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: scale_signal.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 signal[], (i/o) : signal to scale
48 int16 lg, (i) : size of x[]
49 int16 exp (i) : exponent: x = round(x << exp)
50
51 ------------------------------------------------------------------------------
52 FUNCTION DESCRIPTION
53
54 Scale signal to get maximum of dynamic range
55
56
57 ------------------------------------------------------------------------------
58 REQUIREMENTS
59
60
61 ------------------------------------------------------------------------------
62 REFERENCES
63
64 ------------------------------------------------------------------------------
65 PSEUDO-CODE
66
67 ------------------------------------------------------------------------------
68 */
69
70
71 /*----------------------------------------------------------------------------
72 ; INCLUDES
73 ----------------------------------------------------------------------------*/
74
75 #include "pv_amr_wb_type_defs.h"
76 #include "pvamrwbdecoder_basic_op.h"
77 #include "pvamrwbdecoder_acelp.h"
78
79 /*----------------------------------------------------------------------------
80 ; MACROS
81 ; Define module specific macros here
82 ----------------------------------------------------------------------------*/
83
84
85 /*----------------------------------------------------------------------------
86 ; DEFINES
87 ; Include all pre-processor statements here. Include conditional
88 ; compile variables also.
89 ----------------------------------------------------------------------------*/
90
91 /*----------------------------------------------------------------------------
92 ; LOCAL FUNCTION DEFINITIONS
93 ; Function Prototype declaration
94 ----------------------------------------------------------------------------*/
95
96 /*----------------------------------------------------------------------------
97 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
98 ; Variable declaration - defined here and used outside this module
99 ----------------------------------------------------------------------------*/
100
101 /*----------------------------------------------------------------------------
102 ; EXTERNAL FUNCTION REFERENCES
103 ; Declare functions defined elsewhere and referenced in this module
104 ----------------------------------------------------------------------------*/
105
106 /*----------------------------------------------------------------------------
107 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES
108 ; Declare variables used in this module but defined elsewhere
109 ----------------------------------------------------------------------------*/
110
111 /*----------------------------------------------------------------------------
112 ; FUNCTION CODE
113 ----------------------------------------------------------------------------*/
114
scale_signal(int16 x[],int16 lg,int16 exp)115 void scale_signal(
116 int16 x[], /* (i/o) : signal to scale */
117 int16 lg, /* (i) : size of x[] */
118 int16 exp /* (i) : exponent: x = round(x << exp) */
119 )
120 {
121 int16 i;
122 int16 tmp;
123 int16 *pt_x;
124
125
126 int32 L_tmp;
127
128
129 if (exp > 0)
130 {
131 for (i = 0; i < lg; i++)
132 {
133 L_tmp = shl_int32(((int32)x[i] << 16), exp); /* saturation can occur here */
134 x[i] = amr_wb_round(L_tmp);
135 }
136 }
137 else if (exp < 0)
138 {
139 exp = -exp;
140 exp &= 0xf;
141 tmp = (int16)(0x00008000 >> (16 - exp));
142 pt_x = x;
143
144 for (i = lg >> 1; i != 0; i--)
145 {
146 *(pt_x) = add_int16(*(pt_x), tmp) >> exp;
147 pt_x++;
148 *(pt_x) = add_int16(*(pt_x), tmp) >> exp;
149 pt_x++;
150 }
151
152 }
153 return;
154 }
155