1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
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
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18 /****************************************************************************************
19 Portions of this file are derived from the following 3GPP standard:
20
21 3GPP TS 26.073
22 ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23 Available from http://www.3gpp.org
24
25 (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26 Permission to distribute, modify and use this file under the standard license
27 terms listed above has been obtained from the copyright holder.
28 ****************************************************************************************/
29 /*
30 ------------------------------------------------------------------------------
31
32
33
34 Pathname: ./audio/gsm-amr/c/src/convolve.c
35
36 Date: 06/19/2000
37
38 ------------------------------------------------------------------------------
39 REVISION HISTORY
40
41 Description: Optimize for speed. Update to code template.
42
43 Description: Added author name and date, fixed tabs, and added missing
44 sections. Updated Input/Output section.
45
46 Description: Optimized code by calculating two convolution sums per iteration
47 of the outer loop, thereby, decreasing outer loop count by 2.
48 Updated input/output definitions to be the same as the assembly
49 file (convolve.asm). Left Pseudo-code section blank.
50
51 Description: Deleted semi-colon in the Pointers modified section.
52
53 Description: Synchronized file with UMTS version 3.2.0. Updated coding
54 template. Removed unnecessary include files.
55
56 Description: Made the following changes per comments from Phase 2/3 review:
57 1. Fixed typecasting issue with TI C compiler.
58 2. Modified FOR loop to count down, wherever applicable.
59
60 Description: Made the following changes
61 1. Unrolled the correlation loop.
62 2. Performed 2 correlation per pass per sample to avoid recalling
63 the same data twice.
64 3. Eliminated math operations that check for saturation.
65
66 Description:
67 1. Modified loop counter, extra unrolling did speed up code
68
69 Description: Replaced "int" and/or "char" with OSCL defined types.
70
71 Description: Using inlines from fxp_arithmetic.h .
72
73 Description: Replacing fxp_arithmetic.h with basic_op.h.
74
75 Description:
76
77 ------------------------------------------------------------------------------
78 */
79
80 /*----------------------------------------------------------------------------
81 ; INCLUDES
82 ----------------------------------------------------------------------------*/
83 #include "typedef.h"
84 #include "convolve.h"
85 #include "basic_op.h"
86
87 /*----------------------------------------------------------------------------
88 ; MACROS
89 ; Define module specific macros here
90 ----------------------------------------------------------------------------*/
91
92
93 /*----------------------------------------------------------------------------
94 ; DEFINES
95 ; Include all pre-processor statements here. Include conditional
96 ; compile variables also.
97 ----------------------------------------------------------------------------*/
98
99
100 /*----------------------------------------------------------------------------
101 ; LOCAL FUNCTION DEFINITIONS
102 ; Function Prototype declaration
103 ----------------------------------------------------------------------------*/
104
105 /*----------------------------------------------------------------------------
106 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
107 ; Variable declaration - defined here and used outside this module
108 ----------------------------------------------------------------------------*/
109
110
111 /*
112 ------------------------------------------------------------------------------
113 FUNCTION NAME: Convolve
114 ------------------------------------------------------------------------------
115 INPUT AND OUTPUT DEFINITIONS
116
117 Inputs:
118 x = pointer to input vector of L elements of type Word16
119 h = pointer to the filter's impulse response vector of L elements
120 of type Word16
121 y = pointer to the output vector of L elements of type Word16 used for
122 storing the convolution of x and h;
123 L = Length of the convolution; type definition is Word16
124
125 Outputs:
126 y buffer contains the new convolution output
127
128 Returns:
129 None
130
131 Global Variables Used:
132 None
133
134 Local Variables Needed:
135 None
136
137 ------------------------------------------------------------------------------
138 FUNCTION DESCRIPTION
139
140 Perform the convolution between two vectors x[] and h[] and write the result
141 in the vector y[]. All vectors are of length L and only the first L samples
142 of the convolution are computed.
143
144 The convolution is given by:
145
146 y[n] = sum_{i=0}^{n} x[i] h[n-i], n=0,...,L-1
147
148 ------------------------------------------------------------------------------
149 REQUIREMENTS
150
151 None
152
153 ------------------------------------------------------------------------------
154 REFERENCES
155
156 convolve.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001
157
158 ------------------------------------------------------------------------------
159 PSEUDO-CODE
160
161 void Convolve (
162 Word16 x[], // (i) : input vector
163 Word16 h[], // (i) : impulse response
164 Word16 y[], // (o) : output vector
165 Word16 L // (i) : vector size
166 )
167 {
168 Word16 i, n;
169 Word32 s;
170
171 for (n = 0; n < L; n++)
172 {
173 s = 0; move32 ();
174 for (i = 0; i <= n; i++)
175 {
176 s = L_mac (s, x[i], h[n - i]);
177 }
178 s = L_shl (s, 3);
179 y[n] = extract_h (s); move16 ();
180 }
181
182 return;
183 }
184
185 ------------------------------------------------------------------------------
186 RESOURCES USED [optional]
187
188 When the code is written for a specific target processor the
189 the resources used should be documented below.
190
191 HEAP MEMORY USED: x bytes
192
193 STACK MEMORY USED: x bytes
194
195 CLOCK CYCLES: (cycle count equation for this function) + (variable
196 used to represent cycle count for each subroutine
197 called)
198 where: (cycle count variable) = cycle count for [subroutine
199 name]
200
201 ------------------------------------------------------------------------------
202 CAUTION [optional]
203 [State any special notes, constraints or cautions for users of this function]
204
205 ------------------------------------------------------------------------------
206 */
207
Convolve(Word16 x[],Word16 h[],Word16 y[],Word16 L)208 void Convolve(
209 Word16 x[], /* (i) : input vector */
210 Word16 h[], /* (i) : impulse response */
211 Word16 y[], /* (o) : output vector */
212 Word16 L /* (i) : vector size */
213 )
214 {
215 Word16 i, n;
216 Word32 s1, s2;
217
218
219 for (n = 1; n < L; n = n + 2)
220 {
221
222 h = h + n;
223
224 s2 = ((Word32) * (x)) * *(h--);
225 s1 = ((Word32) * (x++)) * *(h);
226
227 for (i = (n - 1) >> 1; i != 0; i--)
228 {
229 s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h--), s2);
230 s1 = amrnb_fxp_mac_16_by_16bb((Word32) * (x++), (Word32) * (h), s1);
231 s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h--), s2);
232 s1 = amrnb_fxp_mac_16_by_16bb((Word32) * (x++), (Word32) * (h), s1);
233 }
234
235 s2 = amrnb_fxp_mac_16_by_16bb((Word32) * (x), (Word32) * (h), s2);
236
237 *(y++) = (Word16)(s1 >> 12);
238 *(y++) = (Word16)(s2 >> 12);
239
240 x = x - n;
241
242 }
243
244 return;
245 }
246