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 ----------------------------------------------------------------------------*/ 114 115 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
