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/weight_a.c
32
33 ------------------------------------------------------------------------------
34 REVISION HISTORY
35
36 Description: Put file into template and first pass at optimization.
37
38 Description: Made changes based on comments from the review meeting. Used
39 pointers instead of index addressing in the arrays.
40
41 Description: Synchronized file with UMTS version 3.2.0. Updated coding
42 template. Removed unnecessary include files.
43
44 Description: Fixed typecasting issue with TI C compiler.
45
46 Description: Made the following changes per comments from Phase 2/3 review:
47 1. Modified FOR loop to count down.
48 2. Used address pre-increment instead of address offsets.
49
50 Description: Replaced "int" and/or "char" with OSCL defined types.
51
52 Description: Changed round function name to pv_round to avoid conflict with
53 round function in C standard library.
54
55 Who: Date:
56 Description:
57
58 ------------------------------------------------------------------------------
59 */
60
61 /*----------------------------------------------------------------------------
62 ; INCLUDES
63 ----------------------------------------------------------------------------*/
64 #include "weight_a.h"
65 #include "typedef.h"
66 #include "cnst.h"
67
68 /*----------------------------------------------------------------------------
69 ; MACROS
70 ; Define module specific macros here
71 ----------------------------------------------------------------------------*/
72
73
74 /*----------------------------------------------------------------------------
75 ; DEFINES
76 ; Include all pre-processor statements here. Include conditional
77 ; compile variables also.
78 ----------------------------------------------------------------------------*/
79
80
81 /*----------------------------------------------------------------------------
82 ; LOCAL FUNCTION DEFINITIONS
83 ; Function Prototype declaration
84 ----------------------------------------------------------------------------*/
85
86
87 /*----------------------------------------------------------------------------
88 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
89 ; Variable declaration - defined here and used outside this module
90 ----------------------------------------------------------------------------*/
91
92
93 /*
94 ------------------------------------------------------------------------------
95 FUNCTION NAME: Weight_Ai
96 ------------------------------------------------------------------------------
97 INPUT AND OUTPUT DEFINITIONS
98
99 Inputs:
100 a = LPC coefficients (Word16)
101 fac = Spectral expansion factors (Word16)
102 a_exp = Spectral expanded LPC coefficients (Word16)
103
104 Outputs:
105 a_exp points to the updated spectral expanded LPC coefficients
106
107 Returns:
108 None.
109
110 Global Variables Used:
111 None.
112
113 Local Variables Needed:
114 None.
115
116 ------------------------------------------------------------------------------
117 FUNCTION DESCRIPTION
118
119 This function calculates the spectral expansion for the LP coefficients of
120 order M.
121 a_exp[i] = a[i] * fac[i-1] ; i=1..M
122
123 ------------------------------------------------------------------------------
124 REQUIREMENTS
125
126 None.
127
128 ------------------------------------------------------------------------------
129 REFERENCES
130
131 weight_a.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001
132
133 ------------------------------------------------------------------------------
134 PSEUDO-CODE
135
136 void Weight_Ai (
137 Word16 a[], // (i) : a[M+1] LPC coefficients (M=10)
138 const Word16 fac[], // (i) : Spectral expansion factors.
139 Word16 a_exp[] // (o) : Spectral expanded LPC coefficients
140 )
141 {
142 Word16 i;
143 a_exp[0] = a[0];
144
145 for (i = 1; i <= M; i++)
146 {
147 a_exp[i] = pv_round (L_mult (a[i], fac[i - 1]));
148 }
149 return;
150 }
151
152 ------------------------------------------------------------------------------
153 RESOURCES USED [optional]
154
155 When the code is written for a specific target processor the
156 the resources used should be documented below.
157
158 HEAP MEMORY USED: x bytes
159
160 STACK MEMORY USED: x bytes
161
162 CLOCK CYCLES: (cycle count equation for this function) + (variable
163 used to represent cycle count for each subroutine
164 called)
165 where: (cycle count variable) = cycle count for [subroutine
166 name]
167
168 ------------------------------------------------------------------------------
169 CAUTION [optional]
170 [State any special notes, constraints or cautions for users of this function]
171
172 ------------------------------------------------------------------------------
173 */
174
Weight_Ai(Word16 a[],const Word16 fac[],Word16 a_exp[])175 void Weight_Ai(
176 Word16 a[], /* (i) : a[M+1] LPC coefficients (M=10) */
177 const Word16 fac[], /* (i) : Spectral expansion factors. */
178 Word16 a_exp[] /* (o) : Spectral expanded LPC coefficients */
179 )
180 {
181 Word16 i;
182
183 *(a_exp) = *(a);
184
185 for (i = M; i >= 1; i--)
186 {
187 a_exp += 1;
188 a += 1;
189 fac += 1;
190 *(a_exp) = (Word16)((((Word32) * (a)) * *(fac - 1)
191 + 0x00004000L) >> 15);
192 }
193
194 return;
195 }
196
197