1/* ----------------------------------------------------------------------------- 2Software License for The Fraunhofer FDK AAC Codec Library for Android 3 4© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten 5Forschung e.V. All rights reserved. 6 7 1. INTRODUCTION 8The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software 9that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding 10scheme for digital audio. This FDK AAC Codec software is intended to be used on 11a wide variety of Android devices. 12 13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient 14general perceptual audio codecs. AAC-ELD is considered the best-performing 15full-bandwidth communications codec by independent studies and is widely 16deployed. AAC has been standardized by ISO and IEC as part of the MPEG 17specifications. 18 19Patent licenses for necessary patent claims for the FDK AAC Codec (including 20those of Fraunhofer) may be obtained through Via Licensing 21(www.vialicensing.com) or through the respective patent owners individually for 22the purpose of encoding or decoding bit streams in products that are compliant 23with the ISO/IEC MPEG audio standards. Please note that most manufacturers of 24Android devices already license these patent claims through Via Licensing or 25directly from the patent owners, and therefore FDK AAC Codec software may 26already be covered under those patent licenses when it is used for those 27licensed purposes only. 28 29Commercially-licensed AAC software libraries, including floating-point versions 30with enhanced sound quality, are also available from Fraunhofer. Users are 31encouraged to check the Fraunhofer website for additional applications 32information and documentation. 33 342. COPYRIGHT LICENSE 35 36Redistribution and use in source and binary forms, with or without modification, 37are permitted without payment of copyright license fees provided that you 38satisfy the following conditions: 39 40You must retain the complete text of this software license in redistributions of 41the FDK AAC Codec or your modifications thereto in source code form. 42 43You must retain the complete text of this software license in the documentation 44and/or other materials provided with redistributions of the FDK AAC Codec or 45your modifications thereto in binary form. You must make available free of 46charge copies of the complete source code of the FDK AAC Codec and your 47modifications thereto to recipients of copies in binary form. 48 49The name of Fraunhofer may not be used to endorse or promote products derived 50from this library without prior written permission. 51 52You may not charge copyright license fees for anyone to use, copy or distribute 53the FDK AAC Codec software or your modifications thereto. 54 55Your modified versions of the FDK AAC Codec must carry prominent notices stating 56that you changed the software and the date of any change. For modified versions 57of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android" 58must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK 59AAC Codec Library for Android." 60 613. NO PATENT LICENSE 62 63NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without 64limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE. 65Fraunhofer provides no warranty of patent non-infringement with respect to this 66software. 67 68You may use this FDK AAC Codec software or modifications thereto only for 69purposes that are authorized by appropriate patent licenses. 70 714. DISCLAIMER 72 73This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright 74holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, 75including but not limited to the implied warranties of merchantability and 76fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 77CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, 78or consequential damages, including but not limited to procurement of substitute 79goods or services; loss of use, data, or profits, or business interruption, 80however caused and on any theory of liability, whether in contract, strict 81liability, or tort (including negligence), arising in any way out of the use of 82this software, even if advised of the possibility of such damage. 83 845. CONTACT INFORMATION 85 86Fraunhofer Institute for Integrated Circuits IIS 87Attention: Audio and Multimedia Departments - FDK AAC LL 88Am Wolfsmantel 33 8991058 Erlangen, Germany 90 91www.iis.fraunhofer.de/amm 92amm-info@iis.fraunhofer.de 93----------------------------------------------------------------------------- */ 94 95/******************* Library for basic calculation routines ******************** 96 97 Author(s): Manuel Jander 98 99 Description: LPC related functions 100 101*******************************************************************************/ 102 103#ifndef FDK_LPC_H 104#define FDK_LPC_H 105 106#include "common_fix.h" 107 108#define LPC_MAX_ORDER 24 109 110/* 111 * Experimental solution for lattice filter substitution. 112 * LPC_SYNTHESIS_IIR macro must be activated in aacdec_tns.cpp. 113 * When LPC_SYNTHESIS_IIR enabled, there will be a substitution of the default 114 * lpc synthesis lattice filter by an IIR synthesis filter (with a conversionof 115 * the filter coefs). LPC_TNS related macros are intended to implement the data 116 * types used by the CLpc_Synthesis variant which is used for this solution. 117 * */ 118 119/* #define LPC_TNS_LOWER_PRECISION */ 120 121typedef FIXP_DBL FIXP_LPC_TNS; 122#define FX_DBL2FX_LPC_TNS(x) (x) 123#define FX_DBL2FXCONST_LPC_TNS(x) (x) 124#define FX_LPC_TNS2FX_DBL(x) (x) 125#define FL2FXCONST_LPC_TNS(val) FL2FXCONST_DBL(val) 126#define MAXVAL_LPC_TNS MAXVAL_DBL 127 128typedef FIXP_SGL FIXP_LPC; 129#define FX_DBL2FX_LPC(x) FX_DBL2FX_SGL((FIXP_DBL)(x)) 130#define FX_DBL2FXCONST_LPC(x) FX_DBL2FXCONST_SGL(x) 131#define FX_LPC2FX_DBL(x) FX_SGL2FX_DBL(x) 132#define FL2FXCONST_LPC(val) FL2FXCONST_SGL(val) 133#define MAXVAL_LPC MAXVAL_SGL 134 135/** 136 * \brief Obtain residual signal through LPC analysis. 137 * \param signal pointer to buffer holding signal to be analysed. Residual is 138 * returned there (in place) 139 * \param signal_size the size of the input data in pData 140 * \param lpcCoeff_m the LPC filter coefficient mantissas 141 * \param lpcCoeff_e the LPC filter coefficient exponent 142 * \param order the LPC filter order (size of coeff) 143 * \param filtState Pointer to state buffer of size order 144 * \param filtStateIndex pointer to state index storage 145 */ 146void CLpc_Analysis(FIXP_DBL signal[], const int signal_size, 147 const FIXP_LPC lpcCoeff_m[], const int lpcCoeff_e, 148 const int order, FIXP_DBL *filtState, int *filtStateIndex); 149 150/** 151 * \brief Synthesize signal fom residual through LPC synthesis, using LP 152 * coefficients. 153 * \param signal pointer to buffer holding the residual signal. The synthesis is 154 * returned there (in place) 155 * \param signal_size the size of the input data in pData 156 * \param inc buffer traversal increment for signal 157 * \param coeff the LPC filter coefficients 158 * \param coeff_e exponent of coeff 159 * \param order the LPC filter order (size of coeff) 160 * \param state state buffer of size LPC_MAX_ORDER 161 * \param pStateIndex pointer to state index storage 162 */ 163void CLpc_Synthesis(FIXP_DBL *signal, const int signal_size, const int signal_e, 164 const int inc, const FIXP_LPC_TNS *lpcCoeff_m, 165 const int lpcCoeff_e, const int order, FIXP_DBL *state, 166 int *pStateIndex); 167void CLpc_Synthesis(FIXP_DBL *signal, const int signal_size, const int signal_e, 168 const int inc, const FIXP_LPC coeff[], const int coeff_e, 169 const int order, FIXP_DBL *filtState, int *pStateIndex); 170 171/** 172 * \brief Synthesize signal fom residual through LPC synthesis, using ParCor 173 * coefficients. The algorithm assumes a filter gain of max 1.0. If the filter 174 * gain is higher, this must be accounted into the values of signal_e 175 * and/or signal_e_out to avoid overflows. 176 * \param signal pointer to buffer holding the residual signal. The synthesis is 177 * returned there (in place) 178 * \param signal_size the size of the input data in pData 179 * \param inc buffer traversal increment for signal 180 * \param coeff the LPC filter coefficients 181 * \param coeff_e exponent of coeff 182 * \param order the LPC filter order (size of coeff) 183 * \param state state buffer of size LPC_MAX_ORDER 184 */ 185void CLpc_SynthesisLattice(FIXP_DBL *signal, const int signal_size, 186 const int signal_e, const int signal_e_out, 187 const int inc, const FIXP_SGL *coeff, 188 const int order, FIXP_DBL *state); 189 190void CLpc_SynthesisLattice(FIXP_DBL *RESTRICT signal, const int signal_size, 191 const int signal_e, const int signal_e_out, 192 const int inc, const FIXP_DBL *RESTRICT coeff, 193 const int order, FIXP_DBL *RESTRICT state); 194 195/** 196 * \brief 197 */ 198INT CLpc_ParcorToLpc(const FIXP_LPC_TNS reflCoeff[], FIXP_LPC_TNS LpcCoeff[], 199 INT numOfCoeff, FIXP_DBL workBuffer[]); 200INT CLpc_ParcorToLpc(const FIXP_LPC reflCoeff[], FIXP_LPC LpcCoeff[], 201 const int numOfCoeff, FIXP_DBL workBuffer[]); 202 203/** 204 * \brief Calculate ParCor (Partial autoCorrelation, reflection) coefficients 205 * from autocorrelation coefficients using the Schur algorithm (instead of 206 * Levinson Durbin). 207 * \param acorr order+1 autocorrelation coefficients 208 * \param reflCoeff output reflection /ParCor coefficients. The first 209 * coefficient which is always 1.0 is ommitted. 210 * \param order number of acorr / reflCoeff coefficients. 211 * \param pPredictionGain_m prediction gain mantissa 212 * \param pPredictionGain_e prediction gain exponent 213 */ 214void CLpc_AutoToParcor(FIXP_DBL acorr[], const int acorr_e, 215 FIXP_LPC reflCoeff[], const int order, 216 FIXP_DBL *pPredictionGain_m, INT *pPredictionGain_e); 217 218#endif /* FDK_LPC_H */ 219