ref: 42ce0306d62d795bb9ead55d71c1ae418657d048
dir: /libfaad/sbr_fbt.c/
/*
** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
** Copyright (C) 2003 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: sbr_fbt.c,v 1.6 2003/11/02 20:24:05 menno Exp $
**/
/* Calculate frequency band tables */
#include "common.h"
#include "structs.h"
#ifdef SBR_DEC
#include <stdlib.h>
#include "sbr_syntax.h"
#include "sbr_fbt.h"
/* calculate the start QMF channel for the master frequency band table */
/* parameter is also called k0 */
uint8_t qmf_start_channel(uint8_t bs_start_freq, uint8_t bs_samplerate_mode,
uint32_t sample_rate)
{
static const uint8_t startMinTable[12] = { 7, 7, 10, 11, 12, 16, 16,
17, 24, 32, 35, 48 };
static const uint8_t offsetIndexTable[12] = { 5, 5, 4, 4, 4, 3, 2, 1, 0,
6, 6, 6 };
static const int8_t offset[7][16] = {
{ -8, -7, -6, -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7 },
{ -5, -4, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13 },
{ -5, -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16 },
{ -6, -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16 },
{ -4, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20 },
{ -2, -1, 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24 },
{ 0, 1, 2, 3, 4, 5, 6, 7, 9, 11, 13, 16, 20, 24, 28, 33 }
};
uint8_t startMin = startMinTable[get_sr_index(sample_rate)];
uint8_t offsetIndex = offsetIndexTable[get_sr_index(sample_rate)];
#if 0 /* replaced with table (startMinTable) */
if (sample_rate >= 64000)
{
startMin = (uint8_t)((5000.*128.)/(float)sample_rate + 0.5);
} else if (sample_rate < 32000) {
startMin = (uint8_t)((3000.*128.)/(float)sample_rate + 0.5);
} else {
startMin = (uint8_t)((4000.*128.)/(float)sample_rate + 0.5);
}
#endif
if (bs_samplerate_mode)
{
return startMin + offset[offsetIndex][bs_start_freq];
#if 0 /* replaced by offsetIndexTable */
switch (sample_rate)
{
case 16000:
return startMin + offset[0][bs_start_freq];
case 22050:
return startMin + offset[1][bs_start_freq];
case 24000:
return startMin + offset[2][bs_start_freq];
case 32000:
return startMin + offset[3][bs_start_freq];
default:
if (sample_rate > 64000)
{
return startMin + offset[5][bs_start_freq];
} else { /* 44100 <= sample_rate <= 64000 */
return startMin + offset[4][bs_start_freq];
}
}
#endif
} else {
return startMin + offset[6][bs_start_freq];
}
}
static int32_t longcmp(const void *a, const void *b)
{
return ((int32_t)(*(int32_t*)a - *(int32_t*)b));
}
/* calculate the stop QMF channel for the master frequency band table */
/* parameter is also called k2 */
uint8_t qmf_stop_channel(uint8_t bs_stop_freq, uint32_t sample_rate,
uint8_t k0)
{
if (bs_stop_freq == 15)
{
return min(64, k0 * 3);
} else if (bs_stop_freq == 14) {
return min(64, k0 * 2);
} else {
static const uint8_t stopMinTable[12] = { 13, 15, 20, 21, 23,
32, 32, 35, 48, 64, 70, 96 };
static const int8_t offset[12][14] = {
{ 0, 2, 4, 6, 8, 11, 14, 18, 22, 26, 31, 37, 44, 51 },
{ 0, 2, 4, 6, 8, 11, 14, 18, 22, 26, 31, 36, 42, 49 },
{ 0, 2, 4, 6, 8, 11, 14, 17, 21, 25, 29, 34, 39, 44 },
{ 0, 2, 4, 6, 8, 11, 14, 17, 20, 24, 28, 33, 38, 43 },
{ 0, 2, 4, 6, 8, 11, 14, 17, 20, 24, 28, 32, 36, 41 },
{ 0, 2, 4, 6, 8, 10, 12, 14, 17, 20, 23, 26, 29, 32 },
{ 0, 2, 4, 6, 8, 10, 12, 14, 17, 20, 23, 26, 29, 32 },
{ 0, 1, 3, 5, 7, 9, 11, 13, 15, 17, 20, 23, 26, 29 },
{ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 14, 16 },
{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },
{ 0, -1, -2, -3, -4, -5, -6, -6, -6, -6, -6, -6, -6, -6 },
{ 0, -3, -6, -9, -12, -15, -18, -20, -22, -24, -26, -28, -30, -32 }
};
#if 0
uint8_t i;
int32_t stopDk[13], stopDk_t[14], k2;
#endif
uint8_t stopMin = stopMinTable[get_sr_index(sample_rate)];
#if 0 /* replaced by table lookup */
if (sample_rate >= 64000)
{
stopMin = (uint8_t)((10000.*128.)/(float)sample_rate + 0.5);
} else if (sample_rate < 32000) {
stopMin = (uint8_t)((6000.*128.)/(float)sample_rate + 0.5);
} else {
stopMin = (uint8_t)((8000.*128.)/(float)sample_rate + 0.5);
}
#endif
#if 0 /* replaced by table lookup */
/* diverging power series */
for (i = 0; i <= 13; i++)
{
stopDk_t[i] = (int32_t)(stopMin*pow(64.0/stopMin, i/13.0) + 0.5);
}
for (i = 0; i < 13; i++)
{
stopDk[i] = stopDk_t[i+1] - stopDk_t[i];
}
/* needed? */
qsort(stopDk, 13, sizeof(stopDk[0]), longcmp);
k2 = stopMin;
for (i = 0; i < bs_stop_freq; i++)
{
k2 += stopDk[i];
}
return min(64, k2);
#endif
/* bs_stop_freq <= 13 */
return min(64, stopMin + offset[get_sr_index(sample_rate)][min(bs_stop_freq, 13)]);
}
return 0;
}
/* calculate the master frequency table from k0, k2, bs_freq_scale
and bs_alter_scale
version for bs_freq_scale = 0
*/
void master_frequency_table_fs0(sbr_info *sbr, uint8_t k0, uint8_t k2,
uint8_t bs_alter_scale)
{
int8_t incr;
uint8_t k;
uint8_t dk;
uint32_t nrBands, k2Achieved;
int32_t k2Diff, vDk[64] = {0};
/* mft only defined for k2 > k0 */
if (k2 <= k0)
{
sbr->N_master = 0;
return;
}
dk = bs_alter_scale ? 2 : 1;
#if 0 /* replaced by float-less design */
nrBands = 2 * (int32_t)((float)(k2-k0)/(dk*2) + (-1+dk)/2.0f);
#else
if (bs_alter_scale)
{
nrBands = (((k2-k0+2)>>2)<<1);
} else {
nrBands = (((k2-k0)>>1)<<1);
}
#endif
nrBands = min(nrBands, 63);
k2Achieved = k0 + nrBands * dk;
k2Diff = k2 - k2Achieved;
for (k = 0; k < nrBands; k++)
vDk[k] = dk;
if (k2Diff)
{
incr = (k2Diff > 0) ? -1 : 1;
k = (k2Diff > 0) ? (nrBands-1) : 0;
while (k2Diff != 0)
{
vDk[k] -= incr;
k += incr;
k2Diff += incr;
}
}
sbr->f_master[0] = k0;
for (k = 1; k <= nrBands; k++)
sbr->f_master[k] = sbr->f_master[k-1] + vDk[k-1];
sbr->N_master = nrBands;
sbr->N_master = min(sbr->N_master, 64);
#if 0
printf("f_master[%d]: ", nrBands);
for (k = 0; k <= nrBands; k++)
{
printf("%d ", sbr->f_master[k]);
}
printf("\n");
#endif
}
/*
This function finds the number of bands using this formula:
bands * log(a1/a0)/log(2.0) + 0.5
*/
static int32_t find_bands(uint8_t warp, uint8_t bands, uint8_t a0, uint8_t a1)
{
real_t div = (real_t)log(2.0);
if (warp) div *= (real_t)1.3;
return (int32_t)(bands * log((float)a1/(float)a0)/div + 0.5);
}
static real_t find_initial_power(uint8_t bands, uint8_t a0, uint8_t a1)
{
return pow((real_t)a1/(real_t)a0, 1.0/(real_t)bands);
}
/*
version for bs_freq_scale > 0
*/
void master_frequency_table(sbr_info *sbr, uint8_t k0, uint8_t k2,
uint8_t bs_freq_scale, uint8_t bs_alter_scale)
{
uint8_t k, bands, twoRegions;
uint8_t k1;
uint8_t nrBand0, nrBand1;
int32_t vDk0[64] = {0}, vDk1[64] = {0};
int32_t vk0[64] = {0}, vk1[64] = {0};
uint8_t temp1[] = { 6, 5, 4 };
real_t q, qk;
int32_t A_1;
/* mft only defined for k2 > k0 */
if (k2 <= k0)
{
sbr->N_master = 0;
return;
}
bands = temp1[bs_freq_scale-1];
if ((float)k2/(float)k0 > 2.2449)
{
twoRegions = 1;
k1 = k0 << 1;
} else {
twoRegions = 0;
k1 = k2;
}
nrBand0 = 2 * find_bands(0, bands, k0, k1);
nrBand0 = min(nrBand0, 63);
q = find_initial_power(nrBand0, k0, k1);
qk = REAL_CONST(k0);
A_1 = (int32_t)(qk + .5);
for (k = 0; k <= nrBand0; k++)
{
int32_t A_0 = A_1;
qk *= q;
A_1 = (int32_t)(qk + 0.5);
vDk0[k] = A_1 - A_0;
}
/* needed? */
qsort(vDk0, nrBand0, sizeof(vDk0[0]), longcmp);
vk0[0] = k0;
for (k = 1; k <= nrBand0; k++)
{
vk0[k] = vk0[k-1] + vDk0[k-1];
}
if (!twoRegions)
{
for (k = 0; k <= nrBand0; k++)
sbr->f_master[k] = vk0[k];
sbr->N_master = nrBand0;
sbr->N_master = min(sbr->N_master, 64);
return;
}
nrBand1 = 2 * find_bands(1 /* warped */, bands, k1, k2);
nrBand1 = min(nrBand1, 63);
q = find_initial_power(nrBand1, k1, k2);
qk = REAL_CONST(k1);
A_1 = (int32_t)(qk + .5);
for (k = 0; k <= nrBand1 - 1; k++)
{
int32_t A_0 = A_1;
qk *= q;
A_1 = (int32_t)(qk + 0.5);
vDk1[k] = A_1 - A_0;
}
if (vDk1[0] < vDk0[nrBand0 - 1])
{
int32_t change;
/* needed? */
qsort(vDk1, nrBand1 + 1, sizeof(vDk1[0]), longcmp);
change = vDk0[nrBand0 - 1] - vDk1[0];
vDk1[0] = vDk0[nrBand0 - 1];
vDk1[nrBand1 - 1] = vDk1[nrBand1 - 1] - change;
}
/* needed? */
qsort(vDk1, nrBand1, sizeof(vDk1[0]), longcmp);
vk1[0] = k1;
for (k = 1; k <= nrBand1; k++)
{
vk1[k] = vk1[k-1] + vDk1[k-1];
}
sbr->N_master = nrBand0 + nrBand1;
sbr->N_master = min(sbr->N_master, 64);
for (k = 0; k <= nrBand0; k++)
{
sbr->f_master[k] = vk0[k];
}
for (k = nrBand0 + 1; k <= sbr->N_master; k++)
{
sbr->f_master[k] = vk1[k - nrBand0];
}
#if 0
printf("f_master[%d]: ", sbr->N_master);
for (k = 0; k <= sbr->N_master; k++)
{
printf("%d ", sbr->f_master[k]);
}
printf("\n");
#endif
}
/* calculate the derived frequency border tables from f_master */
uint8_t derived_frequency_table(sbr_info *sbr, uint8_t bs_xover_band,
uint8_t k2)
{
uint8_t k, i;
uint32_t minus;
/* The following relation shall be satisfied: bs_xover_band < N_Master */
if (sbr->N_master <= bs_xover_band)
return 1;
sbr->N_high = sbr->N_master - bs_xover_band;
sbr->N_low = (sbr->N_high>>1) + (sbr->N_high - ((sbr->N_high>>1)<<1));
sbr->n[0] = sbr->N_low;
sbr->n[1] = sbr->N_high;
for (k = 0; k <= sbr->N_high; k++)
{
sbr->f_table_res[HI_RES][k] = sbr->f_master[k + bs_xover_band];
}
sbr->M = sbr->f_table_res[HI_RES][sbr->N_high] - sbr->f_table_res[HI_RES][0];
sbr->kx = sbr->f_table_res[HI_RES][0];
minus = (sbr->N_high & 1) ? 1 : 0;
for (k = 0; k <= sbr->N_low; k++)
{
if (k == 0)
i = 0;
else
i = 2*k - minus;
sbr->f_table_res[LO_RES][k] = sbr->f_table_res[HI_RES][i];
}
#if 0
printf("f_table_res[HI_RES][%d]: ", sbr->N_high);
for (k = 0; k <= sbr->N_high; k++)
{
printf("%d ", sbr->f_table_res[HI_RES][k]);
}
printf("\n");
#endif
#if 0
printf("f_table_res[LO_RES][%d]: ", sbr->N_low);
for (k = 0; k <= sbr->N_low; k++)
{
printf("%d ", sbr->f_table_res[LO_RES][k]);
}
printf("\n");
#endif
sbr->N_Q = 0;
if (sbr->bs_noise_bands == 0)
{
sbr->N_Q = 1;
} else {
#if 0
sbr->N_Q = max(1, (int32_t)(sbr->bs_noise_bands*(log(k2/(float)sbr->kx)/log(2.0)) + 0.5));
#else
sbr->N_Q = max(1, find_bands(0, sbr->bs_noise_bands, sbr->kx, k2));
#endif
sbr->N_Q = min(5, sbr->N_Q);
}
for (k = 0; k <= sbr->N_Q; k++)
{
if (k == 0)
{
i = 0;
} else {
/* i = i + (int32_t)((sbr->N_low - i)/(sbr->N_Q + 1 - k)); */
i = i + (sbr->N_low - i)/(sbr->N_Q + 1 - k);
}
sbr->f_table_noise[k] = sbr->f_table_res[LO_RES][i];
}
/* build table for mapping k to g in hf patching */
for (k = 0; k < 64; k++)
{
uint8_t g;
for (g = 0; g < sbr->N_Q; g++)
{
if ((sbr->f_table_noise[g] <= k) &&
(k < sbr->f_table_noise[g+1]))
{
sbr->table_map_k_to_g[k] = g;
break;
}
}
}
#if 0
printf("f_table_noise[%d]: ", sbr->N_Q);
for (k = 0; k <= sbr->N_Q; k++)
{
printf("%d ", sbr->f_table_noise[k]);
}
printf("\n");
#endif
return 0;
}
/* TODO: blegh, ugly */
/* Modified to calculate for all possible bs_limiter_bands always
* This reduces the number calls to this functions needed (now only on
* header reset)
*/
void limiter_frequency_table(sbr_info *sbr)
{
#if 0
static const real_t limiterBandsPerOctave[] = { REAL_CONST(1.2),
REAL_CONST(2), REAL_CONST(3) };
#else
static const real_t limiterBandsCompare[] = { REAL_CONST(1.328125),
REAL_CONST(1.1875), REAL_CONST(1.125) };
#endif
uint8_t k, s;
int8_t nrLim;
#if 0
real_t limBands;
#endif
sbr->f_table_lim[0][0] = sbr->f_table_res[LO_RES][0] - sbr->kx;
sbr->f_table_lim[0][1] = sbr->f_table_res[LO_RES][sbr->N_low] - sbr->kx;
sbr->N_L[0] = 1;
for (s = 1; s < 4; s++)
{
int32_t limTable[100 /*TODO*/] = {0};
uint8_t patchBorders[64/*??*/] = {0};
#if 0
limBands = limiterBandsPerOctave[s - 1];
#endif
patchBorders[0] = sbr->kx;
for (k = 1; k <= sbr->noPatches; k++)
{
patchBorders[k] = patchBorders[k-1] + sbr->patchNoSubbands[k-1];
}
for (k = 0; k <= sbr->N_low; k++)
{
limTable[k] = sbr->f_table_res[LO_RES][k];
}
for (k = 1; k < sbr->noPatches; k++)
{
limTable[k+sbr->N_low] = patchBorders[k];
}
/* needed */
qsort(limTable, sbr->noPatches + sbr->N_low, sizeof(limTable[0]), longcmp);
k = 1;
nrLim = sbr->noPatches + sbr->N_low - 1;
if (nrLim < 0) // TODO: BIG FAT PROBLEM
return;
restart:
if (k <= nrLim)
{
real_t nOctaves;
if (limTable[k-1] != 0)
#if 0
nOctaves = REAL_CONST(log((float)limTable[k]/(float)limTable[k-1])/log(2.0));
#endif
nOctaves = (real_t)limTable[k]/(real_t)limTable[k-1];
else
nOctaves = 0;
#if 0
if ((MUL(nOctaves,limBands)) < REAL_CONST(0.49))
#else
if (nOctaves < limiterBandsCompare[s - 1])
#endif
{
uint8_t i;
if (limTable[k] != limTable[k-1])
{
uint8_t found = 0, found2 = 0;
for (i = 0; i <= sbr->noPatches; i++)
{
if (limTable[k] == patchBorders[i])
found = 1;
}
if (found)
{
found2 = 0;
for (i = 0; i <= sbr->noPatches; i++)
{
if (limTable[k-1] == patchBorders[i])
found2 = 1;
}
if (found2)
{
k++;
goto restart;
} else {
/* remove (k-1)th element */
limTable[k-1] = sbr->f_table_res[LO_RES][sbr->N_low];
qsort(limTable, sbr->noPatches + sbr->N_low, sizeof(limTable[0]), longcmp);
nrLim--;
goto restart;
}
}
}
/* remove kth element */
limTable[k] = sbr->f_table_res[LO_RES][sbr->N_low];
qsort(limTable, nrLim, sizeof(limTable[0]), longcmp);
nrLim--;
goto restart;
} else {
k++;
goto restart;
}
}
sbr->N_L[s] = nrLim;
for (k = 0; k <= nrLim; k++)
{
sbr->f_table_lim[s][k] = limTable[k] - sbr->kx;
}
#if 0
printf("f_table_lim[%d][%d]: ", s, sbr->N_L[s]);
for (k = 0; k <= sbr->N_L[s]; k++)
{
printf("%d ", sbr->f_table_lim[s][k]);
}
printf("\n");
#endif
}
}
#endif