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 /**************************** AAC encoder library ****************************** 96 97 Author(s): M.Werner 98 99 Description: Pre echo control 100 101 *******************************************************************************/ 102 103 #include "pre_echo_control.h" 104 #include "psy_configuration.h" 105 106 void FDKaacEnc_InitPreEchoControl(FIXP_DBL *RESTRICT pbThresholdNm1, 107 INT *calcPreEcho, INT numPb, 108 FIXP_DBL *RESTRICT sfbPcmQuantThreshold, 109 INT *mdctScalenm1) { 110 *mdctScalenm1 = PCM_QUANT_THR_SCALE >> 1; 111 112 FDKmemcpy(pbThresholdNm1, sfbPcmQuantThreshold, numPb * sizeof(FIXP_DBL)); 113 114 *calcPreEcho = 1; 115 } 116 117 void FDKaacEnc_PreEchoControl(FIXP_DBL *RESTRICT pbThresholdNm1, 118 INT calcPreEcho, INT numPb, 119 INT maxAllowedIncreaseFactor, 120 FIXP_SGL minRemainingThresholdFactor, 121 FIXP_DBL *RESTRICT pbThreshold, INT mdctScale, 122 INT *mdctScalenm1) { 123 int i; 124 FIXP_DBL tmpThreshold1, tmpThreshold2; 125 int scaling; 126 127 /* If lastWindowSequence in previous frame was start- or stop-window, 128 skip preechocontrol calculation */ 129 if (calcPreEcho == 0) { 130 /* copy thresholds to internal memory */ 131 FDKmemcpy(pbThresholdNm1, pbThreshold, numPb * sizeof(FIXP_DBL)); 132 *mdctScalenm1 = mdctScale; 133 return; 134 } 135 136 if (mdctScale > *mdctScalenm1) { 137 /* if current thresholds are downscaled more than the ones from the last 138 * block */ 139 scaling = 2 * (mdctScale - *mdctScalenm1); 140 for (i = 0; i < numPb; i++) { 141 /* multiplication with return data type fract ist equivalent to int 142 * multiplication */ 143 FDK_ASSERT(scaling >= 0); 144 tmpThreshold1 = maxAllowedIncreaseFactor * (pbThresholdNm1[i] >> scaling); 145 tmpThreshold2 = fMult(minRemainingThresholdFactor, pbThreshold[i]); 146 147 FIXP_DBL tmp = pbThreshold[i]; 148 149 /* copy thresholds to internal memory */ 150 pbThresholdNm1[i] = tmp; 151 152 tmp = fixMin(tmp, tmpThreshold1); 153 pbThreshold[i] = fixMax(tmp, tmpThreshold2); 154 } 155 } else { 156 /* if thresholds of last block are more downscaled than the current ones */ 157 scaling = 2 * (*mdctScalenm1 - mdctScale); 158 for (i = 0; i < numPb; i++) { 159 /* multiplication with return data type fract ist equivalent to int 160 * multiplication */ 161 tmpThreshold1 = (maxAllowedIncreaseFactor >> 1) * pbThresholdNm1[i]; 162 tmpThreshold2 = fMult(minRemainingThresholdFactor, pbThreshold[i]); 163 164 /* copy thresholds to internal memory */ 165 pbThresholdNm1[i] = pbThreshold[i]; 166 167 FDK_ASSERT(scaling >= 0); 168 if ((pbThreshold[i] >> (scaling + 1)) > tmpThreshold1) { 169 pbThreshold[i] = tmpThreshold1 << (scaling + 1); 170 } 171 pbThreshold[i] = fixMax(pbThreshold[i], tmpThreshold2); 172 } 173 } 174 175 *mdctScalenm1 = mdctScale; 176 } 177
