ref: 21c348fd5d20f77b018d0b812361a64fc139dc18
dir: /libfaac/aacquant.c/
/*
* FAAC - Freeware Advanced Audio Coder
* Copyright (C) 2001 Menno Bakker
*
* 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
*
* $Id: aacquant.c,v 1.4 2001/02/28 18:39:34 menno Exp $
*/
#include <math.h>
#include <stdlib.h>
#include <memory.h>
#include "aacquant.h"
#include "coder.h"
#include "huffman.h"
#include "psych.h"
#include "util.h"
#define XRPOW_FTOI(src,dest) ((dest) = (int)(src))
#define QUANTFAC(rx) adj43[rx]
#define ROUNDFAC 0.4054
double *pow43;
double *adj43;
double *adj43asm;
void AACQuantizeInit(CoderInfo *coderInfo, unsigned int numChannels)
{
unsigned int channel, i;
pow43 = (double*)malloc(PRECALC_SIZE*sizeof(double));
adj43 = (double*)malloc(PRECALC_SIZE*sizeof(double));
adj43asm = (double*)malloc(PRECALC_SIZE*sizeof(double));
pow43[0] = 0.0;
for(i=1;i<PRECALC_SIZE;i++)
pow43[i] = pow((double)i, 4.0/3.0);
adj43asm[0] = 0.0;
for (i = 1; i < PRECALC_SIZE; i++)
adj43asm[i] = i - 0.5 - pow(0.5 * (pow43[i - 1] + pow43[i]),0.75);
for (i = 0; i < PRECALC_SIZE-1; i++)
adj43[i] = (i + 1) - pow(0.5 * (pow43[i] + pow43[i + 1]), 0.75);
adj43[i] = 0.5;
for (channel = 0; channel < numChannels; channel++) {
coderInfo[channel].old_value = 0;
coderInfo[channel].CurrentStep = 4;
}
}
void AACQuantizeEnd()
{
if (pow43) free(pow43);
if (adj43) free(adj43);
if (adj43asm) free(adj43asm);
}
int AACQuantize(CoderInfo *coderInfo,
PsyInfo *psyInfo,
ChannelInfo *channelInfo,
int *cb_width,
int num_cb,
double *xr,
int desired_rate)
{
int sb, i, do_q = 0;
int bits, sign;
double *xr_pow, *xmin;
int *xi;
/* Use local copy's */
int *scale_factor = coderInfo->scale_factor;
xr_pow = (double*)malloc(FRAME_LEN*sizeof(double));
xmin = (double*)malloc(MAX_SCFAC_BANDS*sizeof(double));
xi = (int*)malloc(FRAME_LEN*sizeof(int));
if (coderInfo->block_type == ONLY_SHORT_WINDOW) {
SortForGrouping(coderInfo, psyInfo, channelInfo, cb_width, xr);
} else {
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++) {
if (channelInfo->msInfo.is_present && channelInfo->msInfo.ms_used[sb]) {
psyInfo->maskThr[sb] = psyInfo->maskThrMS[sb];
psyInfo->maskEn[sb] = psyInfo->maskEnMS[sb];
}
}
}
/* Set all scalefactors to 0 */
coderInfo->global_gain = 0;
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++)
scale_factor[sb] = 0;
/* Compute xr_pow */
for (i = 0; i < FRAME_LEN; i++) {
double temp = fabs(xr[i]);
xr_pow[i] = sqrt(temp * sqrt(temp));
do_q += (temp > 1E-20);
}
if (do_q) {
bits = SearchStepSize(coderInfo, desired_rate, xr_pow, xi);
coderInfo->old_value = coderInfo->global_gain;
CalcAllowedDist(psyInfo, cb_width, num_cb, xr, xmin);
OuterLoop(coderInfo, xr, xr_pow, xi, xmin, desired_rate);
for ( i = 0; i < FRAME_LEN; i++ ) {
sign = (xr[i] < 0) ? -1 : 1;
xi[i] *= sign;
}
} else {
coderInfo->global_gain = 0;
memset(xi, 0, FRAME_LEN*sizeof(int));
}
CountBitsLong(coderInfo, xi);
/* offset the difference of common_scalefac and scalefactors by SF_OFFSET */
for (i = 0; i < coderInfo->nr_of_sfb; i++) {
if ((coderInfo->book_vector[i]!=INTENSITY_HCB)&&(coderInfo->book_vector[i]!=INTENSITY_HCB2)) {
scale_factor[i] = coderInfo->global_gain - scale_factor[i] + SF_OFFSET;
}
}
coderInfo->global_gain = scale_factor[0];
/* place the codewords and their respective lengths in arrays data[] and len[] respectively */
/* there are 'counter' elements in each array, and these are variable length arrays depending on the input */
coderInfo->spectral_count = 0;
for(i = 0; i < coderInfo->nr_of_sfb; i++) {
OutputBits(
coderInfo,
coderInfo->book_vector[i],
xi,
coderInfo->sfb_offset[i],
coderInfo->sfb_offset[i+1]-coderInfo->sfb_offset[i]);
}
if (xmin) free(xmin);
if (xr_pow) free(xr_pow);
if (xi) free(xi);
return bits;
}
static int SearchStepSize(CoderInfo *coderInfo,
const int desired_rate,
const double *xr,
int *xi)
{
int flag_GoneOver = 0;
int CurrentStep = coderInfo->CurrentStep;
int nBits;
int StepSize = coderInfo->old_value;
int Direction = 0;
do
{
coderInfo->global_gain = StepSize;
nBits = CountBits(coderInfo, xi, xr);
if (CurrentStep == 1 ) {
break; /* nothing to adjust anymore */
}
if (flag_GoneOver) {
CurrentStep /= 2;
}
if (nBits > desired_rate) { /* increase Quantize_StepSize */
if (Direction == -1 && !flag_GoneOver) {
flag_GoneOver = 1;
CurrentStep /= 2; /* late adjust */
}
Direction = 1;
StepSize += CurrentStep;
} else if (nBits < desired_rate) {
if (Direction == 1 && !flag_GoneOver) {
flag_GoneOver = 1;
CurrentStep /= 2; /* late adjust */
}
Direction = -1;
StepSize -= CurrentStep;
} else break;
} while (1);
CurrentStep = coderInfo->old_value - StepSize;
coderInfo->CurrentStep = CurrentStep/4 != 0 ? 4 : 2;
coderInfo->old_value = coderInfo->global_gain;
return nBits;
}
#if 1 /* TAKEHIRO_IEEE754_HACK */
#pragma warning( disable : 4244 4307 )
typedef union {
float f;
int i;
} fi_union;
#define MAGIC_FLOAT (65536*(128))
#define MAGIC_INT 0x4b000000
static void Quantize(const double *xp, int *pi, double istep)
{
int j;
fi_union *fi;
fi = (fi_union *)pi;
for (j = FRAME_LEN/4 - 1; j >= 0; --j) {
double x0 = istep * xp[0];
double x1 = istep * xp[1];
double x2 = istep * xp[2];
double x3 = istep * xp[3];
x0 += MAGIC_FLOAT; fi[0].f = x0;
x1 += MAGIC_FLOAT; fi[1].f = x1;
x2 += MAGIC_FLOAT; fi[2].f = x2;
x3 += MAGIC_FLOAT; fi[3].f = x3;
fi[0].f = x0 + (adj43asm - MAGIC_INT)[fi[0].i];
fi[1].f = x1 + (adj43asm - MAGIC_INT)[fi[1].i];
fi[2].f = x2 + (adj43asm - MAGIC_INT)[fi[2].i];
fi[3].f = x3 + (adj43asm - MAGIC_INT)[fi[3].i];
fi[0].i -= MAGIC_INT;
fi[1].i -= MAGIC_INT;
fi[2].i -= MAGIC_INT;
fi[3].i -= MAGIC_INT;
fi += 4;
xp += 4;
}
}
#else
static void Quantize(const double *xr, int *ix, double istep)
{
int j;
for (j = FRAME_LEN/8; j > 0; --j) {
double x1, x2, x3, x4, x5, x6, x7, x8;
int rx1, rx2, rx3, rx4, rx5, rx6, rx7, rx8;
x1 = *xr++ * istep;
x2 = *xr++ * istep;
XRPOW_FTOI(x1, rx1);
x3 = *xr++ * istep;
XRPOW_FTOI(x2, rx2);
x4 = *xr++ * istep;
XRPOW_FTOI(x3, rx3);
x5 = *xr++ * istep;
XRPOW_FTOI(x4, rx4);
x6 = *xr++ * istep;
XRPOW_FTOI(x5, rx5);
x7 = *xr++ * istep;
XRPOW_FTOI(x6, rx6);
x8 = *xr++ * istep;
XRPOW_FTOI(x7, rx7);
x1 += QUANTFAC(rx1);
XRPOW_FTOI(x8, rx8);
x2 += QUANTFAC(rx2);
XRPOW_FTOI(x1,*ix++);
x3 += QUANTFAC(rx3);
XRPOW_FTOI(x2,*ix++);
x4 += QUANTFAC(rx4);
XRPOW_FTOI(x3,*ix++);
x5 += QUANTFAC(rx5);
XRPOW_FTOI(x4,*ix++);
x6 += QUANTFAC(rx6);
XRPOW_FTOI(x5,*ix++);
x7 += QUANTFAC(rx7);
XRPOW_FTOI(x6,*ix++);
x8 += QUANTFAC(rx8);
XRPOW_FTOI(x7,*ix++);
XRPOW_FTOI(x8,*ix++);
}
}
#endif
static int CountBitsLong(CoderInfo *coderInfo, int *xi)
{
int i, bits = 0;
/* find a good method to section the scalefactor bands into huffman codebook sections */
BitSearch(coderInfo, xi);
/* calculate the amount of bits needed for encoding the huffman codebook numbers */
bits += SortBookNumbers(coderInfo, NULL, 0);
/* calculate the amount of bits needed for the spectral values */
coderInfo->spectral_count = 0;
for(i = 0; i < coderInfo->nr_of_sfb; i++) {
bits += CalcBits(coderInfo,
coderInfo->book_vector[i],
xi,
coderInfo->sfb_offset[i],
coderInfo->sfb_offset[i+1] - coderInfo->sfb_offset[i]);
}
/* the number of bits for the scalefactors */
bits += WriteScalefactors(coderInfo, NULL, 0);
/* the total amount of bits required */
return bits;
}
static int CountBits(CoderInfo *coderInfo, int *ix, const double *xr)
{
int bits = 0, i;
/* since quantize uses table lookup, we need to check this first: */
double w = (IXMAX_VAL) / IPOW20(coderInfo->global_gain);
for ( i = 0; i < FRAME_LEN; i++ ) {
if (xr[i] > w)
return LARGE_BITS;
}
Quantize(xr, ix, IPOW20(coderInfo->global_gain));
bits = CountBitsLong(coderInfo, ix);
return bits;
}
static int InnerLoop(CoderInfo *coderInfo,
double *xr_pow,
int *xi,
int max_bits)
{
int bits;
/* count bits */
bits = CountBits(coderInfo, xi, xr_pow);
/* increase quantizer stepsize until needed bits are below maximum */
while (bits > max_bits) {
coderInfo->global_gain += 1;
bits = CountBits(coderInfo, xi, xr_pow);
}
return bits;
}
static void CalcAllowedDist(PsyInfo *psyInfo, int *cb_width, int num_cb,
double *xr, double *xmin)
{
int sfb, start, end, i;
double en0, xmin0;
end = 0;
for (sfb = 0; sfb < num_cb; sfb++)
{
start = end;
end += cb_width[sfb];
for (en0 = 0.0, i = start; i < end; i++)
{
en0 += xr[i] * xr[i];
}
en0 /= cb_width[sfb];
xmin0 = psyInfo->maskEn[sfb];
if (xmin0 > 0.0)
xmin0 = en0 * psyInfo->maskThr[sfb] / xmin0;
xmin[sfb] = xmin0;
}
}
static int OuterLoop(CoderInfo *coderInfo,
double *xr,
double *xr_pow,
int *xi,
double *xmin,
int target_bits)
{
int sb;
int notdone, over, better;
int store_global_gain, outer_loop_count;
int best_global_gain, age;
calcNoiseResult noiseInfo;
calcNoiseResult bestNoiseInfo;
double sfQuantFac = pow(2.0, 0.1875);
int *scale_factor = coderInfo->scale_factor;
int *best_scale_factor;
double *requant_xr;
int *save_xi;
double *distort;
distort = (double*)malloc(MAX_SCFAC_BANDS*sizeof(double));
best_scale_factor = (int*)malloc(MAX_SCFAC_BANDS*sizeof(int));
requant_xr = (double*)malloc(FRAME_LEN*sizeof(double));
save_xi = (int*)malloc(FRAME_LEN*sizeof(int));
notdone = 1;
outer_loop_count = 0;
do { /* outer iteration loop */
over = 0;
outer_loop_count++;
InnerLoop(coderInfo, xr_pow, xi, target_bits);
store_global_gain = coderInfo->global_gain;
over = CalcNoise(coderInfo, xr, xi, requant_xr, distort, xmin, &noiseInfo);
if (outer_loop_count == 1)
better = 1;
else
better = QuantCompare(&bestNoiseInfo, &noiseInfo);
if (better) {
bestNoiseInfo = noiseInfo;
best_global_gain = store_global_gain;
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++) {
best_scale_factor[sb] = scale_factor[sb];
}
memcpy(save_xi, xi, sizeof(int)*BLOCK_LEN_LONG);
age = 0;
} else
age++;
if (age > 3 && bestNoiseInfo.over_count == 0)
break;
notdone = BalanceNoise(coderInfo, distort, xr_pow);
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++)
if (scale_factor[sb] > 30)
notdone = 0;
if (notdone == 0)
break;
} while (1);
coderInfo->global_gain = best_global_gain;
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++) {
scale_factor[sb] = best_scale_factor[sb];
}
memcpy(xi, save_xi, sizeof(int)*BLOCK_LEN_LONG);
if (requant_xr) free(requant_xr);
if (best_scale_factor) free(best_scale_factor);
if (save_xi) free(save_xi);
if (distort) free(distort);
return 0;
}
static int CalcNoise(CoderInfo *coderInfo,
double *xr,
int *xi,
double *requant_xr,
double *error_energy,
double *xmin,
calcNoiseResult *res
)
{
int i, sb, sbw;
int over = 0, count = 0;
double invQuantFac;
double linediff, noise;
double over_noise = 1;
double tot_noise = 1;
double max_noise = 1E-20;
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++) {
sbw = coderInfo->sfb_offset[sb+1] - coderInfo->sfb_offset[sb];
invQuantFac = pow(2.0, -0.25*(coderInfo->scale_factor[sb] - coderInfo->global_gain));
error_energy[sb] = 0.0;
for (i = coderInfo->sfb_offset[sb]; i < coderInfo->sfb_offset[sb+1]; i++){
requant_xr[i] = pow43[xi[i]] * invQuantFac;
/* measure the distortion in each scalefactor band */
linediff = fabs(xr[i]) - requant_xr[i];
error_energy[sb] += linediff * linediff;
}
error_energy[sb] = error_energy[sb] / sbw;
noise = error_energy[sb] / xmin[sb];
/* multiplying here is adding in dB */
tot_noise *= max(noise, 1E-20);
if (noise>1) {
over++;
/* multiplying here is adding in dB */
over_noise *= noise;
}
max_noise = max(max_noise,noise);
error_energy[sb] = noise;
count++;
}
res->tot_count = count;
res->over_count = over;
res->tot_noise = 10.*log10(max(1e-20,tot_noise ));
res->over_noise = 10.*log10(max(1e+00,over_noise));
res->max_noise = 10.*log10(max(1e-20,max_noise ));
return over;
}
static int QuantCompare(calcNoiseResult *best,
calcNoiseResult *calc)
{
int better;
better = calc->over_count < best->over_count
|| ( calc->over_count == best->over_count &&
calc->over_noise < best->over_noise )
|| ( calc->over_count == best->over_count &&
calc->over_noise == best->over_noise &&
calc->tot_noise < best->tot_noise );
return better;
}
static int BalanceNoise(CoderInfo *coderInfo,
double *distort,
double *xrpow)
{
int status = 0, sb;
AmpScalefacBands(coderInfo, distort, xrpow);
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++)
if (coderInfo->scale_factor[sb] == 0)
status = 1;
return status;
}
static void AmpScalefacBands(CoderInfo *coderInfo,
double *distort,
double *xr_pow)
{
int start, end, l, sfb;
double ifqstep, distort_thresh;
ifqstep = pow(2.0, 0.1875);
distort_thresh = -900;
for (sfb = 0; sfb < coderInfo->nr_of_sfb; sfb++) {
distort_thresh = max(distort[sfb], distort_thresh);
}
if (distort_thresh>1.0)
distort_thresh=1.0;
else
distort_thresh *= .95;
for ( sfb = 0; sfb < coderInfo->nr_of_sfb; sfb++ ) {
if (distort[sfb] > distort_thresh) {
coderInfo->scale_factor[sfb]++;
start = coderInfo->sfb_offset[sfb];
end = coderInfo->sfb_offset[sfb+1];
for ( l = start; l < end; l++ ) {
xr_pow[l] *= ifqstep;
}
}
}
}
static int SortForGrouping(CoderInfo* coderInfo,
PsyInfo *psyInfo,
ChannelInfo *channelInfo,
int *sfb_width_table,
double *xr)
{
int i,j,ii;
int index = 0;
double xr_tmp[1024];
double thr_tmp[150];
double en_tmp[150];
int book=1;
int group_offset=0;
int k=0;
int windowOffset = 0;
/* set up local variables for used quantInfo elements */
int* sfb_offset = coderInfo->sfb_offset;
int* nr_of_sfb = &(coderInfo->nr_of_sfb);
int* window_group_length;
int num_window_groups;
*nr_of_sfb = coderInfo->max_sfb; /* Init to max_sfb */
window_group_length = coderInfo->window_group_length;
num_window_groups = coderInfo->num_window_groups;
/* calc org sfb_offset just for shortblock */
sfb_offset[k]=0;
for (k=1 ; k <*nr_of_sfb+1; k++) {
sfb_offset[k] = sfb_offset[k-1] + sfb_width_table[k-1];
}
/* sort the input spectral coefficients */
index = 0;
group_offset=0;
for (i=0; i< num_window_groups; i++) {
for (k=0; k<*nr_of_sfb; k++) {
for (j=0; j < window_group_length[i]; j++) {
for (ii=0;ii< sfb_width_table[k];ii++)
xr_tmp[index++] = xr[ii+ sfb_offset[k] + 128*j +group_offset];
}
}
group_offset += 128*window_group_length[i];
}
for (k=0; k<1024; k++){
xr[k] = xr_tmp[k];
}
/* now calc the new sfb_offset table for the whole p_spectrum vector*/
index = 0;
sfb_offset[index++] = 0;
windowOffset = 0;
for (i=0; i < num_window_groups; i++) {
for (k=0 ; k <*nr_of_sfb; k++) {
int w;
double worstTHR;
double worstEN;
/* for this window group and this band, find worst case inverse sig-mask-ratio */
if (channelInfo->msInfo.is_present && channelInfo->msInfo.ms_usedS[windowOffset][k]) {
worstTHR = psyInfo->maskThrSMS[windowOffset][k];
worstEN = psyInfo->maskEnSMS[windowOffset][k];
} else {
worstTHR = psyInfo->maskThrS[windowOffset][k];
worstEN = psyInfo->maskEnS[windowOffset][k];
}
for (w=1;w<window_group_length[i];w++) {
if (channelInfo->msInfo.is_present && channelInfo->msInfo.ms_usedS[w+windowOffset][k]) {
if (psyInfo->maskThrSMS[w+windowOffset][k] < worstTHR) {
worstTHR = psyInfo->maskThrSMS[w+windowOffset][k];
worstEN = psyInfo->maskEnSMS[w+windowOffset][k];
}
} else {
if (psyInfo->maskThrS[w+windowOffset][k] < worstTHR) {
worstTHR = psyInfo->maskThrS[w+windowOffset][k];
worstEN = psyInfo->maskEnS[w+windowOffset][k];
}
}
}
thr_tmp[k+ i* *nr_of_sfb] = worstTHR;
en_tmp[k+ i* *nr_of_sfb] = worstEN;
sfb_offset[index] = sfb_offset[index-1] + sfb_width_table[k]*window_group_length[i] ;
index++;
}
windowOffset += window_group_length[i];
}
*nr_of_sfb = *nr_of_sfb * num_window_groups; /* Number interleaved bands. */
for (k = 0; k < *nr_of_sfb; k++){
psyInfo->maskThr[k] = thr_tmp[k];
psyInfo->maskEn[k] = en_tmp[k];
}
return 0;
}