1 /* ----------------------------------------------------------------------------- 2 Software License for The Fraunhofer FDK AAC Codec Library for Android 3 4 Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Frderung der angewandten 5 Forschung e.V. All rights reserved. 6 7 1. INTRODUCTION 8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software 9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding 10 scheme for digital audio. This FDK AAC Codec software is intended to be used on 11 a wide variety of Android devices. 12 13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient 14 general perceptual audio codecs. AAC-ELD is considered the best-performing 15 full-bandwidth communications codec by independent studies and is widely 16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG 17 specifications. 18 19 Patent licenses for necessary patent claims for the FDK AAC Codec (including 20 those of Fraunhofer) may be obtained through Via Licensing 21 (www.vialicensing.com) or through the respective patent owners individually for 22 the purpose of encoding or decoding bit streams in products that are compliant 23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of 24 Android devices already license these patent claims through Via Licensing or 25 directly from the patent owners, and therefore FDK AAC Codec software may 26 already be covered under those patent licenses when it is used for those 27 licensed purposes only. 28 29 Commercially-licensed AAC software libraries, including floating-point versions 30 with enhanced sound quality, are also available from Fraunhofer. Users are 31 encouraged to check the Fraunhofer website for additional applications 32 information and documentation. 33 34 2. COPYRIGHT LICENSE 35 36 Redistribution and use in source and binary forms, with or without modification, 37 are permitted without payment of copyright license fees provided that you 38 satisfy the following conditions: 39 40 You must retain the complete text of this software license in redistributions of 41 the FDK AAC Codec or your modifications thereto in source code form. 42 43 You must retain the complete text of this software license in the documentation 44 and/or other materials provided with redistributions of the FDK AAC Codec or 45 your modifications thereto in binary form. You must make available free of 46 charge copies of the complete source code of the FDK AAC Codec and your 47 modifications thereto to recipients of copies in binary form. 48 49 The name of Fraunhofer may not be used to endorse or promote products derived 50 from this library without prior written permission. 51 52 You may not charge copyright license fees for anyone to use, copy or distribute 53 the FDK AAC Codec software or your modifications thereto. 54 55 Your modified versions of the FDK AAC Codec must carry prominent notices stating 56 that you changed the software and the date of any change. For modified versions 57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android" 58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK 59 AAC Codec Library for Android." 60 61 3. NO PATENT LICENSE 62 63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without 64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE. 65 Fraunhofer provides no warranty of patent non-infringement with respect to this 66 software. 67 68 You may use this FDK AAC Codec software or modifications thereto only for 69 purposes that are authorized by appropriate patent licenses. 70 71 4. DISCLAIMER 72 73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright 74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, 75 including but not limited to the implied warranties of merchantability and 76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, 78 or consequential damages, including but not limited to procurement of substitute 79 goods or services; loss of use, data, or profits, or business interruption, 80 however caused and on any theory of liability, whether in contract, strict 81 liability, or tort (including negligence), arising in any way out of the use of 82 this software, even if advised of the possibility of such damage. 83 84 5. CONTACT INFORMATION 85 86 Fraunhofer Institute for Integrated Circuits IIS 87 Attention: Audio and Multimedia Departments - FDK AAC LL 88 Am Wolfsmantel 33 89 91058 Erlangen, Germany 90 91 www.iis.fraunhofer.de/amm 92 amm-info (at) iis.fraunhofer.de 93 ----------------------------------------------------------------------------- */ 94 95 /*********************** MPEG surround encoder library ************************* 96 97 Author(s): M. Multrus 98 99 Description: Encoder Library 100 Filter functions 101 102 *******************************************************************************/ 103 104 /* Includes ******************************************************************/ 105 #include "sacenc_filter.h" 106 107 /* Defines *******************************************************************/ 108 109 /* Data Types ****************************************************************/ 110 typedef struct T_DC_FILTER { 111 FIXP_DBL c__FDK; 112 FIXP_DBL state__FDK; 113 114 } DC_FILTER; 115 116 /* Constants *****************************************************************/ 117 118 /* Function / Class Declarations *********************************************/ 119 120 /* Function / Class Definition ***********************************************/ 121 FDK_SACENC_ERROR fdk_sacenc_createDCFilter(HANDLE_DC_FILTER *hDCFilter) { 122 FDK_SACENC_ERROR error = SACENC_OK; 123 124 if (NULL == hDCFilter) { 125 error = SACENC_INVALID_HANDLE; 126 } else { 127 FDK_ALLOCATE_MEMORY_1D(*hDCFilter, 1, DC_FILTER); 128 } 129 return error; 130 131 bail: 132 fdk_sacenc_destroyDCFilter(hDCFilter); 133 return ((SACENC_OK == error) ? SACENC_MEMORY_ERROR : error); 134 } 135 136 FDK_SACENC_ERROR fdk_sacenc_initDCFilter(HANDLE_DC_FILTER hDCFilter, 137 const UINT sampleRate) { 138 FDK_SACENC_ERROR error = SACENC_OK; 139 140 FIXP_DBL expC; 141 int s; 142 143 /* Conversion for use of CalcInvLdData: e^x = 2^(x*log10(e)/log10(2) = 144 CalcInvLdData(x*log10(e)/log10(2)/64.0) 1.44269504089 = log10(e)/log10(2) 145 0.5 = scale constant value with 1 Bits 146 */ 147 expC = fDivNormHighPrec((FIXP_DBL)20, (FIXP_DBL)sampleRate, &s); 148 expC = fMultDiv2(FL2FXCONST_DBL(-1.44269504089 * 0.5), expC) >> 149 (LD_DATA_SHIFT - 1 - 1); 150 151 if (s < 0) 152 expC = expC >> (-s); 153 else 154 expC = expC << (s); 155 156 expC = CalcInvLdData(expC); 157 158 hDCFilter->c__FDK = expC; 159 hDCFilter->state__FDK = FL2FXCONST_DBL(0.0f); 160 161 return error; 162 } 163 164 FDK_SACENC_ERROR fdk_sacenc_destroyDCFilter(HANDLE_DC_FILTER *hDCFilter) { 165 FDK_SACENC_ERROR error = SACENC_OK; 166 167 if ((hDCFilter != NULL) && (*hDCFilter != NULL)) { 168 FDKfree(*hDCFilter); 169 170 *hDCFilter = NULL; 171 } 172 173 return error; 174 } 175 176 FDK_SACENC_ERROR fdk_sacenc_applyDCFilter(HANDLE_DC_FILTER hDCFilter, 177 const INT_PCM *const signalIn, 178 INT_PCM *const signalOut, 179 const INT signalLength) { 180 FDK_SACENC_ERROR error = SACENC_OK; 181 182 if ((hDCFilter == NULL) || (signalIn == NULL) || (signalOut == NULL)) { 183 error = SACENC_INVALID_HANDLE; 184 } else { 185 const INT_PCM *const x = signalIn; 186 INT_PCM *const y = signalOut; 187 const FIXP_DBL c = hDCFilter->c__FDK; 188 FIXP_DBL *const state = &hDCFilter->state__FDK; 189 int i; 190 FIXP_DBL x0, x1, y1; 191 192 x1 = x0 = FX_PCM2FX_DBL(x[0]) >> DC_FILTER_SF; 193 y1 = x0 + (*state); 194 195 for (i = 1; i < signalLength; i++) { 196 x0 = FX_PCM2FX_DBL(x[i]) >> DC_FILTER_SF; 197 y[i - 1] = FX_DBL2FX_PCM(y1); 198 y1 = x0 - x1 + fMult(c, y1); 199 x1 = x0; 200 } 201 202 *state = fMult(c, y1) - x1; 203 y[i - 1] = FX_DBL2FX_PCM(y1); 204 } 205 206 return error; 207 } 208
