1 /*
2 * Copyright (C) 2003 - 2016 Sony Corporation
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "ldac.h"
18
19
20 #define LDAC_TH_LOWENERGY_L _scalar(225.47)
21 #define LDAC_TH_LOWENERGY_M _scalar(897.61)
22 #define LDAC_TH_LOWENERGY_H _scalar(3573.44)
23
24 #define LDAC_TH_CENTROID _scalar(45.0)
25 #define LDAC_TH_ZERODIV _scalar(1.0e-6)
26
27 /***************************************************************************************************
28 Calculate Pseudo Spectrum and Low Band Energy
29 ***************************************************************************************************/
calc_mdct_pseudo_spectrum_ldac(SCALAR * p_spec,SCALAR * p_psd,int n)30 static SCALAR calc_mdct_pseudo_spectrum_ldac(
31 SCALAR *p_spec,
32 SCALAR *p_psd,
33 int n)
34 {
35 int isp;
36 SCALAR low_energy, tmp;
37 SCALAR y0, y1, y2;
38
39 {
40 y1 = p_spec[0];
41 y2 = p_spec[1];
42 tmp = y1 * y1 + y2 * y2;
43 low_energy = tmp;
44 p_psd[0] = sqrt(tmp);
45 }
46
47 for (isp = 1; isp < LDAC_NSP_LOWENERGY; isp++) {
48 y0 = y1;
49 y1 = y2;
50 y2 = p_spec[isp+1];
51 tmp = y1 * y1 + (y0-y2) * (y0-y2);
52 low_energy += tmp;
53 p_psd[isp] = sqrt(tmp);
54 }
55
56 for (isp = LDAC_NSP_LOWENERGY; isp < n-1; isp++) {
57 y0 = y1;
58 y1 = y2;
59 y2 = p_spec[isp+1];
60 tmp = y1 * y1 + (y0-y2) * (y0-y2);
61 p_psd[isp] = sqrt(tmp);
62 }
63
64 {
65 tmp = y1 * y1 + y2 * y2;
66 p_psd[n-1] = sqrt(tmp);
67 }
68
69 return low_energy;
70 }
71
72 /***************************************************************************************************
73 Calculate Pseudo Spectrum Centroid
74 ***************************************************************************************************/
calc_spectral_centroid_ldac(SCALAR * p_spec,int nsp)75 static SCALAR calc_spectral_centroid_ldac(
76 SCALAR *p_spec,
77 int nsp)
78 {
79 int isp;
80 SCALAR centroid;
81 SCALAR s1, s2;
82
83 s1 = s2 = _scalar(0.0);
84 for (isp = 0; isp < nsp; isp++) {
85 s1 += (SCALAR)isp * *p_spec;
86 s2 += *p_spec++;
87 }
88
89 if (s2 < LDAC_TH_ZERODIV) {
90 centroid = _scalar(0.0);
91 }
92 else {
93 centroid = s1 / s2;
94 }
95
96 return centroid;
97 }
98
99 /***************************************************************************************************
100 Calculate Number of Zero Cross
101 ***************************************************************************************************/
calc_zero_cross_number_ldac(SCALAR * p_time,int n)102 static int calc_zero_cross_number_ldac(
103 SCALAR *p_time,
104 int n)
105 {
106 int i;
107 int zero_cross = 0;
108 SCALAR prev;
109
110 prev = _scalar(0.0);
111 for (i = 0; i < n; i++) {
112 if (prev * *p_time < _scalar(0.0)) {
113 zero_cross++;
114 }
115 prev = *p_time++;
116 }
117
118 return zero_cross;
119 }
120
121 /***************************************************************************************************
122 Analyze Frame Status
123 ***************************************************************************************************/
ana_frame_status_ldac(SFINFO * p_sfinfo,int nlnn)124 DECLSPEC int ana_frame_status_ldac(
125 SFINFO *p_sfinfo,
126 int nlnn)
127 {
128 AC *p_ac;
129 int ich;
130 int nchs = p_sfinfo->cfg.ch;
131 int nsmpl = npow2_ldac(nlnn+1);
132 int cnt, zero_cross;
133 int a_status[LDAC_PRCNCH];
134 SCALAR low_energy, centroid;
135 SCALAR a_psd_spec[LDAC_NSP_PSEUDOANA];
136
137 for (ich = 0; ich < nchs; ich++) {
138 p_ac = p_sfinfo->ap_ac[ich];
139
140 low_energy = calc_mdct_pseudo_spectrum_ldac(p_ac->p_acsub->a_spec, a_psd_spec, LDAC_NSP_PSEUDOANA);
141
142 centroid = calc_spectral_centroid_ldac(a_psd_spec, LDAC_NSP_PSEUDOANA);
143
144 zero_cross = calc_zero_cross_number_ldac(p_ac->p_acsub->a_time, nsmpl);
145
146 a_status[ich] = LDAC_FRMSTAT_LEV_0;
147 if (low_energy < LDAC_TH_LOWENERGY_L) {
148 a_status[ich] = LDAC_FRMSTAT_LEV_3;
149 }
150 else {
151 if (low_energy < LDAC_TH_LOWENERGY_M) {
152 a_status[ich] = LDAC_FRMSTAT_LEV_2;
153 }
154 else if (low_energy < LDAC_TH_LOWENERGY_H) {
155 a_status[ich] = LDAC_FRMSTAT_LEV_1;
156 }
157
158 cnt = p_ac->frmana_cnt;
159 if ((centroid > LDAC_TH_CENTROID) && (zero_cross >= LDAC_TH_ZCROSNUM)) {
160 cnt++;
161
162 if (cnt >= LDAC_MAXCNT_FRMANA) {
163 cnt = LDAC_MAXCNT_FRMANA;
164 a_status[ich] = LDAC_FRMSTAT_LEV_2;
165 }
166 else if (a_status[ich] <= LDAC_FRMSTAT_LEV_1) {
167 a_status[ich]++;
168 }
169 }
170 else {
171 cnt = 0;
172 }
173 p_ac->frmana_cnt = cnt;
174 }
175 }
176
177 if (nchs == LDAC_CHANNEL_1CH) {
178 return a_status[0];
179 }
180 else {
181 return min_ldac(a_status[0], a_status[1]);
182 }
183 }
184
185