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 - 2013 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 /*****************************************************************************
     85 
     86    Description: FDKaacLdEnc_MdctTransform480:
     87                 The module FDKaacLdEnc_MdctTransform will perform the MDCT.
     88                 The MDCT supports the sine window and
     89                 the zero padded window. The algorithm of the MDCT
     90                 can be divided in  Windowing, PreModulation, Fft and
     91                 PostModulation.
     92 
     93 ******************************************************************************/
     94 
     95 #include "transform.h"
     96 
     97 #include "dct.h"
     98 #include "psy_const.h"
     99 #include "aacEnc_rom.h"
    100 #include "FDK_tools_rom.h"
    101 
    102 INT FDKaacEnc_Transform_Real (const INT_PCM * pTimeData,
    103                               FIXP_DBL *RESTRICT mdctData,
    104                               const INT blockType,
    105                               const INT windowShape,
    106                               INT *prevWindowShape,
    107                               const INT frameLength,
    108                               INT *mdctData_e,
    109                               INT filterType
    110                              ,FIXP_DBL * RESTRICT overlapAddBuffer
    111                              )
    112 {
    113   const INT_PCM * RESTRICT timeData;
    114 
    115   INT i;
    116   /* tl: transform length
    117      fl: left window slope length
    118      nl: left window slope offset
    119      fr: right window slope length
    120      nr: right window slope offset
    121      See FDK_tools/doc/intern/mdct.tex for more detail. */
    122   int tl, fl, nl, fr, nr;
    123 
    124   const FIXP_WTP * RESTRICT pLeftWindowPart;
    125   const FIXP_WTP * RESTRICT pRightWindowPart;
    126 
    127   /*
    128    * MDCT scale:
    129    * + 1: fMultDiv2() in windowing.
    130    * + 1: Because of factor 1/2 in Princen-Bradley compliant windowed TDAC.
    131    */
    132   *mdctData_e = 1+1;
    133 
    134   tl = frameLength;
    135   timeData = pTimeData;
    136 
    137   switch( blockType ) {
    138     case LONG_WINDOW:
    139       {
    140         int offset = (windowShape == LOL_WINDOW) ? ((frameLength * 3)>>2) : 0;
    141         fl = frameLength - offset;
    142         fr = frameLength - offset;
    143       }
    144       break;
    145     case STOP_WINDOW:
    146       fl = frameLength >> 3;
    147       fr = frameLength;
    148       break;
    149     case START_WINDOW: /* or StopStartSequence */
    150       fl = frameLength;
    151       fr = frameLength >> 3;
    152       break;
    153     case SHORT_WINDOW:
    154       fl = fr = frameLength >> 3;
    155       tl >>= 3;
    156       timeData = pTimeData + 3*fl + (fl/2);
    157       break;
    158     default:
    159       FDK_ASSERT(0);
    160       return -1;
    161       break;
    162   }
    163 
    164   /* Taken from FDK_tools/src/mdct.cpp Derive NR and NL */
    165   nr = (tl - fr)>>1;
    166   nl = (tl - fl)>>1;
    167 
    168   pLeftWindowPart = FDKgetWindowSlope(fl, *prevWindowShape);
    169   pRightWindowPart = FDKgetWindowSlope(fr, windowShape);
    170 
    171   /* windowing */
    172   if (filterType != FB_ELD)
    173   {
    174     /* Left window slope offset */
    175     for (i=0; i<nl ; i++)
    176     {
    177 #if SAMPLE_BITS == DFRACT_BITS   /* SPC_BITS and DFRACT_BITS should be equal. */
    178       mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] >> ( 1 );
    179 #else
    180       mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] << (DFRACT_BITS - SAMPLE_BITS - 1);
    181 #endif
    182     }
    183     /* Left window slope */
    184     for (i=0; i<fl/2; i++)
    185     {
    186       FIXP_DBL tmp0;
    187       tmp0 = fMultDiv2((FIXP_PCM)timeData[i+nl], pLeftWindowPart[i].v.im);
    188       mdctData[(tl/2)+i+nl] = fMultSubDiv2(tmp0, (FIXP_PCM)timeData[tl-nl-i-1], pLeftWindowPart[i].v.re);
    189     }
    190 
    191     /* Right window slope offset */
    192     for(i=0; i<nr; i++)
    193     {
    194 #if SAMPLE_BITS == DFRACT_BITS    /* This should be SPC_BITS instead of DFRACT_BITS. */
    195       mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] >> (1);
    196 #else
    197       mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] << (DFRACT_BITS - SAMPLE_BITS - 1);
    198 #endif
    199     }
    200     /* Right window slope */
    201     for (i=0; i<fr/2; i++)
    202     {
    203       FIXP_DBL tmp1;
    204       tmp1 = fMultDiv2((FIXP_PCM)timeData[tl+nr+i], pRightWindowPart[i].v.re);
    205       mdctData[(tl/2)-nr-i-1] = -fMultAddDiv2(tmp1, (FIXP_PCM)timeData[(tl*2)-nr-i-1], pRightWindowPart[i].v.im);
    206     }
    207   }
    208 
    209   if (filterType == FB_ELD)
    210   {
    211     const FIXP_WTB *pWindowELD=NULL;
    212     int i, N = frameLength, L = frameLength;
    213 
    214     if (frameLength == 512) {
    215       pWindowELD = ELDAnalysis512;
    216     } else {
    217       pWindowELD = ELDAnalysis480;
    218     }
    219 
    220     for(i=0;i<N/4;i++)
    221     {
    222       FIXP_DBL z0, outval;
    223 
    224       z0 = (fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i])<< (WTS0-1)) + (fMult((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N/2+i])<< (WTS0-1));
    225 
    226       outval  = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1));
    227       outval += (fMultDiv2((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N+N/2+i]) >> (-WTS1) );
    228       outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i])>> (-WTS2-1));
    229 
    230       overlapAddBuffer[N/2+i] = overlapAddBuffer[i];
    231 
    232       overlapAddBuffer[i] = z0;
    233       mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1));
    234 
    235       mdctData[N-1-i] = outval;
    236       overlapAddBuffer[N+N/2-1-i] = outval;
    237     }
    238 
    239     for(i=N/4;i<N/2;i++)
    240     {
    241       FIXP_DBL z0, outval;
    242 
    243       z0 = fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i]) << (WTS0-1);
    244 
    245       outval  = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1)) ;
    246       outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i]) >> (-WTS2-1));
    247 
    248       overlapAddBuffer[N/2+i] = overlapAddBuffer[i] + (fMult((FIXP_PCM)timeData[L-N/4+i], pWindowELD[N/2+i])<< (WTS0-1) );
    249 
    250       overlapAddBuffer[i] = z0;
    251       mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1));
    252 
    253       mdctData[N-1-i] = outval;
    254       overlapAddBuffer[N+N/2-1-i] = outval;
    255     }
    256   }
    257 
    258   dct_IV(mdctData, tl, mdctData_e);
    259 
    260   *prevWindowShape = windowShape;
    261 
    262   return 0;
    263 }
    264 
    265