/*
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* Copyright (C) 2003 - 2016 Sony Corporation
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "ldac.h"
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#define LDAC_TH_LOWENERGY_L _scalar(225.47)
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#define LDAC_TH_LOWENERGY_M _scalar(897.61)
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#define LDAC_TH_LOWENERGY_H _scalar(3573.44)
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#define LDAC_TH_CENTROID _scalar(45.0)
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#define LDAC_TH_ZERODIV _scalar(1.0e-6)
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/***************************************************************************************************
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Calculate Pseudo Spectrum and Low Band Energy
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***************************************************************************************************/
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static SCALAR calc_mdct_pseudo_spectrum_ldac(
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SCALAR *p_spec,
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SCALAR *p_psd,
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int n)
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{
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int isp;
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SCALAR low_energy, tmp;
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SCALAR y0, y1, y2;
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{
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y1 = p_spec[0];
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y2 = p_spec[1];
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tmp = y1 * y1 + y2 * y2;
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low_energy = tmp;
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p_psd[0] = sqrt(tmp);
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}
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for (isp = 1; isp < LDAC_NSP_LOWENERGY; isp++) {
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y0 = y1;
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y1 = y2;
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y2 = p_spec[isp+1];
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tmp = y1 * y1 + (y0-y2) * (y0-y2);
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low_energy += tmp;
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p_psd[isp] = sqrt(tmp);
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}
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for (isp = LDAC_NSP_LOWENERGY; isp < n-1; isp++) {
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y0 = y1;
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y1 = y2;
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y2 = p_spec[isp+1];
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tmp = y1 * y1 + (y0-y2) * (y0-y2);
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p_psd[isp] = sqrt(tmp);
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}
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{
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tmp = y1 * y1 + y2 * y2;
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p_psd[n-1] = sqrt(tmp);
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}
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return low_energy;
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}
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/***************************************************************************************************
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Calculate Pseudo Spectrum Centroid
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***************************************************************************************************/
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static SCALAR calc_spectral_centroid_ldac(
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SCALAR *p_spec,
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int nsp)
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{
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int isp;
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SCALAR centroid;
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SCALAR s1, s2;
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s1 = s2 = _scalar(0.0);
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for (isp = 0; isp < nsp; isp++) {
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s1 += (SCALAR)isp * *p_spec;
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s2 += *p_spec++;
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}
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if (s2 < LDAC_TH_ZERODIV) {
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centroid = _scalar(0.0);
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}
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else {
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centroid = s1 / s2;
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}
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return centroid;
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}
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/***************************************************************************************************
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Calculate Number of Zero Cross
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***************************************************************************************************/
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static int calc_zero_cross_number_ldac(
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SCALAR *p_time,
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int n)
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{
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int i;
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int zero_cross = 0;
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SCALAR prev;
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prev = _scalar(0.0);
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for (i = 0; i < n; i++) {
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if (prev * *p_time < _scalar(0.0)) {
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zero_cross++;
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}
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prev = *p_time++;
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}
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return zero_cross;
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}
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/***************************************************************************************************
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Analyze Frame Status
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***************************************************************************************************/
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DECLSPEC int ana_frame_status_ldac(
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SFINFO *p_sfinfo,
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int nlnn)
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{
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AC *p_ac;
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int ich;
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int nchs = p_sfinfo->cfg.ch;
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int nsmpl = npow2_ldac(nlnn+1);
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int cnt, zero_cross;
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int a_status[LDAC_PRCNCH];
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SCALAR low_energy, centroid;
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SCALAR a_psd_spec[LDAC_NSP_PSEUDOANA];
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for (ich = 0; ich < nchs; ich++) {
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p_ac = p_sfinfo->ap_ac[ich];
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low_energy = calc_mdct_pseudo_spectrum_ldac(p_ac->p_acsub->a_spec, a_psd_spec, LDAC_NSP_PSEUDOANA);
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centroid = calc_spectral_centroid_ldac(a_psd_spec, LDAC_NSP_PSEUDOANA);
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zero_cross = calc_zero_cross_number_ldac(p_ac->p_acsub->a_time, nsmpl);
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a_status[ich] = LDAC_FRMSTAT_LEV_0;
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if (low_energy < LDAC_TH_LOWENERGY_L) {
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a_status[ich] = LDAC_FRMSTAT_LEV_3;
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}
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else {
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if (low_energy < LDAC_TH_LOWENERGY_M) {
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a_status[ich] = LDAC_FRMSTAT_LEV_2;
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}
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else if (low_energy < LDAC_TH_LOWENERGY_H) {
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a_status[ich] = LDAC_FRMSTAT_LEV_1;
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}
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cnt = p_ac->frmana_cnt;
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if ((centroid > LDAC_TH_CENTROID) && (zero_cross >= LDAC_TH_ZCROSNUM)) {
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cnt++;
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if (cnt >= LDAC_MAXCNT_FRMANA) {
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cnt = LDAC_MAXCNT_FRMANA;
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a_status[ich] = LDAC_FRMSTAT_LEV_2;
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}
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else if (a_status[ich] <= LDAC_FRMSTAT_LEV_1) {
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a_status[ich]++;
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}
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}
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else {
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cnt = 0;
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}
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p_ac->frmana_cnt = cnt;
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}
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}
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if (nchs == LDAC_CHANNEL_1CH) {
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return a_status[0];
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}
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else {
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return min_ldac(a_status[0], a_status[1]);
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}
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}
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