ref: f8fb982129460df2d5ae12ac034e22429d3f01f4
parent: a6fd9fd656be01df4b98d66a6a048b5a04a76830
author: knik <knik>
date: Sun Apr 13 04:37:47 EDT 2003
improved quantizer (true VBR) new noise allocation scheme (better psymodel)
--- a/libfaac/aacquant.c
+++ b/libfaac/aacquant.c
@@ -1,7 +1,7 @@
/*
* FAAC - Freeware Advanced Audio Coder
* Copyright (C) 2001 Menno Bakker
- * Copyright (C) 2002 Krzysztof Nikiel
+ * Copyright (C) 2002, 2003 Krzysztof Nikiel
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -17,7 +17,7 @@
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
- * $Id: aacquant.c,v 1.16 2003/03/27 17:06:50 knik Exp $
+ * $Id: aacquant.c,v 1.17 2003/04/13 08:37:47 knik Exp $
*/
#include <math.h>
@@ -46,19 +46,10 @@
int *sfb_width_table,
double *xr);
-static int SearchStepSize(CoderInfo *coderInfo,
- const int desired_rate,
- const double *xr,
- int *xi);
-
static void CalcAllowedDist(PsyInfo *psyInfo, int *cb_offset, int num_cb,
double *xr, double *xmin, int quality);
-static int CountBits(CoderInfo *coderInfo, int *ix, const double *xr);
-static int CountBitsLong(CoderInfo *coderInfo, int *xi);
-
-
double *pow43;
double *adj43;
double *adj43asm;
@@ -109,8 +100,6 @@
{const double ifqstep = pow(2.0, 0.25);
const double logstep_1 = 1.0 / log(ifqstep);
- const int sfcmax = 40;
- const int sfcmin = -10;
int sb;
int nsfb = coderInfo->nr_of_sfb;
int start, end;
@@ -120,17 +109,24 @@
for (sb = 0; sb < nsfb; sb++)
{- double qfac_1 = pow(2.0, -0.25*(coderInfo->scale_factor[sb] - coderInfo->global_gain));
+ double qfac_1;
start = coderInfo->sfb_offset[sb];
end = coderInfo->sfb_offset[sb+1];
+ qfac_1 = pow(2.0, -0.25*(coderInfo->scale_factor[sb] - coderInfo->global_gain));
+
en0 = 0.0;
enq = 0.0;
for (l = start; l < end; l++)
{- double xq = pow43[xi[l]];
+ double xq;
+ if (!sb && !xi[l])
+ continue;
+
+ xq = pow43[xi[l]];
+
en0 += xr[l] * xr[l];
enq += xq * xq;
}
@@ -144,11 +140,6 @@
shift -= 1000;
shift += coderInfo->scale_factor[sb];
-
- if (shift < sfcmin)
- shift = sfcmin;
- if (shift > sfcmax)
- shift = sfcmax;
coderInfo->scale_factor[sb] = shift;
}
}
@@ -215,17 +206,11 @@
if (do_q) {CalcAllowedDist(psyInfo, coderInfo->sfb_offset,
coderInfo->nr_of_sfb, xr, xmin, quality);
- bits = SearchStepSize(coderInfo, 9 * quality, xr_pow, xi);
+ coderInfo->global_gain = 0;
FixNoise(coderInfo, xr, xr_pow, xi, xmin);
BalanceEnergy(coderInfo, xr, xi);
UpdateRequant(coderInfo, xi);
-#if 0
- printf("global gain: %d\n", coderInfo->global_gain);- for (i = 0; i < coderInfo->nr_of_sfb; i++)
- printf("sf %d: %d\n", i, coderInfo->scale_factor[i]);-#endif
-
for ( i = 0; i < FRAME_LEN; i++ ) {sign = (xr[i] < 0) ? -1 : 1;
xi[i] *= sign;
@@ -236,7 +221,7 @@
SetMemory(xi, 0, FRAME_LEN*sizeof(int));
}
- CountBitsLong(coderInfo, xi);
+ BitSearch(coderInfo, xi);
/* offset the difference of common_scalefac and scalefactors by SF_OFFSET */
for (i = 0; i < coderInfo->nr_of_sfb; i++) {@@ -245,6 +230,11 @@
}
}
coderInfo->global_gain = scale_factor[0];
+#if 0
+ printf("global gain: %d\n", coderInfo->global_gain);+ for (i = 0; i < coderInfo->nr_of_sfb; i++)
+ printf("sf %d: %d\n", i, coderInfo->scale_factor[i]);+#endif
/* 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 */
@@ -261,74 +251,7 @@
return bits;
}
-static int SearchStepSize(CoderInfo *coderInfo,
- const int desired_rate,
- const double *xr,
- int *xi)
-{- int flag_GoneOver = 0;
- int CurrentStep = coderInfo->CurrentStep & 0xf;
- int lastshort = coderInfo->CurrentStep & 0x10;
- int thisshort = (coderInfo->block_type == ONLY_SHORT_WINDOW) ? 0x10 : 0;
- int nBits;
- int StepSize = coderInfo->old_value;
- int Direction = 0;
- int blockshift = 0;
- if (thisshort > lastshort)
- blockshift = -7;
- if (thisshort < lastshort)
- blockshift = +7;
-
- if (blockshift && (StepSize + blockshift) >= 0)
- StepSize += blockshift;
-
- 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);
-
- while (nBits > desired_rate)
- {- StepSize++;
- coderInfo->global_gain = StepSize;
- nBits = CountBits(coderInfo, xi, xr);
- }
-
- CurrentStep = coderInfo->old_value - StepSize;
- CurrentStep += blockshift;
-
- coderInfo->CurrentStep = CurrentStep/4 != 0 ? 4 : 2;
- coderInfo->old_value = coderInfo->global_gain;
-
- coderInfo->CurrentStep |= thisshort;
-
- return nBits;
-}
-
#if 1 /* TAKEHIRO_IEEE754_HACK */
#pragma warning( disable : 4244 4307 )
@@ -433,68 +356,39 @@
}
#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 void CalcAllowedDist(PsyInfo *psyInfo, int *cb_offset, int num_cb,
double *xr, double *xmin, int quality)
{- int sfb, start, end;
- double xmin0;
- const double globalthr = 12.0 / (double)quality;
+ int sfb, start, end, l;
+ const double globalthr = 38.0 / (double)quality;
+ int last = cb_offset[num_cb];
+ double mid = 0.5 * 5.0 / cb_offset[num_cb];
+ double totnrg = 0.0;
+ static const double minfix = 1.5;
+ for (l = 0; l < last; l++)
+ totnrg += xr[l] * xr[l];
+
+ totnrg /= last;
+
for (sfb = 0; sfb < num_cb; sfb++)
{+ double thr, tmp;
+ double enrg = 0.0;
+
start = cb_offset[sfb];
end = cb_offset[sfb + 1];
- xmin0 = psyInfo->maskEn[sfb];
- if (xmin0 > 0.0)
- xmin0 = psyInfo->maskThr[sfb] * pow(end, 0.6) * globalthr / xmin0;
+ for (l = start; l < end; l++)
+ enrg += xr[l]*xr[l];
- xmin[sfb] = xmin0;
+ thr = pow((double)(end-start)*totnrg/enrg, 0.5*(num_cb-sfb)/num_cb + 0.0);
+
+ tmp = minfix * pow((double)(start + 400) / (double)last, 0.6);
+ if (tmp < thr)
+ thr = tmp;
+
+ xmin[sfb] = psyInfo->maskThr[sfb] * globalthr * thr;
}
}
@@ -509,12 +403,18 @@
double quantvol, diffvol;
double quantfac;
double tmp;
- int done = 0;
const double ifqstep = pow(2.0, 0.1875);
- const int sfacmax = 30;
+ const double log_ifqstep = 1.0 / log(ifqstep);
+ const double maxstep = 0.05;
for (sb = 0; sb < coderInfo->nr_of_sfb; sb++)
{+ double sfacfix;
+ double fixstep = 0.25;
+ int sfac;
+ double fac;
+ int dist;
+
if (!xmin[sb])
continue;
@@ -521,6 +421,30 @@
start = coderInfo->sfb_offset[sb];
end = coderInfo->sfb_offset[sb+1];
+ tmp = 0.0;
+ for (i = start; i < end; i++)
+ {+ if (xr_pow[i] > tmp)
+ tmp = xr_pow[i];
+ }
+
+ //printf("band %d: tmp: %f\n", sb, tmp);+ if (tmp < 10.0)
+ {+ for (i = start; i < end; i++)
+ xi[i] = 0;
+ coderInfo->scale_factor[sb] = 10;
+ continue;
+ }
+
+ sfacfix = 1.0 / tmp;
+ sfac = log(sfacfix) * log_ifqstep - 0.5;
+ for (i = start; i < end; i++)
+ xr_pow[i] *= sfacfix;
+ coderInfo->scale_factor[sb] = sfac;
+ QuantizeBand(xr_pow, xi, IPOW20(coderInfo->global_gain), start, end);
+ //printf("\tsfac: %d\n", sfac);+
calcdist:
quantfac = pow(2.0, 0.25*(coderInfo->scale_factor[sb] - coderInfo->global_gain));
@@ -529,28 +453,46 @@
for (i = start; i < end; i++)
{tmp = pow43[xi[i]];
- quantvol += tmp;
+ quantvol += tmp * tmp;
diffvol += fabs(fabs(xr[i]) * quantfac - tmp);
}
- if (diffvol / quantvol > xmin[sb]) // distorion to high
+ quantvol = sqrt(quantvol/(double)(end-start)) * (double)(end-start);
+ //printf("\tdiffvol: %f, qvol: %f\n", diffvol, quantvol);+
+ dist = (diffvol / quantvol) > xmin[sb];
+ fac = 0.0;
+ if (fabs(fixstep) > maxstep)
{- if (coderInfo->scale_factor[sb] < sfacmax)
+ if ((dist && (fixstep < 0))
+ || (!dist && (fixstep > 0)))
{+ fixstep = -0.5 * fixstep;
+ }
+
+ fac = 1.0 + fixstep;
+ }
+ else if (dist)
+ {+ fac = 1.0 + fabs(fixstep);
+ }
+
+ if (fac != 0.0)
+ {+ if (coderInfo->scale_factor[sb] < -10)
+ {for (i = start; i < end; i++)
- xr_pow[i] *= ifqstep;
- coderInfo->scale_factor[sb]++;
+ xr_pow[i] *= fac;
+ sfacfix *= fac;
+ coderInfo->scale_factor[sb] = log(sfacfix) * log_ifqstep - 0.5;
QuantizeBand(xr_pow, xi, IPOW20(coderInfo->global_gain), start, end);
goto calcdist;
}
}
- else
- done++;
//printf("%d: %g\t%g - %g(%d)\n", sb, quantvol, diffvol/quantvol, xmin[sb], coderInfo->scale_factor[sb]);}
-
- return done;
+ return 0;
}
static int SortForGrouping(CoderInfo* coderInfo,