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: agc2_amr_wb.cpp 35 36 Date: 05/08/2007 37 38 ------------------------------------------------------------------------------ 39 REVISION HISTORY 40 41 42 Description: 43 44 ------------------------------------------------------------------------------ 45 INPUT AND OUTPUT DEFINITIONS 46 47 int16 * sig_in, (i) : postfilter input signal 48 int16 * sig_out, (i/o) : postfilter output signal 49 int16 l_trm (i) : subframe size 50 51 52 ------------------------------------------------------------------------------ 53 FUNCTION DESCRIPTION 54 55 Performs adaptive gain control 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 "pvamrwbdecoder_cnst.h" 76 #include "pvamrwbdecoder_acelp.h" 77 #include "pv_amr_wb_type_defs.h" 78 #include "pvamrwbdecoder_basic_op.h" 79 #include "pvamrwb_math_op.h" 80 81 /*---------------------------------------------------------------------------- 82 ; MACROS 83 ; Define module specific macros here 84 ----------------------------------------------------------------------------*/ 85 86 87 /*---------------------------------------------------------------------------- 88 ; DEFINES 89 ; Include all pre-processor statements here. Include conditional 90 ; compile variables also. 91 ----------------------------------------------------------------------------*/ 92 93 /*---------------------------------------------------------------------------- 94 ; LOCAL FUNCTION DEFINITIONS 95 ; Function Prototype declaration 96 ----------------------------------------------------------------------------*/ 97 98 /*---------------------------------------------------------------------------- 99 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 100 ; Variable declaration - defined here and used outside this module 101 ----------------------------------------------------------------------------*/ 102 103 /*---------------------------------------------------------------------------- 104 ; EXTERNAL FUNCTION REFERENCES 105 ; Declare functions defined elsewhere and referenced in this module 106 ----------------------------------------------------------------------------*/ 107 108 /*---------------------------------------------------------------------------- 109 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 110 ; Declare variables used in this module but defined elsewhere 111 ----------------------------------------------------------------------------*/ 112 113 /*---------------------------------------------------------------------------- 114 ; FUNCTION CODE 115 ----------------------------------------------------------------------------*/ 116 117 void agc2_amr_wb( 118 int16 * sig_in, /* (i) : postfilter input signal */ 119 int16 * sig_out, /* (i/o) : postfilter output signal */ 120 int16 l_trm /* (i) : subframe size */ 121 ) 122 { 123 124 int16 i, exp; 125 int16 gain_in, gain_out, g0; 126 int32 s; 127 128 int16 temp; 129 130 /* calculate gain_out with exponent */ 131 132 temp = sig_out[0] >> 2; 133 s = fxp_mul_16by16(temp, temp) << 1; 134 for (i = 1; i < l_trm; i++) 135 { 136 temp = sig_out[i] >> 2; 137 s = mac_16by16_to_int32(s, temp, temp); 138 } 139 140 141 if (s == 0) 142 { 143 return; 144 } 145 exp = normalize_amr_wb(s) - 1; 146 gain_out = amr_wb_round(s << exp); 147 148 /* calculate gain_in with exponent */ 149 150 temp = sig_in[0] >> 2; 151 s = mul_16by16_to_int32(temp, temp); 152 for (i = 1; i < l_trm; i++) 153 { 154 temp = sig_in[i] >> 2; 155 s = mac_16by16_to_int32(s, temp, temp); 156 } 157 158 159 if (s == 0) 160 { 161 g0 = 0; 162 } 163 else 164 { 165 i = normalize_amr_wb(s); 166 gain_in = amr_wb_round(s << i); 167 exp -= i; 168 169 /* 170 * g0 = sqrt(gain_in/gain_out) 171 */ 172 173 s = div_16by16(gain_out, gain_in); 174 s = shl_int32(s, 7); /* s = gain_out / gain_in */ 175 s = shr_int32(s, exp); /* add exponent */ 176 177 s = one_ov_sqrt(s); 178 g0 = amr_wb_round(shl_int32(s, 9)); 179 } 180 /* sig_out(n) = gain(n) sig_out(n) */ 181 182 for (i = 0; i < l_trm; i++) 183 { 184 sig_out[i] = extract_h(shl_int32(fxp_mul_16by16(sig_out[i], g0), 3)); 185 186 } 187 188 return; 189 } 190 191
