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author | The Android Open Source Project <initial-contribution@android.com> | 2012-07-11 10:15:24 -0700 |
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committer | The Android Open Source Project <initial-contribution@android.com> | 2012-07-11 10:15:24 -0700 |
commit | 2228e360595641dd906bf1773307f43d304f5b2e (patch) | |
tree | 57f3d390ebb0782cc0de0fb984c8ea7e45b4f386 /libFDK/include/FDK_crc.h | |
download | fdk-aac-2228e360595641dd906bf1773307f43d304f5b2e.tar.gz fdk-aac-2228e360595641dd906bf1773307f43d304f5b2e.tar.bz2 fdk-aac-2228e360595641dd906bf1773307f43d304f5b2e.zip |
Snapshot 2bda038c163298531d47394bc2c09e1409c5d0db
Change-Id: If584e579464f28b97d50e51fc76ba654a5536c54
Diffstat (limited to 'libFDK/include/FDK_crc.h')
-rw-r--r-- | libFDK/include/FDK_crc.h | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/libFDK/include/FDK_crc.h b/libFDK/include/FDK_crc.h new file mode 100644 index 0000000..b5b8d6b --- /dev/null +++ b/libFDK/include/FDK_crc.h @@ -0,0 +1,231 @@ + +/* ----------------------------------------------------------------------------------------------------------- +Software License for The Fraunhofer FDK AAC Codec Library for Android + +© Copyright 1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. + All rights reserved. + + 1. INTRODUCTION +The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements +the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. +This FDK AAC Codec software is intended to be used on a wide variety of Android devices. + +AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual +audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by +independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part +of the MPEG specifications. + +Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) +may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners +individually for the purpose of encoding or decoding bit streams in products that are compliant with +the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license +these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec +software may already be covered under those patent licenses when it is used for those licensed purposes only. + +Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, +are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional +applications information and documentation. + +2. COPYRIGHT LICENSE + +Redistribution and use in source and binary forms, with or without modification, are permitted without +payment of copyright license fees provided that you satisfy the following conditions: + +You must retain the complete text of this software license in redistributions of the FDK AAC Codec or +your modifications thereto in source code form. + +You must retain the complete text of this software license in the documentation and/or other materials +provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. +You must make available free of charge copies of the complete source code of the FDK AAC Codec and your +modifications thereto to recipients of copies in binary form. + +The name of Fraunhofer may not be used to endorse or promote products derived from this library without +prior written permission. + +You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec +software or your modifications thereto. + +Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software +and the date of any change. For modified versions of the FDK AAC Codec, the term +"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term +"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." + +3. NO PATENT LICENSE + +NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, +ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with +respect to this software. + +You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized +by appropriate patent licenses. + +4. DISCLAIMER + +This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors +"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties +of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR +CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, +including but not limited to procurement of substitute goods or services; loss of use, data, or profits, +or business interruption, however caused and on any theory of liability, whether in contract, strict +liability, or tort (including negligence), arising in any way out of the use of this software, even if +advised of the possibility of such damage. + +5. CONTACT INFORMATION + +Fraunhofer Institute for Integrated Circuits IIS +Attention: Audio and Multimedia Departments - FDK AAC LL +Am Wolfsmantel 33 +91058 Erlangen, Germany + +www.iis.fraunhofer.de/amm +amm-info@iis.fraunhofer.de +----------------------------------------------------------------------------------------------------------- */ + +/******************************** MPEG Audio Encoder ************************** + + Initial author: + contents/description: CRC calculation + +******************************************************************************/ + +#ifndef FDK_CRC_H +#define FDK_CRC_H + + + +#include "FDK_bitstream.h" + + +#define MAX_CRC_REGS 3 /*!< Maximal number of overlapping crc region in ADTS channel pair element is two. + Select three independent regions preventively. */ + +/** + * This structure describes single crc region used for crc calculation. + */ +typedef struct +{ + UCHAR isActive; + INT maxBits; + UINT bitBufCntBits; + UINT validBits; + +} CCrcRegData; + +/** + * CRC info structure. + */ +typedef struct +{ + CCrcRegData crcRegData[MAX_CRC_REGS]; /*!< Multiple crc region description. */ + const USHORT *pCrcLookup; /*!< Pointer to lookup table filled in FDK_crcInit(). */ + + USHORT crcPoly; /*!< CRC generator polynom. */ + USHORT crcMask; /*!< CRC mask. */ + USHORT startValue; /*!< CRC start value. */ + UCHAR crcLen; /*!< CRC length. */ + + UINT regStart; /*!< Start region marker for synchronization. */ + UINT regStop; /*!< Stop region marker for synchronization. */ + + USHORT crcValue; /*!< Crc value to be calculated. */ + +} FDK_CRCINFO; + +/** + * CRC info handle. + */ +typedef FDK_CRCINFO* HANDLE_FDK_CRCINFO; + + +/** + * \brief Initialize CRC structure. + * + * The function initializes existing crc info structure with denoted configuration. + * + * \param hCrcInfo Pointer to an outlying allocated crc info structure. + * \param crcPoly Configure crc polynom. + * \param crcStartValue Configure crc start value. + * \param crcLen Configure crc length. + * + * \return none + */ +void FDKcrcInit( + HANDLE_FDK_CRCINFO hCrcInfo, + const UINT crcPoly, + const UINT crcStartValue, + const UINT crcLen + ); + +/** + * \brief Reset CRC info structure. + * + * This function clears all intern states of the crc structure. + * + * \param hCrcInfo Pointer to crc info stucture. + * + * \return none + */ +void FDKcrcReset( + HANDLE_FDK_CRCINFO hCrcInfo + ); + + +/** + * \brief Start CRC region with maximum number of bits. + * + * This function marks position in bitstream to be used as start point for crc calculation. + * Bitstream range for crc calculation can be limited or kept dynamic depending on mBits parameter. + * The crc region has to be terminated with FDKcrcEndReg() in each case. + * + * \param hCrcInfo Pointer to crc info stucture. + * \param hBs Pointer to current bit buffer structure. + * \param mBits Number of bits in crc region to be calculated. + * - mBits > 0: Zero padding will be used for CRC calculation, if there + * are less than mBits bits available. + * - mBits < 0: No zero padding is done. + * - mBits = 0: The number of bits used in crc calculation is dynamically, + * depending on bitstream position between FDKcrcStartReg() and + * FDKcrcEndReg() call. + * + * \return ID for the created region, -1 in case of an error + */ +INT FDKcrcStartReg( + HANDLE_FDK_CRCINFO hCrcInfo, + const HANDLE_FDK_BITSTREAM hBs, + const INT mBits + ); + + +/** + * \brief Ends CRC region. + * + * This function terminates crc region specified with FDKcrcStartReg(). The number of bits in crc region depends + * on mBits parameter of FDKcrcStartReg(). + * This function calculates and updates crc in info structure. + * + * \param hCrcInfo Pointer to crc info stucture. + * \param hBs Pointer to current bit buffer structure. + * \param reg Crc region ID created in FDKcrcStartReg(). + * + * \return 0 on success + */ +INT FDKcrcEndReg( + HANDLE_FDK_CRCINFO hCrcInfo, + const HANDLE_FDK_BITSTREAM hBs, + const INT reg + ); + + +/** + * \brief This function returns crc value from info struct. + * + * \param hCrcInfo Pointer to crc info stucture. + * + * \return CRC value masked with crc length. + */ +USHORT FDKcrcGetCRC( + const HANDLE_FDK_CRCINFO hCrcInfo + ); + + +#endif /* FDK_CRC_H */ |