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 /**************************** SBR decoder library ****************************** 96 97 Author(s): 98 99 Description: 100 101 *******************************************************************************/ 102 103 /*! 104 \file 105 \brief CRC check coutines 106 */ 107 108 #include "sbr_crc.h" 109 110 #include "FDK_bitstream.h" 111 #include "transcendent.h" 112 113 #define MAXCRCSTEP 16 114 #define MAXCRCSTEP_LD 4 115 116 /*! 117 \brief crc calculation 118 */ 119 static ULONG calcCRC(HANDLE_CRC hCrcBuf, ULONG bValue, int nBits) { 120 int i; 121 ULONG bMask = (1UL << (nBits - 1)); 122 123 for (i = 0; i < nBits; i++, bMask >>= 1) { 124 USHORT flag = (hCrcBuf->crcState & hCrcBuf->crcMask) ? 1 : 0; 125 USHORT flag1 = (bMask & bValue) ? 1 : 0; 126 127 flag ^= flag1; 128 hCrcBuf->crcState <<= 1; 129 if (flag) hCrcBuf->crcState ^= hCrcBuf->crcPoly; 130 } 131 132 return (hCrcBuf->crcState); 133 } 134 135 /*! 136 \brief crc 137 */ 138 static int getCrc(HANDLE_FDK_BITSTREAM hBs, ULONG NrBits) { 139 int i; 140 CRC_BUFFER CrcBuf; 141 142 CrcBuf.crcState = SBR_CRC_START; 143 CrcBuf.crcPoly = SBR_CRC_POLY; 144 CrcBuf.crcMask = SBR_CRC_MASK; 145 146 int CrcStep = NrBits >> MAXCRCSTEP_LD; 147 148 int CrcNrBitsRest = (NrBits - CrcStep * MAXCRCSTEP); 149 ULONG bValue; 150 151 for (i = 0; i < CrcStep; i++) { 152 bValue = FDKreadBits(hBs, MAXCRCSTEP); 153 calcCRC(&CrcBuf, bValue, MAXCRCSTEP); 154 } 155 156 bValue = FDKreadBits(hBs, CrcNrBitsRest); 157 calcCRC(&CrcBuf, bValue, CrcNrBitsRest); 158 159 return (CrcBuf.crcState & SBR_CRC_RANGE); 160 } 161 162 /*! 163 \brief crc interface 164 \return 1: CRC OK, 0: CRC check failure 165 */ 166 int SbrCrcCheck(HANDLE_FDK_BITSTREAM hBs, /*!< handle to bit-buffer */ 167 LONG NrBits) /*!< max. CRC length */ 168 { 169 int crcResult = 1; 170 ULONG NrCrcBits; 171 ULONG crcCheckResult; 172 LONG NrBitsAvailable; 173 ULONG crcCheckSum; 174 175 crcCheckSum = FDKreadBits(hBs, 10); 176 177 NrBitsAvailable = FDKgetValidBits(hBs); 178 if (NrBitsAvailable <= 0) { 179 return 0; 180 } 181 182 NrCrcBits = fixMin((INT)NrBits, (INT)NrBitsAvailable); 183 184 crcCheckResult = getCrc(hBs, NrCrcBits); 185 FDKpushBack(hBs, (NrBitsAvailable - FDKgetValidBits(hBs))); 186 187 if (crcCheckResult != crcCheckSum) { 188 crcResult = 0; 189 } 190 191 return (crcResult); 192 } 193
