1
2/* -----------------------------------------------------------------------------------------------------------
3Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5© Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
6  All rights reserved.
7
8 1.    INTRODUCTION
9The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12
13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16of the MPEG specifications.
17
18Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20individually for the purpose of encoding or decoding bit streams in products that are compliant with
21the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23software may already be covered under those patent licenses when it is used for those licensed purposes only.
24
25Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27applications information and documentation.
28
292.    COPYRIGHT LICENSE
30
31Redistribution and use in source and binary forms, with or without modification, are permitted without
32payment of copyright license fees provided that you satisfy the following conditions:
33
34You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35your modifications thereto in source code form.
36
37You must retain the complete text of this software license in the documentation and/or other materials
38provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40modifications thereto to recipients of copies in binary form.
41
42The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43prior written permission.
44
45You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46software or your modifications thereto.
47
48Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49and 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
533.    NO PATENT LICENSE
54
55NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57respect to this software.
58
59You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60by appropriate patent licenses.
61
624.    DISCLAIMER
63
64This 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
66of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69or business interruption, however caused and on any theory of liability, whether in contract, strict
70liability, or tort (including negligence), arising in any way out of the use of this software, even if
71advised of the possibility of such damage.
72
735.    CONTACT INFORMATION
74
75Fraunhofer Institute for Integrated Circuits IIS
76Attention: Audio and Multimedia Departments - FDK AAC LL
77Am Wolfsmantel 33
7891058 Erlangen, Germany
79
80www.iis.fraunhofer.de/amm
81amm-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 */
105typedef struct
106{
107  UCHAR isActive;
108  INT   maxBits;
109  UINT  bitBufCntBits;
110  UINT  validBits;
111
112} CCrcRegData;
113
114/**
115 *  CRC info structure.
116 */
117typedef 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 */
137typedef 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 */
152void 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 */
168void 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 */
192INT 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 */
212INT 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 */
226USHORT FDKcrcGetCRC(
227        const HANDLE_FDK_CRCINFO        hCrcInfo
228        );
229
230
231#endif /* FDK_CRC_H */
232