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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 <memory.h>
#include <string.h>
#ifdef WEBRTC_ANDROID
#include <stdlib.h>
#endif
#include "modules/audio_coding/codecs/isac/main/source/pitch_estimator.h"
#include "modules/audio_coding/codecs/isac/main/source/isac_vad.h"
static void WebRtcIsac_AllPoleFilter(double* InOut,
double* Coef,
size_t lengthInOut,
int orderCoef) {
/* the state of filter is assumed to be in InOut[-1] to InOut[-orderCoef] */
double scal;
double sum;
size_t n;
int k;
//if (fabs(Coef[0]-1.0)<0.001) {
if ( (Coef[0] > 0.9999) && (Coef[0] < 1.0001) )
{
for(n = 0; n < lengthInOut; n++)
{
sum = Coef[1] * InOut[-1];
for(k = 2; k <= orderCoef; k++){
sum += Coef[k] * InOut[-k];
}
*InOut++ -= sum;
}
}
else
{
scal = 1.0 / Coef[0];
for(n=0;n<lengthInOut;n++)
{
*InOut *= scal;
for(k=1;k<=orderCoef;k++){
*InOut -= scal*Coef[k]*InOut[-k];
}
InOut++;
}
}
}
static void WebRtcIsac_AllZeroFilter(double* In,
double* Coef,
size_t lengthInOut,
int orderCoef,
double* Out) {
/* the state of filter is assumed to be in In[-1] to In[-orderCoef] */
size_t n;
int k;
double tmp;
for(n = 0; n < lengthInOut; n++)
{
tmp = In[0] * Coef[0];
for(k = 1; k <= orderCoef; k++){
tmp += Coef[k] * In[-k];
}
*Out++ = tmp;
In++;
}
}
static void WebRtcIsac_ZeroPoleFilter(double* In,
double* ZeroCoef,
double* PoleCoef,
size_t lengthInOut,
int orderCoef,
double* Out) {
/* the state of the zero section is assumed to be in In[-1] to In[-orderCoef] */
/* the state of the pole section is assumed to be in Out[-1] to Out[-orderCoef] */
WebRtcIsac_AllZeroFilter(In,ZeroCoef,lengthInOut,orderCoef,Out);
WebRtcIsac_AllPoleFilter(Out,PoleCoef,lengthInOut,orderCoef);
}
void WebRtcIsac_AutoCorr(double* r, const double* x, size_t N, size_t order) {
size_t lag, n;
double sum, prod;
const double *x_lag;
for (lag = 0; lag <= order; lag++)
{
sum = 0.0f;
x_lag = &x[lag];
prod = x[0] * x_lag[0];
for (n = 1; n < N - lag; n++) {
sum += prod;
prod = x[n] * x_lag[n];
}
sum += prod;
r[lag] = sum;
}
}
static void WebRtcIsac_BwExpand(double* out,
double* in,
double coef,
size_t length) {
size_t i;
double chirp;
chirp = coef;
out[0] = in[0];
for (i = 1; i < length; i++) {
out[i] = chirp * in[i];
chirp *= coef;
}
}
void WebRtcIsac_WeightingFilter(const double* in,
double* weiout,
double* whiout,
WeightFiltstr* wfdata) {
double tmpbuffer[PITCH_FRAME_LEN + PITCH_WLPCBUFLEN];
double corr[PITCH_WLPCORDER+1], rc[PITCH_WLPCORDER+1];
double apol[PITCH_WLPCORDER+1], apolr[PITCH_WLPCORDER+1];
double rho=0.9, *inp, *dp, *dp2;
double whoutbuf[PITCH_WLPCBUFLEN + PITCH_WLPCORDER];
double weoutbuf[PITCH_WLPCBUFLEN + PITCH_WLPCORDER];
double *weo, *who, opol[PITCH_WLPCORDER+1], ext[PITCH_WLPCWINLEN];
int k, n, endpos, start;
/* Set up buffer and states */
memcpy(tmpbuffer, wfdata->buffer, sizeof(double) * PITCH_WLPCBUFLEN);
memcpy(tmpbuffer+PITCH_WLPCBUFLEN, in, sizeof(double) * PITCH_FRAME_LEN);
memcpy(wfdata->buffer, tmpbuffer+PITCH_FRAME_LEN, sizeof(double) * PITCH_WLPCBUFLEN);
dp=weoutbuf;
dp2=whoutbuf;
for (k=0;k<PITCH_WLPCORDER;k++) {
*dp++ = wfdata->weostate[k];
*dp2++ = wfdata->whostate[k];
opol[k]=0.0;
}
opol[0]=1.0;
opol[PITCH_WLPCORDER]=0.0;
weo=dp;
who=dp2;
endpos=PITCH_WLPCBUFLEN + PITCH_SUBFRAME_LEN;
inp=tmpbuffer + PITCH_WLPCBUFLEN;
for (n=0; n<PITCH_SUBFRAMES; n++) {
/* Windowing */
start=endpos-PITCH_WLPCWINLEN;
for (k=0; k<PITCH_WLPCWINLEN; k++) {
ext[k]=wfdata->window[k]*tmpbuffer[start+k];
}
/* Get LPC polynomial */
WebRtcIsac_AutoCorr(corr, ext, PITCH_WLPCWINLEN, PITCH_WLPCORDER);
corr[0]=1.01*corr[0]+1.0; /* White noise correction */
WebRtcIsac_LevDurb(apol, rc, corr, PITCH_WLPCORDER);
WebRtcIsac_BwExpand(apolr, apol, rho, PITCH_WLPCORDER+1);
/* Filtering */
WebRtcIsac_ZeroPoleFilter(inp, apol, apolr, PITCH_SUBFRAME_LEN, PITCH_WLPCORDER, weo);
WebRtcIsac_ZeroPoleFilter(inp, apolr, opol, PITCH_SUBFRAME_LEN, PITCH_WLPCORDER, who);
inp+=PITCH_SUBFRAME_LEN;
endpos+=PITCH_SUBFRAME_LEN;
weo+=PITCH_SUBFRAME_LEN;
who+=PITCH_SUBFRAME_LEN;
}
/* Export filter states */
for (k=0;k<PITCH_WLPCORDER;k++) {
wfdata->weostate[k]=weoutbuf[PITCH_FRAME_LEN+k];
wfdata->whostate[k]=whoutbuf[PITCH_FRAME_LEN+k];
}
/* Export output data */
memcpy(weiout, weoutbuf+PITCH_WLPCORDER, sizeof(double) * PITCH_FRAME_LEN);
memcpy(whiout, whoutbuf+PITCH_WLPCORDER, sizeof(double) * PITCH_FRAME_LEN);
}
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