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 26.173
22 ANSI-C code for the Adaptive Multi-Rate - Wideband (AMR-WB) speech codec
23 Available from http://www.3gpp.org
24
25 (C) 2007, 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 Filename: isp_isf.cpp
35
36 Date: 05/08/2004
37
38 ------------------------------------------------------------------------------
39 REVISION HISTORY
40
41
42 Description:
43
44 ------------------------------------------------------------------------------
45 INPUT AND OUTPUT DEFINITIONS
46
47 int16 isf[], (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5)
48 int16 isp[], (o) Q15 : isp[m] (range: -1<=val<1)
49 int16 m (i) : LPC order
50
51
52 ------------------------------------------------------------------------------
53 FUNCTION DESCRIPTION
54
55 Isf_isp Transformation isf to isp
56
57 The transformation from isf[i] to isp[i] is
58 approximated by a look-up table and interpolation.
59
60
61
62 ------------------------------------------------------------------------------
63 REQUIREMENTS
64
65
66 ------------------------------------------------------------------------------
67 REFERENCES
68
69 ------------------------------------------------------------------------------
70 PSEUDO-CODE
71
72 ------------------------------------------------------------------------------
73 */
74
75
76 /*----------------------------------------------------------------------------
77 ; INCLUDES
78 ----------------------------------------------------------------------------*/
79
80
81 #include "pv_amr_wb_type_defs.h"
82 #include "pvamrwbdecoder_basic_op.h"
83 #include "pvamrwbdecoder_acelp.h"
84
85 /*----------------------------------------------------------------------------
86 ; MACROS
87 ; Define module specific macros here
88 ----------------------------------------------------------------------------*/
89
90
91 /*----------------------------------------------------------------------------
92 ; DEFINES
93 ; Include all pre-processor statements here. Include conditional
94 ; compile variables also.
95 ----------------------------------------------------------------------------*/
96
97 /*----------------------------------------------------------------------------
98 ; LOCAL FUNCTION DEFINITIONS
99 ; Function Prototype declaration
100 ----------------------------------------------------------------------------*/
101
102 /*----------------------------------------------------------------------------
103 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
104 ; Variable declaration - defined here and used outside this module
105 ----------------------------------------------------------------------------*/
106
107 /* Look-up table for transformations */
108
109 /* table of cos(x) in Q15 */
110
111 static const int16 table[129] =
112 {
113 32767,
114 32758, 32729, 32679, 32610, 32522, 32413, 32286, 32138,
115 31972, 31786, 31581, 31357, 31114, 30853, 30572, 30274,
116 29957, 29622, 29269, 28899, 28511, 28106, 27684, 27246,
117 26791, 26320, 25833, 25330, 24812, 24279, 23732, 23170,
118 22595, 22006, 21403, 20788, 20160, 19520, 18868, 18205,
119 17531, 16846, 16151, 15447, 14733, 14010, 13279, 12540,
120 11793, 11039, 10279, 9512, 8740, 7962, 7180, 6393,
121 5602, 4808, 4011, 3212, 2411, 1608, 804, 0,
122 -804, -1608, -2411, -3212, -4011, -4808, -5602, -6393,
123 -7180, -7962, -8740, -9512, -10279, -11039, -11793, -12540,
124 -13279, -14010, -14733, -15447, -16151, -16846, -17531, -18205,
125 -18868, -19520, -20160, -20788, -21403, -22006, -22595, -23170,
126 -23732, -24279, -24812, -25330, -25833, -26320, -26791, -27246,
127 -27684, -28106, -28511, -28899, -29269, -29622, -29957, -30274,
128 -30572, -30853, -31114, -31357, -31581, -31786, -31972, -32138,
129 -32286, -32413, -32522, -32610, -32679, -32729, -32758, -32768
130 };
131
132
133 /*----------------------------------------------------------------------------
134 ; EXTERNAL FUNCTION REFERENCES
135 ; Declare functions defined elsewhere and referenced in this module
136 ----------------------------------------------------------------------------*/
137
138 /*----------------------------------------------------------------------------
139 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
140 ; Declare variables used in this module but defined elsewhere
141 ----------------------------------------------------------------------------*/
142
143 /*----------------------------------------------------------------------------
144 ; FUNCTION CODE
145 ----------------------------------------------------------------------------*/
146
147
Isf_isp(int16 isf[],int16 isp[],int16 m)148 void Isf_isp(
149 int16 isf[], /* (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */
150 int16 isp[], /* (o) Q15 : isp[m] (range: -1<=val<1) */
151 int16 m /* (i) : LPC order */
152 )
153 {
154 int16 i, ind, offset;
155 int32 L_tmp;
156
157 for (i = 0; i < m - 1; i++)
158 {
159 isp[i] = isf[i];
160 }
161 isp[m - 1] = shl_int16(isf[m - 1], 1);
162
163 for (i = 0; i < m; i++)
164 {
165 ind = isp[i] >> 7; /* ind = b7-b15 of isf[i] */
166 offset = (isp[i] & 0x007f); /* offset = b0-b6 of isf[i] */
167
168 /* isp[i] = table[ind]+ ((table[ind+1]-table[ind])*offset) / 128 */
169
170 L_tmp = mul_16by16_to_int32(table[ind + 1] - table[ind], offset);
171 isp[i] = add_int16(table[ind], (int16)(L_tmp >> 8));
172 }
173
174 return;
175 }
176