libSBRenc/src/env_bit.cpp

   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
  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.
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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.
  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
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  46 software or your modifications thereto.
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  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
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  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 /*!
  85   \file
  86   \brief  Remaining SBR Bit Writing Routines
  87 */
  88
  89 #include "env_bit.h"
  90 #include "cmondata.h"
  91
  92
  93 #ifndef min
  94 #define min(a,b) ( a < b ? a:b)
  95 #endif
  96
  97 #ifndef max
  98 #define max(a,b) ( a > b ? a:b)
  99 #endif
 100
 101 /* ***************************** crcAdvance **********************************/
 102 /**
 103  * @fn
 104  * @brief    updates crc data register
 105  * @return   none
 106  *
 107  * This function updates the crc register
 108  *
 109  */
 110 static void crcAdvance(USHORT crcPoly,
 111                        USHORT crcMask,
 112                        USHORT *crc,
 113                        ULONG   bValue,
 114                        INT     bBits
 115                       )
 116 {
 117   INT i;
 118   USHORT flag;
 119
 120   for (i=bBits-1; i>=0; i--) {
 121     flag = ((*crc) & crcMask) ? (1) : (0) ;
 122     flag ^= (bValue & (1<<i)) ? (1) : (0) ;
 123
 124     (*crc)<<=1;
 125     if(flag) (*crc) ^= crcPoly;
 126   }
 127 }
 128
 129
 130 /* ***************************** FDKsbrEnc_InitSbrBitstream **********************************/
 131 /**
 132  * @fn
 133  * @brief    Inittialisation of sbr bitstream, write of dummy header and CRC
 134  * @return   none
 135  *
 136  *
 137  *
 138  */
 139
 140 INT  FDKsbrEnc_InitSbrBitstream(HANDLE_COMMON_DATA  hCmonData,
 141                                 UCHAR              *memoryBase,      /*!< Pointer to bitstream buffer */
 142                                 INT                 memorySize,      /*!< Length of bitstream buffer in bytes */
 143                                 HANDLE_FDK_CRCINFO  hCrcInfo,
 144                                 UINT                sbrSyntaxFlags)  /*!< SBR syntax flags */
 145 {
 146   INT crcRegion = 0;
 147
 148   /* reset bit buffer */
 149   FDKresetBitbuffer(&hCmonData->sbrBitbuf, BS_WRITER);
 150
 151   FDKinitBitStream(&hCmonData->tmpWriteBitbuf, memoryBase,
 152                    memorySize, 0, BS_WRITER);
 153
 154   if (sbrSyntaxFlags & SBR_SYNTAX_CRC) {
 155     if (sbrSyntaxFlags & SBR_SYNTAX_DRM_CRC)
 156     { /* Init and start CRC region */
 157       FDKwriteBits (&hCmonData->sbrBitbuf, 0x0, SI_SBR_DRM_CRC_BITS);
 158       FDKcrcInit( hCrcInfo, 0x001d, 0xFFFF, SI_SBR_DRM_CRC_BITS );
 159       crcRegion = FDKcrcStartReg( hCrcInfo, &hCmonData->sbrBitbuf, 0 );
 160     } else {
 161       FDKwriteBits (&hCmonData->sbrBitbuf, 0x0, SI_SBR_CRC_BITS);
 162     }
 163   }
 164
 165   return (crcRegion);
 166 }
 167
 168
 169 /* ************************** FDKsbrEnc_AssembleSbrBitstream *******************************/
 170 /**
 171  * @fn
 172  * @brief    Formats the SBR payload
 173  * @return   nothing
 174  *
 175  * Also the CRC will be calculated here.
 176  *
 177  */
 178
 179 void
 180 FDKsbrEnc_AssembleSbrBitstream( HANDLE_COMMON_DATA  hCmonData,
 181                                 HANDLE_FDK_CRCINFO  hCrcInfo,
 182                                 INT                 crcRegion,
 183                                 UINT                sbrSyntaxFlags)
 184 {
 185   USHORT crcReg =  SBR_CRCINIT;
 186   INT numCrcBits,i;
 187
 188   /* check if SBR is present */
 189   if ( hCmonData==NULL )
 190     return;
 191
 192   hCmonData->sbrFillBits = 0; /* Fill bits are written only for GA streams */
 193
 194   if ( sbrSyntaxFlags & SBR_SYNTAX_DRM_CRC )
 195   {
 196     /*
 197      * Calculate and write DRM CRC
 198      */
 199     FDKcrcEndReg( hCrcInfo, &hCmonData->sbrBitbuf, crcRegion );
 200     FDKwriteBits( &hCmonData->tmpWriteBitbuf, FDKcrcGetCRC(hCrcInfo)^0xFF, SI_SBR_DRM_CRC_BITS );
 201   }
 202   else
 203   {
 204     if ( !(sbrSyntaxFlags & SBR_SYNTAX_LOW_DELAY) )
 205     {
 206       /* Do alignment here, because its defined as part of the sbr_extension_data */
 207       int sbrLoad = hCmonData->sbrHdrBits + hCmonData->sbrDataBits;
 208
 209       if ( sbrSyntaxFlags & SBR_SYNTAX_CRC ) {
 210         sbrLoad += SI_SBR_CRC_BITS;
 211       }
 212
 213       sbrLoad += 4;         /* Do byte Align with 4 bit offset. ISO/IEC 14496-3:2005(E) page 39. */
 214
 215       hCmonData->sbrFillBits = (8 - (sbrLoad % 8)) % 8;
 216
 217       /*
 218         append fill bits
 219       */
 220       FDKwriteBits(&hCmonData->sbrBitbuf, 0,  hCmonData->sbrFillBits );
 221
 222       FDK_ASSERT(FDKgetValidBits(&hCmonData->sbrBitbuf) % 8 == 4);
 223     }
 224
 225     /*
 226       calculate crc
 227     */
 228     if ( sbrSyntaxFlags & SBR_SYNTAX_CRC ) {
 229       FDK_BITSTREAM  tmpCRCBuf = hCmonData->sbrBitbuf;
 230       FDKresetBitbuffer( &tmpCRCBuf, BS_READER );
 231
 232       numCrcBits = hCmonData->sbrHdrBits + hCmonData->sbrDataBits + hCmonData->sbrFillBits;
 233
 234       for(i=0;i<numCrcBits;i++){
 235         INT bit;
 236         bit = FDKreadBits(&tmpCRCBuf,1);
 237         crcAdvance(SBR_CRC_POLY,SBR_CRC_MASK,&crcReg,bit,1);
 238       }
 239       crcReg &= (SBR_CRC_RANGE);
 240
 241       /*
 242        * Write CRC data.
 243        */
 244       FDKwriteBits (&hCmonData->tmpWriteBitbuf, crcReg, SI_SBR_CRC_BITS);
 245     }
 246   }
 247
 248   FDKsyncCache(&hCmonData->tmpWriteBitbuf);
 249 }
 250