A big "thank you" to pnlarsson on IRC for allowing me access to his system to debug this. Closes issue #11584. git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@94541 65c4cc65-6c06-0410-ace0-fbb531ad65f3
312 lines
8.2 KiB
C
312 lines
8.2 KiB
C
/*
|
|
* Asterisk -- An open source telephony toolkit.
|
|
*
|
|
* Copyright (C) 1999 - 2005, Digium, Inc.
|
|
*
|
|
* Mark Spencer <markster@digium.com>
|
|
*
|
|
* The lpc10 code is from a library used by nautilus, modified to be a bit
|
|
* nicer to the compiler.
|
|
* See http://www.arl.wustl.edu/~jaf/
|
|
*
|
|
* 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 Translate between signed linear and LPC10 (Linear Predictor Code)
|
|
*
|
|
* \ingroup codecs
|
|
*/
|
|
|
|
#include "asterisk.h"
|
|
|
|
ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
|
|
|
|
#include "asterisk/translate.h"
|
|
#include "asterisk/config.h"
|
|
#include "asterisk/module.h"
|
|
#include "asterisk/utils.h"
|
|
|
|
#include "lpc10/lpc10.h"
|
|
|
|
/* Sample frame data */
|
|
#include "slin_lpc10_ex.h"
|
|
#include "lpc10_slin_ex.h"
|
|
|
|
/* We use a very strange format here... I have no idea why... The frames are 180
|
|
samples long, which isn't even an even number of milliseconds... Not only that
|
|
but we hvae to waste two bits of each frame to keep them ending on a byte boundary
|
|
because the frames are 54 bits long */
|
|
|
|
#define LPC10_BYTES_IN_COMPRESSED_FRAME (LPC10_BITS_IN_COMPRESSED_FRAME + 7)/8
|
|
|
|
#define BUFFER_SAMPLES 8000
|
|
|
|
struct lpc10_coder_pvt {
|
|
union {
|
|
struct lpc10_encoder_state *enc;
|
|
struct lpc10_decoder_state *dec;
|
|
} lpc10;
|
|
/* Enough to store a full second */
|
|
short buf[BUFFER_SAMPLES];
|
|
int longer;
|
|
};
|
|
|
|
static int lpc10_enc_new(struct ast_trans_pvt *pvt)
|
|
{
|
|
struct lpc10_coder_pvt *tmp = pvt->pvt;
|
|
|
|
return (tmp->lpc10.enc = create_lpc10_encoder_state()) ? 0 : -1;
|
|
}
|
|
|
|
static int lpc10_dec_new(struct ast_trans_pvt *pvt)
|
|
{
|
|
struct lpc10_coder_pvt *tmp = pvt->pvt;
|
|
|
|
return (tmp->lpc10.dec = create_lpc10_decoder_state()) ? 0 : -1;
|
|
}
|
|
|
|
static struct ast_frame *lintolpc10_sample(void)
|
|
{
|
|
static struct ast_frame f;
|
|
f.frametype = AST_FRAME_VOICE;
|
|
f.subclass = AST_FORMAT_SLINEAR;
|
|
f.datalen = sizeof(slin_lpc10_ex);
|
|
/* Assume 8000 Hz */
|
|
f.samples = LPC10_SAMPLES_PER_FRAME;
|
|
f.mallocd = 0;
|
|
f.offset = 0;
|
|
f.src = __PRETTY_FUNCTION__;
|
|
f.data = slin_lpc10_ex;
|
|
return &f;
|
|
}
|
|
|
|
static struct ast_frame *lpc10tolin_sample(void)
|
|
{
|
|
static struct ast_frame f;
|
|
f.frametype = AST_FRAME_VOICE;
|
|
f.subclass = AST_FORMAT_LPC10;
|
|
f.datalen = sizeof(lpc10_slin_ex);
|
|
/* All frames are 22 ms long (maybe a little more -- why did he choose
|
|
LPC10_SAMPLES_PER_FRAME sample frames anyway?? */
|
|
f.samples = LPC10_SAMPLES_PER_FRAME;
|
|
f.mallocd = 0;
|
|
f.offset = 0;
|
|
f.src = __PRETTY_FUNCTION__;
|
|
f.data = lpc10_slin_ex;
|
|
return &f;
|
|
}
|
|
|
|
static void extract_bits(INT32 *bits, unsigned char *c)
|
|
{
|
|
int x;
|
|
for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
|
|
if (*c & (0x80 >> (x & 7)))
|
|
bits[x] = 1;
|
|
else
|
|
bits[x] = 0;
|
|
if ((x & 7) == 7)
|
|
c++;
|
|
}
|
|
}
|
|
|
|
/* XXX note lpc10_encode() produces one bit per word in bits[] */
|
|
static void build_bits(unsigned char *c, INT32 *bits)
|
|
{
|
|
unsigned char mask=0x80;
|
|
int x;
|
|
*c = 0;
|
|
for (x=0;x<LPC10_BITS_IN_COMPRESSED_FRAME;x++) {
|
|
if (bits[x])
|
|
*c |= mask;
|
|
mask = mask >> 1;
|
|
if ((x % 8)==7) {
|
|
c++;
|
|
*c = 0;
|
|
mask = 0x80;
|
|
}
|
|
}
|
|
}
|
|
|
|
static int lpc10tolin_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
|
|
{
|
|
struct lpc10_coder_pvt *tmp = pvt->pvt;
|
|
int16_t *dst = (int16_t *)pvt->outbuf;
|
|
int len = 0;
|
|
|
|
while (len + LPC10_BYTES_IN_COMPRESSED_FRAME <= f->datalen) {
|
|
int x;
|
|
float tmpbuf[LPC10_SAMPLES_PER_FRAME];
|
|
INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX see note */
|
|
if (pvt->samples + LPC10_SAMPLES_PER_FRAME > BUFFER_SAMPLES) {
|
|
ast_log(LOG_WARNING, "Out of buffer space\n");
|
|
return -1;
|
|
}
|
|
extract_bits(bits, f->data + len);
|
|
if (lpc10_decode(bits, tmpbuf, tmp->lpc10.dec)) {
|
|
ast_log(LOG_WARNING, "Invalid lpc10 data\n");
|
|
return -1;
|
|
}
|
|
for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++) {
|
|
/* Convert to a short between -1.0 and 1.0 */
|
|
dst[pvt->samples + x] = (int16_t)(32768.0 * tmpbuf[x]);
|
|
}
|
|
|
|
pvt->samples += LPC10_SAMPLES_PER_FRAME;
|
|
pvt->datalen += 2*LPC10_SAMPLES_PER_FRAME;
|
|
len += LPC10_BYTES_IN_COMPRESSED_FRAME;
|
|
}
|
|
if (len != f->datalen)
|
|
printf("Decoded %d, expected %d\n", len, f->datalen);
|
|
return 0;
|
|
}
|
|
|
|
static int lintolpc10_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
|
|
{
|
|
struct lpc10_coder_pvt *tmp = pvt->pvt;
|
|
|
|
/* Just add the frames to our stream */
|
|
if (pvt->samples + f->samples > BUFFER_SAMPLES) {
|
|
ast_log(LOG_WARNING, "Out of buffer space\n");
|
|
return -1;
|
|
}
|
|
memcpy(tmp->buf + pvt->samples, f->data, f->datalen);
|
|
pvt->samples += f->samples;
|
|
return 0;
|
|
}
|
|
|
|
static struct ast_frame *lintolpc10_frameout(struct ast_trans_pvt *pvt)
|
|
{
|
|
struct lpc10_coder_pvt *tmp = pvt->pvt;
|
|
int x;
|
|
int datalen = 0; /* output frame */
|
|
int samples = 0; /* output samples */
|
|
float tmpbuf[LPC10_SAMPLES_PER_FRAME];
|
|
INT32 bits[LPC10_BITS_IN_COMPRESSED_FRAME]; /* XXX what ??? */
|
|
/* We can't work on anything less than a frame in size */
|
|
if (pvt->samples < LPC10_SAMPLES_PER_FRAME)
|
|
return NULL;
|
|
while (pvt->samples >= LPC10_SAMPLES_PER_FRAME) {
|
|
/* Encode a frame of data */
|
|
for (x=0;x<LPC10_SAMPLES_PER_FRAME;x++)
|
|
tmpbuf[x] = (float)tmp->buf[x + samples] / 32768.0;
|
|
lpc10_encode(tmpbuf, bits, tmp->lpc10.enc);
|
|
build_bits((unsigned char *) pvt->outbuf + datalen, bits);
|
|
datalen += LPC10_BYTES_IN_COMPRESSED_FRAME;
|
|
samples += LPC10_SAMPLES_PER_FRAME;
|
|
pvt->samples -= LPC10_SAMPLES_PER_FRAME;
|
|
/* Use one of the two left over bits to record if this is a 22 or 23 ms frame...
|
|
important for IAX use */
|
|
tmp->longer = 1 - tmp->longer;
|
|
}
|
|
/* Move the data at the end of the buffer to the front */
|
|
if (pvt->samples)
|
|
memmove(tmp->buf, tmp->buf + samples, pvt->samples * 2);
|
|
return ast_trans_frameout(pvt, datalen, samples);
|
|
}
|
|
|
|
|
|
static void lpc10_destroy(struct ast_trans_pvt *arg)
|
|
{
|
|
struct lpc10_coder_pvt *pvt = arg->pvt;
|
|
/* Enc and DEC are both just allocated, so they can be freed */
|
|
ast_free(pvt->lpc10.enc);
|
|
}
|
|
|
|
static struct ast_translator lpc10tolin = {
|
|
.name = "lpc10tolin",
|
|
.srcfmt = AST_FORMAT_LPC10,
|
|
.dstfmt = AST_FORMAT_SLINEAR,
|
|
.newpvt = lpc10_dec_new,
|
|
.framein = lpc10tolin_framein,
|
|
.destroy = lpc10_destroy,
|
|
.sample = lpc10tolin_sample,
|
|
.desc_size = sizeof(struct lpc10_coder_pvt),
|
|
.buffer_samples = BUFFER_SAMPLES,
|
|
.plc_samples = LPC10_SAMPLES_PER_FRAME,
|
|
.buf_size = BUFFER_SAMPLES * 2,
|
|
};
|
|
|
|
static struct ast_translator lintolpc10 = {
|
|
.name = "lintolpc10",
|
|
.srcfmt = AST_FORMAT_SLINEAR,
|
|
.dstfmt = AST_FORMAT_LPC10,
|
|
.newpvt = lpc10_enc_new,
|
|
.framein = lintolpc10_framein,
|
|
.frameout = lintolpc10_frameout,
|
|
.destroy = lpc10_destroy,
|
|
.sample = lintolpc10_sample,
|
|
.desc_size = sizeof(struct lpc10_coder_pvt),
|
|
.buffer_samples = BUFFER_SAMPLES,
|
|
.buf_size = LPC10_BYTES_IN_COMPRESSED_FRAME * (1 + BUFFER_SAMPLES / LPC10_SAMPLES_PER_FRAME),
|
|
};
|
|
|
|
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 == NULL)
|
|
return 0;
|
|
if (cfg == CONFIG_STATUS_FILEUNCHANGED)
|
|
return 0;
|
|
for (var = ast_variable_browse(cfg, "plc"); var; var = var->next) {
|
|
if (!strcasecmp(var->name, "genericplc")) {
|
|
lpc10tolin.useplc = ast_true(var->value) ? 1 : 0;
|
|
ast_verb(3, "codec_lpc10: %susing generic PLC\n",
|
|
lpc10tolin.useplc ? "" : "not ");
|
|
}
|
|
}
|
|
ast_config_destroy(cfg);
|
|
return 0;
|
|
}
|
|
|
|
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(&lintolpc10);
|
|
res |= ast_unregister_translator(&lpc10tolin);
|
|
|
|
return res;
|
|
}
|
|
|
|
static int load_module(void)
|
|
{
|
|
int res;
|
|
|
|
if (parse_config(0))
|
|
return AST_MODULE_LOAD_DECLINE;
|
|
res = ast_register_translator(&lpc10tolin);
|
|
if (!res)
|
|
res = ast_register_translator(&lintolpc10);
|
|
else
|
|
ast_unregister_translator(&lpc10tolin);
|
|
if (res)
|
|
return AST_MODULE_LOAD_FAILURE;
|
|
return AST_MODULE_LOAD_SUCCESS;
|
|
}
|
|
|
|
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "LPC10 2.4kbps Coder/Decoder",
|
|
.load = load_module,
|
|
.unload = unload_module,
|
|
.reload = reload,
|
|
);
|