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      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 /***************************  Fraunhofer IIS FDK Tools  ***********************
     85 
     86    Author(s):   M. Lohwasser
     87    Description: auto-correlation functions
     88 
     89 ******************************************************************************/
     90 
     91 #include "autocorr2nd.h"
     92 
     93 
     94 
     95 /*  If the accumulator does not provide enough overflow bits,
     96     products have to be shifted down in the autocorrelation below. */
     97 #define SHIFT_FACTOR (5)
     98 #define SHIFT >> (SHIFT_FACTOR)
     99 
    100 
    101 #if defined(__CC_ARM) || defined(__arm__)
    102 #include "arm/autocorr2nd.cpp"
    103 #endif
    104 
    105 
    106 /*!
    107  *
    108  * \brief Calculate second order autocorrelation using 2 accumulators
    109  *
    110  */
    111 #if !defined(FUNCTION_autoCorr2nd_real)
    112 INT
    113 autoCorr2nd_real (ACORR_COEFS *ac,          /*!< Pointer to autocorrelation coeffs */
    114                   const FIXP_DBL *reBuffer, /*!< Pointer to to real part of input samples */
    115                   const int len             /*!< Number input samples */
    116                  )
    117 {
    118   int   j, autoCorrScaling, mScale;
    119 
    120   FIXP_DBL accu1, accu2, accu3, accu4, accu5;
    121 
    122   const FIXP_DBL *pReBuf;
    123 
    124   const FIXP_DBL *realBuf = reBuffer;
    125 
    126   /*
    127     r11r,r22r
    128     r01r,r12r
    129     r02r
    130   */
    131   pReBuf = realBuf-2;
    132   accu5 = ( (fMultDiv2(pReBuf[0], pReBuf[2]) +
    133              fMultDiv2(pReBuf[1], pReBuf[3])) SHIFT);
    134   pReBuf++;
    135 
    136   //len must be even
    137   accu1 = fPow2Div2(pReBuf[0]) SHIFT;
    138   accu3 = fMultDiv2(pReBuf[0], pReBuf[1]) SHIFT;
    139   pReBuf++;
    140 
    141   for ( j = (len - 2)>>1; j != 0; j--,pReBuf+=2 ) {
    142 
    143     accu1 += ( (fPow2Div2(pReBuf[0]) +
    144                 fPow2Div2(pReBuf[1])) SHIFT);
    145 
    146     accu3 += ( (fMultDiv2(pReBuf[0], pReBuf[1]) +
    147                 fMultDiv2(pReBuf[1], pReBuf[2])) SHIFT);
    148 
    149     accu5 += ( (fMultDiv2(pReBuf[0], pReBuf[2]) +
    150                 fMultDiv2(pReBuf[1], pReBuf[3])) SHIFT);
    151 
    152   }
    153 
    154   accu2 = (fPow2Div2(realBuf[-2]) SHIFT);
    155   accu2 += accu1;
    156 
    157   accu1 += (fPow2Div2(realBuf[len - 2]) SHIFT);
    158 
    159   accu4  = (fMultDiv2(realBuf[-1],realBuf[-2]) SHIFT);
    160   accu4 += accu3;
    161 
    162   accu3 += (fMultDiv2(realBuf[len - 1],realBuf[len - 2]) SHIFT);
    163 
    164   mScale = CntLeadingZeros( (accu1 | accu2 | fAbs(accu3) | fAbs(accu4) | fAbs(accu5)) ) - 1;
    165   autoCorrScaling = mScale - 1 - SHIFT_FACTOR; /* -1 because of fMultDiv2*/
    166 
    167   /* Scale to common scale factor */
    168   ac->r11r = accu1 << mScale;
    169   ac->r22r = accu2 << mScale;
    170   ac->r01r = accu3 << mScale;
    171   ac->r12r = accu4 << mScale;
    172   ac->r02r = accu5 << mScale;
    173 
    174   ac->det = (fMultDiv2(ac->r11r,ac->r22r) - fMultDiv2(ac->r12r,ac->r12r)) ;
    175   mScale  = CountLeadingBits(fAbs(ac->det));
    176 
    177   ac->det     <<= mScale;
    178   ac->det_scale = mScale - 1;
    179 
    180   return autoCorrScaling;
    181 }
    182 #endif
    183 
    184 #ifndef LOW_POWER_SBR_ONLY
    185 #if !defined(FUNCTION_autoCorr2nd_cplx)
    186 INT
    187 autoCorr2nd_cplx (ACORR_COEFS *ac,           /*!< Pointer to autocorrelation coeffs */
    188                   const FIXP_DBL *reBuffer,  /*!< Pointer to real part of input samples */
    189                   const FIXP_DBL *imBuffer,  /*!< Pointer to imag part of input samples */
    190                   const int len              /*!< Number of input samples */
    191                  )
    192 {
    193 
    194   int   j, autoCorrScaling, mScale, len_scale;
    195 
    196   FIXP_DBL accu0, accu1,accu2, accu3, accu4, accu5, accu6, accu7, accu8;
    197 
    198   const FIXP_DBL *pReBuf, *pImBuf;
    199 
    200   const FIXP_DBL *realBuf = reBuffer;
    201   const FIXP_DBL *imagBuf = imBuffer;
    202 
    203   (len>64) ? (len_scale = 6) : (len_scale = 5);
    204   /*
    205     r00r,
    206     r11r,r22r
    207     r01r,r12r
    208     r01i,r12i
    209     r02r,r02i
    210   */
    211   accu1 = accu3 = accu5 = accu7 = accu8 = FL2FXCONST_DBL(0.0f);
    212 
    213   pReBuf  = realBuf-2, pImBuf  = imagBuf-2;
    214   accu7 += ( (fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >> len_scale);
    215   accu8 += ( (fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >> len_scale);
    216 
    217   pReBuf = realBuf-1, pImBuf = imagBuf-1;
    218   for ( j = (len - 1); j != 0; j--,pReBuf++,pImBuf++ ){
    219     accu1 += ( (fPow2Div2(pReBuf[0]           ) + fPow2Div2(pImBuf[0]           )) >> len_scale);
    220     accu3 += ( (fMultDiv2(pReBuf[0], pReBuf[1]) + fMultDiv2(pImBuf[0], pImBuf[1])) >> len_scale);
    221     accu5 += ( (fMultDiv2(pImBuf[1], pReBuf[0]) - fMultDiv2(pReBuf[1], pImBuf[0])) >> len_scale);
    222     accu7 += ( (fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >> len_scale);
    223     accu8 += ( (fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >> len_scale);
    224   }
    225 
    226   accu2 = ( (fPow2Div2(realBuf[-2]) + fPow2Div2(imagBuf[-2])) >> len_scale);
    227   accu2 += accu1;
    228 
    229   accu1 += ( (fPow2Div2(realBuf[len-2]) +
    230               fPow2Div2(imagBuf[len-2])) >> len_scale);
    231   accu0 = ( (fPow2Div2(realBuf[len-1]) +
    232              fPow2Div2(imagBuf[len-1])) >> len_scale) -
    233           ( (fPow2Div2(realBuf[-1]) +
    234              fPow2Div2(imagBuf[-1])) >> len_scale);
    235   accu0 += accu1;
    236 
    237   accu4 = ( (fMultDiv2(realBuf[-1], realBuf[-2]) +
    238              fMultDiv2(imagBuf[-1], imagBuf[-2])) >> len_scale);
    239   accu4 += accu3;
    240 
    241   accu3 += ( (fMultDiv2(realBuf[len-1], realBuf[len-2]) +
    242               fMultDiv2(imagBuf[len-1], imagBuf[len-2])) >> len_scale);
    243 
    244   accu6 = ( (fMultDiv2(imagBuf[-1], realBuf[-2]) -
    245              fMultDiv2(realBuf[-1], imagBuf[-2])) >> len_scale);
    246   accu6 += accu5;
    247 
    248   accu5 += ( (fMultDiv2(imagBuf[len - 1], realBuf[len - 2]) -
    249               fMultDiv2(realBuf[len - 1], imagBuf[len - 2])) >> len_scale);
    250 
    251   mScale = CntLeadingZeros( (accu0 | accu1 | accu2 | fAbs(accu3) | fAbs(accu4) | fAbs(accu5) |
    252                              fAbs(accu6) | fAbs(accu7) | fAbs(accu8)) ) - 1;
    253   autoCorrScaling = mScale - 1 - len_scale; /* -1 because of fMultDiv2*/
    254 
    255   /* Scale to common scale factor */
    256   ac->r00r = (FIXP_DBL)accu0 << mScale;
    257   ac->r11r = (FIXP_DBL)accu1 << mScale;
    258   ac->r22r = (FIXP_DBL)accu2 << mScale;
    259   ac->r01r = (FIXP_DBL)accu3 << mScale;
    260   ac->r12r = (FIXP_DBL)accu4 << mScale;
    261   ac->r01i = (FIXP_DBL)accu5 << mScale;
    262   ac->r12i = (FIXP_DBL)accu6 << mScale;
    263   ac->r02r = (FIXP_DBL)accu7 << mScale;
    264   ac->r02i = (FIXP_DBL)accu8 << mScale;
    265 
    266   ac->det = ( fMultDiv2(ac->r11r,ac->r22r) >> 1 ) -
    267             ( (fMultDiv2(ac->r12r,ac->r12r) + fMultDiv2(ac->r12i,ac->r12i)) >> 1 );
    268   mScale = CountLeadingBits(fAbs(ac->det));
    269 
    270   ac->det <<= mScale;
    271   ac->det_scale = mScale - 2;
    272 
    273   return autoCorrScaling;
    274 }
    275 #endif /* FUNCTION_autoCorr2nd_cplx */
    276 #endif /* LOW_POWER_SBR_ONLY */
    277 
    278 
    279