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: isp_isf.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 isf[], (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) 48 int16 isp[], (o) Q15 : isp[m] (range: -1<=val<1) 49 int16 m (i) : LPC order 50 51 52 ------------------------------------------------------------------------------ 53 FUNCTION DESCRIPTION 54 55 Isf_isp Transformation isf to isp 56 57 The transformation from isf[i] to isp[i] is 58 approximated by a look-up table and interpolation. 59 60 61 62 ------------------------------------------------------------------------------ 63 REQUIREMENTS 64 65 66 ------------------------------------------------------------------------------ 67 REFERENCES 68 69 ------------------------------------------------------------------------------ 70 PSEUDO-CODE 71 72 ------------------------------------------------------------------------------ 73 */ 74 75 76 /*---------------------------------------------------------------------------- 77 ; INCLUDES 78 ----------------------------------------------------------------------------*/ 79 80 81 #include "pv_amr_wb_type_defs.h" 82 #include "pvamrwbdecoder_basic_op.h" 83 #include "pvamrwbdecoder_acelp.h" 84 85 /*---------------------------------------------------------------------------- 86 ; MACROS 87 ; Define module specific macros here 88 ----------------------------------------------------------------------------*/ 89 90 91 /*---------------------------------------------------------------------------- 92 ; DEFINES 93 ; Include all pre-processor statements here. Include conditional 94 ; compile variables also. 95 ----------------------------------------------------------------------------*/ 96 97 /*---------------------------------------------------------------------------- 98 ; LOCAL FUNCTION DEFINITIONS 99 ; Function Prototype declaration 100 ----------------------------------------------------------------------------*/ 101 102 /*---------------------------------------------------------------------------- 103 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 104 ; Variable declaration - defined here and used outside this module 105 ----------------------------------------------------------------------------*/ 106 107 /* Look-up table for transformations */ 108 109 /* table of cos(x) in Q15 */ 110 111 static const int16 table[129] = 112 { 113 32767, 114 32758, 32729, 32679, 32610, 32522, 32413, 32286, 32138, 115 31972, 31786, 31581, 31357, 31114, 30853, 30572, 30274, 116 29957, 29622, 29269, 28899, 28511, 28106, 27684, 27246, 117 26791, 26320, 25833, 25330, 24812, 24279, 23732, 23170, 118 22595, 22006, 21403, 20788, 20160, 19520, 18868, 18205, 119 17531, 16846, 16151, 15447, 14733, 14010, 13279, 12540, 120 11793, 11039, 10279, 9512, 8740, 7962, 7180, 6393, 121 5602, 4808, 4011, 3212, 2411, 1608, 804, 0, 122 -804, -1608, -2411, -3212, -4011, -4808, -5602, -6393, 123 -7180, -7962, -8740, -9512, -10279, -11039, -11793, -12540, 124 -13279, -14010, -14733, -15447, -16151, -16846, -17531, -18205, 125 -18868, -19520, -20160, -20788, -21403, -22006, -22595, -23170, 126 -23732, -24279, -24812, -25330, -25833, -26320, -26791, -27246, 127 -27684, -28106, -28511, -28899, -29269, -29622, -29957, -30274, 128 -30572, -30853, -31114, -31357, -31581, -31786, -31972, -32138, 129 -32286, -32413, -32522, -32610, -32679, -32729, -32758, -32768 130 }; 131 132 133 /*---------------------------------------------------------------------------- 134 ; EXTERNAL FUNCTION REFERENCES 135 ; Declare functions defined elsewhere and referenced in this module 136 ----------------------------------------------------------------------------*/ 137 138 /*---------------------------------------------------------------------------- 139 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 140 ; Declare variables used in this module but defined elsewhere 141 ----------------------------------------------------------------------------*/ 142 143 /*---------------------------------------------------------------------------- 144 ; FUNCTION CODE 145 ----------------------------------------------------------------------------*/ 146 147 148 void Isf_isp( 149 int16 isf[], /* (i) Q15 : isf[m] normalized (range: 0.0<=val<=0.5) */ 150 int16 isp[], /* (o) Q15 : isp[m] (range: -1<=val<1) */ 151 int16 m /* (i) : LPC order */ 152 ) 153 { 154 int16 i, ind, offset; 155 int32 L_tmp; 156 157 for (i = 0; i < m - 1; i++) 158 { 159 isp[i] = isf[i]; 160 } 161 isp[m - 1] = shl_int16(isf[m - 1], 1); 162 163 for (i = 0; i < m; i++) 164 { 165 ind = isp[i] >> 7; /* ind = b7-b15 of isf[i] */ 166 offset = (isp[i] & 0x007f); /* offset = b0-b6 of isf[i] */ 167 168 /* isp[i] = table[ind]+ ((table[ind+1]-table[ind])*offset) / 128 */ 169 170 L_tmp = mul_16by16_to_int32(table[ind + 1] - table[ind], offset); 171 isp[i] = add_int16(table[ind], (int16)(L_tmp >> 8)); 172 } 173 174 return; 175 } 176
