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
185
186
187
188
189
190
191
|
/*---------------------------------------------------------------------------*\
FILE........: mbest.c
AUTHOR......: David Rowe
DATE CREATED: Jan 2017
Multistage vector quantiser search algorithm that keeps multiple
candidates from each stage.
\*---------------------------------------------------------------------------*/
/*
Copyright David Rowe 2017
All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License version 2.1, as
published by the Free Software Foundation. This program 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 General Public
License for more details.
You should have received a copy of the GNU Lesser General Public License
along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include "mbest.h"
#include <assert.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct MBEST *mbest_create(int entries) {
int i, j;
struct MBEST *mbest;
assert(entries > 0);
mbest = (struct MBEST *)malloc(sizeof(struct MBEST));
assert(mbest != NULL);
mbest->entries = entries;
mbest->list =
(struct MBEST_LIST *)malloc(entries * sizeof(struct MBEST_LIST));
assert(mbest->list != NULL);
for (i = 0; i < mbest->entries; i++) {
for (j = 0; j < MBEST_STAGES; j++) mbest->list[i].index[j] = 0;
mbest->list[i].error = 1E32;
}
return mbest;
}
void mbest_destroy(struct MBEST *mbest) {
assert(mbest != NULL);
free(mbest->list);
free(mbest);
}
/* apply weighting to VQ for efficient VQ search */
void mbest_precompute_weight(float cb[], float w[], int k, int m) {
for (int j = 0; j < m; j++) {
for (int i = 0; i < k; i++) cb[k * j + i] *= w[i];
}
}
/*---------------------------------------------------------------------------*\
mbest_insert
Insert the results of a vector to codebook entry comparison. The
list is ordered in order of error, so those entries with the
smallest error will be first on the list.
\*---------------------------------------------------------------------------*/
void mbest_insert(struct MBEST *mbest, int index[], float error) {
int i, found;
struct MBEST_LIST *list = mbest->list;
int entries = mbest->entries;
found = 0;
for (i = 0; i < entries && !found; i++)
if (error < list[i].error) {
found = 1;
memmove(&list[i + 1], &list[i],
sizeof(struct MBEST_LIST) * (entries - i - 1));
memcpy(&list[i].index[0], &index[0], sizeof(int) * MBEST_STAGES);
list[i].error = error;
}
}
void mbest_print(char title[], struct MBEST *mbest) {
int i, j;
fprintf(stderr, "%s\n", title);
for (i = 0; i < mbest->entries; i++) {
for (j = 0; j < MBEST_STAGES; j++)
fprintf(stderr, " %4d ", mbest->list[i].index[j]);
fprintf(stderr, " %f\n", (double)mbest->list[i].error);
}
}
/*---------------------------------------------------------------------------*\
mbest_search
Searches vec[] to a codebbook of vectors, and maintains a list of the mbest
closest matches.
\*---------------------------------------------------------------------------*/
void mbest_search(const float *cb, /* VQ codebook to search */
float vec[], /* target vector */
int k, /* dimension of vector */
int m, /* number on entries in codebook */
struct MBEST *mbest, /* list of closest matches */
int index[] /* indexes that lead us here */
) {
int j;
/* note weighting can be applied externally by modifying cb[] and vec:
float e = 0.0;
for(i=0; i<k; i++)
e += pow(w[i]*(cb[j*k+i] - vec[i]),2.0)
|
\|/
for(i=0; i<k; i++)
e += pow(w[i]*cb[j*k+i] - w[i]*vec[i]),2.0)
|
\|/
for(i=0; i<k; i++)
e += pow(cb1[j*k+i] - vec1[i]),2.0)
where cb1[j*k+i] = w[i]*cb[j*k+i], and vec1[i] = w[i]*vec[i]
*/
for (j = 0; j < m; j++) {
float e = 0.0;
for (int i = 0; i < k; i++) {
float diff = *cb++ - vec[i];
e += diff * diff;
}
index[0] = j;
if (e < mbest->list[mbest->entries - 1].error)
mbest_insert(mbest, index, e);
}
}
/*---------------------------------------------------------------------------*\
mbest_search450
Searches vec[] to a codebbook of vectors, and maintains a list of the mbest
closest matches. Only searches the first NewAmp2_K Vectors
\*---------------------------------------------------------------------------*/
void mbest_search450(const float *cb, float vec[], float w[], int k,
int shorterK, int m, struct MBEST *mbest, int index[])
{
float e;
int i, j;
float diff;
for (j = 0; j < m; j++) {
e = 0.0;
for (i = 0; i < k; i++) {
// Only search first NEWAMP2_K Vectors
if (i < shorterK) {
diff = cb[j * k + i] - vec[i];
e += diff * w[i] * diff * w[i];
}
}
index[0] = j;
mbest_insert(mbest, index, e);
}
}
|
