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asterisk/codecs/codec_g726.c
George Joseph 747beb1ed1 modules: change module LOAD_FAILUREs to LOAD_DECLINES 
In all non-pbx modules, AST_MODULE_LOAD_FAILURE has been changed
to AST_MODULE_LOAD_DECLINE.  This prevents asterisk from exiting
if a module can't be loaded.  If the user wishes to retain the
FAILURE behavior for a specific module, they can use the "require"
or "preload-require" keyword in modules.conf.

A new API was added to logger: ast_is_logger_initialized().  This
allows asterisk.c/check_init() to print to the error log once the
logger subsystem is ready instead of just to stdout.  If something
does fail before the logger is initialized, we now print to stderr
instead of stdout.

Change-Id: I5f4b50623d9b5a6cb7c5624a8c5c1274c13b2b25
2017-04-12 15:57:21 -06:00

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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 codword 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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