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: dec_acelp_2p_in_64.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 index, (i): 12 bits index 48 int16 code[] (o): Q9 algebraic (fixed) codebook excitation 49 50 ------------------------------------------------------------------------------ 51 FUNCTION DESCRIPTION 52 53 12 bits algebraic codebook decoder. 54 2 tracks x 32 positions per track = 64 samples. 55 56 12 bits --> 2 pulses in a frame of 64 samples. 57 58 All pulses can have two (2) possible amplitudes: +1 or -1. 59 Each pulse can have 32 possible positions. 60 61 ------------------------------------------------------------------------------ 62 REQUIREMENTS 63 64 65 ------------------------------------------------------------------------------ 66 REFERENCES 67 68 ------------------------------------------------------------------------------ 69 PSEUDO-CODE 70 71 ------------------------------------------------------------------------------ 72 */ 73 74 75 /*---------------------------------------------------------------------------- 76 ; INCLUDES 77 ----------------------------------------------------------------------------*/ 78 79 #include "pv_amr_wb_type_defs.h" 80 #include "pvamrwbdecoder_basic_op.h" 81 #include "pvamrwbdecoder_cnst.h" 82 #include "pvamrwbdecoder_acelp.h" 83 84 /*---------------------------------------------------------------------------- 85 ; MACROS 86 ; Define module specific macros here 87 ----------------------------------------------------------------------------*/ 88 89 90 /*---------------------------------------------------------------------------- 91 ; DEFINES 92 ; Include all pre-processor statements here. Include conditional 93 ; compile variables also. 94 ----------------------------------------------------------------------------*/ 95 #define L_CODE 64 /* codevector length */ 96 #define NB_TRACK 2 /* number of track */ 97 #define NB_POS 32 /* number of position */ 98 99 100 /*---------------------------------------------------------------------------- 101 ; LOCAL FUNCTION DEFINITIONS 102 ; Function Prototype declaration 103 ----------------------------------------------------------------------------*/ 104 105 /*---------------------------------------------------------------------------- 106 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 107 ; Variable declaration - defined here and used outside this module 108 ----------------------------------------------------------------------------*/ 109 110 /*---------------------------------------------------------------------------- 111 ; EXTERNAL FUNCTION REFERENCES 112 ; Declare functions defined elsewhere and referenced in this module 113 ----------------------------------------------------------------------------*/ 114 115 /*---------------------------------------------------------------------------- 116 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 117 ; Declare variables used in this module but defined elsewhere 118 ----------------------------------------------------------------------------*/ 119 120 /*---------------------------------------------------------------------------- 121 ; FUNCTION CODE 122 ----------------------------------------------------------------------------*/ 123 124 void dec_acelp_2p_in_64( 125 int16 index, /* (i): 12 bits index */ 126 int16 code[] /* (o): Q9 algebraic (fixed) codebook excitation */ 127 ) 128 { 129 int16 i; 130 131 pv_memset(code, 0, L_CODE*sizeof(*code)); 132 133 /* decode the positions and signs of pulses and build the codeword */ 134 135 i = (index >> 5) & 0x003E; 136 137 if (((index >> 6) & NB_POS) == 0) 138 { 139 code[i] = 512; 140 } 141 else 142 { 143 code[i] = -512; 144 } 145 146 i = ((index & 0x001F) << 1) + 1; 147 148 if ((index & NB_POS) == 0) 149 { 150 code[i] = 512; 151 } 152 else 153 { 154 code[i] = -512; 155 } 156 157 } 158
