libMpegTPDec/src/tpdec_adts.h

   1
   2 /* -----------------------------------------------------------------------------------------------------------
   3 Software License for The Fraunhofer FDK AAC Codec Library for Android
   4
   5 © Copyright  1995 - 2013 Fraunhofer-Gesellschaft zur Förderung 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
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  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:
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  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.
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  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.
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  42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
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  46 software or your modifications thereto.
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  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."
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  53 3.    NO PATENT LICENSE
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  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
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  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-4 AAC Decoder  **************************
  85
  86    Author(s):   Josef Hoepfl
  87    Description: ADTS interface
  88
  89 ******************************************************************************/
  90
  91 #ifndef TPDEC_ADTS_H
  92 #define TPDEC_ADTS_H
  93
  94 #include "tpdec_lib.h"
  95
  96
  97 #define ADTS_SYNCWORD               ( 0xfff )
  98 #define ADTS_SYNCLENGTH             ( 12 )     /* in bits */
  99 #define ADTS_HEADERLENGTH           ( 56 )     /* minimum header size in bits */
 100 #define ADTS_FIXED_HEADERLENGTH     ( 28 )     /* in bits */
 101 #define ADTS_VARIABLE_HEADERLENGTH  ( ADTS_HEADERLENGTH - ADTS_FIXED_HEADERLENGTH )
 102
 103 #ifdef CHECK_TWO_SYNCS
 104  #define ADTS_MIN_TP_BUF_SIZE       ( 8191 + 2 )
 105 #else
 106  #define ADTS_MIN_TP_BUF_SIZE       ( 8191 )
 107 #endif
 108
 109 #include "FDK_crc.h"
 110
 111 typedef struct {
 112   /* ADTS header fields */
 113   UCHAR mpeg_id;
 114   UCHAR layer;
 115   UCHAR protection_absent;
 116   UCHAR profile;
 117   UCHAR sample_freq_index;
 118   UCHAR private_bit;
 119   UCHAR channel_config;
 120   UCHAR original;
 121   UCHAR home;
 122   UCHAR copyright_id;
 123   UCHAR copyright_start;
 124   USHORT frame_length;
 125   USHORT adts_fullness;
 126   UCHAR num_raw_blocks;
 127   UCHAR num_pce_bits;
 128 } STRUCT_ADTS_BS;
 129
 130 struct STRUCT_ADTS {
 131
 132   STRUCT_ADTS_BS bs;
 133
 134   UCHAR decoderCanDoMpeg4;
 135   UCHAR BufferFullnesStartFlag;
 136
 137   FDK_CRCINFO crcInfo;             /* CRC state info */
 138   USHORT      crcReadValue;        /* CRC value read from bitstream data */
 139   USHORT      rawDataBlockDist[4]; /* distance between each raw data block. Not the same as found in the bitstream */
 140 } ;
 141
 142 typedef struct STRUCT_ADTS *HANDLE_ADTS;
 143
 144 /*!
 145   \brief Initialize ADTS CRC
 146
 147   The function initialzes the crc buffer and the crc lookup table.
 148
 149   \return  none
 150 */
 151 void adtsRead_CrcInit( HANDLE_ADTS pAdts );
 152
 153 /**
 154  * \brief Starts CRC region with a maximum number of bits
 155  *        If mBits is positive zero padding will be used for CRC calculation, if there
 156  *        are less than mBits bits available.
 157  *        If mBits is negative no zero padding is done.
 158  *        If mBits is zero the memory for the buffer is allocated dynamically, the
 159  *        number of bits is not limited.
 160  *
 161  * \param pAdts ADTS data handle
 162  * \param hBs bitstream handle, on which the CRC region referes to
 163  * \param mBits max number of bits in crc region to be considered
 164  *
 165  * \return  ID for the created region, -1 in case of an error
 166  */
 167 int adtsRead_CrcStartReg(
 168         HANDLE_ADTS pAdts,
 169         HANDLE_FDK_BITSTREAM hBs,
 170         int mBits
 171         );
 172
 173 /**
 174  * \brief Ends CRC region identified by reg
 175  *
 176  * \param pAdts ADTS data handle
 177  * \param hBs bitstream handle, on which the CRC region referes to
 178  * \param reg CRC regions ID returned by adtsRead_CrcStartReg()
 179  *
 180  * \return  none
 181  */
 182 void adtsRead_CrcEndReg(
 183         HANDLE_ADTS pAdts,
 184         HANDLE_FDK_BITSTREAM hBs,
 185         int reg
 186         );
 187
 188 /**
 189  * \brief Check CRC
 190  *
 191  * Checks if the currently calculated CRC matches the CRC field read from the bitstream
 192  * Deletes all CRC regions.
 193  *
 194  * \param pAdts ADTS data handle
 195  *
 196  * \return Returns 0 if they are identical otherwise 1
 197  */
 198 TRANSPORTDEC_ERROR adtsRead_CrcCheck( HANDLE_ADTS pAdts );
 199
 200
 201 /**
 202  * \brief Check if we have a valid ADTS frame at the current bitbuffer position
 203  *
 204  * This function assumes enough bits in buffer for the current frame.
 205  * It reads out the header bits to prepare the bitbuffer for the decode loop.
 206  * In case the header bits show an invalid bitstream/frame, the whole frame is skipped.
 207  *
 208  * \param pAdts ADTS data handle which is filled with parsed ADTS header data
 209  * \param bs handle of bitstream from whom the ADTS header is read
 210  *
 211  * \return  error status
 212  */
 213 TRANSPORTDEC_ERROR adtsRead_DecodeHeader(
 214         HANDLE_ADTS           pAdts,
 215         CSAudioSpecificConfig *pAsc,
 216         HANDLE_FDK_BITSTREAM  bs,
 217         const INT             ignoreBufferFullness
 218         );
 219
 220 /**
 221  * \brief Get the raw data block length of the given block number.
 222  *
 223  * \param pAdts ADTS data handle
 224  * \param blockNum current raw data block index
 225  * \param pLength pointer to an INT where the length of the given raw data block is stored into
 226  *                the returned value might be -1, in which case the raw data block length is unknown.
 227  *
 228  * \return  error status
 229  */
 230 int adtsRead_GetRawDataBlockLength(
 231         HANDLE_ADTS pAdts,
 232         INT         blockNum
 233         );
 234
 235
 236 #endif /* TPDEC_ADTS_H */