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 32 33 34 Pathname: ./audio/gsm-amr/c/src/d3_14pf.c 35 Functions: decode_3i40_14bits 36 37 Date: 01/28/2002 38 39 ------------------------------------------------------------------------------ 40 REVISION HISTORY 41 42 Description: Modified to place file in the correct template format. Eliminated 43 use of special functions to perform simple mathematical operations. 44 45 Description: Per review comments... 46 (1) Removed include of "count.h" and "basic_op.h" 47 (2) Updated the pathname to indicate the correct file. (Line 39) 48 49 Description: Replaced "int" and/or "char" with OSCL defined types. 50 51 Description: 52 53 ------------------------------------------------------------------------------ 54 MODULE DESCRIPTION 55 56 57 FUNCTION: decode_3i40_14bits (decod_ACELP()) 58 59 PURPOSE: Algebraic codebook decoder. For details about the encoding see 60 c3_14pf.c 61 */ 62 63 /*---------------------------------------------------------------------------- 64 ; INCLUDES 65 ----------------------------------------------------------------------------*/ 66 #include "typedef.h" 67 #include "cnst.h" 68 #include "d3_14pf.h" 69 70 /*---------------------------------------------------------------------------- 71 ; MACROS 72 ; Define module specific macros here 73 ----------------------------------------------------------------------------*/ 74 75 /*---------------------------------------------------------------------------- 76 ; DEFINES 77 ; Include all pre-processor statements here. Include conditional 78 ; compile variables also. 79 ----------------------------------------------------------------------------*/ 80 #define NB_PULSE 3 /* number of pulses */ 81 82 83 /*---------------------------------------------------------------------------- 84 ; LOCAL FUNCTION DEFINITIONS 85 ; Function Prototype declaration 86 ----------------------------------------------------------------------------*/ 87 88 /*---------------------------------------------------------------------------- 89 ; LOCAL VARIABLE DEFINITIONS 90 ; Variable declaration - defined here and used outside this module 91 ----------------------------------------------------------------------------*/ 92 93 /* 94 ------------------------------------------------------------------------------ 95 FUNCTION NAME: decode_3i40_14bits 96 ------------------------------------------------------------------------------ 97 INPUT AND OUTPUT DEFINITIONS 98 99 Inputs: 100 sign -- Word16 -- signs of 3 pulses. 101 index -- Word16 -- Positions of the 3 pulses. 102 103 Outputs: 104 cod[] -- array of type Word16 -- algebraic (fixed) codebook excitation 105 106 Returns: 107 None 108 109 Global Variables Used: 110 None 111 112 Local Variables Needed: 113 None 114 115 ------------------------------------------------------------------------------ 116 FUNCTION DESCRIPTION 117 118 119 ------------------------------------------------------------------------------ 120 REQUIREMENTS 121 122 None 123 124 ------------------------------------------------------------------------------ 125 REFERENCES 126 127 d2_9pf.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 128 129 ------------------------------------------------------------------------------ 130 PSEUDO-CODE 131 132 133 ------------------------------------------------------------------------------ 134 RESOURCES USED [optional] 135 136 When the code is written for a specific target processor the 137 the resources used should be documented below. 138 139 HEAP MEMORY USED: x bytes 140 141 STACK MEMORY USED: x bytes 142 143 CLOCK CYCLES: (cycle count equation for this function) + (variable 144 used to represent cycle count for each subroutine 145 called) 146 where: (cycle count variable) = cycle count for [subroutine 147 name] 148 149 ------------------------------------------------------------------------------ 150 CAUTION [optional] 151 [State any special notes, constraints or cautions for users of this function] 152 153 ------------------------------------------------------------------------------ 154 */ 155 156 void decode_3i40_14bits( 157 Word16 sign, /* i : signs of 3 pulses. */ 158 Word16 index, /* i : Positions of the 3 pulses. */ 159 Word16 cod[] /* o : algebraic (fixed) codebook excitation */ 160 ) 161 { 162 Word16 i; 163 Word16 j; 164 165 Word16 pos[NB_PULSE]; 166 167 /* Decode the positions */ 168 169 i = index & 0x7; 170 171 pos[0] = i * 5; 172 173 174 175 176 177 index >>= 3; 178 179 j = index & 0x1; 180 181 index >>= 1; 182 183 i = index & 0x7; 184 185 pos[1] = i * 5 + j * 2 + 1; 186 187 188 189 190 191 index >>= 3; 192 193 j = index & 0x1; 194 195 index >>= 1; 196 197 i = index & 0x7; 198 199 pos[2] = i * 5 + j * 2 + 2; 200 201 202 /* decode the signs and build the codeword */ 203 204 for (i = 0; i < L_SUBFR; i++) 205 { 206 cod[i] = 0; 207 } 208 209 for (j = 0; j < NB_PULSE; j++) 210 { 211 i = sign & 1; 212 213 /* This line is equivalent to... 214 * 215 * 216 * if (i == 1) 217 * { 218 * cod[pos[j]] = 8191; 219 * } 220 * if (i == 0) 221 * { 222 * cod[pos[j]] = -8192; 223 * } 224 */ 225 226 cod[pos[j]] = i * 16383 - 8192; 227 228 sign >>= 1; 229 230 } 231 232 return; 233 } 234
