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freeswitch/src/mod/codecs/mod_isac/pitch_estimator.c
Anthony Minessale 224943f0b6 remove case from mod_iSAC sheesh....
2012-01-24 16:58:28 -06:00

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/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "pitch_estimator.h"
#include <math.h>
#include <memory.h>
#ifdef WEBRTC_ANDROID
#include <stdlib.h>
#endif
static const double kInterpolWin[8] = {-0.00067556028640, 0.02184247643159, -0.12203175715679, 0.60086484101160,
0.60086484101160, -0.12203175715679, 0.02184247643159, -0.00067556028640};
/* interpolation filter */
__inline static void IntrepolFilter(double *data_ptr, double *intrp)
{
*intrp = kInterpolWin[0] * data_ptr[-3];
*intrp += kInterpolWin[1] * data_ptr[-2];
*intrp += kInterpolWin[2] * data_ptr[-1];
*intrp += kInterpolWin[3] * data_ptr[0];
*intrp += kInterpolWin[4] * data_ptr[1];
*intrp += kInterpolWin[5] * data_ptr[2];
*intrp += kInterpolWin[6] * data_ptr[3];
*intrp += kInterpolWin[7] * data_ptr[4];
}
/* 2D parabolic interpolation */
/* probably some 0.5 factors can be eliminated, and the square-roots can be removed from the Cholesky fact. */
__inline static void Intrpol2D(double T[3][3], double *x, double *y, double *peak_val)
{
double c, b[2], A[2][2];
double t1, t2, d;
double delta1, delta2;
// double T[3][3] = {{-1.25, -.25,-.25}, {-.25, .75, .75}, {-.25, .75, .75}};
// should result in: delta1 = 0.5; delta2 = 0.0; peak_val = 1.0
c = T[1][1];
b[0] = 0.5 * (T[1][2] + T[2][1] - T[0][1] - T[1][0]);
b[1] = 0.5 * (T[1][0] + T[2][1] - T[0][1] - T[1][2]);
A[0][1] = -0.5 * (T[0][1] + T[2][1] - T[1][0] - T[1][2]);
t1 = 0.5 * (T[0][0] + T[2][2]) - c;
t2 = 0.5 * (T[2][0] + T[0][2]) - c;
d = (T[0][1] + T[1][2] + T[1][0] + T[2][1]) - 4.0 * c - t1 - t2;
A[0][0] = -t1 - 0.5 * d;
A[1][1] = -t2 - 0.5 * d;
/* deal with singularities or ill-conditioned cases */
if ( (A[0][0] < 1e-7) || ((A[0][0] * A[1][1] - A[0][1] * A[0][1]) < 1e-7) ) {
*peak_val = T[1][1];
return;
}
/* Cholesky decomposition: replace A by upper-triangular factor */
A[0][0] = sqrt(A[0][0]);
A[0][1] = A[0][1] / A[0][0];
A[1][1] = sqrt(A[1][1] - A[0][1] * A[0][1]);
/* compute [x; y] = -0.5 * inv(A) * b */
t1 = b[0] / A[0][0];
t2 = (b[1] - t1 * A[0][1]) / A[1][1];
delta2 = t2 / A[1][1];
delta1 = 0.5 * (t1 - delta2 * A[0][1]) / A[0][0];
delta2 *= 0.5;
/* limit norm */
t1 = delta1 * delta1 + delta2 * delta2;
if (t1 > 1.0) {
delta1 /= t1;
delta2 /= t1;
}
*peak_val = 0.5 * (b[0] * delta1 + b[1] * delta2) + c;
*x += delta1;
*y += delta2;
}
static void PCorr(const double *in, double *outcorr)
{
double sum, ysum, prod;
const double *x, *inptr;
int k, n;
//ysum = 1e-6; /* use this with float (i.s.o. double)! */
ysum = 1e-13;
sum = 0.0;
x = in + PITCH_MAX_LAG/2 + 2;
for (n = 0; n < PITCH_CORR_LEN2; n++) {
ysum += in[n] * in[n];
sum += x[n] * in[n];
}
outcorr += PITCH_LAG_SPAN2 - 1; /* index of last element in array */
*outcorr = sum / sqrt(ysum);
for (k = 1; k < PITCH_LAG_SPAN2; k++) {
ysum -= in[k-1] * in[k-1];
ysum += in[PITCH_CORR_LEN2 + k - 1] * in[PITCH_CORR_LEN2 + k - 1];
sum = 0.0;
inptr = &in[k];
prod = x[0] * inptr[0];
for (n = 1; n < PITCH_CORR_LEN2; n++) {
sum += prod;
prod = x[n] * inptr[n];
}
sum += prod;
outcorr--;
*outcorr = sum / sqrt(ysum);
}
}
void WebRtcIsac_InitializePitch(const double *in,
const double old_lag,
const double old_gain,
PitchAnalysisStruct *State,
double *lags)
{
double buf_dec[PITCH_CORR_LEN2+PITCH_CORR_STEP2+PITCH_MAX_LAG/2+2];
double ratio, log_lag, gain_bias;
double bias;
double corrvec1[PITCH_LAG_SPAN2];
double corrvec2[PITCH_LAG_SPAN2];
int m, k;
// Allocating 10 extra entries at the begining of the CorrSurf
double corrSurfBuff[10 + (2*PITCH_BW+3)*(PITCH_LAG_SPAN2+4)];
double* CorrSurf[2*PITCH_BW+3];
double *CorrSurfPtr1, *CorrSurfPtr2;
double LagWin[3] = {0.2, 0.5, 0.98};
int ind1, ind2, peaks_ind, peak, max_ind;
int peaks[PITCH_MAX_NUM_PEAKS];
double adj, gain_tmp;
double corr, corr_max;
double intrp_a, intrp_b, intrp_c, intrp_d;
double peak_vals[PITCH_MAX_NUM_PEAKS];
double lags1[PITCH_MAX_NUM_PEAKS];
double lags2[PITCH_MAX_NUM_PEAKS];
double T[3][3];
int row;
for(k = 0; k < 2*PITCH_BW+3; k++)
{
CorrSurf[k] = &corrSurfBuff[10 + k * (PITCH_LAG_SPAN2+4)];
}
/* reset CorrSurf matrix */
memset(corrSurfBuff, 0, sizeof(double) * (10 + (2*PITCH_BW+3) * (PITCH_LAG_SPAN2+4)));
//warnings -DH
max_ind = 0;
peak = 0;
/* copy old values from state buffer */
memcpy(buf_dec, State->dec_buffer, sizeof(double) * (PITCH_CORR_LEN2+PITCH_CORR_STEP2+PITCH_MAX_LAG/2-PITCH_FRAME_LEN/2+2));
/* decimation; put result after the old values */
WebRtcIsac_DecimateAllpass(in, State->decimator_state, PITCH_FRAME_LEN,
&buf_dec[PITCH_CORR_LEN2+PITCH_CORR_STEP2+PITCH_MAX_LAG/2-PITCH_FRAME_LEN/2+2]);
/* low-pass filtering */
for (k = PITCH_CORR_LEN2+PITCH_CORR_STEP2+PITCH_MAX_LAG/2-PITCH_FRAME_LEN/2+2; k < PITCH_CORR_LEN2+PITCH_CORR_STEP2+PITCH_MAX_LAG/2+2; k++)
buf_dec[k] += 0.75 * buf_dec[k-1] - 0.25 * buf_dec[k-2];
/* copy end part back into state buffer */
memcpy(State->dec_buffer, buf_dec+PITCH_FRAME_LEN/2, sizeof(double) * (PITCH_CORR_LEN2+PITCH_CORR_STEP2+PITCH_MAX_LAG/2-PITCH_FRAME_LEN/2+2));
/* compute correlation for first and second half of the frame */
PCorr(buf_dec, corrvec1);
PCorr(buf_dec + PITCH_CORR_STEP2, corrvec2);
/* bias towards pitch lag of previous frame */
log_lag = log(0.5 * old_lag);
gain_bias = 4.0 * old_gain * old_gain;
if (gain_bias > 0.8) gain_bias = 0.8;
for (k = 0; k < PITCH_LAG_SPAN2; k++)
{
ratio = log((double) (k + (PITCH_MIN_LAG/2-2))) - log_lag;
bias = 1.0 + gain_bias * exp(-5.0 * ratio * ratio);
corrvec1[k] *= bias;
}
/* taper correlation functions */
for (k = 0; k < 3; k++) {
gain_tmp = LagWin[k];
corrvec1[k] *= gain_tmp;
corrvec2[k] *= gain_tmp;
corrvec1[PITCH_LAG_SPAN2-1-k] *= gain_tmp;
corrvec2[PITCH_LAG_SPAN2-1-k] *= gain_tmp;
}
corr_max = 0.0;
/* fill middle row of correlation surface */
ind1 = 0;
ind2 = 0;
CorrSurfPtr1 = &CorrSurf[PITCH_BW][2];
for (k = 0; k < PITCH_LAG_SPAN2; k++) {
corr = corrvec1[ind1++] + corrvec2[ind2++];
CorrSurfPtr1[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr1[k] - &CorrSurf[0][0]);
}
}
/* fill first and last rows of correlation surface */
ind1 = 0;
ind2 = PITCH_BW;
CorrSurfPtr1 = &CorrSurf[0][2];
CorrSurfPtr2 = &CorrSurf[2*PITCH_BW][PITCH_BW+2];
for (k = 0; k < PITCH_LAG_SPAN2-PITCH_BW; k++) {
ratio = ((double) (ind1 + 12)) / ((double) (ind2 + 12));
adj = 0.2 * ratio * (2.0 - ratio); /* adjustment factor; inverse parabola as a function of ratio */
corr = adj * (corrvec1[ind1] + corrvec2[ind2]);
CorrSurfPtr1[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr1[k] - &CorrSurf[0][0]);
}
corr = adj * (corrvec1[ind2++] + corrvec2[ind1++]);
CorrSurfPtr2[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr2[k] - &CorrSurf[0][0]);
}
}
/* fill second and next to last rows of correlation surface */
ind1 = 0;
ind2 = PITCH_BW-1;
CorrSurfPtr1 = &CorrSurf[1][2];
CorrSurfPtr2 = &CorrSurf[2*PITCH_BW-1][PITCH_BW+1];
for (k = 0; k < PITCH_LAG_SPAN2-PITCH_BW+1; k++) {
ratio = ((double) (ind1 + 12)) / ((double) (ind2 + 12));
adj = 0.9 * ratio * (2.0 - ratio); /* adjustment factor; inverse parabola as a function of ratio */
corr = adj * (corrvec1[ind1] + corrvec2[ind2]);
CorrSurfPtr1[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr1[k] - &CorrSurf[0][0]);
}
corr = adj * (corrvec1[ind2++] + corrvec2[ind1++]);
CorrSurfPtr2[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr2[k] - &CorrSurf[0][0]);
}
}
/* fill remainder of correlation surface */
for (m = 2; m < PITCH_BW; m++) {
ind1 = 0;
ind2 = PITCH_BW - m; /* always larger than ind1 */
CorrSurfPtr1 = &CorrSurf[m][2];
CorrSurfPtr2 = &CorrSurf[2*PITCH_BW-m][PITCH_BW+2-m];
for (k = 0; k < PITCH_LAG_SPAN2-PITCH_BW+m; k++) {
ratio = ((double) (ind1 + 12)) / ((double) (ind2 + 12));
adj = ratio * (2.0 - ratio); /* adjustment factor; inverse parabola as a function of ratio */
corr = adj * (corrvec1[ind1] + corrvec2[ind2]);
CorrSurfPtr1[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr1[k] - &CorrSurf[0][0]);
}
corr = adj * (corrvec1[ind2++] + corrvec2[ind1++]);
CorrSurfPtr2[k] = corr;
if (corr > corr_max) {
corr_max = corr; /* update maximum */
max_ind = (int)(&CorrSurfPtr2[k] - &CorrSurf[0][0]);
}
}
}
/* threshold value to qualify as a peak */
corr_max *= 0.6;
peaks_ind = 0;
/* find peaks */
for (m = 1; m < PITCH_BW+1; m++) {
if (peaks_ind == PITCH_MAX_NUM_PEAKS) break;
CorrSurfPtr1 = &CorrSurf[m][2];
for (k = 2; k < PITCH_LAG_SPAN2-PITCH_BW-2+m; k++) {
corr = CorrSurfPtr1[k];
if (corr > corr_max) {
if ( (corr > CorrSurfPtr1[k - (PITCH_LAG_SPAN2+5)]) && (corr > CorrSurfPtr1[k - (PITCH_LAG_SPAN2+4)]) ) {
if ( (corr > CorrSurfPtr1[k + (PITCH_LAG_SPAN2+4)]) && (corr > CorrSurfPtr1[k + (PITCH_LAG_SPAN2+5)]) ) {
/* found a peak; store index into matrix */
peaks[peaks_ind++] = (int)(&CorrSurfPtr1[k] - &CorrSurf[0][0]);
if (peaks_ind == PITCH_MAX_NUM_PEAKS) break;
}
}
}
}
}
for (m = PITCH_BW+1; m < 2*PITCH_BW; m++) {
if (peaks_ind == PITCH_MAX_NUM_PEAKS) break;
CorrSurfPtr1 = &CorrSurf[m][2];
for (k = 2+m-PITCH_BW; k < PITCH_LAG_SPAN2-2; k++) {
corr = CorrSurfPtr1[k];
if (corr > corr_max) {
if ( (corr > CorrSurfPtr1[k - (PITCH_LAG_SPAN2+5)]) && (corr > CorrSurfPtr1[k - (PITCH_LAG_SPAN2+4)]) ) {
if ( (corr > CorrSurfPtr1[k + (PITCH_LAG_SPAN2+4)]) && (corr > CorrSurfPtr1[k + (PITCH_LAG_SPAN2+5)]) ) {
/* found a peak; store index into matrix */
peaks[peaks_ind++] = (int)(&CorrSurfPtr1[k] - &CorrSurf[0][0]);
if (peaks_ind == PITCH_MAX_NUM_PEAKS) break;
}
}
}
}
}
if (peaks_ind > 0) {
/* examine each peak */
CorrSurfPtr1 = &CorrSurf[0][0];
for (k = 0; k < peaks_ind; k++) {
peak = peaks[k];
/* compute four interpolated values around current peak */
IntrepolFilter(&CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+5)], &intrp_a);
IntrepolFilter(&CorrSurfPtr1[peak - 1 ], &intrp_b);
IntrepolFilter(&CorrSurfPtr1[peak ], &intrp_c);
IntrepolFilter(&CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+4)], &intrp_d);
/* determine maximum of the interpolated values */
corr = CorrSurfPtr1[peak];
corr_max = intrp_a;
if (intrp_b > corr_max) corr_max = intrp_b;
if (intrp_c > corr_max) corr_max = intrp_c;
if (intrp_d > corr_max) corr_max = intrp_d;
/* determine where the peak sits and fill a 3x3 matrix around it */
row = peak / (PITCH_LAG_SPAN2+4);
lags1[k] = (double) ((peak - row * (PITCH_LAG_SPAN2+4)) + PITCH_MIN_LAG/2 - 4);
lags2[k] = (double) (lags1[k] + PITCH_BW - row);
if ( corr > corr_max ) {
T[0][0] = CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+5)];
T[2][0] = CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+4)];
T[1][1] = corr;
T[0][2] = CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+4)];
T[2][2] = CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+5)];
T[1][0] = intrp_a;
T[0][1] = intrp_b;
T[2][1] = intrp_c;
T[1][2] = intrp_d;
} else {
if (intrp_a == corr_max) {
lags1[k] -= 0.5;
lags2[k] += 0.5;
IntrepolFilter(&CorrSurfPtr1[peak - 2*(PITCH_LAG_SPAN2+5)], &T[0][0]);
IntrepolFilter(&CorrSurfPtr1[peak - (2*PITCH_LAG_SPAN2+9)], &T[2][0]);
T[1][1] = intrp_a;
T[0][2] = intrp_b;
T[2][2] = intrp_c;
T[1][0] = CorrSurfPtr1[peak - (2*PITCH_LAG_SPAN2+9)];
T[0][1] = CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+5)];
T[2][1] = CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+4)];
T[1][2] = corr;
} else if (intrp_b == corr_max) {
lags1[k] -= 0.5;
lags2[k] -= 0.5;
IntrepolFilter(&CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+6)], &T[0][0]);
T[2][0] = intrp_a;
T[1][1] = intrp_b;
IntrepolFilter(&CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+3)], &T[0][2]);
T[2][2] = intrp_d;
T[1][0] = CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+5)];
T[0][1] = CorrSurfPtr1[peak - 1];
T[2][1] = corr;
T[1][2] = CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+4)];
} else if (intrp_c == corr_max) {
lags1[k] += 0.5;
lags2[k] += 0.5;
T[0][0] = intrp_a;
IntrepolFilter(&CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+4)], &T[2][0]);
T[1][1] = intrp_c;
T[0][2] = intrp_d;
IntrepolFilter(&CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+5)], &T[2][2]);
T[1][0] = CorrSurfPtr1[peak - (PITCH_LAG_SPAN2+4)];
T[0][1] = corr;
T[2][1] = CorrSurfPtr1[peak + 1];
T[1][2] = CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+5)];
} else {
lags1[k] += 0.5;
lags2[k] -= 0.5;
T[0][0] = intrp_b;
T[2][0] = intrp_c;
T[1][1] = intrp_d;
IntrepolFilter(&CorrSurfPtr1[peak + 2*(PITCH_LAG_SPAN2+4)], &T[0][2]);
IntrepolFilter(&CorrSurfPtr1[peak + (2*PITCH_LAG_SPAN2+9)], &T[2][2]);
T[1][0] = corr;
T[0][1] = CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+4)];
T[2][1] = CorrSurfPtr1[peak + (PITCH_LAG_SPAN2+5)];
T[1][2] = CorrSurfPtr1[peak + (2*PITCH_LAG_SPAN2+9)];
}
}
/* 2D parabolic interpolation gives more accurate lags and peak value */
Intrpol2D(T, &lags1[k], &lags2[k], &peak_vals[k]);
}
/* determine the highest peak, after applying a bias towards short lags */
corr_max = 0.0;
for (k = 0; k < peaks_ind; k++) {
corr = peak_vals[k] * pow(PITCH_PEAK_DECAY, log(lags1[k] + lags2[k]));
if (corr > corr_max) {
corr_max = corr;
peak = k;
}
}
lags1[peak] *= 2.0;
lags2[peak] *= 2.0;
if (lags1[peak] < (double) PITCH_MIN_LAG) lags1[peak] = (double) PITCH_MIN_LAG;
if (lags2[peak] < (double) PITCH_MIN_LAG) lags2[peak] = (double) PITCH_MIN_LAG;
if (lags1[peak] > (double) PITCH_MAX_LAG) lags1[peak] = (double) PITCH_MAX_LAG;
if (lags2[peak] > (double) PITCH_MAX_LAG) lags2[peak] = (double) PITCH_MAX_LAG;
/* store lags of highest peak in output array */
lags[0] = lags1[peak];
lags[1] = lags1[peak];
lags[2] = lags2[peak];
lags[3] = lags2[peak];
}
else
{
row = max_ind / (PITCH_LAG_SPAN2+4);
lags1[0] = (double) ((max_ind - row * (PITCH_LAG_SPAN2+4)) + PITCH_MIN_LAG/2 - 4);
lags2[0] = (double) (lags1[0] + PITCH_BW - row);
if (lags1[0] < (double) PITCH_MIN_LAG) lags1[0] = (double) PITCH_MIN_LAG;
if (lags2[0] < (double) PITCH_MIN_LAG) lags2[0] = (double) PITCH_MIN_LAG;
if (lags1[0] > (double) PITCH_MAX_LAG) lags1[0] = (double) PITCH_MAX_LAG;
if (lags2[0] > (double) PITCH_MAX_LAG) lags2[0] = (double) PITCH_MAX_LAG;
/* store lags of highest peak in output array */
lags[0] = lags1[0];
lags[1] = lags1[0];
lags[2] = lags2[0];
lags[3] = lags2[0];
}
}
/* create weighting matrix by orthogonalizing a basis of polynomials of increasing order
* t = (0:4)';
* A = [t.^0, t.^1, t.^2, t.^3, t.^4];
* [Q, dummy] = qr(A);
* P.Weight = Q * diag([0, .1, .5, 1, 1]) * Q'; */
static const double kWeight[5][5] = {
{ 0.29714285714286, -0.30857142857143, -0.05714285714286, 0.05142857142857, 0.01714285714286},
{-0.30857142857143, 0.67428571428571, -0.27142857142857, -0.14571428571429, 0.05142857142857},
{-0.05714285714286, -0.27142857142857, 0.65714285714286, -0.27142857142857, -0.05714285714286},
{ 0.05142857142857, -0.14571428571429, -0.27142857142857, 0.67428571428571, -0.30857142857143},
{ 0.01714285714286, 0.05142857142857, -0.05714285714286, -0.30857142857143, 0.29714285714286}
};
void WebRtcIsac_PitchAnalysis(const double *in, /* PITCH_FRAME_LEN samples */
double *out, /* PITCH_FRAME_LEN+QLOOKAHEAD samples */
PitchAnalysisStruct *State,
double *lags,
double *gains)
{
double HPin[PITCH_FRAME_LEN];
double Weighted[PITCH_FRAME_LEN];
double Whitened[PITCH_FRAME_LEN + QLOOKAHEAD];
double inbuf[PITCH_FRAME_LEN + QLOOKAHEAD];
double out_G[PITCH_FRAME_LEN + QLOOKAHEAD]; // could be removed by using out instead
double out_dG[4][PITCH_FRAME_LEN + QLOOKAHEAD];
double old_lag, old_gain;
double nrg_wht, tmp;
double Wnrg, Wfluct, Wgain;
double H[4][4];
double grad[4];
double dG[4];
int k, m, n, iter;
/* high pass filtering using second order pole-zero filter */
WebRtcIsac_Highpass(in, HPin, State->hp_state, PITCH_FRAME_LEN);
/* copy from state into buffer */
memcpy(Whitened, State->whitened_buf, sizeof(double) * QLOOKAHEAD);
/* compute weighted and whitened signals */
WebRtcIsac_WeightingFilter(HPin, &Weighted[0], &Whitened[QLOOKAHEAD], &(State->Wghtstr));
/* copy from buffer into state */
memcpy(State->whitened_buf, Whitened+PITCH_FRAME_LEN, sizeof(double) * QLOOKAHEAD);
old_lag = State->PFstr_wght.oldlagp[0];
old_gain = State->PFstr_wght.oldgainp[0];
/* inital pitch estimate */
WebRtcIsac_InitializePitch(Weighted, old_lag, old_gain, State, lags);
/* Iterative optimization of lags - to be done */
/* compute energy of whitened signal */
nrg_wht = 0.0;
for (k = 0; k < PITCH_FRAME_LEN + QLOOKAHEAD; k++)
nrg_wht += Whitened[k] * Whitened[k];
/* Iterative optimization of gains */
/* set weights for energy, gain fluctiation, and spectral gain penalty functions */
Wnrg = 1.0 / nrg_wht;
Wgain = 0.005;
Wfluct = 3.0;
/* set initial gains */
for (k = 0; k < 4; k++)
gains[k] = PITCH_MAX_GAIN_06;
/* two iterations should be enough */
for (iter = 0; iter < 2; iter++) {
/* compute Jacobian of pre-filter output towards gains */
WebRtcIsac_PitchfilterPre_gains(Whitened, out_G, out_dG, &(State->PFstr_wght), lags, gains);
/* gradient and approximate Hessian (lower triangle) for minimizing the filter's output power */
for (k = 0; k < 4; k++) {
tmp = 0.0;
for (n = 0; n < PITCH_FRAME_LEN + QLOOKAHEAD; n++)
tmp += out_G[n] * out_dG[k][n];
grad[k] = tmp * Wnrg;
}
for (k = 0; k < 4; k++) {
for (m = 0; m <= k; m++) {
tmp = 0.0;
for (n = 0; n < PITCH_FRAME_LEN + QLOOKAHEAD; n++)
tmp += out_dG[m][n] * out_dG[k][n];
H[k][m] = tmp * Wnrg;
}
}
/* add gradient and Hessian (lower triangle) for dampening fast gain changes */
for (k = 0; k < 4; k++) {
tmp = kWeight[k+1][0] * old_gain;
for (m = 0; m < 4; m++)
tmp += kWeight[k+1][m+1] * gains[m];
grad[k] += tmp * Wfluct;
}
for (k = 0; k < 4; k++) {
for (m = 0; m <= k; m++) {
H[k][m] += kWeight[k+1][m+1] * Wfluct;
}
}
/* add gradient and Hessian for dampening gain */
for (k = 0; k < 3; k++) {
tmp = 1.0 / (1 - gains[k]);
grad[k] += tmp * tmp * Wgain;
H[k][k] += 2.0 * tmp * (tmp * tmp * Wgain);
}
tmp = 1.0 / (1 - gains[3]);
grad[3] += 1.33 * (tmp * tmp * Wgain);
H[3][3] += 2.66 * tmp * (tmp * tmp * Wgain);
/* compute Cholesky factorization of Hessian
* by overwritting the upper triangle; scale factors on diagonal
* (for non pc-platforms store the inverse of the diagonals seperately to minimize divisions) */
H[0][1] = H[1][0] / H[0][0];
H[0][2] = H[2][0] / H[0][0];
H[0][3] = H[3][0] / H[0][0];
H[1][1] -= H[0][0] * H[0][1] * H[0][1];
H[1][2] = (H[2][1] - H[0][1] * H[2][0]) / H[1][1];
H[1][3] = (H[3][1] - H[0][1] * H[3][0]) / H[1][1];
H[2][2] -= H[0][0] * H[0][2] * H[0][2] + H[1][1] * H[1][2] * H[1][2];
H[2][3] = (H[3][2] - H[0][2] * H[3][0] - H[1][2] * H[1][1] * H[1][3]) / H[2][2];
H[3][3] -= H[0][0] * H[0][3] * H[0][3] + H[1][1] * H[1][3] * H[1][3] + H[2][2] * H[2][3] * H[2][3];
/* Compute update as delta_gains = -inv(H) * grad */
/* copy and negate */
for (k = 0; k < 4; k++)
dG[k] = -grad[k];
/* back substitution */
dG[1] -= dG[0] * H[0][1];
dG[2] -= dG[0] * H[0][2] + dG[1] * H[1][2];
dG[3] -= dG[0] * H[0][3] + dG[1] * H[1][3] + dG[2] * H[2][3];
/* scale */
for (k = 0; k < 4; k++)
dG[k] /= H[k][k];
/* back substitution */
dG[2] -= dG[3] * H[2][3];
dG[1] -= dG[3] * H[1][3] + dG[2] * H[1][2];
dG[0] -= dG[3] * H[0][3] + dG[2] * H[0][2] + dG[1] * H[0][1];
/* update gains and check range */
for (k = 0; k < 4; k++) {
gains[k] += dG[k];
if (gains[k] > PITCH_MAX_GAIN)
gains[k] = PITCH_MAX_GAIN;
else if (gains[k] < 0.0)
gains[k] = 0.0;
}
}
/* update state for next frame */
WebRtcIsac_PitchfilterPre(Whitened, out, &(State->PFstr_wght), lags, gains);
/* concatenate previous input's end and current input */
memcpy(inbuf, State->inbuf, sizeof(double) * QLOOKAHEAD);
memcpy(inbuf+QLOOKAHEAD, in, sizeof(double) * PITCH_FRAME_LEN);
/* lookahead pitch filtering for masking analysis */
WebRtcIsac_PitchfilterPre_la(inbuf, out, &(State->PFstr), lags, gains);
/* store last part of input */
for (k = 0; k < QLOOKAHEAD; k++)
State->inbuf[k] = inbuf[k + PITCH_FRAME_LEN];
}
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