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: weight_amrwb_lpc.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 a[], (i) Q12 : a[m+1] LPC coefficients 48 int16 ap[], (o) Q12 : Spectral expanded LPC coefficients 49 int16 gamma, (i) Q15 : Spectral expansion factor. 50 int16 m (i) : LPC order. 51 52 ------------------------------------------------------------------------------ 53 FUNCTION DESCRIPTION 54 55 Weighting of LPC coefficients. 56 ap[i] = a[i] (gamma i) 57 58 ------------------------------------------------------------------------------ 59 REQUIREMENTS 60 61 62 ------------------------------------------------------------------------------ 63 REFERENCES 64 65 ------------------------------------------------------------------------------ 66 PSEUDO-CODE 67 68 ------------------------------------------------------------------------------ 69 */ 70 71 72 /*---------------------------------------------------------------------------- 73 ; INCLUDES 74 ----------------------------------------------------------------------------*/ 75 76 #include "pv_amr_wb_type_defs.h" 77 #include "pvamrwbdecoder_basic_op.h" 78 #include "pvamrwbdecoder_acelp.h" 79 80 /*---------------------------------------------------------------------------- 81 ; MACROS 82 ; Define module specific macros here 83 ----------------------------------------------------------------------------*/ 84 85 86 /*---------------------------------------------------------------------------- 87 ; DEFINES 88 ; Include all pre-processor statements here. Include conditional 89 ; compile variables also. 90 ----------------------------------------------------------------------------*/ 91 92 /*---------------------------------------------------------------------------- 93 ; LOCAL FUNCTION DEFINITIONS 94 ; Function Prototype declaration 95 ----------------------------------------------------------------------------*/ 96 97 /*---------------------------------------------------------------------------- 98 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS 99 ; Variable declaration - defined here and used outside this module 100 ----------------------------------------------------------------------------*/ 101 102 /*---------------------------------------------------------------------------- 103 ; EXTERNAL FUNCTION REFERENCES 104 ; Declare functions defined elsewhere and referenced in this module 105 ----------------------------------------------------------------------------*/ 106 107 /*---------------------------------------------------------------------------- 108 ; EXTERNAL GLOBAL STORE/BUFFER/POINTER REFERENCES 109 ; Declare variables used in this module but defined elsewhere 110 ----------------------------------------------------------------------------*/ 111 112 /*---------------------------------------------------------------------------- 113 ; FUNCTION CODE 114 ----------------------------------------------------------------------------*/ 115 116 void weight_amrwb_lpc( 117 int16 a[], /* (i) Q12 : a[m+1] LPC coefficients */ 118 int16 ap[], /* (o) Q12 : Spectral expanded LPC coefficients */ 119 int16 gamma, /* (i) Q15 : Spectral expansion factor. */ 120 int16 m /* (i) : LPC order. */ 121 ) 122 { 123 int16 i, fac; 124 int32 roundFactor = 0x00004000L; 125 ap[0] = a[0]; 126 fac = gamma; 127 for (i = 1; i < m; i++) 128 { 129 ap[i] = (int16)(fxp_mac_16by16(a[i], fac, roundFactor) >> 15); 130 fac = (int16)(fxp_mac_16by16(fac, gamma, roundFactor) >> 15); 131 } 132 ap[i] = (int16)(fxp_mac_16by16(a[i], fac, roundFactor) >> 15); 133 134 return; 135 } 136
