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 Pathname: ./audio/gsm-amr/c/src/residu.c
32
33 ------------------------------------------------------------------------------
34 REVISION HISTORY
35
36 Description: Updated template used to PV coding template. First attempt at
37 optimizing code.
38
39 Description: Deleted stores listed in the Local Stores Needed/Modified
40 section.
41
42 Description: Updated file per comments gathered from Phase 2/3 review.
43
44 Description: Updating to reflect variable name changes made in residu.asm
45
46 Description: Synchronized file with UMTS version 3.2.0. Updated coding
47 template. Removed unnecessary include files.
48
49 Description: Made the following changes per comments from Phase 2/3 review:
50 1. Modified FOR loops to count down.
51 2. Fixed typecasting issue with TI C compiler.
52
53 Description: Made the following changes
54 1. Unrolled the convolutional loop.
55 2. Performed 4 convolution per pass to avoid recalling the same
56 filter coefficient as many times.
57 2. Eliminated math operations that check for saturation.
58
59 Description: Replaced "int" and/or "char" with OSCL defined types.
60
61 Description: Changed round function name to pv_round to avoid conflict with
62 round function in C standard library.
63
64 Who: Date:
65 Description:
66
67 ------------------------------------------------------------------------------
68 */
69
70 /*----------------------------------------------------------------------------
71 ; INCLUDES
72 ----------------------------------------------------------------------------*/
73 #include "residu.h"
74 #include "typedef.h"
75 #include "cnst.h"
76
77 /*----------------------------------------------------------------------------
78 ; MACROS
79 ; Define module specific macros here
80 ----------------------------------------------------------------------------*/
81
82 /*----------------------------------------------------------------------------
83 ; DEFINES
84 ; Include all pre-processor statements here. Include conditional
85 ; compile variables also.
86 ----------------------------------------------------------------------------*/
87
88 /*----------------------------------------------------------------------------
89 ; LOCAL FUNCTION DEFINITIONS
90 ; Function Prototype declaration
91 ----------------------------------------------------------------------------*/
92
93 /*----------------------------------------------------------------------------
94 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
95 ; Variable declaration - defined here and used outside this module
96 ----------------------------------------------------------------------------*/
97
98
99 /*
100 ------------------------------------------------------------------------------
101 FUNCTION NAME: Residu
102 ------------------------------------------------------------------------------
103 INPUT AND OUTPUT DEFINITIONS
104
105 Inputs:
106 coef_ptr = pointer to buffer containing the prediction coefficients
107 input_ptr = pointer to buffer containing the speech signal
108 input_len = filter order
109 residual_ptr = pointer to buffer of residual signal
110
111 Outputs:
112 residual_ptr buffer contains the newly calculated the residual signal
113
114 Returns:
115 None
116
117 Global Variables Used:
118 None
119
120 Local Variables Needed:
121 None
122
123 ------------------------------------------------------------------------------
124 FUNCTION DESCRIPTION
125
126 This function computes the LP residual by filtering the input speech through
127 the LP inverse filter A(z).
128
129 ------------------------------------------------------------------------------
130 REQUIREMENTS
131
132 None
133
134 ------------------------------------------------------------------------------
135 REFERENCES
136
137 residu.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001
138
139 ------------------------------------------------------------------------------
140 PSEUDO-CODE
141
142 Note: Input argument names were changed to be more descriptive. Shown below
143 are the original names. Shown below are the name changes:
144 a[] <--> coef_ptr[]
145 x[] <--> input_ptr[]
146 y[] <--> residual_ptr[]
147 lg <--> input_len
148
149
150 void Residu (
151 Word16 a[], // (i) : prediction coefficients
152 Word16 x[], // (i) : speech signal
153 Word16 y[], // (o) : residual signal
154 Word16 lg // (i) : size of filtering
155 )
156 {
157 Word16 i, j;
158 Word32 s;
159
160 for (i = 0; i < lg; i++)
161 {
162 s = L_mult (x[i], a[0]);
163 for (j = 1; j <= M; j++)
164 {
165 s = L_mac (s, a[j], x[i - j]);
166 }
167 s = L_shl (s, 3);
168 y[i] = pv_round (s);
169 }
170 return;
171 }
172
173 ------------------------------------------------------------------------------
174 RESOURCES USED [optional]
175
176 When the code is written for a specific target processor the
177 the resources used should be documented below.
178
179 HEAP MEMORY USED: x bytes
180
181 STACK MEMORY USED: x bytes
182
183 CLOCK CYCLES: (cycle count equation for this function) + (variable
184 used to represent cycle count for each subroutine
185 called)
186 where: (cycle count variable) = cycle count for [subroutine
187 name]
188
189 ------------------------------------------------------------------------------
190 CAUTION [optional]
191 [State any special notes, constraints or cautions for users of this function]
192
193 ------------------------------------------------------------------------------
194 */
195
Residu(Word16 coef_ptr[],Word16 input_ptr[],Word16 residual_ptr[],Word16 input_len)196 void Residu(
197 Word16 coef_ptr[], /* (i) : prediction coefficients*/
198 Word16 input_ptr[], /* (i) : speech signal */
199 Word16 residual_ptr[], /* (o) : residual signal */
200 Word16 input_len /* (i) : size of filtering */
201 )
202 {
203
204
205 Word16 i, j;
206 Word32 s1;
207 Word32 s2;
208 Word32 s3;
209 Word32 s4;
210 Word16 *p_input1;
211 Word16 *p_input2;
212 Word16 *p_input3;
213 Word16 *p_input4;
214 Word16 *p_coef;
215 Word16 *p_residual_ptr = &residual_ptr[input_len-1];
216 Word16 *p_input_ptr = &input_ptr[input_len-1-M];
217
218 for (i = input_len >> 2; i != 0; i--)
219 {
220 s1 = 0x0000800L;
221 s2 = 0x0000800L;
222 s3 = 0x0000800L;
223 s4 = 0x0000800L;
224 p_coef = &coef_ptr[M];
225 p_input1 = p_input_ptr--;
226 p_input2 = p_input_ptr--;
227 p_input3 = p_input_ptr--;
228 p_input4 = p_input_ptr--;
229
230 for (j = M >> 1; j != 0; j--)
231 {
232 s1 += ((Word32) * (p_coef) * *(p_input1++));
233 s2 += ((Word32) * (p_coef) * *(p_input2++));
234 s3 += ((Word32) * (p_coef) * *(p_input3++));
235 s4 += ((Word32) * (p_coef--) * *(p_input4++));
236 s1 += ((Word32) * (p_coef) * *(p_input1++));
237 s2 += ((Word32) * (p_coef) * *(p_input2++));
238 s3 += ((Word32) * (p_coef) * *(p_input3++));
239 s4 += ((Word32) * (p_coef--) * *(p_input4++));
240 }
241
242 s1 += (((Word32) * (p_coef)) * *(p_input1));
243 s2 += (((Word32) * (p_coef)) * *(p_input2));
244 s3 += (((Word32) * (p_coef)) * *(p_input3));
245 s4 += (((Word32) * (p_coef)) * *(p_input4));
246
247 *(p_residual_ptr--) = (Word16)(s1 >> 12);
248 *(p_residual_ptr--) = (Word16)(s2 >> 12);
249 *(p_residual_ptr--) = (Word16)(s3 >> 12);
250 *(p_residual_ptr--) = (Word16)(s4 >> 12);
251
252 }
253
254 return;
255 }
256