freeswitch/libs/voipcodecs/src/gsm0610_long_term.c
2008-02-17 05:11:21 +00:00

410 lines
12 KiB
C

/*
* VoIPcodecs - a series of DSP components for telephony
*
* gsm0610_long_term.c - GSM 06.10 full rate speech codec.
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2006 Steve Underwood
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2, or
* the Lesser GNU General Public License version 2.1, as published by
* the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* This code is based on the widely used GSM 06.10 code available from
* http://kbs.cs.tu-berlin.de/~jutta/toast.html
*
* $Id: gsm0610_long_term.c,v 1.11 2008/02/09 15:31:36 steveu Exp $
*/
/*! \file */
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <assert.h>
#include <inttypes.h>
#if defined(HAVE_TGMATH_H)
#include <tgmath.h>
#endif
#if defined(HAVE_MATH_H)
#include <math.h>
#endif
#include <stdlib.h>
#include "voipcodecs/telephony.h"
#include "voipcodecs/bitstream.h"
#include "voipcodecs/dc_restore.h"
#include "voipcodecs/gsm0610.h"
#include "gsm0610_local.h"
/* Table 4.3a Decision level of the LTP gain quantizer */
static const int16_t gsm_DLB[4] =
{
6554, 16384, 26214, 32767
};
/* Table 4.3b Quantization levels of the LTP gain quantizer */
static const int16_t gsm_QLB[4] =
{
3277, 11469, 21299, 32767
};
/* 4.2.11 .. 4.2.12 LONG TERM PREDICTOR (LTP) SECTION */
#if defined(__GNUC__) && defined(__i386__)
int32_t gsm0610_max_cross_corr(const int16_t *wt, const int16_t *dp, int16_t *Nc_out)
{
int32_t lmax;
int32_t out;
__asm__ __volatile__(
" emms;\n"
" pushl %%ebx;\n"
" movl $0,%%edx;\n" /* Will be maximum inner-product */
" movl $40,%%ebx;\n"
" movl %%ebx,%%ecx;\n" /* Will be index of max inner-product */
" subl $80,%%esi;\n"
" .p2align 2;\n"
"1:\n"
" movq (%%edi),%%mm0;\n"
" movq (%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm0;\n"
" movq 8(%%edi),%%mm1;\n"
" movq 8(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 16(%%edi),%%mm1;\n"
" movq 16(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 24(%%edi),%%mm1;\n"
" movq 24(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 32(%%edi),%%mm1;\n"
" movq 32(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 40(%%edi),%%mm1;\n"
" movq 40(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 48(%%edi),%%mm1;\n"
" movq 48(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 56(%%edi),%%mm1;\n"
" movq 56(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 64(%%edi),%%mm1;\n"
" movq 64(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq 72(%%edi),%%mm1;\n"
" movq 72(%%esi),%%mm2;\n"
" pmaddwd %%mm2,%%mm1;\n"
" paddd %%mm1,%%mm0;\n"
" movq %%mm0,%%mm1;\n"
" punpckhdq %%mm0,%%mm1;\n" /* mm1 has high int32 of mm0 dup'd */
" paddd %%mm1,%%mm0;\n"
" movd %%mm0,%%eax;\n" /* eax has result */
" cmpl %%edx,%%eax;\n"
" jle 2f;\n"
" movl %%eax,%%edx;\n"
" movl %%ebx,%%ecx;\n"
" .p2align 2;\n"
"2:\n"
" subl $2,%%esi;\n"
" incl %%ebx;\n"
" cmpl $120,%%ebx;\n"
" jle 1b;\n"
" popl %%ebx;\n"
" emms;\n"
: "=d" (lmax), "=c" (out)
: "D" (wt), "S" (dp)
: "eax"
);
*Nc_out = out;
return lmax;
}
/*- End of function --------------------------------------------------------*/
#endif
/* This procedure computes the LTP gain (bc) and the LTP lag (Nc)
for the long term analysis filter. This is done by calculating a
maximum of the cross-correlation function between the current
sub-segment short term residual signal d[0..39] (output of
the short term analysis filter; for simplification the index
of this array begins at 0 and ends at 39 for each sub-segment of the
RPE-LTP analysis) and the previous reconstructed short term
residual signal dp[ -120 .. -1 ]. A dynamic scaling must be
performed to avoid overflow. */
/* This procedure exists in three versions. First, the integer
version; then, the two floating point versions (as another
function), with or without scaling. */
static int16_t evaluate_ltp_parameters(int16_t d[40],
int16_t *dp, // [-120..-1] IN
int16_t *Nc_out)
{
int k;
int16_t Nc;
int16_t bc;
int16_t wt[40];
int32_t L_max;
int32_t L_power;
int16_t R;
int16_t S;
int16_t dmax;
int16_t scale;
int16_t temp;
int32_t L_temp;
#if !(defined(__GNUC__) && defined(__i386__))
int16_t lambda;
#endif
/* Search of the optimum scaling of d[0..39]. */
dmax = 0;
for (k = 0; k < 40; k++)
{
temp = d[k];
temp = gsm_abs(temp);
if (temp > dmax)
dmax = temp;
/*endif*/
}
/*endfor*/
if (dmax == 0)
{
temp = 0;
}
else
{
assert(dmax > 0);
temp = gsm0610_norm((int32_t) dmax << 16);
}
/*endif*/
if (temp > 6)
scale = 0;
else
scale = (int16_t) (6 - temp);
/*endif*/
assert(scale >= 0);
/* Initialization of a working array wt */
for (k = 0; k < 40; k++)
wt[k] = d[k] >> scale;
/*endfor*/
/* Search for the maximum cross-correlation and coding of the LTP lag */
#if defined(__GNUC__) && defined(__i386__)
L_max = gsm0610_max_cross_corr(wt, dp, &Nc);
#else
L_max = 0;
Nc = 40; /* index for the maximum cross-correlation */
for (lambda = 40; lambda <= 120; lambda++)
{
int32_t L_result;
L_result = (wt[0]*dp[0 - lambda])
+ (wt[1]*dp[1 - lambda])
+ (wt[2]*dp[2 - lambda])
+ (wt[3]*dp[3 - lambda])
+ (wt[4]*dp[4 - lambda])
+ (wt[5]*dp[5 - lambda])
+ (wt[6]*dp[6 - lambda])
+ (wt[7]*dp[7 - lambda])
+ (wt[8]*dp[8 - lambda])
+ (wt[9]*dp[9 - lambda])
+ (wt[10]*dp[10 - lambda])
+ (wt[11]*dp[11 - lambda])
+ (wt[12]*dp[12 - lambda])
+ (wt[13]*dp[13 - lambda])
+ (wt[14]*dp[14 - lambda])
+ (wt[15]*dp[15 - lambda])
+ (wt[16]*dp[16 - lambda])
+ (wt[17]*dp[17 - lambda])
+ (wt[18]*dp[18 - lambda])
+ (wt[19]*dp[19 - lambda])
+ (wt[20]*dp[20 - lambda])
+ (wt[21]*dp[21 - lambda])
+ (wt[22]*dp[22 - lambda])
+ (wt[23]*dp[23 - lambda])
+ (wt[24]*dp[24 - lambda])
+ (wt[25]*dp[25 - lambda])
+ (wt[26]*dp[26 - lambda])
+ (wt[27]*dp[27 - lambda])
+ (wt[28]*dp[28 - lambda])
+ (wt[29]*dp[29 - lambda])
+ (wt[30]*dp[30 - lambda])
+ (wt[31]*dp[31 - lambda])
+ (wt[32]*dp[32 - lambda])
+ (wt[33]*dp[33 - lambda])
+ (wt[34]*dp[34 - lambda])
+ (wt[35]*dp[35 - lambda])
+ (wt[36]*dp[36 - lambda])
+ (wt[37]*dp[37 - lambda])
+ (wt[38]*dp[38 - lambda])
+ (wt[39]*dp[39 - lambda]);
if (L_result > L_max)
{
Nc = lambda;
L_max = L_result;
}
/*endif*/
}
/*endfor*/
#endif
*Nc_out = Nc;
L_max <<= 1;
/* Rescaling of L_max */
assert(scale <= 100 && scale >= -100);
L_max = L_max >> (6 - scale);
assert(Nc <= 120 && Nc >= 40);
/* Compute the power of the reconstructed short term residual signal dp[..] */
L_power = 0;
for (k = 0; k < 40; k++)
{
L_temp = dp[k - Nc] >> 3;
L_power += L_temp*L_temp;
}
/*endfor*/
L_power <<= 1; /* from L_MULT */
/* Normalization of L_max and L_power */
if (L_max <= 0)
return 0;
/*endif*/
if (L_max >= L_power)
return 3;
/*endif*/
temp = gsm0610_norm(L_power);
R = (int16_t) ((L_max << temp) >> 16);
S = (int16_t) ((L_power << temp) >> 16);
/* Coding of the LTP gain */
/* Table 4.3a must be used to obtain the level DLB[i] for the
quantization of the LTP gain b to get the coded version bc. */
for (bc = 0; bc <= 2; bc++)
{
if (R <= gsm_mult(S, gsm_DLB[bc]))
break;
/*endif*/
}
/*endfor*/
return bc;
}
/*- End of function --------------------------------------------------------*/
/* 4.2.12 */
static void long_term_analysis_filtering(int16_t bc,
int16_t Nc,
int16_t *dp, // previous d [-120..-1] IN
int16_t d[40],
int16_t dpp[40],
int16_t e[40])
{
int k;
/* In this part, we have to decode the bc parameter to compute
the samples of the estimate dpp[0..39]. The decoding of bc needs the
use of table 4.3b. The long term residual signal e[0..39]
is then calculated to be fed to the RPE encoding section. */
for (k = 0; k < 40; k++)
{
dpp[k] = gsm_mult_r(gsm_QLB[bc], dp[k - Nc]);
e[k] = gsm_sub(d[k], dpp[k]);
}
/*endfor*/
}
/*- End of function --------------------------------------------------------*/
/* 4x for 160 samples */
void gsm0610_long_term_predictor(gsm0610_state_t *s,
int16_t d[40],
int16_t *dp, // [-120..-1] d' IN
int16_t e[40],
int16_t dpp[40],
int16_t *Nc,
int16_t *bc)
{
vc_assert(d);
vc_assert(dp);
vc_assert(e);
vc_assert(dpp);
vc_assert(Nc);
vc_assert(bc);
*bc = evaluate_ltp_parameters(d, dp, Nc);
long_term_analysis_filtering(*bc, *Nc, dp, d, dpp, e);
}
/*- End of function --------------------------------------------------------*/
/* 4.3.2 */
void gsm0610_long_term_synthesis_filtering(gsm0610_state_t *s,
int16_t Ncr,
int16_t bcr,
int16_t erp[40],
int16_t *drp) // [-120..-1] IN, [0..40] OUT
{
int k;
int16_t brp;
int16_t drpp;
int16_t Nr;
/* This procedure uses the bcr and Ncr parameter to realize the
long term synthesis filter. The decoding of bcr needs
table 4.3b. */
/* Check the limits of Nr. */
Nr = (Ncr < 40 || Ncr > 120) ? s->nrp : Ncr;
s->nrp = Nr;
assert (Nr >= 40 && Nr <= 120);
/* Decode the LTP gain, bcr */
brp = gsm_QLB[bcr];
/* Compute the reconstructed short term residual signal, drp[0..39] */
assert(brp != INT16_MIN);
for (k = 0; k < 40; k++)
{
drpp = gsm_mult_r(brp, drp[k - Nr]);
drp[k] = gsm_add(erp[k], drpp);
}
/*endfor*/
/* Update the reconstructed short term residual signal, drp[-1..-120] */
for (k = 0; k < 120; k++)
drp[k - 120] = drp[k - 80];
/*endfor*/
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/