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: Chaos measure calculation 88 89 ******************************************************************************/ 90 91 #include "chaosmeasure.h" 92 93 /***************************************************************************** 94 functionname: FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast 95 description: Eberlein method of chaos measure calculation by high-pass 96 filtering amplitude spectrum 97 A special case of FDKaacEnc_CalculateChaosMeasureTonalGeneric -- 98 highly optimized 99 *****************************************************************************/ 100 static void 101 FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast( FIXP_DBL *RESTRICT paMDCTDataNM0, 102 INT numberOfLines, 103 FIXP_DBL *RESTRICT chaosMeasure ) 104 { 105 INT i, j; 106 107 /* calculate chaos measure by "peak filter" */ 108 for (i=0; i<2; i++) { 109 /* make even and odd pass through data */ 110 FIXP_DBL left,center; /* left, center tap of filter */ 111 112 left = (FIXP_DBL)((LONG)paMDCTDataNM0[i]^((LONG)paMDCTDataNM0[i]>>(DFRACT_BITS-1))); 113 center = (FIXP_DBL)((LONG)paMDCTDataNM0[i+2]^((LONG)paMDCTDataNM0[i+2]>>(DFRACT_BITS-1))); 114 115 for (j = i+2; j < numberOfLines - 2; j+=2) { 116 FIXP_DBL right = (FIXP_DBL)((LONG)paMDCTDataNM0[j+2]^((LONG)paMDCTDataNM0[j+2]>>(DFRACT_BITS-1))); 117 FIXP_DBL tmp = (left>>1)+(right>>1); 118 119 if (tmp < center ) { 120 INT leadingBits = CntLeadingZeros(center)-1; 121 tmp = schur_div(tmp<<leadingBits, center<<leadingBits, 8); 122 chaosMeasure[j] = fMult(tmp,tmp); 123 } 124 else { 125 chaosMeasure[j] = (FIXP_DBL)MAXVAL_DBL; 126 } 127 128 left = center; 129 center = right; 130 } 131 } 132 133 /* provide chaos measure for first few lines */ 134 chaosMeasure[0] = chaosMeasure[2]; 135 chaosMeasure[1] = chaosMeasure[2]; 136 137 /* provide chaos measure for last few lines */ 138 for (i = (numberOfLines-3); i < numberOfLines; i++) 139 chaosMeasure[i] = FL2FXCONST_DBL(0.5); 140 } 141 142 143 /***************************************************************************** 144 functionname: FDKaacEnc_CalculateChaosMeasure 145 description: calculates a chaosmeasure for every line, different methods 146 are available. 0 means tonal, 1 means noiselike 147 returns: 148 input: MDCT data, number of lines 149 output: chaosMeasure 150 *****************************************************************************/ 151 void 152 FDKaacEnc_CalculateChaosMeasure( FIXP_DBL *paMDCTDataNM0, 153 INT numberOfLines, 154 FIXP_DBL *chaosMeasure ) 155 156 { 157 FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast( paMDCTDataNM0, 158 numberOfLines, 159 chaosMeasure ); 160 } 161 162
