1 2 /* ----------------------------------------------------------------------------------------------------------- 3 Software License for The Fraunhofer FDK AAC Codec Library for Android 4 5 Copyright 1995 - 2012 Fraunhofer-Gesellschaft zur Frderung der angewandten Forschung e.V. 6 All rights reserved. 7 8 1. INTRODUCTION 9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements 10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. 11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices. 12 13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual 14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by 15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part 16 of the MPEG specifications. 17 18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) 19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners 20 individually for the purpose of encoding or decoding bit streams in products that are compliant with 21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license 22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec 23 software may already be covered under those patent licenses when it is used for those licensed purposes only. 24 25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, 26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional 27 applications information and documentation. 28 29 2. COPYRIGHT LICENSE 30 31 Redistribution and use in source and binary forms, with or without modification, are permitted without 32 payment of copyright license fees provided that you satisfy the following conditions: 33 34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or 35 your modifications thereto in source code form. 36 37 You must retain the complete text of this software license in the documentation and/or other materials 38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. 39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your 40 modifications thereto to recipients of copies in binary form. 41 42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without 43 prior written permission. 44 45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec 46 software or your modifications thereto. 47 48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software 49 and the date of any change. For modified versions of the FDK AAC Codec, the term 50 "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term 51 "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." 52 53 3. NO PATENT LICENSE 54 55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, 56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with 57 respect to this software. 58 59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized 60 by appropriate patent licenses. 61 62 4. DISCLAIMER 63 64 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors 65 "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties 66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, 68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits, 69 or business interruption, however caused and on any theory of liability, whether in contract, strict 70 liability, or tort (including negligence), arising in any way out of the use of this software, even if 71 advised of the possibility of such damage. 72 73 5. CONTACT INFORMATION 74 75 Fraunhofer Institute for Integrated Circuits IIS 76 Attention: Audio and Multimedia Departments - FDK AAC LL 77 Am Wolfsmantel 33 78 91058 Erlangen, Germany 79 80 www.iis.fraunhofer.de/amm 81 amm-info (at) iis.fraunhofer.de 82 ----------------------------------------------------------------------------------------------------------- */ 83 84 /******************************** MPEG Audio Encoder ************************** 85 86 Initial author: M.Werner 87 contents/description: Pre echo control 88 89 ******************************************************************************/ 90 91 #include "pre_echo_control.h" 92 #include "psy_configuration.h" 93 94 void FDKaacEnc_InitPreEchoControl(FIXP_DBL *RESTRICT pbThresholdNm1, 95 INT *calcPreEcho, 96 INT numPb, 97 FIXP_DBL *RESTRICT sfbPcmQuantThreshold, 98 INT *mdctScalenm1) 99 { 100 *mdctScalenm1 = PCM_QUANT_THR_SCALE>>1; 101 102 FDKmemcpy(pbThresholdNm1, sfbPcmQuantThreshold, numPb*sizeof(FIXP_DBL)); 103 104 *calcPreEcho = 1; 105 } 106 107 108 void FDKaacEnc_PreEchoControl(FIXP_DBL *RESTRICT pbThresholdNm1, 109 INT calcPreEcho, 110 INT numPb, 111 INT maxAllowedIncreaseFactor, 112 FIXP_SGL minRemainingThresholdFactor, 113 FIXP_DBL *RESTRICT pbThreshold, 114 INT mdctScale, 115 INT *mdctScalenm1) 116 { 117 int i; 118 FIXP_DBL tmpThreshold1, tmpThreshold2; 119 int scaling; 120 121 /* If lastWindowSequence in previous frame was start- or stop-window, 122 skip preechocontrol calculation */ 123 if (calcPreEcho==0) { 124 /* copy thresholds to internal memory */ 125 FDKmemcpy(pbThresholdNm1, pbThreshold, numPb*sizeof(FIXP_DBL)); 126 *mdctScalenm1 = mdctScale; 127 return; 128 } 129 130 if ( mdctScale > *mdctScalenm1 ) { 131 /* if current thresholds are downscaled more than the ones from the last block */ 132 scaling = 2*(mdctScale-*mdctScalenm1); 133 for(i = 0; i < numPb; i++) { 134 135 /* multiplication with return data type fract ist equivalent to int multiplication */ 136 FDK_ASSERT(scaling>=0); 137 tmpThreshold1 = maxAllowedIncreaseFactor * (pbThresholdNm1[i]>>scaling); 138 tmpThreshold2 = fMult(minRemainingThresholdFactor, pbThreshold[i]); 139 140 FIXP_DBL tmp = pbThreshold[i]; 141 142 /* copy thresholds to internal memory */ 143 pbThresholdNm1[i] = tmp; 144 145 tmp = fixMin(tmp, tmpThreshold1); 146 pbThreshold[i] = fixMax(tmp, tmpThreshold2); 147 } 148 } 149 else { 150 /* if thresholds of last block are more downscaled than the current ones */ 151 scaling = 2*(*mdctScalenm1-mdctScale); 152 for(i = 0; i < numPb; i++) { 153 154 /* multiplication with return data type fract ist equivalent to int multiplication */ 155 tmpThreshold1 = (maxAllowedIncreaseFactor>>1) * pbThresholdNm1[i]; 156 tmpThreshold2 = fMult(minRemainingThresholdFactor, pbThreshold[i]); 157 158 /* copy thresholds to internal memory */ 159 pbThresholdNm1[i] = pbThreshold[i]; 160 161 FDK_ASSERT(scaling>=0); 162 if((pbThreshold[i]>>(scaling+1)) > tmpThreshold1) { 163 pbThreshold[i] = tmpThreshold1<<(scaling+1); 164 } 165 pbThreshold[i] = fixMax(pbThreshold[i], tmpThreshold2); 166 } 167 } 168 169 *mdctScalenm1 = mdctScale; 170 } 171
