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
|
/*****************************************************************************
**
** ITU-T G.722.1 (2005-05) - Fixed point implementation for main body and Annex C
** > Software Release 2.1 (2008-06)
** (Simple repackaging; no change from 2005-05 Release 2.0 code)
**
** © 2004 Polycom, Inc.
**
** All rights reserved.
**
*****************************************************************************/
/*****************************************************************************
* Filename: rmlt_coefs_to_samples.c
*
* Purpose: Convert Reversed MLT (Modulated Lapped Transform)
* Coefficients to Samples
*
* The "Reversed MLT" is an overlapped block transform which uses
* even symmetry * on the left, odd symmetry on the right and a
* Type IV DCT as the block transform. * It is thus similar to a
* MLT which uses odd symmetry on the left, even symmetry * on the
* right and a Type IV DST as the block transform. In fact, it is
* equivalent * to reversing the order of the samples, performing
* an MLT and then negating all * the even-numbered coefficients.
*
*****************************************************************************/
/***************************************************************************
Include files
***************************************************************************/
#include "defs.h"
#include "tables.h"
#include "count.h"
/***************************************************************************
Function: rmlt_coefs_to_samples
Syntax: void rmlt_coefs_to_samples(Word16 *coefs,
Word16 *old_samples,
Word16 *out_samples,
Word16 dct_length,
Word16 mag_shift)
inputs: Word16 *coefs
Word16 *old_samples
Word16 dct_length
Word16 mag_shift
outputs: Word16 *out_samples
Description: Converts the mlt_coefs to samples
Design Notes:
WMOPS: 7kHz | 24kbit | 32kbit
-------|--------------|----------------
AVG | 1.91 | 1.91
-------|--------------|----------------
MAX | 1.91 | 1.91
-------|--------------|----------------
14kHz | 24kbit | 32kbit | 48kbit
-------|--------------|----------------|----------------
AVG | 3.97 | 3.97 | 3.97
-------|--------------|----------------|----------------
MAX | 3.97 | 3.97 | 3.97
-------|--------------|----------------|----------------
***************************************************************************/
void rmlt_coefs_to_samples(Word16 *coefs,
Word16 *old_samples,
Word16 *out_samples,
Word16 dct_length,
Word16 mag_shift)
{
Word16 index, vals_left;
Word16 new_samples[MAX_DCT_LENGTH];
Word16 *new_ptr, *old_ptr;
Word16 *win_new, *win_old;
Word16 *out_ptr;
Word16 half_dct_size;
Word32 sum;
half_dct_size = shr(dct_length,1);
/* Perform a Type IV (inverse) DCT on the coefficients */
dct_type_iv_s(coefs, new_samples, dct_length);
test();
if (mag_shift > 0)
{
for(index=0;index<dct_length;index++)
{
new_samples[index] = shr(new_samples[index],mag_shift);
move16();
}
}
else
{
test();
if (mag_shift < 0)
{
mag_shift = negate(mag_shift);
for(index=0;index<dct_length;index++)
{
new_samples[index] = shl(new_samples[index],mag_shift);
move16();
}
}
}
/* Get the first half of the windowed samples */
out_ptr = out_samples;
move16();
test();
if (dct_length==DCT_LENGTH)
{
win_new = rmlt_to_samples_window;
move16();
win_old = rmlt_to_samples_window + dct_length;
move16();
}
else
{
win_new = max_rmlt_to_samples_window;
move16();
win_old = max_rmlt_to_samples_window + dct_length;
move16();
}
old_ptr = old_samples;
move16();
new_ptr = new_samples + half_dct_size;
move16();
for (vals_left = half_dct_size; vals_left > 0; vals_left--)
{
sum = 0L;
move32();
sum = L_mac(sum,*win_new++, *--new_ptr);
sum = L_mac(sum,*--win_old, *old_ptr++);
*out_ptr++ = itu_round(L_shl(sum,2));
move16();
}
/* Get the second half of the windowed samples */
for (vals_left = half_dct_size; vals_left > 0; vals_left--)
{
sum = 0L;
move32();
sum = L_mac(sum,*win_new++, *new_ptr++);
sum = L_mac(sum,negate(*--win_old), *--old_ptr);
*out_ptr++ = itu_round(L_shl(sum,2));
move16();
}
/* Save the second half of the new samples for */
/* next time, when they will be the old samples. */
/* pointer arithmetic */
new_ptr = new_samples + half_dct_size;
move16();
old_ptr = old_samples;
move16();
for (vals_left = half_dct_size; vals_left > 0; vals_left--)
{
*old_ptr++ = *new_ptr++;
move16();
}
}
|
