libAACdec/src/block.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
  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-4 AAC Decoder  **************************
  85
  86    Author(s):   Josef Hoepfl
  87    Description: long/short-block decoding
  88
  89 ******************************************************************************/
  90
  91 #ifndef BLOCK_H
  92 #define BLOCK_H
  93
  94 #include "common_fix.h"
  95
  96 #include "channelinfo.h"
  97 #include "FDK_bitstream.h"
  98
  99 /* PNS (of block) */
 100 void CPns_Read (CPnsData *pPnsData,
 101                 HANDLE_FDK_BITSTREAM bs,
 102                 const CodeBookDescription *hcb,
 103                 SHORT *pScaleFactor,
 104                 UCHAR global_gain,
 105                 int band,
 106                 int group);
 107
 108
 109 void CPns_Apply (const CPnsData *pPnsData,
 110                  const CIcsInfo *pIcsInfo,
 111                  SPECTRAL_PTR pSpectrum,
 112                  const SHORT    *pSpecScale,
 113                  const SHORT    *pScaleFactor,
 114                  const SamplingRateInfo *pSamplingRateInfo,
 115                  const INT granuleLength,
 116                  const int channel);
 117
 118
 119
 120 /* TNS (of block) */
 121 /*!
 122   \brief Read tns data-present flag from bitstream
 123
 124   The function reads the data-present flag for tns from
 125   the bitstream.
 126
 127   \return  none
 128 */
 129 void CTns_ReadDataPresentFlag(HANDLE_FDK_BITSTREAM bs,
 130                               CTnsData *pTnsData);
 131
 132 void CTns_ReadDataPresentUsac(
 133         HANDLE_FDK_BITSTREAM hBs,
 134         CTnsData *pTnsData0,
 135         CTnsData *pTnsData1,
 136         const CIcsInfo *pIcsInfo,
 137         const UINT flags,
 138         const int fCommonWindow
 139         );
 140
 141 AAC_DECODER_ERROR CTns_Read(HANDLE_FDK_BITSTREAM bs,
 142                             CTnsData *pTnsData,
 143                             const CIcsInfo *pIcsInfo,
 144                             const UINT flags);
 145
 146 void CTns_Apply ( CTnsData *RESTRICT pTnsData, /*!< pointer to aac decoder info */
 147                   const CIcsInfo *pIcsInfo,
 148                   SPECTRAL_PTR pSpectralCoefficient,
 149                   const SamplingRateInfo *pSamplingRateInfo,
 150                   const INT granuleLength);
 151
 152 /* Block */
 153
 154 LONG CBlock_GetEscape(HANDLE_FDK_BITSTREAM bs, const LONG q);
 155
 156 /**
 157  * \brief Read scale factor data. See chapter 4.6.2.3.2 of ISO/IEC 14496-3.
 158  *        The SF_OFFSET = 100 value referenced in chapter 4.6.2.3.3 is already substracted
 159  *        from the scale factor values. Also includes PNS data reading.
 160  * \param bs bit stream handle data source
 161  * \param pAacDecoderChannelInfo channel context info were decoded data is stored into.
 162  * \param flags the decoder flags.
 163  */
 164 AAC_DECODER_ERROR CBlock_ReadScaleFactorData(
 165         CAacDecoderChannelInfo *pAacDecoderChannelInfo,
 166         HANDLE_FDK_BITSTREAM bs,
 167         const UINT flags
 168         );
 169
 170 /**
 171  * \brief Read Huffman encoded spectral data.
 172  * \param pAacDecoderChannelInfo channel context info.
 173  * \param pSamplingRateInfo sampling rate info (sfb offsets).
 174  * \param flags syntax flags.
 175  */
 176 AAC_DECODER_ERROR  CBlock_ReadSpectralData(HANDLE_FDK_BITSTREAM bs,
 177                                            CAacDecoderChannelInfo *pAacDecoderChannelInfo,
 178                                            const SamplingRateInfo *pSamplingRateInfo,
 179                                            const UINT  flags);
 180
 181
 182 AAC_DECODER_ERROR CBlock_ReadSectionData(HANDLE_FDK_BITSTREAM bs,
 183                                          CAacDecoderChannelInfo *pAacDecoderChannelInfo,
 184                                          const SamplingRateInfo *pSamplingRateInfo,
 185                                          const UINT  flags);
 186
 187 /**
 188  * \brief find a common exponent (shift factor) for all sfb in each Spectral window, and store them into
 189  *        CAacDecoderChannelInfo::specScale.
 190  * \param pAacDecoderChannelInfo channel context info.
 191  * \param pSamplingRateInfo sampling rate info (sfb offsets).
 192  */
 193 void CBlock_ScaleSpectralData(CAacDecoderChannelInfo *pAacDecoderChannelInfo, SamplingRateInfo *pSamplingRateInfo);
 194
 195 /**
 196  * \brief Apply TNS and PNS tools.
 197  */
 198 void ApplyTools ( CAacDecoderChannelInfo *pAacDecoderChannelInfo[],
 199                   const SamplingRateInfo *pSamplingRateInfo,
 200                   const UINT flags,
 201                   const int channel );
 202
 203 /**
 204  * \brief Transform MDCT spectral data into time domain
 205  */
 206 void CBlock_FrequencyToTime(CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
 207                             CAacDecoderChannelInfo *pAacDecoderChannelInfo,
 208                             INT_PCM outSamples[],
 209                             const SHORT frameLen,
 210                             const int stride,
 211                             const int frameOk,
 212                             FIXP_DBL *pWorkBuffer1);
 213
 214 /**
 215  * \brief Transform double lapped MDCT (AAC-ELD) spectral data into time domain.
 216  */
 217 void CBlock_FrequencyToTimeLowDelay(CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
 218                                     CAacDecoderChannelInfo *pAacDecoderChannelInfo,
 219                                     INT_PCM outSamples[],
 220                                     const short frameLen,
 221                                     const char stride);
 222
 223 AAC_DECODER_ERROR CBlock_InverseQuantizeSpectralData(CAacDecoderChannelInfo *pAacDecoderChannelInfo, SamplingRateInfo *pSamplingRateInfo);
 224
 225 /**
 226  * \brief Calculate 2^(lsb/4) * value^(4/3)
 227  * \param pValue pointer to quantized value. The inverse quantized result is stored back here.
 228  * \param lsb 2 LSBs of the scale factor (scaleFactor % 4) applied as power 2 factor to the
 229  *        resulting inverse quantized value.
 230  * \return the exponent of the result (mantissa) stored into *pValue.
 231  */
 232 FDK_INLINE
 233 int EvaluatePower43 ( FIXP_DBL *pValue,
 234                       UINT lsb )
 235 {
 236   FIXP_DBL value;
 237   UINT freeBits;
 238   UINT exponent;
 239
 240   value = *pValue;
 241   freeBits = fNormz (value) ;
 242   exponent = DFRACT_BITS - freeBits ;
 243   FDK_ASSERT (exponent < 14);
 244
 245   UINT x = (((int)value << freeBits) >> 19) ;
 246   UINT tableIndex = (x & 0x0FFF) >> 4 ;
 247   FIXP_DBL invQVal ;
 248
 249   x = x & 0x0F;
 250
 251   UINT r0=(LONG)InverseQuantTable [tableIndex+0];
 252   UINT r1=(LONG)InverseQuantTable [tableIndex+1];
 253   USHORT nx=16-x;
 254   UINT temp=(r0)*nx+(r1)*x;
 255   invQVal = (FIXP_DBL)temp;
 256
 257   FDK_ASSERT(lsb < 4);
 258   *pValue = fMultDiv2 (invQVal, MantissaTable [lsb][exponent]) ;
 259
 260   /* + 1 compensates fMultDiv2(). */
 261   return ExponentTable [lsb][exponent] + 1;
 262 }
 263
 264 /**
 265  * \brief determine the required shift scale for the given quantized value and scale (factor % 4) value.
 266  */
 267 FDK_INLINE int GetScaleFromValue (FIXP_DBL value, unsigned int lsb)
 268 {
 269   if (value!=(FIXP_DBL)0)
 270   {
 271     int scale = EvaluatePower43 (&value, lsb) ;
 272     return CntLeadingZeros (value) - scale - 2 ;
 273   }
 274   else
 275     return 0; /* Return zero, because its useless to scale a zero value, saves workload and avoids scaling overshifts. */
 276 }
 277
 278
 279 //#ifdef AACDEC_HUFFMANDECODER_ENABLE
 280
 281 /*!
 282   \brief Read huffman codeword
 283
 284   The function reads the huffman codeword from the bitstream and
 285   returns the index value.
 286
 287   \return  index value
 288 */
 289 inline int CBlock_DecodeHuffmanWord( HANDLE_FDK_BITSTREAM bs,                           /*!< pointer to bitstream */
 290                                      const CodeBookDescription *hcb )                   /*!< pointer to codebook description */
 291 {
 292   UINT val;
 293   UINT index = 0;
 294   const USHORT (*CodeBook) [HuffmanEntries] = hcb->CodeBook;
 295
 296   while (1)
 297   {
 298     val = CodeBook[index][FDKreadBits(bs,HuffmanBits)]; /* Expensive memory access */
 299
 300     if ((val & 1) == 0)
 301     {
 302       index = val>>2;
 303       continue;
 304     }
 305     else
 306     {
 307       if (val & 2)
 308       {
 309         FDKpushBackCache(bs,1);
 310       }
 311
 312       val >>= 2;
 313       break;
 314     }
 315   }
 316
 317   return val;
 318 }
 319
 320 //#endif /* AACDEC_HUFFMANDECODER_ENABLE */
 321
 322 #endif /* #ifndef BLOCK_H */