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