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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 encoder library ******************************
     96 
     97    Author(s):   M. Werner
     98 
     99    Description: Block switching
    100 
    101 *******************************************************************************/
    102 
    103 #ifndef BLOCK_SWITCH_H
    104 #define BLOCK_SWITCH_H
    105 
    106 #include "common_fix.h"
    107 
    108 #include "psy_const.h"
    109 
    110 /****************** Defines ******************************/
    111 #define BLOCK_SWITCH_WINDOWS 8 /* number of windows for energy calculation */
    112 
    113 #define BLOCK_SWITCHING_IIR_LEN \
    114   2 /* Length of HighPass-IIR-Filter for Attack-Detection */
    115 #define BLOCK_SWITCH_ENERGY_SHIFT                                        \
    116   7 /* should be logDualis(BLOCK_SWITCH_WINDOW_LEN) to avoid overflow in \
    117        windowNrgs. */
    118 
    119 #define LAST_WINDOW 0
    120 #define THIS_WINDOW 1
    121 
    122 /****************** Structures ***************************/
    123 typedef struct {
    124   INT lastWindowSequence;
    125   INT windowShape;
    126   INT lastWindowShape;
    127   UINT nBlockSwitchWindows; /* number of windows for energy calculation */
    128   INT attack;
    129   INT lastattack;
    130   INT attackIndex;
    131   INT lastAttackIndex;
    132   INT allowShortFrames; /* for Low Delay, don't allow short frames */
    133   INT allowLookAhead;   /* for Low Delay, don't do look-ahead */
    134   INT noOfGroups;
    135   INT groupLen[MAX_NO_OF_GROUPS];
    136   FIXP_DBL maxWindowNrg; /* max energy in subwindows */
    137 
    138   FIXP_DBL
    139   windowNrg[2][BLOCK_SWITCH_WINDOWS]; /* time signal energy in Subwindows
    140                                          (last and current) */
    141   FIXP_DBL windowNrgF[2][BLOCK_SWITCH_WINDOWS]; /* filtered time signal energy
    142                                                    in segments (last and
    143                                                    current) */
    144   FIXP_DBL accWindowNrg; /* recursively accumulated windowNrgF */
    145 
    146   FIXP_DBL iirStates[BLOCK_SWITCHING_IIR_LEN]; /* filter delay-line */
    147 
    148 } BLOCK_SWITCHING_CONTROL;
    149 
    150 void FDKaacEnc_InitBlockSwitching(
    151     BLOCK_SWITCHING_CONTROL *blockSwitchingControl, INT isLowDelay);
    152 
    153 int FDKaacEnc_BlockSwitching(BLOCK_SWITCHING_CONTROL *blockSwitchingControl,
    154                              const INT granuleLength, const int isLFE,
    155                              const INT_PCM *pTimeSignal);
    156 
    157 int FDKaacEnc_SyncBlockSwitching(
    158     BLOCK_SWITCHING_CONTROL *blockSwitchingControlLeft,
    159     BLOCK_SWITCHING_CONTROL *blockSwitchingControlRight, const INT noOfChannels,
    160     const INT commonWindow);
    161 
    162 #endif /* #ifndef BLOCK_SWITCH_H */
    163