.
*/
static struct ast_translator_pvt *lintoulaw_new(void)
{
struct ulaw_encoder_pvt *tmp;
if ((tmp = ast_calloc(1, sizeof(*tmp)))) {
localusecnt++;
ast_update_use_count();
tmp->tail = 0;
}
return (struct ast_translator_pvt *)tmp;
}
/*!
* \brief ulawToLin_FrameIn
* Fill an input buffer with packed 4-bit ulaw values if there is room
* left.
*
* Results:
* Foo
*
* Side effects:
* tmp->tail is the number of packed values in the buffer.
*/
static int ulawtolin_framein(struct ast_translator_pvt *pvt, struct ast_frame *f)
{
struct ulaw_decoder_pvt *tmp = (struct ulaw_decoder_pvt *)pvt;
int x;
unsigned char *b;
if(f->datalen == 0) { /* perform PLC with nominal framesize of 20ms/160 samples */
if((tmp->tail + 160) * 2 > sizeof(tmp->outbuf)) {
ast_log(LOG_WARNING, "Out of buffer space\n");
return -1;
}
if(useplc) {
plc_fillin(&tmp->plc, tmp->outbuf+tmp->tail, 160);
tmp->tail += 160;
}
return 0;
}
if ((tmp->tail + f->datalen) * 2 > sizeof(tmp->outbuf)) {
ast_log(LOG_WARNING, "Out of buffer space\n");
return -1;
}
/* Reset ssindex and signal to frame's specified values */
b = f->data;
for (x=0;x<f->datalen;x++)
tmp->outbuf[tmp->tail + x] = AST_MULAW(b[x]);
if(useplc)
plc_rx(&tmp->plc, tmp->outbuf+tmp->tail, f->datalen);
tmp->tail += f->datalen;
return 0;
}
/*!
* \brief ulawToLin_FrameOut
* Convert 4-bit ulaw encoded signals to 16-bit signed linear.
*
* Results:
* Converted signals are placed in tmp->f.data, tmp->f.datalen
* and tmp->f.samples are calculated.
*
* Side effects:
* None.
*/
static struct ast_frame *ulawtolin_frameout(struct ast_translator_pvt *pvt)
{
struct ulaw_decoder_pvt *tmp = (struct ulaw_decoder_pvt *)pvt;
if (!tmp->tail)
return NULL;
tmp->f.frametype = AST_FRAME_VOICE;
tmp->f.subclass = AST_FORMAT_SLINEAR;
tmp->f.datalen = tmp->tail * 2;
tmp->f.samples = tmp->tail;
tmp->f.mallocd = 0;
tmp->f.offset = AST_FRIENDLY_OFFSET;
tmp->f.src = __PRETTY_FUNCTION__;
tmp->f.data = tmp->outbuf;
tmp->tail = 0;
return &tmp->f;
}
/*!
* \brief LinToulaw_FrameIn
* Fill an input buffer with 16-bit signed linear PCM values.
*
* Results:
* None.
*
* Side effects:
* tmp->tail is number of signal values in the input buffer.
*/
static int lintoulaw_framein(struct ast_translator_pvt *pvt, struct ast_frame *f)
{
struct ulaw_encoder_pvt *tmp = (struct ulaw_encoder_pvt *)pvt;
int x;
short *s;
if (tmp->tail + f->datalen / 2 >= sizeof(tmp->outbuf)) {
ast_log(LOG_WARNING, "Out of buffer space\n");
return -1;
}
s = f->data;
for (x=0;x<f->datalen/2;x++)
tmp->outbuf[x+tmp->tail] = AST_LIN2MU(s[x]);
tmp->tail += f->datalen/2;
return 0;
}
/*!
* \brief LinToulaw_FrameOut
* Convert a buffer of raw 16-bit signed linear PCM to a buffer
* of 4-bit ulaw packed two to a byte (Big Endian).
*
* Results:
* Foo
*
* Side effects:
* Leftover inbuf data gets packed, tail gets updated.
*/
static struct ast_frame *lintoulaw_frameout(struct ast_translator_pvt *pvt)
{
struct ulaw_encoder_pvt *tmp = (struct ulaw_encoder_pvt *)pvt;
if (tmp->tail) {
tmp->f.frametype = AST_FRAME_VOICE;
tmp->f.subclass = AST_FORMAT_ULAW;
tmp->f.samples = tmp->tail;
tmp->f.mallocd = 0;
tmp->f.offset = AST_FRIENDLY_OFFSET;
tmp->f.src = __PRETTY_FUNCTION__;
tmp->f.data = tmp->outbuf;
tmp->f.datalen = tmp->tail;
tmp->tail = 0;
return &tmp->f;
} else
return NULL;
}
/*!
* \brief ulawToLin_Sample
*/
static struct ast_frame *ulawtolin_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;
}
/*!
* \brief LinToulaw_Sample
*/
static struct ast_frame *lintoulaw_sample(void)
{
static struct ast_frame f;
f.frametype = AST_FRAME_VOICE;
f.subclass = AST_FORMAT_SLINEAR;
f.datalen = sizeof(slin_ulaw_ex);
/* Assume 8000 Hz */
f.samples = sizeof(slin_ulaw_ex) / 2;
f.mallocd = 0;
f.offset = 0;
f.src = __PRETTY_FUNCTION__;
f.data = slin_ulaw_ex;
return &f;
}
/*!
* \brief ulaw_Destroy
* Destroys a private workspace.
*
* Results:
* It's gone!
*
* Side effects:
* None.
*/
static void ulaw_destroy(struct ast_translator_pvt *pvt)
{
free(pvt);
localusecnt--;
ast_update_use_count();
}
/*!
* \brief The complete translator for ulawToLin.
*/
static struct ast_translator ulawtolin = {
"ulawtolin",
AST_FORMAT_ULAW,
AST_FORMAT_SLINEAR,
ulawtolin_new,
ulawtolin_framein,
ulawtolin_frameout,
ulaw_destroy,
/* NULL */
ulawtolin_sample
};
/*!
* \brief The complete translator for LinToulaw.
*/
static struct ast_translator lintoulaw = {
"lintoulaw",
AST_FORMAT_SLINEAR,
AST_FORMAT_ULAW,
lintoulaw_new,
lintoulaw_framein,
lintoulaw_frameout,
ulaw_destroy,
/* NULL */
lintoulaw_sample
};
static void parse_config(void)
{
struct ast_config *cfg;
struct ast_variable *var;
if ((cfg = ast_config_load("codecs.conf"))) {
if ((var = ast_variable_browse(cfg, "plc"))) {
while (var) {
if (!strcasecmp(var->name, "genericplc")) {
useplc = ast_true(var->value) ? 1 : 0;
if (option_verbose > 2)
ast_verbose(VERBOSE_PREFIX_3 "codec_ulaw: %susing generic PLC\n", useplc ? "" : "not ");
}
var = var->next;
}
}
ast_config_destroy(cfg);
}
}
int reload(void)
{
parse_config();
return 0;
}
int unload_module(void)
{
int res;
ast_mutex_lock(&localuser_lock);
res = ast_unregister_translator(&lintoulaw);
if (!res)
res = ast_unregister_translator(&ulawtolin);
if (localusecnt)
res = -1;
ast_mutex_unlock(&localuser_lock);
return res;
}
int load_module(void)
{
int res;
parse_config();
res = ast_register_translator(&ulawtolin);
if (!res)
res = ast_register_translator(&lintoulaw);
else
ast_unregister_translator(&ulawtolin);
return res;
}
/*
* Return a description of this module.
*/
char *description(void)
{
return tdesc;
}
int usecount(void)
{
int res;
STANDARD_USECOUNT(res);
return res;
}
char *key()
{
return ASTERISK_GPL_KEY;
}