Home | History | Annotate | Download | only in src
      1 
      2 /* -----------------------------------------------------------------------------------------------------------
      3 Software License for The Fraunhofer FDK AAC Codec Library for Android
      4 
      5  Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur Frderung 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 (at) iis.fraunhofer.de
     82 ----------------------------------------------------------------------------------------------------------- */
     83 
     84 /*****************************  MPEG-4 AAC Decoder  **************************
     85 
     86    Author(s):   Josef Hoepfl
     87    Description: temporal noise shaping tool
     88 
     89 ******************************************************************************/
     90 
     91 #include "aacdec_tns.h"
     92 #include "aac_rom.h"
     93 #include "FDK_bitstream.h"
     94 #include "channelinfo.h"
     95 
     96 
     97 
     98 /*!
     99   \brief Reset tns data
    100 
    101   The function resets the tns data
    102 
    103   \return  none
    104 */
    105 void CTns_Reset(CTnsData *pTnsData)
    106 {
    107   /* Note: the following FDKmemclear should not be required. */
    108   FDKmemclear(pTnsData->Filter, TNS_MAX_WINDOWS*TNS_MAXIMUM_FILTERS*sizeof(CFilter));
    109   FDKmemclear(pTnsData->NumberOfFilters, TNS_MAX_WINDOWS*sizeof(UCHAR));
    110   pTnsData->DataPresent = 0;
    111   pTnsData->Active = 0;
    112 }
    113 
    114 void CTns_ReadDataPresentFlag(HANDLE_FDK_BITSTREAM bs,    /*!< pointer to bitstream */
    115                               CTnsData *pTnsData)         /*!< pointer to aac decoder channel info */
    116 {
    117   pTnsData->DataPresent = (UCHAR) FDKreadBits(bs,1);
    118 }
    119 
    120 /*!
    121   \brief Read tns data from bitstream
    122 
    123   The function reads the elements for tns from
    124   the bitstream.
    125 
    126   \return  none
    127 */
    128 AAC_DECODER_ERROR CTns_Read(HANDLE_FDK_BITSTREAM bs,
    129                             CTnsData *pTnsData,
    130                             const CIcsInfo *pIcsInfo,
    131                             const UINT flags)
    132 {
    133   UCHAR n_filt,order;
    134   UCHAR length,coef_res,coef_compress;
    135   UCHAR window;
    136   UCHAR wins_per_frame = GetWindowsPerFrame(pIcsInfo);
    137   UCHAR isLongFlag = IsLongBlock(pIcsInfo);
    138   AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
    139 
    140   if (!pTnsData->DataPresent) {
    141     return ErrorStatus;
    142   }
    143 
    144   for (window = 0; window < wins_per_frame; window++)
    145   {
    146     pTnsData->NumberOfFilters[window] = n_filt = (UCHAR) FDKreadBits(bs, isLongFlag ? 2 : 1);
    147 
    148     if (pTnsData->NumberOfFilters[window] > TNS_MAXIMUM_FILTERS){
    149         pTnsData->NumberOfFilters[window] = n_filt = TNS_MAXIMUM_FILTERS;
    150     }
    151 
    152     if (n_filt)
    153     {
    154       int index;
    155       UCHAR nextstopband;
    156 
    157       coef_res = (UCHAR) FDKreadBits(bs,1);
    158 
    159       nextstopband = GetScaleFactorBandsTotal(pIcsInfo);
    160 
    161       for (index=0; index < n_filt; index++)
    162       {
    163         CFilter *filter = &pTnsData->Filter[window][index];
    164 
    165         length = (UCHAR)FDKreadBits(bs, isLongFlag ? 6 : 4);
    166 
    167         if (length > nextstopband){
    168           length = nextstopband;
    169         }
    170 
    171         filter->StartBand = nextstopband - length;
    172         filter->StopBand  = nextstopband;
    173         nextstopband = filter->StartBand;
    174 
    175         {
    176           filter->Order = order = (UCHAR) FDKreadBits(bs, isLongFlag ? 5 : 3);
    177         }
    178 
    179         if (filter->Order > TNS_MAXIMUM_ORDER){
    180           filter->Order = order = TNS_MAXIMUM_ORDER;
    181         }
    182 
    183         if (order)
    184         {
    185           UCHAR coef,s_mask;
    186           UCHAR i;
    187           SCHAR n_mask;
    188           static const UCHAR sgn_mask[] = {  0x2,  0x4,  0x8 };
    189           static const SCHAR neg_mask[] = { ~0x3, ~0x7, ~0xF };
    190 
    191           filter->Direction = FDKreadBits(bs,1) ? -1 : 1;
    192 
    193           coef_compress = (UCHAR) FDKreadBits(bs,1);
    194 
    195           filter->Resolution = coef_res + 3;
    196 
    197           s_mask = sgn_mask[coef_res + 1 - coef_compress];
    198           n_mask = neg_mask[coef_res + 1 - coef_compress];
    199 
    200           for (i=0; i < order; i++)
    201           {
    202             coef = (UCHAR) FDKreadBits(bs,filter->Resolution - coef_compress);
    203             filter->Coeff[i] = (coef & s_mask) ? (coef | n_mask) : coef;
    204           }
    205         }
    206       }
    207     }
    208   }
    209 
    210   pTnsData->Active = 1;
    211 
    212   return ErrorStatus;
    213 }
    214 
    215 
    216 static void CTns_Filter (FIXP_DBL *spec, int size, int inc, FIXP_TCC coeff [], int order)
    217 {
    218   // - Simple all-pole filter of order "order" defined by
    219   //   y(n) =  x(n) - a(2)*y(n-1) - ... - a(order+1)*y(n-order)
    220   //
    221   // - The state variables of the filter are initialized to zero every time
    222   //
    223   // - The output data is written over the input data ("in-place operation")
    224   //
    225   // - An input vector of "size" samples is processed and the index increment
    226   //   to the next data sample is given by "inc"
    227 
    228   int i,j,N;
    229   FIXP_DBL *pSpec;
    230   FIXP_DBL maxVal=FL2FXCONST_DBL(0.0);
    231   INT s;
    232 
    233   FDK_ASSERT(order <= TNS_MAXIMUM_ORDER);
    234   C_ALLOC_SCRATCH_START(state, FIXP_DBL, TNS_MAXIMUM_ORDER);
    235   FDKmemclear(state, order*sizeof(FIXP_DBL));
    236 
    237   for (i=0; i<size; i++) {
    238     maxVal = fixMax(maxVal,fixp_abs(spec[i]));
    239   }
    240 
    241   if ( maxVal > FL2FXCONST_DBL(0.03125*0.70710678118) )
    242     s = fixMax(CntLeadingZeros(maxVal)-6,0);
    243   else
    244     s = fixMax(CntLeadingZeros(maxVal)-5,0);
    245 
    246   s = fixMin(s,2);
    247   s = s-1;
    248 
    249   if (inc == -1)
    250     pSpec = &spec[size - 1];
    251   else
    252     pSpec = &spec[0];
    253 
    254   FIXP_TCC *pCoeff;
    255 
    256 #define FIRST_PART_FLTR                                              \
    257     FIXP_DBL x, *pState = state;                                     \
    258     pCoeff = coeff;                                                  \
    259                                                                      \
    260     if (s < 0)                                                       \
    261       x = (pSpec [0]>>1) + fMultDiv2 (*pCoeff++, pState [0]) ;       \
    262     else                                                             \
    263       x = (pSpec [0]<<s) + fMultDiv2 (*pCoeff++, pState [0]) ;
    264 
    265 #define INNER_FLTR_INLINE                                            \
    266       x = fMultAddDiv2 (x, *pCoeff, pState [1]);                     \
    267       pState [0] = pState [1] - (fMultDiv2 (*pCoeff++, x) <<2) ;     \
    268       pState++;
    269 
    270 #define LAST_PART_FLTR                                               \
    271       if (s < 0)                                                     \
    272         *pSpec = x << 1;                                             \
    273       else                                                           \
    274         *pSpec = x >> s;                                             \
    275       *pState =(-x) << 1;                                            \
    276       pSpec   += inc ;
    277 
    278 
    279    if (order>8)
    280    {
    281       N = (order-1)&7;
    282 
    283       for (i = size ; i != 0 ; i--)
    284       {
    285         FIRST_PART_FLTR
    286 
    287         for (j = N; j > 0 ; j--) { INNER_FLTR_INLINE }
    288 
    289         INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE
    290         INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE
    291 
    292         LAST_PART_FLTR
    293       }
    294 
    295    } else if (order>4) {
    296 
    297       N = (order-1)&3;
    298 
    299       for (i = size ; i != 0 ; i--)
    300       {
    301         FIRST_PART_FLTR
    302         for (j = N; j > 0 ; j--) { INNER_FLTR_INLINE }
    303 
    304         INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE INNER_FLTR_INLINE
    305 
    306         LAST_PART_FLTR
    307       }
    308 
    309    } else {
    310 
    311       N = order-1;
    312 
    313       for (i = size ; i != 0 ; i--)
    314       {
    315         FIRST_PART_FLTR
    316 
    317         for (j = N; j > 0 ; j--) { INNER_FLTR_INLINE }
    318 
    319         LAST_PART_FLTR
    320       }
    321    }
    322 
    323    C_ALLOC_SCRATCH_END(state, FIXP_DBL, TNS_MAXIMUM_ORDER);
    324 }
    325 
    326 /*!
    327   \brief Apply tns to spectral lines
    328 
    329   The function applies the tns to the spectrum,
    330 
    331   \return  none
    332 */
    333 void CTns_Apply (
    334         CTnsData *RESTRICT pTnsData, /*!< pointer to aac decoder info */
    335         const CIcsInfo *pIcsInfo,
    336         SPECTRAL_PTR pSpectralCoefficient,
    337         const SamplingRateInfo *pSamplingRateInfo,
    338         const INT granuleLength
    339         )
    340 {
    341   int window,index,start,stop,size;
    342 
    343 
    344   if (pTnsData->Active)
    345   {
    346       C_AALLOC_SCRATCH_START(coeff, FIXP_TCC, TNS_MAXIMUM_ORDER);
    347 
    348       for (window=0; window < GetWindowsPerFrame(pIcsInfo); window++)
    349       {
    350         FIXP_DBL *pSpectrum = SPEC(pSpectralCoefficient, window, granuleLength);
    351 
    352         for (index=0; index < pTnsData->NumberOfFilters[window]; index++)
    353         {
    354           CFilter *RESTRICT filter = &pTnsData->Filter[window][index];
    355 
    356           if (filter->Order > 0)
    357           {
    358              FIXP_TCC *pCoeff;
    359              int tns_max_bands;
    360 
    361              pCoeff = &coeff[filter->Order-1];
    362              if (filter->Resolution == 3)
    363              {
    364                int i;
    365                for (i=0; i < filter->Order; i++)
    366                  *pCoeff-- = FDKaacDec_tnsCoeff3[filter->Coeff[i]+4];
    367              }
    368              else
    369              {
    370                int i;
    371                for (i=0; i < filter->Order; i++)
    372                  *pCoeff-- = FDKaacDec_tnsCoeff4[filter->Coeff[i]+8];
    373              }
    374 
    375              switch (granuleLength) {
    376                case 480:
    377                  tns_max_bands = tns_max_bands_tbl_480[pSamplingRateInfo->samplingRateIndex];
    378                  break;
    379                case 512:
    380                  tns_max_bands = tns_max_bands_tbl_512[pSamplingRateInfo->samplingRateIndex];
    381                  break;
    382                default:
    383                  tns_max_bands = GetMaximumTnsBands(pIcsInfo, pSamplingRateInfo->samplingRateIndex);
    384                  break;
    385              }
    386 
    387              start = fixMin( fixMin(filter->StartBand, tns_max_bands),
    388                              GetScaleFactorBandsTransmitted(pIcsInfo) );
    389 
    390              start = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo)[start];
    391 
    392              stop = fixMin( fixMin(filter->StopBand, tns_max_bands),
    393                             GetScaleFactorBandsTransmitted(pIcsInfo) );
    394 
    395              stop = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo)[stop];
    396 
    397              size = stop - start;
    398 
    399              if (size > 0) {
    400                CTns_Filter(&pSpectrum[start],
    401                             size,
    402                             filter->Direction,
    403                             coeff,
    404                             filter->Order );
    405              }
    406           }
    407         }
    408       }
    409       C_AALLOC_SCRATCH_END(coeff, FIXP_TCC, TNS_MAXIMUM_ORDER);
    410   }
    411 
    412 }
    413