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
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
|
/* ------------------------------------------------------------------
* Copyright (C) 1998-2009 PacketVideo
*
* 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.
* -------------------------------------------------------------------
*/
/****************************************************************************************
Portions of this file are derived from the following 3GPP standard:
3GPP TS 26.073
ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
Available from http://www.3gpp.org
(C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
Permission to distribute, modify and use this file under the standard license
terms listed above has been obtained from the copyright holder.
****************************************************************************************/
/*
------------------------------------------------------------------------------
Pathname: ./audio/gsm-amr/c/src/convolve.c
Date: 06/19/2000
------------------------------------------------------------------------------
REVISION HISTORY
Description: Optimize for speed. Update to code template.
Description: Added author name and date, fixed tabs, and added missing
sections. Updated Input/Output section.
Description: Optimized code by calculating two convolution sums per iteration
of the outer loop, thereby, decreasing outer loop count by 2.
Updated input/output definitions to be the same as the assembly
file (convolve.asm). Left Pseudo-code section blank.
Description: Deleted semi-colon in the Pointers modified section.
Description: Synchronized file with UMTS version 3.2.0. Updated coding
template. Removed unnecessary include files.
Description: Made the following changes per comments from Phase 2/3 review:
1. Fixed typecasting issue with TI C compiler.
2. Modified FOR loop to count down, wherever applicable.
Description: Made the following changes
1. Unrolled the correlation loop.
2. Performed 2 correlation per pass per sample to avoid recalling
the same data twice.
3. Eliminated math operations that check for saturation.
Description:
1. Modified loop counter, extra unrolling did speed up code
Description: Replaced "int" and/or "char" with OSCL defined types.
Description: Using inlines from fxp_arithmetic.h .
Description: Replacing fxp_arithmetic.h with basic_op.h.
Description:
------------------------------------------------------------------------------
*/
/*----------------------------------------------------------------------------
; INCLUDES
----------------------------------------------------------------------------*/
#include "typedef.h"
#include "convolve.h"
#include "basic_op.h"
/*----------------------------------------------------------------------------
; MACROS
; Define module specific macros here
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; DEFINES
; Include all pre-processor statements here. Include conditional
; compile variables also.
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL FUNCTION DEFINITIONS
; Function Prototype declaration
----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------
; LOCAL STORE/BUFFER/POINTER DEFINITIONS
; Variable declaration - defined here and used outside this module
----------------------------------------------------------------------------*/
/*
------------------------------------------------------------------------------
FUNCTION NAME: Convolve
------------------------------------------------------------------------------
INPUT AND OUTPUT DEFINITIONS
Inputs:
x = pointer to input vector of L elements of type Word16
h = pointer to the filter's impulse response vector of L elements
of type Word16
y = pointer to the output vector of L elements of type Word16 used for
storing the convolution of x and h;
L = Length of the convolution; type definition is Word16
Outputs:
y buffer contains the new convolution output
Returns:
None
Global Variables Used:
None
Local Variables Needed:
None
------------------------------------------------------------------------------
FUNCTION DESCRIPTION
Perform the convolution between two vectors x[] and h[] and write the result
in the vector y[]. All vectors are of length L and only the first L samples
of the convolution are computed.
The convolution is given by:
y[n] = sum_{i=0}^{n} x[i] h[n-i], n=0,...,L-1
------------------------------------------------------------------------------
REQUIREMENTS
None
------------------------------------------------------------------------------
REFERENCES
convolve.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001
------------------------------------------------------------------------------
PSEUDO-CODE
void Convolve (
Word16 x[], // (i) : input vector
Word16 h[], // (i) : impulse response
Word16 y[], // (o) : output vector
Word16 L // (i) : vector size
)
{
Word16 i, n;
Word32 s;
for (n = 0; n < L; n++)
{
s = 0; move32 ();
for (i = 0; i <= n; i++)
{
s = L_mac (s, x[i], h[n - i]);
}
s = L_shl (s, 3);
y[n] = extract_h (s); move16 ();
}
return;
}
------------------------------------------------------------------------------
RESOURCES USED [optional]
When the code is written for a specific target processor the
the resources used should be documented below.
HEAP MEMORY USED: x bytes
STACK MEMORY USED: x bytes
CLOCK CYCLES: (cycle count equation for this function) + (variable
used to represent cycle count for each subroutine
called)
where: (cycle count variable) = cycle count for [subroutine
name]
------------------------------------------------------------------------------
CAUTION [optional]
[State any special notes, constraints or cautions for users of this function]
------------------------------------------------------------------------------
*/
void Convolve(
Word16 x[], /* (i) : input vector */
Word16 h[], /* (i) : impulse response */
Word16 y[], /* (o) : output vector */
Word16 L /* (i) : vector size */
)
{
Word16 i, n;
Word32 s1, s2;
for (n = 1; n < L; n = n + 2)
{
h = h + n;
s2 = ((Word32) * (x)) * *(h--);
s1 = ((Word32) * (x++)) * *(h);
for (i = (n - 1) >> 1; i != 0; i--)
{
s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h--), s2);
s1 = amrnb_fxp_mac_16_by_16bb((Word32) * (x++), (Word32) * (h), s1);
s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h--), s2);
s1 = amrnb_fxp_mac_16_by_16bb((Word32) * (x++), (Word32) * (h), s1);
}
s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h), s2);
*(y++) = (Word16)(s1 >> 12);
*(y++) = (Word16)(s2 >> 12);
x = x - n;
}
return;
}
|
