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1 
2 /* -----------------------------------------------------------------------------------------------------------
3 Software License for The Fraunhofer FDK AAC Codec Library for Android
4 
5 � Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur F�rderung 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@iis.fraunhofer.de
82 ----------------------------------------------------------------------------------------------------------- */
83 
84 /******************************** MPEG Audio Encoder **************************
85 
86    Initial author:
87    contents/description: CRC calculation
88 
89 ******************************************************************************/
90 
91 #ifndef FDK_CRC_H
92 #define FDK_CRC_H
93 
94 
95 
96 #include "FDK_bitstream.h"
97 
98 
99 #define MAX_CRC_REGS 3    /*!< Maximal number of overlapping crc region in ADTS channel pair element is two.
100                                Select three independent regions preventively. */
101 
102 /**
103  *  This structure describes single crc region used for crc calculation.
104  */
105 typedef struct
106 {
107   UCHAR isActive;
108   INT   maxBits;
109   UINT  bitBufCntBits;
110   UINT  validBits;
111 
112 } CCrcRegData;
113 
114 /**
115  *  CRC info structure.
116  */
117 typedef struct
118 {
119     CCrcRegData  crcRegData[MAX_CRC_REGS];   /*!< Multiple crc region description. */
120     const USHORT       *pCrcLookup;          /*!< Pointer to lookup table filled in FDK_crcInit(). */
121 
122     USHORT              crcPoly;             /*!< CRC generator polynom. */
123     USHORT              crcMask;             /*!< CRC mask. */
124     USHORT              startValue;          /*!< CRC start value. */
125     UCHAR               crcLen;              /*!< CRC length. */
126 
127     UINT                regStart;            /*!< Start region marker for synchronization. */
128     UINT                regStop;             /*!< Stop region marker for synchronization. */
129 
130     USHORT              crcValue;            /*!< Crc value to be calculated. */
131 
132 } FDK_CRCINFO;
133 
134 /**
135  *  CRC info handle.
136  */
137 typedef FDK_CRCINFO* HANDLE_FDK_CRCINFO;
138 
139 
140 /**
141  * \brief  Initialize CRC structure.
142  *
143  * The function initializes existing crc info structure with denoted configuration.
144  *
145  * \param hCrcInfo              Pointer to an outlying allocated crc info structure.
146  * \param crcPoly               Configure crc polynom.
147  * \param crcStartValue         Configure crc start value.
148  * \param crcLen                Configure crc length.
149  *
150  * \return  none
151  */
152 void FDKcrcInit(
153         HANDLE_FDK_CRCINFO              hCrcInfo,
154         const UINT                      crcPoly,
155         const UINT                      crcStartValue,
156         const UINT                      crcLen
157         );
158 
159 /**
160  * \brief  Reset CRC info structure.
161  *
162  * This function clears all intern states of the crc structure.
163  *
164  * \param hCrcInfo              Pointer to crc info stucture.
165  *
166  * \return  none
167  */
168 void FDKcrcReset(
169         HANDLE_FDK_CRCINFO              hCrcInfo
170         );
171 
172 
173 /**
174  * \brief  Start CRC region with maximum number of bits.
175  *
176  * This function marks position in bitstream to be used as start point for crc calculation.
177  * Bitstream range for crc calculation can be limited or kept dynamic depending on mBits parameter.
178  * The crc region has to be terminated with FDKcrcEndReg() in each case.
179  *
180  * \param hCrcInfo              Pointer to crc info stucture.
181  * \param hBs                   Pointer to current bit buffer structure.
182  * \param mBits                 Number of bits in crc region to be calculated.
183  *                              - mBits > 0: Zero padding will be used for CRC calculation, if there
184  *                                           are less than mBits bits available.
185  *                              - mBits < 0: No zero padding is done.
186  *                              - mBits = 0: The number of bits used in crc calculation is dynamically,
187  *                                           depending on bitstream position between FDKcrcStartReg() and
188  *                                           FDKcrcEndReg() call.
189  *
190  * \return  ID for the created region, -1 in case of an error
191  */
192 INT FDKcrcStartReg(
193         HANDLE_FDK_CRCINFO              hCrcInfo,
194         const HANDLE_FDK_BITSTREAM      hBs,
195         const INT                       mBits
196         );
197 
198 
199 /**
200  * \brief  Ends CRC region.
201  *
202  * This function terminates crc region specified with FDKcrcStartReg(). The number of bits in crc region depends
203  * on mBits parameter of FDKcrcStartReg().
204  * This function calculates and updates crc in info structure.
205  *
206  * \param hCrcInfo              Pointer to crc info stucture.
207  * \param hBs                   Pointer to current bit buffer structure.
208  * \param reg                   Crc region ID created in FDKcrcStartReg().
209  *
210  * \return  0 on success
211  */
212 INT FDKcrcEndReg(
213         HANDLE_FDK_CRCINFO              hCrcInfo,
214         const HANDLE_FDK_BITSTREAM      hBs,
215         const INT                       reg
216         );
217 
218 
219 /**
220  * \brief  This function returns crc value from info struct.
221  *
222  * \param hCrcInfo              Pointer to crc info stucture.
223  *
224  * \return  CRC value masked with crc length.
225  */
226 USHORT FDKcrcGetCRC(
227         const HANDLE_FDK_CRCINFO        hCrcInfo
228         );
229 
230 
231 #endif /* FDK_CRC_H */
232