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      1 /* -----------------------------------------------------------------------------
      2 Software License for The Fraunhofer FDK AAC Codec Library for Android
      3 
      4  Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Frderung der angewandten
      5 Forschung e.V. All rights reserved.
      6 
      7  1.    INTRODUCTION
      8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
      9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
     10 scheme for digital audio. This FDK AAC Codec software is intended to be used on
     11 a wide variety of Android devices.
     12 
     13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
     14 general perceptual audio codecs. AAC-ELD is considered the best-performing
     15 full-bandwidth communications codec by independent studies and is widely
     16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG
     17 specifications.
     18 
     19 Patent licenses for necessary patent claims for the FDK AAC Codec (including
     20 those of Fraunhofer) may be obtained through Via Licensing
     21 (www.vialicensing.com) or through the respective patent owners individually for
     22 the purpose of encoding or decoding bit streams in products that are compliant
     23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
     24 Android devices already license these patent claims through Via Licensing or
     25 directly from the patent owners, and therefore FDK AAC Codec software may
     26 already be covered under those patent licenses when it is used for those
     27 licensed purposes only.
     28 
     29 Commercially-licensed AAC software libraries, including floating-point versions
     30 with enhanced sound quality, are also available from Fraunhofer. Users are
     31 encouraged to check the Fraunhofer website for additional applications
     32 information and documentation.
     33 
     34 2.    COPYRIGHT LICENSE
     35 
     36 Redistribution and use in source and binary forms, with or without modification,
     37 are permitted without payment of copyright license fees provided that you
     38 satisfy the following conditions:
     39 
     40 You must retain the complete text of this software license in redistributions of
     41 the FDK AAC Codec or your modifications thereto in source code form.
     42 
     43 You must retain the complete text of this software license in the documentation
     44 and/or other materials provided with redistributions of the FDK AAC Codec or
     45 your modifications thereto in binary form. You must make available free of
     46 charge copies of the complete source code of the FDK AAC Codec and your
     47 modifications thereto to recipients of copies in binary form.
     48 
     49 The name of Fraunhofer may not be used to endorse or promote products derived
     50 from this library without prior written permission.
     51 
     52 You may not charge copyright license fees for anyone to use, copy or distribute
     53 the FDK AAC Codec software or your modifications thereto.
     54 
     55 Your modified versions of the FDK AAC Codec must carry prominent notices stating
     56 that you changed the software and the date of any change. For modified versions
     57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
     58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
     59 AAC Codec Library for Android."
     60 
     61 3.    NO PATENT LICENSE
     62 
     63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
     64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
     65 Fraunhofer provides no warranty of patent non-infringement with respect to this
     66 software.
     67 
     68 You may use this FDK AAC Codec software or modifications thereto only for
     69 purposes that are authorized by appropriate patent licenses.
     70 
     71 4.    DISCLAIMER
     72 
     73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
     74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
     75 including but not limited to the implied warranties of merchantability and
     76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
     77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
     78 or consequential damages, including but not limited to procurement of substitute
     79 goods or services; loss of use, data, or profits, or business interruption,
     80 however caused and on any theory of liability, whether in contract, strict
     81 liability, or tort (including negligence), arising in any way out of the use of
     82 this software, even if advised of the possibility of such damage.
     83 
     84 5.    CONTACT INFORMATION
     85 
     86 Fraunhofer Institute for Integrated Circuits IIS
     87 Attention: Audio and Multimedia Departments - FDK AAC LL
     88 Am Wolfsmantel 33
     89 91058 Erlangen, Germany
     90 
     91 www.iis.fraunhofer.de/amm
     92 amm-info (at) iis.fraunhofer.de
     93 ----------------------------------------------------------------------------- */
     94 
     95 /**************************** AAC decoder library ******************************
     96 
     97    Author(s):   Josef Hoepfl
     98 
     99    Description: individual channel stream info
    100 
    101 *******************************************************************************/
    102 
    103 #include "channelinfo.h"
    104 #include "aac_rom.h"
    105 #include "aac_ram.h"
    106 #include "FDK_bitstream.h"
    107 
    108 AAC_DECODER_ERROR IcsReadMaxSfb(HANDLE_FDK_BITSTREAM bs, CIcsInfo *pIcsInfo,
    109                                 const SamplingRateInfo *pSamplingRateInfo) {
    110   AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
    111   int nbits;
    112 
    113   if (IsLongBlock(pIcsInfo)) {
    114     nbits = 6;
    115     pIcsInfo->TotalSfBands = pSamplingRateInfo->NumberOfScaleFactorBands_Long;
    116   } else {
    117     nbits = 4;
    118     pIcsInfo->TotalSfBands = pSamplingRateInfo->NumberOfScaleFactorBands_Short;
    119   }
    120   pIcsInfo->MaxSfBands = (UCHAR)FDKreadBits(bs, nbits);
    121 
    122   if (pIcsInfo->MaxSfBands > pIcsInfo->TotalSfBands) {
    123     ErrorStatus = AAC_DEC_PARSE_ERROR;
    124   }
    125 
    126   return ErrorStatus;
    127 }
    128 
    129 AAC_DECODER_ERROR IcsRead(HANDLE_FDK_BITSTREAM bs, CIcsInfo *pIcsInfo,
    130                           const SamplingRateInfo *pSamplingRateInfo,
    131                           const UINT flags) {
    132   AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
    133 
    134   pIcsInfo->Valid = 0;
    135 
    136   if (flags & AC_ELD) {
    137     pIcsInfo->WindowSequence = BLOCK_LONG;
    138     pIcsInfo->WindowShape = 0;
    139   } else {
    140     if (!(flags & (AC_USAC | AC_RSVD50 | AC_RSV603DA))) {
    141       FDKreadBits(bs, 1);
    142     }
    143     pIcsInfo->WindowSequence = (BLOCK_TYPE)FDKreadBits(bs, 2);
    144     pIcsInfo->WindowShape = (UCHAR)FDKreadBits(bs, 1);
    145     if (flags & AC_LD) {
    146       if (pIcsInfo->WindowShape) {
    147         pIcsInfo->WindowShape = 2; /* select low overlap instead of KBD */
    148       }
    149     }
    150   }
    151 
    152   /* Sanity check */
    153   if ((flags & (AC_ELD | AC_LD)) && pIcsInfo->WindowSequence != BLOCK_LONG) {
    154     pIcsInfo->WindowSequence = BLOCK_LONG;
    155     ErrorStatus = AAC_DEC_PARSE_ERROR;
    156     goto bail;
    157   }
    158 
    159   ErrorStatus = IcsReadMaxSfb(bs, pIcsInfo, pSamplingRateInfo);
    160   if (ErrorStatus != AAC_DEC_OK) {
    161     goto bail;
    162   }
    163 
    164   if (IsLongBlock(pIcsInfo)) {
    165     if (!(flags & (AC_ELD | AC_SCALABLE | AC_BSAC | AC_USAC | AC_RSVD50 |
    166                    AC_RSV603DA))) /* If not ELD nor Scalable nor BSAC nor USAC
    167                                      syntax then ... */
    168     {
    169       if ((UCHAR)FDKreadBits(bs, 1) != 0) /* UCHAR PredictorDataPresent */
    170       {
    171         ErrorStatus = AAC_DEC_UNSUPPORTED_PREDICTION;
    172         goto bail;
    173       }
    174     }
    175 
    176     pIcsInfo->WindowGroups = 1;
    177     pIcsInfo->WindowGroupLength[0] = 1;
    178   } else {
    179     INT i;
    180     UINT mask;
    181 
    182     pIcsInfo->ScaleFactorGrouping = (UCHAR)FDKreadBits(bs, 7);
    183 
    184     pIcsInfo->WindowGroups = 0;
    185 
    186     for (i = 0; i < (8 - 1); i++) {
    187       mask = 1 << (6 - i);
    188       pIcsInfo->WindowGroupLength[i] = 1;
    189 
    190       if (pIcsInfo->ScaleFactorGrouping & mask) {
    191         pIcsInfo->WindowGroupLength[pIcsInfo->WindowGroups]++;
    192       } else {
    193         pIcsInfo->WindowGroups++;
    194       }
    195     }
    196 
    197     /* loop runs to i < 7 only */
    198     pIcsInfo->WindowGroupLength[8 - 1] = 1;
    199     pIcsInfo->WindowGroups++;
    200   }
    201 
    202 bail:
    203   if (ErrorStatus == AAC_DEC_OK) pIcsInfo->Valid = 1;
    204 
    205   return ErrorStatus;
    206 }
    207 
    208 /*
    209   interleave codebooks the following way
    210 
    211     9 (84w) |  1 (51w)
    212    10 (82w) |  2 (39w)
    213   SCL (65w) |  4 (38w)
    214     3 (39w) |  5 (41w)
    215             |  6 (40w)
    216             |  7 (31w)
    217             |  8 (31w)
    218      (270w)     (271w)
    219 */
    220 
    221 /*
    222   Table entries are sorted as following:
    223   | num_swb_long_window | sfbands_long | num_swb_short_window | sfbands_short |
    224 */
    225 AAC_DECODER_ERROR getSamplingRateInfo(SamplingRateInfo *t, UINT samplesPerFrame,
    226                                       UINT samplingRateIndex,
    227                                       UINT samplingRate) {
    228   int index = 0;
    229 
    230   /* Search closest samplerate according to ISO/IEC 13818-7:2005(E) 8.2.4 (Table
    231    * 38): */
    232   if ((samplingRateIndex >= 15) || (samplesPerFrame == 768)) {
    233     const UINT borders[] = {(UINT)-1, 92017, 75132, 55426, 46009, 37566,
    234                             27713,    23004, 18783, 13856, 11502, 9391};
    235     UINT i, samplingRateSearch = samplingRate;
    236 
    237     if (samplesPerFrame == 768) {
    238       samplingRateSearch = (samplingRate * 4) / 3;
    239     }
    240 
    241     for (i = 0; i < 11; i++) {
    242       if (borders[i] > samplingRateSearch &&
    243           samplingRateSearch >= borders[i + 1]) {
    244         break;
    245       }
    246     }
    247     samplingRateIndex = i;
    248   }
    249 
    250   t->samplingRateIndex = samplingRateIndex;
    251   t->samplingRate = samplingRate;
    252 
    253   switch (samplesPerFrame) {
    254     case 1024:
    255       index = 0;
    256       break;
    257     case 960:
    258       index = 1;
    259       break;
    260     case 768:
    261       index = 2;
    262       break;
    263     case 512:
    264       index = 3;
    265       break;
    266     case 480:
    267       index = 4;
    268       break;
    269 
    270     default:
    271       return AAC_DEC_UNSUPPORTED_FORMAT;
    272   }
    273 
    274   t->ScaleFactorBands_Long =
    275       sfbOffsetTables[index][samplingRateIndex].sfbOffsetLong;
    276   t->ScaleFactorBands_Short =
    277       sfbOffsetTables[index][samplingRateIndex].sfbOffsetShort;
    278   t->NumberOfScaleFactorBands_Long =
    279       sfbOffsetTables[index][samplingRateIndex].numberOfSfbLong;
    280   t->NumberOfScaleFactorBands_Short =
    281       sfbOffsetTables[index][samplingRateIndex].numberOfSfbShort;
    282 
    283   if (t->ScaleFactorBands_Long == NULL ||
    284       t->NumberOfScaleFactorBands_Long == 0) {
    285     t->samplingRate = 0;
    286     return AAC_DEC_UNSUPPORTED_FORMAT;
    287   }
    288 
    289   FDK_ASSERT((UINT)t->ScaleFactorBands_Long[t->NumberOfScaleFactorBands_Long] ==
    290              samplesPerFrame);
    291   FDK_ASSERT(
    292       t->ScaleFactorBands_Short == NULL ||
    293       (UINT)t->ScaleFactorBands_Short[t->NumberOfScaleFactorBands_Short] * 8 ==
    294           samplesPerFrame);
    295 
    296   return AAC_DEC_OK;
    297 }
    298