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: normalize_amr_wb.cpp 35 36 Date: 12/10/2004 37 38 ------------------------------------------------------------------------------ 39 REVISION HISTORY 40 41 42 Description: 43 44 ------------------------------------------------------------------------------ 45 INPUT AND OUTPUT DEFINITIONS 46 47 Input 48 Int32 x 32-bit integer non-zero input 49 Returns 50 Int16 i number of leading zeros on x 51 52 53 ------------------------------------------------------------------------------ 54 FUNCTION DESCRIPTION 55 56 Returns number of leading zeros on the non-zero input 57 58 ------------------------------------------------------------------------------ 59 REQUIREMENTS 60 61 62 ------------------------------------------------------------------------------ 63 REFERENCES 64 65 ------------------------------------------------------------------------------ 66 PSEUDO-CODE 67 68 ------------------------------------------------------------------------------ 69 */ 70 71 72 /*---------------------------------------------------------------------------- 73 ; INCLUDES 74 ----------------------------------------------------------------------------*/ 75 76 #include "pv_amr_wb_type_defs.h" 77 #include "normalize_amr_wb.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 #if defined(PV_ARM_V5) 116 #elif defined(PV_ARM_GCC_V5) 117 118 /* function is inlined in header file */ 119 120 121 #else 122 123 int16 normalize_amr_wb(int32 x) 124 { 125 /*---------------------------------------------------------------------------- 126 ; Define all local variables 127 ----------------------------------------------------------------------------*/ 128 int16 i; 129 130 131 if (x > 0x0FFFFFFF) 132 { 133 i = 0; /* most likely case */ 134 } 135 else if (x > 0x00FFFFFF) 136 { 137 i = 3; /* second most likely case */ 138 } 139 else if (x > 0x0000FFFF) 140 { 141 i = x > 0x000FFFFF ? 7 : 11; 142 } 143 else 144 { 145 if (x > 0x000000FF) 146 { 147 i = x > 0x00000FFF ? 15 : 19; 148 } 149 else 150 { 151 i = x > 0x0000000F ? 23 : 27; 152 } 153 } 154 155 156 x <<= i; 157 158 switch (x & 0x78000000) 159 { 160 case 0x08000000: 161 i += 3; 162 break; 163 164 case 0x18000000: 165 case 0x10000000: 166 i += 2; 167 break; 168 case 0x28000000: 169 case 0x20000000: 170 case 0x38000000: 171 case 0x30000000: 172 i++; 173 174 default: 175 ; 176 } 177 178 return i; 179 180 } 181 182 #endif 183 184
