lag_wind.cpp revision b841f14f8e51f2365945281fbfa54ef6a1b1b5a6
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/**************************************************************************************** 19Portions 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) 26Permission to distribute, modify and use this file under the standard license 27terms listed above has been obtained from the copyright holder. 28****************************************************************************************/ 29/* 30------------------------------------------------------------------------------ 31 32 33 34 Pathname: ./audio/gsm-amr/c/src/lag_wind.c 35 36 Date: 01/31/2002 37 38------------------------------------------------------------------------------ 39 REVISION HISTORY 40 41 Description: 42 1. Eliminated unused include files. 43 2. Replaced array addressing by pointers 44 3. Eliminated l_extract() function call 45 46 Description: Added casting to eliminate warnings 47 48 Description: Replaced "int" and/or "char" with OSCL defined types. 49 50 Description: 51 52------------------------------------------------------------------------------ 53*/ 54 55/*---------------------------------------------------------------------------- 56; INCLUDES 57----------------------------------------------------------------------------*/ 58#include "lag_wind.h" 59#include "lag_wind_tab.h" 60#include "basic_op.h" 61 62/*---------------------------------------------------------------------------- 63; MACROS 64; Define module specific macros here 65----------------------------------------------------------------------------*/ 66 67 68/*---------------------------------------------------------------------------- 69; DEFINES 70; Include all pre-processor statements here. Include conditional 71; compile variables also. 72----------------------------------------------------------------------------*/ 73 74 75/*---------------------------------------------------------------------------- 76; LOCAL FUNCTION DEFINITIONS 77; Function Prototype declaration 78----------------------------------------------------------------------------*/ 79 80 81/*---------------------------------------------------------------------------- 82; LOCAL STORE/BUFFER/POINTER DEFINITIONS 83; Variable declaration - defined here and used outside this module 84----------------------------------------------------------------------------*/ 85 86 87/* 88------------------------------------------------------------------------------ 89 FUNCTION NAME: lag_wind 90------------------------------------------------------------------------------ 91 INPUT AND OUTPUT DEFINITIONS 92 93 Inputs: 94 m = LPC order of type Word16 95 r_h[] = pointer to autocorrelations (msb) of type Word16 96 r_l[] = pointer to autocorrelations (lsb) of type Word16 97 pOverflow = pointer to overflow flag 98 99 Outputs: 100 None 101 102 Returns: 103 None 104 105 Global Variables Used: 106 None. 107 108 Local Variables Needed: 109 None. 110 111------------------------------------------------------------------------------ 112 FUNCTION DESCRIPTION 113 114 File : lag_wind.c 115 Purpose : Lag windowing of autocorrelations. 116 117 FUNCTION: Lag_window() 118 119 PURPOSE: Lag windowing of autocorrelations. 120 121 DESCRIPTION: 122 r[i] = r[i]*lag_wind[i], i=1,...,10 123 124 r[i] and lag_wind[i] are in special double precision format. 125 See "oper_32b.c" for the format. 126 127------------------------------------------------------------------------------ 128 REQUIREMENTS 129 130 None. 131 132------------------------------------------------------------------------------ 133 REFERENCES 134 135 lag_wind.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001 136 137------------------------------------------------------------------------------ 138 PSEUDO-CODE 139 140 Word16 i; 141 Word32 x; 142 143 for (i = 1; i <= m; i++) 144 { 145 x = Mpy_32 (r_h[i], r_l[i], lag_h[i - 1], lag_l[i - 1], pOverflow); 146 L_Extract (x, &r_h[i], &r_l[i], pOverflow); 147 } 148 return; 149 150------------------------------------------------------------------------------ 151 RESOURCES USED [optional] 152 153 When the code is written for a specific target processor the 154 the resources used should be documented below. 155 156 HEAP MEMORY USED: x bytes 157 158 STACK MEMORY USED: x bytes 159 160 CLOCK CYCLES: (cycle count equation for this function) + (variable 161 used to represent cycle count for each subroutine 162 called) 163 where: (cycle count variable) = cycle count for [subroutine 164 name] 165 166------------------------------------------------------------------------------ 167 CAUTION [optional] 168 [State any special notes, constraints or cautions for users of this function] 169 170------------------------------------------------------------------------------ 171*/ 172void Lag_window( 173 Word16 m, /* (i) : LPC order */ 174 Word16 r_h[], /* (i/o) : Autocorrelations (msb) */ 175 Word16 r_l[], /* (i/o) : Autocorrelations (lsb) */ 176 Flag *pOverflow 177) 178{ 179 Word16 i; 180 Word32 x; 181 const Word16 *p_lag_h = &lag_h[0]; 182 const Word16 *p_lag_l = &lag_l[0]; 183 Word16 *p_r_h = &r_h[1]; 184 Word16 *p_r_l = &r_l[1]; 185 186 for (i = m; i != 0 ; i--) 187 { 188 x = Mpy_32(*(p_r_h), *(p_r_l), *(p_lag_h++), *(p_lag_l++), pOverflow); 189 *(p_r_h) = (Word16)(x >> 16); 190 *(p_r_l++) = (x >> 1) - (*(p_r_h++) << 15); 191 } 192 193 return; 194} 195 196