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rockbox/apps/codecs/libfaad/sbr_hfgen.c

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/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003-2004 M. Bakker, Ahead Software AG, http://www.nero.com
**
** This program is free software; you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation; either version 2 of the License, or
** (at your option) any later version.
**
** 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
**
** Any non-GPL usage of this software or parts of this software is strictly
** forbidden.
**
** Commercial non-GPL licensing of this software is possible.
** For more info contact Ahead Software through Mpeg4AAClicense@nero.com.
**
** $Id$
**/
/* High Frequency generation */
#include "common.h"
#include "structs.h"
#ifdef SBR_DEC
#include "sbr_syntax.h"
#include "sbr_hfgen.h"
#include "sbr_fbt.h"
/* static function declarations */
#ifdef SBR_LOW_POWER
static void calc_prediction_coef_lp(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
complex_t *alpha_0, complex_t *alpha_1, real_t *rxx);
static void calc_aliasing_degree(sbr_info *sbr, real_t *rxx, real_t *deg);
#else
static void calc_prediction_coef(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
complex_t *alpha_0, complex_t *alpha_1, uint8_t k);
#endif
static void calc_chirp_factors(sbr_info *sbr, uint8_t ch);
static void patch_construction(sbr_info *sbr);
void hf_generation(sbr_info *sbr,
qmf_t Xlow[MAX_NTSRHFG][64],
qmf_t Xhigh[MAX_NTSRHFG][64]
#ifdef SBR_LOW_POWER
,real_t *deg
#endif
,uint8_t ch)
{
uint8_t l, i, x;
complex_t alpha_0[64] MEM_ALIGN_ATTR;
complex_t alpha_1[64] MEM_ALIGN_ATTR;
#ifdef SBR_LOW_POWER
real_t rxx[64];
#endif
uint8_t offset = sbr->tHFAdj;
uint8_t first = sbr->t_E[ch][0];
uint8_t last = sbr->t_E[ch][sbr->L_E[ch]];
calc_chirp_factors(sbr, ch);
#ifdef SBR_LOW_POWER
memset(deg, 0, 64*sizeof(real_t));
#endif
if ((ch == 0) && (sbr->Reset))
patch_construction(sbr);
/* calculate the prediction coefficients */
#ifdef SBR_LOW_POWER
calc_prediction_coef_lp(sbr, Xlow, alpha_0, alpha_1, rxx);
calc_aliasing_degree(sbr, rxx, deg);
#endif
/* actual HF generation */
for (i = 0; i < sbr->noPatches; i++)
{
for (x = 0; x < sbr->patchNoSubbands[i]; x++)
{
real_t a0_r, a0_i, a1_r, a1_i;
real_t bw, bw2;
uint8_t q, p, k, g;
/* find the low and high band for patching */
k = sbr->kx + x;
for (q = 0; q < i; q++)
{
k += sbr->patchNoSubbands[q];
}
p = sbr->patchStartSubband[i] + x;
#ifdef SBR_LOW_POWER
if (x != 0 /*x < sbr->patchNoSubbands[i]-1*/)
deg[k] = deg[p];
else
deg[k] = 0;
#endif
g = sbr->table_map_k_to_g[k];
bw = sbr->bwArray[ch][g];
bw2 = MUL_C(bw, bw);
/* do the patching */
/* with or without filtering */
if (bw2 > 0)
{
real_t temp1_r, temp2_r, temp3_r;
#ifndef SBR_LOW_POWER
real_t temp1_i, temp2_i, temp3_i;
calc_prediction_coef(sbr, Xlow, alpha_0, alpha_1, p);
#endif
a0_r = MUL_C(RE(alpha_0[p]), bw);
a1_r = MUL_C(RE(alpha_1[p]), bw2);
#ifndef SBR_LOW_POWER
a0_i = MUL_C(IM(alpha_0[p]), bw);
a1_i = MUL_C(IM(alpha_1[p]), bw2);
#endif
temp2_r = QMF_RE(Xlow[first - 2 + offset][p]);
temp3_r = QMF_RE(Xlow[first - 1 + offset][p]);
#ifndef SBR_LOW_POWER
temp2_i = QMF_IM(Xlow[first - 2 + offset][p]);
temp3_i = QMF_IM(Xlow[first - 1 + offset][p]);
#endif
for (l = first; l < last; l++)
{
temp1_r = temp2_r;
temp2_r = temp3_r;
temp3_r = QMF_RE(Xlow[l + offset][p]);
#ifndef SBR_LOW_POWER
temp1_i = temp2_i;
temp2_i = temp3_i;
temp3_i = QMF_IM(Xlow[l + offset][p]);
#endif
#ifdef SBR_LOW_POWER
QMF_RE(Xhigh[l + offset][k]) = temp3_r +
(MUL_R(a0_r, temp2_r) + MUL_R(a1_r, temp1_r));
#else
QMF_RE(Xhigh[l + offset][k]) = temp3_r +
(MUL_R(a0_r, temp2_r) - MUL_R(a0_i, temp2_i) +
MUL_R(a1_r, temp1_r) - MUL_R(a1_i, temp1_i));
QMF_IM(Xhigh[l + offset][k]) = temp3_i +
(MUL_R(a0_i, temp2_r) + MUL_R(a0_r, temp2_i) +
MUL_R(a1_i, temp1_r) + MUL_R(a1_r, temp1_i));
#endif
}
} else {
for (l = first; l < last; l++)
{
QMF_RE(Xhigh[l + offset][k]) = QMF_RE(Xlow[l + offset][p]);
#ifndef SBR_LOW_POWER
QMF_IM(Xhigh[l + offset][k]) = QMF_IM(Xlow[l + offset][p]);
#endif
}
}
}
}
if (sbr->Reset)
{
limiter_frequency_table(sbr);
}
}
typedef struct
{
complex_t r01;
complex_t r02;
complex_t r11;
complex_t r12;
complex_t r22;
real_t det;
} acorr_coef;
/* Within auto_correlation(...) a pre-shift of >>ACDET_EXP is needed to avoid
* overflow when multiply-adding the FRACT-variables -- FRACT part is 31 bits.
* After the calculation has been finished the result 'ac->det' needs to be
* post-shifted by <<(4*ACDET_EXP). This pre-/post-shifting is needed for
* FIXED_POINT only. */
#ifdef FIXED_POINT
#define ACDET_EXP 3
#define ACDET_PRE(A) (A)>>ACDET_EXP
#define ACDET_POST(A) (A)<<(4*ACDET_EXP)
#else
#define ACDET_PRE(A) (A)
#define ACDET_POST(A) (A)
#endif
#ifdef SBR_LOW_POWER
static void auto_correlation(sbr_info *sbr, acorr_coef *ac,
qmf_t buffer[MAX_NTSRHFG][64],
uint8_t bd, uint8_t len)
{
real_t r01 = 0, r02 = 0, r11 = 0;
real_t tmp1, tmp2;
int8_t j;
uint8_t offset = sbr->tHFAdj;
const real_t rel = FRAC_CONST(0.999999); // 1 / (1 + 1e-6f);
for (j = offset; j < len + offset; j++)
{
real_t buf_j = ACDET_PRE(QMF_RE(buffer[j ][bd]));
real_t buf_j_1 = ACDET_PRE(QMF_RE(buffer[j-1][bd]));
real_t buf_j_2 = ACDET_PRE(QMF_RE(buffer[j-2][bd]));
r01 += MUL_F(buf_j , buf_j_1);
r02 += MUL_F(buf_j , buf_j_2);
r11 += MUL_F(buf_j_1, buf_j_1);
}
tmp1 = ACDET_PRE(QMF_RE(buffer[len+offset-1][bd]));
tmp2 = ACDET_PRE(QMF_RE(buffer[ offset-1][bd]));
RE(ac->r12) = r01 - MUL_F(tmp1, tmp1) + MUL_F(tmp2, tmp2);
tmp1 = ACDET_PRE(QMF_RE(buffer[len+offset-2][bd]));
tmp2 = ACDET_PRE(QMF_RE(buffer[ offset-2][bd]));
RE(ac->r22) = r11 - MUL_F(tmp1, tmp1) + MUL_F(tmp2, tmp2);
RE(ac->r01) = r01;
RE(ac->r02) = r02;
RE(ac->r11) = r11;
ac->det = MUL_F(RE(ac->r11), RE(ac->r22)) - MUL_F(MUL_F(RE(ac->r12), RE(ac->r12)), rel);
ac->det = ACDET_POST(ac->det);
}
#else
static void auto_correlation(sbr_info *sbr, acorr_coef *ac, qmf_t buffer[MAX_NTSRHFG][64],
uint8_t bd, uint8_t len)
{
real_t r01r = 0, r01i = 0, r02r = 0, r02i = 0, r11r = 0;
real_t temp1_r, temp1_i, temp2_r, temp2_i, temp3_r, temp3_i;
real_t temp4_r, temp4_i, temp5_r, temp5_i;
int8_t j;
uint8_t offset = sbr->tHFAdj;
const real_t rel = FRAC_CONST(0.999999); // 1 / (1 + 1e-6f);
temp2_r = ACDET_PRE(QMF_RE(buffer[offset-2][bd]));
temp2_i = ACDET_PRE(QMF_IM(buffer[offset-2][bd]));
temp3_r = ACDET_PRE(QMF_RE(buffer[offset-1][bd]));
temp3_i = ACDET_PRE(QMF_IM(buffer[offset-1][bd]));
// Save these because they are needed after loop
temp4_r = temp2_r;
temp4_i = temp2_i;
temp5_r = temp3_r;
temp5_i = temp3_i;
for (j = offset; j < len + offset; j++)
{
temp1_r = temp2_r;
temp1_i = temp2_i;
temp2_r = temp3_r;
temp2_i = temp3_i;
temp3_r = ACDET_PRE(QMF_RE(buffer[j][bd]));
temp3_i = ACDET_PRE(QMF_IM(buffer[j][bd]));
r01r += MUL_F(temp3_r, temp2_r) + MUL_F(temp3_i, temp2_i);
r01i += MUL_F(temp3_i, temp2_r) - MUL_F(temp3_r, temp2_i);
r02r += MUL_F(temp3_r, temp1_r) + MUL_F(temp3_i, temp1_i);
r02i += MUL_F(temp3_i, temp1_r) - MUL_F(temp3_r, temp1_i);
r11r += MUL_F(temp2_r, temp2_r) + MUL_F(temp2_i, temp2_i);
}
RE(ac->r12) = r01r - (MUL_F(temp3_r, temp2_r) + MUL_F(temp3_i, temp2_i)) +
(MUL_F(temp5_r, temp4_r) + MUL_F(temp5_i, temp4_i));
IM(ac->r12) = r01i - (MUL_F(temp3_i, temp2_r) - MUL_F(temp3_r, temp2_i)) +
(MUL_F(temp5_i, temp4_r) - MUL_F(temp5_r, temp4_i));
RE(ac->r22) = r11r - (MUL_F(temp2_r, temp2_r) + MUL_F(temp2_i, temp2_i)) +
(MUL_F(temp4_r, temp4_r) + MUL_F(temp4_i, temp4_i));
RE(ac->r01) = r01r;
IM(ac->r01) = r01i;
RE(ac->r02) = r02r;
IM(ac->r02) = r02i;
RE(ac->r11) = r11r;
ac->det = MUL_F(RE(ac->r11), RE(ac->r22)) - MUL_F((MUL_F(RE(ac->r12), RE(ac->r12)) + MUL_F(IM(ac->r12), IM(ac->r12))), rel);
ac->det = ACDET_POST(ac->det);
}
#endif
/* calculate linear prediction coefficients using the covariance method */
#ifndef SBR_LOW_POWER
static void calc_prediction_coef(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
complex_t *alpha_0, complex_t *alpha_1, uint8_t k)
{
real_t tmp, mul;
acorr_coef ac;
auto_correlation(sbr, &ac, Xlow, k, sbr->numTimeSlotsRate + 6);
if (ac.det == 0)
{
RE(alpha_1[k]) = 0;
IM(alpha_1[k]) = 0;
} else {
mul = DIV_R(REAL_CONST(1.0), ac.det);
tmp = (MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(IM(ac.r01), IM(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11)));
RE(alpha_1[k]) = MUL_R(tmp, mul);
tmp = (MUL_R(IM(ac.r01), RE(ac.r12)) + MUL_R(RE(ac.r01), IM(ac.r12)) - MUL_R(IM(ac.r02), RE(ac.r11)));
IM(alpha_1[k]) = MUL_R(tmp, mul);
}
if (RE(ac.r11) == 0)
{
RE(alpha_0[k]) = 0;
IM(alpha_0[k]) = 0;
} else {
mul = DIV_R(REAL_CONST(1.0), RE(ac.r11));
tmp = -(RE(ac.r01) + MUL_R(RE(alpha_1[k]), RE(ac.r12)) + MUL_R(IM(alpha_1[k]), IM(ac.r12)));
RE(alpha_0[k]) = MUL_R(tmp, mul);
tmp = -(IM(ac.r01) + MUL_R(IM(alpha_1[k]), RE(ac.r12)) - MUL_R(RE(alpha_1[k]), IM(ac.r12)));
IM(alpha_0[k]) = MUL_R(tmp, mul);
}
if ((MUL_R(RE(alpha_0[k]),RE(alpha_0[k])) + MUL_R(IM(alpha_0[k]),IM(alpha_0[k])) >= REAL_CONST(16)) ||
(MUL_R(RE(alpha_1[k]),RE(alpha_1[k])) + MUL_R(IM(alpha_1[k]),IM(alpha_1[k])) >= REAL_CONST(16)))
{
RE(alpha_0[k]) = 0;
IM(alpha_0[k]) = 0;
RE(alpha_1[k]) = 0;
IM(alpha_1[k]) = 0;
}
}
#else
static void calc_prediction_coef_lp(sbr_info *sbr, qmf_t Xlow[MAX_NTSRHFG][64],
complex_t *alpha_0, complex_t *alpha_1, real_t *rxx)
{
uint8_t k;
real_t tmp, mul;
acorr_coef ac;
for (k = 1; k < sbr->f_master[0]; k++)
{
auto_correlation(sbr, &ac, Xlow, k, sbr->numTimeSlotsRate + 6);
if (ac.det == 0)
{
RE(alpha_0[k]) = 0;
RE(alpha_1[k]) = 0;
} else {
mul = DIV_R(REAL_CONST(1.0), ac.det);
tmp = MUL_R(RE(ac.r01), RE(ac.r22)) - MUL_R(RE(ac.r12), RE(ac.r02));
RE(alpha_0[k]) = -MUL_R(tmp, mul);
tmp = MUL_R(RE(ac.r01), RE(ac.r12)) - MUL_R(RE(ac.r02), RE(ac.r11));
RE(alpha_1[k]) = MUL_R(tmp, mul);
}
if ((RE(alpha_0[k]) >= REAL_CONST(4)) || (RE(alpha_1[k]) >= REAL_CONST(4)))
{
RE(alpha_0[k]) = REAL_CONST(0);
RE(alpha_1[k]) = REAL_CONST(0);
}
/* reflection coefficient */
if (RE(ac.r11) == 0)
{
rxx[k] = COEF_CONST(0.0);
} else {
rxx[k] = DIV_C(RE(ac.r01), RE(ac.r11));
rxx[k] = -rxx[k];
if (rxx[k] > COEF_CONST( 1.0)) rxx[k] = COEF_CONST(1.0);
if (rxx[k] < COEF_CONST(-1.0)) rxx[k] = COEF_CONST(-1.0);
}
}
}
static void calc_aliasing_degree(sbr_info *sbr, real_t *rxx, real_t *deg)
{
uint8_t k;
rxx[0] = COEF_CONST(0.0);
deg[1] = COEF_CONST(0.0);
for (k = 2; k < sbr->k0; k++)
{
deg[k] = COEF_CONST(0.0);
if ((k % 2 == 0) && (rxx[k] < COEF_CONST(0.0)))
{
if (rxx[k-1] < COEF_CONST(0.0))
{
deg[k] = COEF_CONST(1.0);
if (rxx[k-2] > COEF_CONST(0.0))
{
deg[k-1] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
}
} else if (rxx[k-2] > COEF_CONST(0.0)) {
deg[k] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
}
}
if ((k % 2 == 1) && (rxx[k] > COEF_CONST(0.0)))
{
if (rxx[k-1] > COEF_CONST(0.0))
{
deg[k] = COEF_CONST(1.0);
if (rxx[k-2] < COEF_CONST(0.0))
{
deg[k-1] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
}
} else if (rxx[k-2] < COEF_CONST(0.0)) {
deg[k] = COEF_CONST(1.0) - MUL_C(rxx[k-1], rxx[k-1]);
}
}
}
}
#endif
/* FIXED POINT: bwArray = COEF */
static real_t mapNewBw(uint8_t invf_mode, uint8_t invf_mode_prev)
{
switch (invf_mode)
{
case 1: /* LOW */
if (invf_mode_prev == 0) /* NONE */
return COEF_CONST(0.6);
else
return COEF_CONST(0.75);
case 2: /* MID */
return COEF_CONST(0.9);
case 3: /* HIGH */
return COEF_CONST(0.98);
default: /* NONE */
if (invf_mode_prev == 1) /* LOW */
return COEF_CONST(0.6);
else
return COEF_CONST(0.0);
}
}
/* FIXED POINT: bwArray = COEF */
static void calc_chirp_factors(sbr_info *sbr, uint8_t ch)
{
uint8_t i;
for (i = 0; i < sbr->N_Q; i++)
{
sbr->bwArray[ch][i] = mapNewBw(sbr->bs_invf_mode[ch][i], sbr->bs_invf_mode_prev[ch][i]);
if (sbr->bwArray[ch][i] < sbr->bwArray_prev[ch][i])
sbr->bwArray[ch][i] = MUL_F(sbr->bwArray[ch][i], FRAC_CONST(0.75)) + MUL_F(sbr->bwArray_prev[ch][i], FRAC_CONST(0.25));
else
sbr->bwArray[ch][i] = MUL_F(sbr->bwArray[ch][i], FRAC_CONST(0.90625)) + MUL_F(sbr->bwArray_prev[ch][i], FRAC_CONST(0.09375));
if (sbr->bwArray[ch][i] < COEF_CONST(0.015625))
sbr->bwArray[ch][i] = COEF_CONST(0.0);
if (sbr->bwArray[ch][i] > COEF_CONST(0.99609375))
sbr->bwArray[ch][i] = COEF_CONST(0.99609375);
sbr->bwArray_prev[ch][i] = sbr->bwArray[ch][i];
sbr->bs_invf_mode_prev[ch][i] = sbr->bs_invf_mode[ch][i];
}
}
static void patch_construction(sbr_info *sbr)
{
uint8_t i, k;
uint8_t odd, sb;
uint8_t msb = sbr->k0;
uint8_t usb = sbr->kx;
uint8_t goalSbTab[] = { 21, 23, 32, 43, 46, 64, 85, 93, 128, 0, 0, 0 };
/* (uint8_t)(2.048e6/sbr->sample_rate + 0.5); */
uint8_t goalSb = goalSbTab[get_sr_index(sbr->sample_rate)];
sbr->noPatches = 0;
if (goalSb < (sbr->kx + sbr->M))
{
for (i = 0, k = 0; sbr->f_master[i] < goalSb; i++)
k = i+1;
} else {
k = sbr->N_master;
}
if (sbr->N_master == 0)
{
sbr->noPatches = 0;
sbr->patchNoSubbands[0] = 0;
sbr->patchStartSubband[0] = 0;
return;
}
do
{
int8_t j = k + 1;
do
{
j--;
sb = sbr->f_master[j];
odd = (sb - 2 + sbr->k0) % 2;
} while (sb > (sbr->k0 - 1 + msb - odd));
sbr->patchNoSubbands[sbr->noPatches] = max(sb - usb, 0);
sbr->patchStartSubband[sbr->noPatches] = sbr->k0 - odd -
sbr->patchNoSubbands[sbr->noPatches];
if (sbr->patchNoSubbands[sbr->noPatches] > 0)
{
usb = sb;
msb = sb;
sbr->noPatches++;
} else {
msb = sbr->kx;
}
if (sbr->f_master[k] - sb < 3)
k = sbr->N_master;
} while (sb != (sbr->kx + sbr->M));
if ((sbr->patchNoSubbands[sbr->noPatches-1] < 3) && (sbr->noPatches > 1))
{
sbr->noPatches--;
}
sbr->noPatches = min(sbr->noPatches, 5);
}
#endif
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