1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
|
/*
* Siren Encoder/Decoder library
*
* @author: Youness Alaoui <kakaroto@kakaroto.homelinux.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "siren7.h"
#define PI 3.1415926
typedef struct {
float cos;
float msin;
} dct_table_type;
static float dct_core_320[100];
static float dct_core_640[100];
static dct_table_type dct_table_5[5];
static dct_table_type dct_table_10[10];
static dct_table_type dct_table_20[20];
static dct_table_type dct_table_40[40];
static dct_table_type dct_table_80[80];
static dct_table_type dct_table_160[160];
static dct_table_type dct_table_320[320];
static dct_table_type dct_table_640[640];
static dct_table_type *dct_tables[8] = {dct_table_5,
dct_table_10,
dct_table_20,
dct_table_40,
dct_table_80,
dct_table_160,
dct_table_320,
dct_table_640};
static int dct4_initialized = 0;
void siren_dct4_init() {
int i, j = 0;
double scale_320 = (float) sqrt(2.0/320);
double scale_640 = (float) sqrt(2.0/640);
double angle;
double scale;
/* set up dct4 tables */
for(i = 0; i < 10; i++) {
angle = (float) ((i + 0.5) * PI);
for (j = 0 ; j < 10; j++) {
dct_core_320[(i*10)+j] = (float) (scale_320 * cos((j + 0.5) * angle / 10));
dct_core_640[(i*10)+j] = (float) (scale_640 * cos((j + 0.5) * angle / 10));
}
}
for(i = 0; i < 8; i++) {
scale = (float) (PI / ((5 << i) * 4));
for (j = 0 ; j < (5 << i); j++) {
angle = (float) (j + 0.5) * scale;
dct_tables[i][j].cos = (float) cos(angle);
dct_tables[i][j].msin = (float) -sin(angle);
}
}
dct4_initialized = 1;
}
void siren_dct4(float *Source, float *Destination, int dct_length) {
int log_length = 0;
float * dct_core = NULL;
dct_table_type ** dct_table_ptr_ptr = NULL;
dct_table_type * dct_table_ptr = NULL;
float OutBuffer1[640];
float OutBuffer2[640];
float *Out_ptr;
float *NextOut_ptr;
float *In_Ptr = NULL;
float *In_Ptr_low = NULL;
float *In_Ptr_high = NULL;
float In_val_low;
float In_val_high;
float *Out_ptr_low = NULL;
float *Out_ptr_high = NULL;
float mult1, mult2, mult3, mult4, mult5, mult6, mult7, mult8, mult9, mult10;
int i,j;
if (dct4_initialized == 0)
siren_dct4_init();
if (dct_length == 640) {
log_length = 5;
dct_core = dct_core_640;
} else {
log_length = 4;
dct_core = dct_core_320;
}
Out_ptr = OutBuffer1;
NextOut_ptr = OutBuffer2;
In_Ptr = Source;
for (i = 0; i <= log_length; i++) {
for (j = 0; j < (1 << i); j++) {
Out_ptr_low = Out_ptr + (j * (dct_length >> i));
Out_ptr_high = Out_ptr + ( (j+1) * (dct_length >> i));
do {
In_val_low = *In_Ptr++;
In_val_high = *In_Ptr++;
*Out_ptr_low++ = In_val_low + In_val_high;
*--Out_ptr_high = In_val_low - In_val_high;
} while (Out_ptr_low < Out_ptr_high);
}
In_Ptr = Out_ptr;
Out_ptr = NextOut_ptr;
NextOut_ptr = In_Ptr;
}
for (i = 0; i < (2 << log_length); i++) {
for (j = 0 ; j < 10 ; j ++) {
mult1 = In_Ptr[(i*10)] * dct_core[j*10];
mult2 = In_Ptr[(i*10) + 1] * dct_core[(j*10) + 1];
mult3 = In_Ptr[(i*10) + 2] * dct_core[(j*10) + 2];
mult4 = In_Ptr[(i*10) + 3] * dct_core[(j*10) + 3];
mult5 = In_Ptr[(i*10) + 4] * dct_core[(j*10) + 4];
mult6 = In_Ptr[(i*10) + 5] * dct_core[(j*10) + 5];
mult7 = In_Ptr[(i*10) + 6] * dct_core[(j*10) + 6];
mult8 = In_Ptr[(i*10) + 7] * dct_core[(j*10) + 7];
mult9 = In_Ptr[(i*10) + 8] * dct_core[(j*10) + 8];
mult10 = In_Ptr[(i*10) + 9] * dct_core[(j*10) + 9];
Out_ptr[(i*10)+j] = mult1 + mult2 + mult3 + mult4 +
mult5 + mult6 + mult7 + mult8 +
mult9 + mult10;
}
}
In_Ptr = Out_ptr;
Out_ptr = NextOut_ptr;
NextOut_ptr = In_Ptr;
dct_table_ptr_ptr = dct_tables;
for (i = log_length; i >= 0; i--) {
dct_table_ptr_ptr++;
for (j = 0; j < (1 << i); j++) {
dct_table_ptr = *dct_table_ptr_ptr;
if ( i == 0 )
Out_ptr_low = Destination + (j * (dct_length >> i));
else
Out_ptr_low = Out_ptr + (j * (dct_length >> i));
Out_ptr_high = Out_ptr_low + (dct_length >> i);
In_Ptr_low = In_Ptr + (j * (dct_length >> i));
In_Ptr_high = In_Ptr_low + (dct_length >> (i+1));
do {
*Out_ptr_low++ = (*In_Ptr_low * (*dct_table_ptr).cos) - (*In_Ptr_high * (*dct_table_ptr).msin);
*--Out_ptr_high = (*In_Ptr_high++ * (*dct_table_ptr).cos) + (*In_Ptr_low++ * (*dct_table_ptr).msin);
dct_table_ptr++;
*Out_ptr_low++ = (*In_Ptr_low * (*dct_table_ptr).cos) + (*In_Ptr_high * (*dct_table_ptr).msin);
*--Out_ptr_high = (*In_Ptr_low++ * (*dct_table_ptr).msin) - (*In_Ptr_high++ * (*dct_table_ptr).cos);
dct_table_ptr++;
} while (Out_ptr_low < Out_ptr_high);
}
In_Ptr = Out_ptr;
Out_ptr = NextOut_ptr;
NextOut_ptr = In_Ptr;
}
}
|
