1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3
4 © Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung 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@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 */
calcCRC(HANDLE_CRC hCrcBuf,ULONG bValue,int nBits)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 */
getCrc(HANDLE_FDK_BITSTREAM hBs,ULONG NrBits)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 */
SbrCrcCheck(HANDLE_FDK_BITSTREAM hBs,LONG NrBits)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