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asterisk/codecs/codec_g726.c

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/*
* Asterisk -- An open source telephony toolkit.
*
* Copyright (C) 1999 - 2006, Digium, Inc.
*
* Mark Spencer <markster@digium.com>
* Kevin P. Fleming <kpfleming@digium.com>
*
* Based on frompcm.c and topcm.c from the Emiliano MIPL browser/
* interpreter. See http://www.bsdtelephony.com.mx
*
* 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_g726.c - translate between signed linear and ITU G.726-32kbps (both RFC3551 and AAL2 codeword packing)
*
* \ingroup codecs
*/
/*** MODULEINFO
<support_level>core</support_level>
***/
#include "asterisk.h"
#include "asterisk/lock.h"
#include "asterisk/linkedlists.h"
#include "asterisk/module.h"
#include "asterisk/config.h"
#include "asterisk/translate.h"
#include "asterisk/utils.h"
#define WANT_ASM
#include "log2comp.h"
/* define NOT_BLI to use a faster but not bit-level identical version */
/* #define NOT_BLI */
#if defined(NOT_BLI)
# if defined(_MSC_VER)
typedef __int64 sint64;
# elif defined(__GNUC__)
typedef long long sint64;
# else
# error 64-bit integer type is not defined for your compiler/platform
# endif
#endif
#define BUFFER_SAMPLES 8096 /* size for the translation buffers */
#define BUF_SHIFT 5
/* Sample frame data */
#include "asterisk/slin.h"
#include "ex_g726.h"
/*
* The following is the definition of the state structure
* used by the G.726 encoder and decoder to preserve their internal
* state between successive calls. The meanings of the majority
* of the state structure fields are explained in detail in the
* CCITT Recommendation G.721. The field names are essentially identical
* to variable names in the bit level description of the coding algorithm
* included in this Recommendation.
*/
struct g726_state {
long yl; /* Locked or steady state step size multiplier. */
int yu; /* Unlocked or non-steady state step size multiplier. */
int dms; /* Short term energy estimate. */
int dml; /* Long term energy estimate. */
int ap; /* Linear weighting coefficient of 'yl' and 'yu'. */
int a[2]; /* Coefficients of pole portion of prediction filter.
* stored as fixed-point 1==2^14 */
int b[6]; /* Coefficients of zero portion of prediction filter.
* stored as fixed-point 1==2^14 */
int pk[2]; /* Signs of previous two samples of a partially
* reconstructed signal. */
int dq[6]; /* Previous 6 samples of the quantized difference signal
* stored as fixed point 1==2^12,
* or in internal floating point format */
int sr[2]; /* Previous 2 samples of the quantized difference signal
* stored as fixed point 1==2^12,
* or in internal floating point format */
int td; /* delayed tone detect, new in 1988 version */
};
static int qtab_721[7] = {-124, 80, 178, 246, 300, 349, 400};
/*
* Maps G.721 code word to reconstructed scale factor normalized log
* magnitude values.
*/
static int _dqlntab[16] = {-2048, 4, 135, 213, 273, 323, 373, 425,
425, 373, 323, 273, 213, 135, 4, -2048};
/* Maps G.721 code word to log of scale factor multiplier. */
static int _witab[16] = {-12, 18, 41, 64, 112, 198, 355, 1122,
1122, 355, 198, 112, 64, 41, 18, -12};
/*
* Maps G.721 code words to a set of values whose long and short
* term averages are computed and then compared to give an indication
* how stationary (steady state) the signal is.
*/
static int _fitab[16] = {0, 0, 0, 0x200, 0x200, 0x200, 0x600, 0xE00,
0xE00, 0x600, 0x200, 0x200, 0x200, 0, 0, 0};
/*
* g72x_init_state()
*
* This routine initializes and/or resets the g726_state structure
* pointed to by 'state_ptr'.
* All the initial state values are specified in the CCITT G.721 document.
*/
static void g726_init_state(struct g726_state *state_ptr)
{
int cnta;
state_ptr->yl = 34816;
state_ptr->yu = 544;
state_ptr->dms = 0;
state_ptr->dml = 0;
state_ptr->ap = 0;
for (cnta = 0; cnta < 2; cnta++) {
state_ptr->a[cnta] = 0;
state_ptr->pk[cnta] = 0;
#ifdef NOT_BLI
state_ptr->sr[cnta] = 1;
#else
state_ptr->sr[cnta] = 32;
#endif
}
for (cnta = 0; cnta < 6; cnta++) {
state_ptr->b[cnta] = 0;
#ifdef NOT_BLI
state_ptr->dq[cnta] = 1;
#else
state_ptr->dq[cnta] = 32;
#endif
}
state_ptr->td = 0;
}
/*
* quan()
*
* quantizes the input val against the table of integers.
* It returns i if table[i - 1] <= val < table[i].
*
* Using linear search for simple coding.
*/
static int quan(int val, int *table, int size)
{
int i;
for (i = 0; i < size && val >= *table; ++i, ++table)
;
return i;
}
#ifdef NOT_BLI /* faster non-identical version */
/*
* predictor_zero()
*
* computes the estimated signal from 6-zero predictor.
*
*/
static int predictor_zero(struct g726_state *state_ptr)
{ /* divide by 2 is necessary here to handle negative numbers correctly */
int i;
sint64 sezi;
for (sezi = 0, i = 0; i < 6; i++) /* ACCUM */
sezi += (sint64)state_ptr->b[i] * state_ptr->dq[i];
return (int)(sezi >> 13) / 2 /* 2^14 */;
}
/*
* predictor_pole()
*
* computes the estimated signal from 2-pole predictor.
*
*/
static int predictor_pole(struct g726_state *state_ptr)
{ /* divide by 2 is necessary here to handle negative numbers correctly */
return (int)(((sint64)state_ptr->a[1] * state_ptr->sr[1] +
(sint64)state_ptr->a[0] * state_ptr->sr[0]) >> 13) / 2 /* 2^14 */;
}
#else /* NOT_BLI - identical version */
/*
* fmult()
*
* returns the integer product of the fixed-point number "an" (1==2^12) and
* "floating point" representation (4-bit exponent, 6-bit mantessa) "srn".
*/
static int fmult(int an, int srn)
{
int anmag, anexp, anmant;
int wanexp, wanmant;
int retval;
anmag = (an > 0) ? an : ((-an) & 0x1FFF);
anexp = ilog2(anmag) - 5;
anmant = (anmag == 0) ? 32 :
(anexp >= 0) ? anmag >> anexp : anmag << -anexp;
wanexp = anexp + ((srn >> 6) & 0xF) - 13;
wanmant = (anmant * (srn & 077) + 0x30) >> 4;
retval = (wanexp >= 0) ? ((wanmant << wanexp) & 0x7FFF) :
(wanmant >> -wanexp);
return (((an ^ srn) < 0) ? -retval : retval);
}
static int predictor_zero(struct g726_state *state_ptr)
{
int i;
int sezi;
for (sezi = 0, i = 0; i < 6; i++) /* ACCUM */
sezi += fmult(state_ptr->b[i] >> 2, state_ptr->dq[i]);
return sezi;
}
static int predictor_pole(struct g726_state *state_ptr)
{
return (fmult(state_ptr->a[1] >> 2, state_ptr->sr[1]) +
fmult(state_ptr->a[0] >> 2, state_ptr->sr[0]));
}
#endif /* NOT_BLI */
/*
* step_size()
*
* computes the quantization step size of the adaptive quantizer.
*
*/
static int step_size(struct g726_state *state_ptr)
{
int y, dif, al;
if (state_ptr->ap >= 256) {
return state_ptr->yu;
}
y = state_ptr->yl >> 6;
dif = state_ptr->yu - y;
al = state_ptr->ap >> 2;
if (dif > 0) {
y += (dif * al) >> 6;
} else if (dif < 0) {
y += (dif * al + 0x3F) >> 6;
}
return y;
}
/*
* quantize()
*
* Given a raw sample, 'd', of the difference signal and a
* quantization step size scale factor, 'y', this routine returns the
* ADPCM codeword to which that sample gets quantized. The step
* size scale factor division operation is done in the log base 2 domain
* as a subtraction.
*/
static int quantize(
int d, /* Raw difference signal sample */
int y, /* Step size multiplier */
int *table, /* quantization table */
int size) /* table size of integers */
{
int dqm; /* Magnitude of 'd' */
int exp; /* Integer part of base 2 log of 'd' */
int mant; /* Fractional part of base 2 log */
int dl; /* Log of magnitude of 'd' */
int dln; /* Step size scale factor normalized log */
int i;
/*
* LOG
*
* Compute base 2 log of 'd', and store in 'dl'.
*/
dqm = abs(d);
exp = ilog2(dqm);
if (exp < 0) {
exp = 0;
}
mant = ((dqm << 7) >> exp) & 0x7F; /* Fractional portion. */
dl = (exp << 7) | mant;
/*
* SUBTB
*
* "Divide" by step size multiplier.
*/
dln = dl - (y >> 2);
/*
* QUAN
*
* Obtain codeword i for 'd'.
*/
i = quan(dln, table, size);
if (d < 0) { /* take 1's complement of i */
return ((size << 1) + 1 - i);
} else if (i == 0) { /* take 1's complement of 0 */
return ((size << 1) + 1); /* new in 1988 */
} else {
return i;
}
}
/*
* reconstruct()
*
* Returns reconstructed difference signal 'dq' obtained from
* codeword 'i' and quantization step size scale factor 'y'.
* Multiplication is performed in log base 2 domain as addition.
*/
static int reconstruct(
int sign, /* 0 for non-negative value */
int dqln, /* G.72x codeword */
int y) /* Step size multiplier */
{
int dql; /* Log of 'dq' magnitude */
int dex; /* Integer part of log */
int dqt;
int dq; /* Reconstructed difference signal sample */
dql = dqln + (y >> 2); /* ADDA */
if (dql < 0) {
#ifdef NOT_BLI
return (sign) ? -1 : 1;
#else
return (sign) ? -0x8000 : 0;
#endif
} else { /* ANTILOG */
dex = (dql >> 7) & 15;
dqt = 128 + (dql & 127);
#ifdef NOT_BLI
dq = ((dqt << 19) >> (14 - dex));
return (sign) ? -dq : dq;
#else
dq = (dqt << 7) >> (14 - dex);
return (sign) ? (dq - 0x8000) : dq;
#endif
}
}
/*
* update()
*
* updates the state variables for each output code
*/
static void update(
int code_size, /* distinguish 723_40 with others */
int y, /* quantizer step size */
int wi, /* scale factor multiplier */
int fi, /* for long/short term energies */
int dq, /* quantized prediction difference */
int sr, /* reconstructed signal */
int dqsez, /* difference from 2-pole predictor */
struct g726_state *state_ptr) /* coder state pointer */
{
int cnt;
int mag; /* Adaptive predictor, FLOAT A */
#ifndef NOT_BLI
int exp;
#endif
int a2p=0; /* LIMC */
int a1ul; /* UPA1 */
int pks1; /* UPA2 */
int fa1;
int tr; /* tone/transition detector */
int ylint, thr2, dqthr;
int ylfrac, thr1;
int pk0;
pk0 = (dqsez < 0) ? 1 : 0; /* needed in updating predictor poles */
#ifdef NOT_BLI
mag = abs(dq / 0x1000); /* prediction difference magnitude */
#else
mag = dq & 0x7FFF; /* prediction difference magnitude */
#endif
/* TRANS */
ylint = state_ptr->yl >> 15; /* exponent part of yl */
ylfrac = (state_ptr->yl >> 10) & 0x1F; /* fractional part of yl */
thr1 = (32 + ylfrac) << ylint; /* threshold */
thr2 = (ylint > 9) ? 31 << 10 : thr1; /* limit thr2 to 31 << 10 */
dqthr = (thr2 + (thr2 >> 1)) >> 1; /* dqthr = 0.75 * thr2 */
if (state_ptr->td == 0) { /* signal supposed voice */
tr = 0;
} else if (mag <= dqthr) { /* supposed data, but small mag */
tr = 0; /* treated as voice */
} else { /* signal is data (modem) */
tr = 1;
}
/*
* Quantizer scale factor adaptation.
*/
/* FUNCTW & FILTD & DELAY */
/* update non-steady state step size multiplier */
state_ptr->yu = y + ((wi - y) >> 5);
/* LIMB */
if (state_ptr->yu < 544) { /* 544 <= yu <= 5120 */
state_ptr->yu = 544;
} else if (state_ptr->yu > 5120) {
state_ptr->yu = 5120;
}
/* FILTE & DELAY */
/* update steady state step size multiplier */
state_ptr->yl += state_ptr->yu + ((-state_ptr->yl) >> 6);
/*
* Adaptive predictor coefficients.
*/
if (tr == 1) { /* reset a's and b's for modem signal */
state_ptr->a[0] = 0;
state_ptr->a[1] = 0;
state_ptr->b[0] = 0;
state_ptr->b[1] = 0;
state_ptr->b[2] = 0;
state_ptr->b[3] = 0;
state_ptr->b[4] = 0;
state_ptr->b[5] = 0;
} else { /* update a's and b's */
pks1 = pk0 ^ state_ptr->pk[0]; /* UPA2 */
/* update predictor pole a[1] */
a2p = state_ptr->a[1] - (state_ptr->a[1] >> 7);
if (dqsez != 0) {
fa1 = (pks1) ? state_ptr->a[0] : -state_ptr->a[0];
if (fa1 < -8191) { /* a2p = function of fa1 */
a2p -= 0x100;
} else if (fa1 > 8191) {
a2p += 0xFF;
} else {
a2p += fa1 >> 5;
}
if (pk0 ^ state_ptr->pk[1]) {
/* LIMC */
if (a2p <= -12160) {
a2p = -12288;
} else if (a2p >= 12416) {
a2p = 12288;
} else {
a2p -= 0x80;
}
} else if (a2p <= -12416) {
a2p = -12288;
} else if (a2p >= 12160) {
a2p = 12288;
} else {
a2p += 0x80;
}
}
/* TRIGB & DELAY */
state_ptr->a[1] = a2p;
/* UPA1 */
/* update predictor pole a[0] */
state_ptr->a[0] -= state_ptr->a[0] >> 8;
if (dqsez != 0) {
if (pks1 == 0)
state_ptr->a[0] += 192;
else
state_ptr->a[0] -= 192;
}
/* LIMD */
a1ul = 15360 - a2p;
if (state_ptr->a[0] < -a1ul) {
state_ptr->a[0] = -a1ul;
} else if (state_ptr->a[0] > a1ul) {
state_ptr->a[0] = a1ul;
}
/* UPB : update predictor zeros b[6] */
for (cnt = 0; cnt < 6; cnt++) {
if (code_size == 5) { /* for 40Kbps G.723 */
state_ptr->b[cnt] -= state_ptr->b[cnt] >> 9;
} else { /* for G.721 and 24Kbps G.723 */
state_ptr->b[cnt] -= state_ptr->b[cnt] >> 8;
}
if (mag) { /* XOR */
if ((dq ^ state_ptr->dq[cnt]) >= 0) {
state_ptr->b[cnt] += 128;
} else {
state_ptr->b[cnt] -= 128;
}
}
}
}
for (cnt = 5; cnt > 0; cnt--)
state_ptr->dq[cnt] = state_ptr->dq[cnt-1];
#ifdef NOT_BLI
state_ptr->dq[0] = dq;
#else
/* FLOAT A : convert dq[0] to 4-bit exp, 6-bit mantissa f.p. */
if (mag == 0) {
state_ptr->dq[0] = (dq >= 0) ? 0x20 : 0x20 - 0x400;
} else {
exp = ilog2(mag) + 1;
state_ptr->dq[0] = (dq >= 0) ?
(exp << 6) + ((mag << 6) >> exp) :
(exp << 6) + ((mag << 6) >> exp) - 0x400;
}
#endif
state_ptr->sr[1] = state_ptr->sr[0];
#ifdef NOT_BLI
state_ptr->sr[0] = sr;
#else
/* FLOAT B : convert sr to 4-bit exp., 6-bit mantissa f.p. */
if (sr == 0) {
state_ptr->sr[0] = 0x20;
} else if (sr > 0) {
exp = ilog2(sr) + 1;
state_ptr->sr[0] = (exp << 6) + ((sr << 6) >> exp);
} else if (sr > -0x8000) {
mag = -sr;
exp = ilog2(mag) + 1;
state_ptr->sr[0] = (exp << 6) + ((mag << 6) >> exp) - 0x400;
} else
state_ptr->sr[0] = 0x20 - 0x400;
#endif
/* DELAY A */
state_ptr->pk[1] = state_ptr->pk[0];
state_ptr->pk[0] = pk0;
/* TONE */
if (tr == 1) { /* this sample has been treated as data */
state_ptr->td = 0; /* next one will be treated as voice */
} else if (a2p < -11776) { /* small sample-to-sample correlation */
state_ptr->td = 1; /* signal may be data */
} else { /* signal is voice */
state_ptr->td = 0;
}
/*
* Adaptation speed control.
*/
state_ptr->dms += (fi - state_ptr->dms) >> 5; /* FILTA */
state_ptr->dml += (((fi << 2) - state_ptr->dml) >> 7); /* FILTB */
if (tr == 1) {
state_ptr->ap = 256;
} else if (y < 1536) { /* SUBTC */
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
} else if (state_ptr->td == 1) {
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
} else if (abs((state_ptr->dms << 2) - state_ptr->dml) >=
(state_ptr->dml >> 3)) {
state_ptr->ap += (0x200 - state_ptr->ap) >> 4;
} else {
state_ptr->ap += (-state_ptr->ap) >> 4;
}
}
/*
* g726_decode()
*
* Description:
*
* Decodes a 4-bit code of G.726-32 encoded data of i and
* returns the resulting linear PCM, A-law or u-law value.
* return -1 for unknown out_coding value.
*/
static int g726_decode(int i, struct g726_state *state_ptr)
{
int sezi, sez, se; /* ACCUM */
int y; /* MIX */
int sr; /* ADDB */
int dq;
int dqsez;
i &= 0x0f; /* mask to get proper bits */
#ifdef NOT_BLI
sezi = predictor_zero(state_ptr);
sez = sezi;
se = sezi + predictor_pole(state_ptr); /* estimated signal */
#else
sezi = predictor_zero(state_ptr);
sez = sezi >> 1;
se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */
#endif
y = step_size(state_ptr); /* dynamic quantizer step size */
dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized diff. */
#ifdef NOT_BLI
sr = se + dq; /* reconst. signal */
dqsez = dq + sez; /* pole prediction diff. */
#else
sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */
dqsez = sr - se + sez; /* pole prediction diff. */
#endif
update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr);
#ifdef NOT_BLI
return (sr >> 10); /* sr was 26-bit dynamic range */
#else
return (sr << 2); /* sr was 14-bit dynamic range */
#endif
}
/*
* g726_encode()
*
* Encodes the input vale of linear PCM, A-law or u-law data sl and returns
* the resulting code. -1 is returned for unknown input coding value.
*/
static int g726_encode(int sl, struct g726_state *state_ptr)
{
int sezi, se, sez; /* ACCUM */
int d; /* SUBTA */
int sr; /* ADDB */
int y; /* MIX */
int dqsez; /* ADDC */
int dq, i;
#ifdef NOT_BLI
sl <<= 10; /* 26-bit dynamic range */
sezi = predictor_zero(state_ptr);
sez = sezi;
se = sezi + predictor_pole(state_ptr); /* estimated signal */
#else
sl >>= 2; /* 14-bit dynamic range */
sezi = predictor_zero(state_ptr);
sez = sezi >> 1;
se = (sezi + predictor_pole(state_ptr)) >> 1; /* estimated signal */
#endif
d = sl - se; /* estimation difference */
/* quantize the prediction difference */
y = step_size(state_ptr); /* quantizer step size */
#ifdef NOT_BLI
d /= 0x1000;
#endif
i = quantize(d, y, qtab_721, 7); /* i = G726 code */
dq = reconstruct(i & 8, _dqlntab[i], y); /* quantized est diff */
#ifdef NOT_BLI
sr = se + dq; /* reconst. signal */
dqsez = dq + sez; /* pole prediction diff. */
#else
sr = (dq < 0) ? se - (dq & 0x3FFF) : se + dq; /* reconst. signal */
dqsez = sr - se + sez; /* pole prediction diff. */
#endif
update(4, y, _witab[i] << 5, _fitab[i], dq, sr, dqsez, state_ptr);
return i;
}
/*
* Private workspace for translating signed linear signals to G726.
* Don't bother to define two distinct structs.
*/
struct g726_coder_pvt {
/* buffer any odd byte in input - 0x80 + (value & 0xf) if present */
unsigned char next_flag;
struct g726_state g726;
};
/*! \brief init a new instance of g726_coder_pvt. */
static int lintog726_new(struct ast_trans_pvt *pvt)
{
struct g726_coder_pvt *tmp = pvt->pvt;
g726_init_state(&tmp->g726);
return 0;
}
/*! \brief decode packed 4-bit G726 values (AAL2 packing) and store in buffer. */
static int g726aal2tolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
{
struct g726_coder_pvt *tmp = pvt->pvt;
unsigned char *src = f->data.ptr;
int16_t *dst = pvt->outbuf.i16 + pvt->samples;
unsigned int i;
for (i = 0; i < f->datalen; i++) {
*dst++ = g726_decode((src[i] >> 4) & 0xf, &tmp->g726);
*dst++ = g726_decode(src[i] & 0x0f, &tmp->g726);
}
pvt->samples += f->samples;
pvt->datalen += 2 * f->samples; /* 2 bytes/sample */
return 0;
}
/*! \brief compress and store data (4-bit G726 samples, AAL2 packing) in outbuf */
static int lintog726aal2_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
struct g726_coder_pvt *tmp = pvt->pvt;
int16_t *src = f->data.ptr;
unsigned int i;
for (i = 0; i < f->samples; i++) {
unsigned char d = g726_encode(src[i], &tmp->g726); /* this sample */
if (tmp->next_flag & 0x80) { /* merge with leftover sample */
pvt->outbuf.c[pvt->datalen++] = ((tmp->next_flag & 0xf)<< 4) | d;
pvt->samples += 2; /* 2 samples per byte */
tmp->next_flag = 0;
} else {
tmp->next_flag = 0x80 | d;
}
}
return 0;
}
/*! \brief decode packed 4-bit G726 values (RFC3551 packing) and store in buffer. */
static int g726tolin_framein (struct ast_trans_pvt *pvt, struct ast_frame *f)
{
struct g726_coder_pvt *tmp = pvt->pvt;
unsigned char *src = f->data.ptr;
int16_t *dst = pvt->outbuf.i16 + pvt->samples;
unsigned int i;
for (i = 0; i < f->datalen; i++) {
*dst++ = g726_decode(src[i] & 0x0f, &tmp->g726);
*dst++ = g726_decode((src[i] >> 4) & 0xf, &tmp->g726);
}
pvt->samples += f->samples;
pvt->datalen += 2 * f->samples; /* 2 bytes/sample */
return 0;
}
/*! \brief compress and store data (4-bit G726 samples, RFC3551 packing) in outbuf */
static int lintog726_framein(struct ast_trans_pvt *pvt, struct ast_frame *f)
{
struct g726_coder_pvt *tmp = pvt->pvt;
int16_t *src = f->data.ptr;
unsigned int i;
for (i = 0; i < f->samples; i++) {
unsigned char d = g726_encode(src[i], &tmp->g726); /* this sample */
if (tmp->next_flag & 0x80) { /* merge with leftover sample */
pvt->outbuf.c[pvt->datalen++] = (d << 4) | (tmp->next_flag & 0xf);
pvt->samples += 2; /* 2 samples per byte */
tmp->next_flag = 0;
} else {
tmp->next_flag = 0x80 | d;
}
}
return 0;
}
static struct ast_translator g726tolin = {
.name = "g726tolin",
.src_codec = {
.name = "g726",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "slin",
.newpvt = lintog726_new, /* same for both directions */
.framein = g726tolin_framein,
.sample = g726_sample,
.desc_size = sizeof(struct g726_coder_pvt),
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES * 2,
};
static struct ast_translator lintog726 = {
.name = "lintog726",
.src_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "g726",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "g726",
.newpvt = lintog726_new, /* same for both directions */
.framein = lintog726_framein,
.sample = slin8_sample,
.desc_size = sizeof(struct g726_coder_pvt),
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES/2,
};
static struct ast_translator g726aal2tolin = {
.name = "g726aal2tolin",
.src_codec = {
.name = "g726aal2",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "slin",
.newpvt = lintog726_new, /* same for both directions */
.framein = g726aal2tolin_framein,
.sample = g726_sample,
.desc_size = sizeof(struct g726_coder_pvt),
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES * 2,
};
static struct ast_translator lintog726aal2 = {
.name = "lintog726aal2",
.src_codec = {
.name = "slin",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.dst_codec = {
.name = "g726aal2",
.type = AST_MEDIA_TYPE_AUDIO,
.sample_rate = 8000,
},
.format = "g726aal2",
.newpvt = lintog726_new, /* same for both directions */
.framein = lintog726aal2_framein,
.sample = slin8_sample,
.desc_size = sizeof(struct g726_coder_pvt),
.buffer_samples = BUFFER_SAMPLES,
.buf_size = BUFFER_SAMPLES / 2,
};
static int unload_module(void)
{
int res = 0;
res |= ast_unregister_translator(&g726tolin);
res |= ast_unregister_translator(&lintog726);
res |= ast_unregister_translator(&g726aal2tolin);
res |= ast_unregister_translator(&lintog726aal2);
return res;
}
static int load_module(void)
{
int res = 0;
res |= ast_register_translator(&g726tolin);
res |= ast_register_translator(&lintog726);
res |= ast_register_translator(&g726aal2tolin);
res |= ast_register_translator(&lintog726aal2);
if (res) {
unload_module();
return AST_MODULE_LOAD_DECLINE;
}
return AST_MODULE_LOAD_SUCCESS;
}
AST_MODULE_INFO(ASTERISK_GPL_KEY, AST_MODFLAG_DEFAULT, "ITU G.726-32kbps G726 Transcoder",
.support_level = AST_MODULE_SUPPORT_CORE,
.load = load_module,
.unload = unload_module,
);
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