libFDK/include/qmf.h

   1
   2 /* -----------------------------------------------------------------------------------------------------------
   3 Software License for The Fraunhofer FDK AAC Codec Library for Android
   4
   5 © Copyright  1995 - 2013 Fraunhofer-Gesellschaft zur Förderung 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
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  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:
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  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.
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  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.
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  42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
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  44
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  46 software or your modifications thereto.
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  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."
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  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
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  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@iis.fraunhofer.de
  82 ----------------------------------------------------------------------------------------------------------- */
  83
  84 /*!
  85   \file   qmf.h
  86   \brief  Complex qmf analysis/synthesis
  87   \author Markus Werner
  88
  89 */
  90 #ifndef __QMF_H
  91 #define __QMF_H
  92
  93
  94
  95 #include "common_fix.h"
  96 #include "FDK_tools_rom.h"
  97 #include "dct.h"
  98
  99 /*
 100  * Filter coefficient type definition
 101  */
 102 #ifdef QMF_DATA_16BIT
 103 #define FIXP_QMF FIXP_SGL
 104 #define FX_DBL2FX_QMF FX_DBL2FX_SGL
 105 #define FX_QMF2FX_DBL FX_SGL2FX_DBL
 106 #define QFRACT_BITS FRACT_BITS
 107 #else
 108 #define FIXP_QMF FIXP_DBL
 109 #define FX_DBL2FX_QMF
 110 #define FX_QMF2FX_DBL
 111 #define QFRACT_BITS DFRACT_BITS
 112 #endif
 113
 114 /* ARM neon optimized QMF analysis filter requires 32 bit input.
 115    Implemented for RVCT only, currently disabled. See src/arm/qmf_arm.cpp:45 */
 116 #define FIXP_QAS FIXP_PCM
 117 #define QAS_BITS SAMPLE_BITS
 118
 119 #ifdef QMFSYN_STATES_16BIT
 120 #define FIXP_QSS FIXP_SGL
 121 #define QSS_BITS FRACT_BITS
 122 #else
 123 #define FIXP_QSS FIXP_DBL
 124 #define QSS_BITS DFRACT_BITS
 125 #endif
 126
 127 /* Flags for QMF intialization */
 128 /* Low Power mode flag */
 129 #define QMF_FLAG_LP           1
 130 /* Filter is not symetric. This flag is set internally in the QMF initialization as required. */
 131 #define QMF_FLAG_NONSYMMETRIC 2
 132 /* Complex Low Delay Filter Bank (or std symmetric filter bank) */
 133 #define QMF_FLAG_CLDFB        4
 134 /* Flag indicating that the states should be kept. */
 135 #define QMF_FLAG_KEEP_STATES  8
 136 /* Complex Low Delay Filter Bank used in MPEG Surround Encoder */
 137 #define QMF_FLAG_MPSLDFB     16
 138 /* Complex Low Delay Filter Bank used in MPEG Surround Encoder allows a optimized calculation of the modulation in qmfForwardModulationHQ() */
 139 #define QMF_FLAG_MPSLDFB_OPTIMIZE_MODULATION  32
 140 /* Flag to indicate HE-AAC down-sampled SBR mode (decoder) -> adapt analysis post twiddling */
 141 #define QMF_FLAG_DOWNSAMPLED  64
 142
 143
 144 typedef struct
 145 {
 146   int lb_scale;        /*!< Scale of low band area                   */
 147   int ov_lb_scale;     /*!< Scale of adjusted overlap low band area  */
 148   int hb_scale;        /*!< Scale of high band area                  */
 149   int ov_hb_scale;     /*!< Scale of adjusted overlap high band area */
 150 } QMF_SCALE_FACTOR;
 151
 152 struct QMF_FILTER_BANK
 153 {
 154   const FIXP_PFT *p_filter;     /*!< Pointer to filter coefficients */
 155
 156   void *FilterStates;           /*!< Pointer to buffer of filter states
 157                                      FIXP_PCM in analyse and
 158                                      FIXP_DBL in synthesis filter */
 159   int FilterSize;               /*!< Size of prototype filter. */
 160   const FIXP_QTW *t_cos;        /*!< Modulation tables. */
 161   const FIXP_QTW *t_sin;
 162   int filterScale;              /*!< filter scale */
 163
 164   int no_channels;              /*!< Total number of channels (subbands) */
 165   int no_col;                   /*!< Number of time slots       */
 166   int lsb;                      /*!< Top of low subbands */
 167   int usb;                      /*!< Top of high subbands */
 168
 169   int outScalefactor;           /*!< Scale factor of output data (syn only) */
 170   FIXP_DBL outGain;             /*!< Gain output data (syn only) (init with 0x80000000 to ignore) */
 171
 172   UINT flags;                   /*!< flags */
 173   UCHAR p_stride;               /*!< Stride Factor of polyphase filters */
 174
 175 };
 176
 177 typedef struct QMF_FILTER_BANK *HANDLE_QMF_FILTER_BANK;
 178
 179 void
 180 qmfAnalysisFiltering( HANDLE_QMF_FILTER_BANK anaQmf,  /*!< Handle of Qmf Analysis Bank   */
 181                       FIXP_QMF **qmfReal,             /*!< Pointer to real subband slots */
 182                       FIXP_QMF **qmfImag,             /*!< Pointer to imag subband slots */
 183                       QMF_SCALE_FACTOR *scaleFactor,  /*!< Scale factors of QMF data     */
 184                       const INT_PCM *timeIn,          /*!< Time signal */
 185                       const int  stride,              /*!< Stride factor of audio data   */
 186                       FIXP_QMF  *pWorkBuffer          /*!< pointer to temporal working buffer */
 187                       );
 188
 189 void
 190 qmfSynthesisFiltering( HANDLE_QMF_FILTER_BANK synQmf,       /*!< Handle of Qmf Synthesis Bank  */
 191                        FIXP_QMF  **QmfBufferReal,           /*!< Pointer to real subband slots */
 192                        FIXP_QMF  **QmfBufferImag,           /*!< Pointer to imag subband slots */
 193                        const QMF_SCALE_FACTOR *scaleFactor, /*!< Scale factors of QMF data     */
 194                        const int   ov_len,                  /*!< Length of band overlap        */
 195                        INT_PCM    *timeOut,                 /*!< Time signal */
 196                        const int   stride,                  /*!< Stride factor of audio data   */
 197                        FIXP_QMF   *pWorkBuffer              /*!< pointer to temporal working buffer */
 198                        );
 199
 200 int
 201 qmfInitAnalysisFilterBank( HANDLE_QMF_FILTER_BANK h_Qmf, /*!< QMF Handle */
 202                            FIXP_QAS *pFilterStates,      /*!< Pointer to filter state buffer */
 203                            int noCols,                   /*!< Number of time slots  */
 204                            int lsb,                      /*!< Number of lower bands */
 205                            int usb,                      /*!< Number of upper bands */
 206                            int no_channels,              /*!< Number of critically sampled bands */
 207                            int flags);                   /*!< Flags */
 208
 209 void
 210 qmfAnalysisFilteringSlot( HANDLE_QMF_FILTER_BANK anaQmf,  /*!< Handle of Qmf Synthesis Bank  */
 211                           FIXP_QMF      *qmfReal,         /*!< Low and High band, real */
 212                           FIXP_QMF      *qmfImag,         /*!< Low and High band, imag */
 213                           const INT_PCM *timeIn,          /*!< Pointer to input */
 214                           const int      stride,          /*!< stride factor of input */
 215                           FIXP_QMF      *pWorkBuffer      /*!< pointer to temporal working buffer */
 216                          );
 217
 218 int
 219 qmfInitSynthesisFilterBank( HANDLE_QMF_FILTER_BANK h_Qmf, /*!< QMF Handle */
 220                             FIXP_QSS *pFilterStates,      /*!< Pointer to filter state buffer */
 221                             int noCols,                   /*!< Number of time slots  */
 222                             int lsb,                      /*!< Number of lower bands */
 223                             int usb,                      /*!< Number of upper bands */
 224                             int no_channels,              /*!< Number of critically sampled bands */
 225                             int flags);                   /*!< Flags */
 226
 227 void qmfSynthesisFilteringSlot( HANDLE_QMF_FILTER_BANK  synQmf,
 228                                 const FIXP_QMF *realSlot,
 229                                 const FIXP_QMF *imagSlot,
 230                                 const int       scaleFactorLowBand,
 231                                 const int       scaleFactorHighBand,
 232                                 INT_PCM        *timeOut,
 233                                 const int       stride,
 234                                 FIXP_QMF       *pWorkBuffer);
 235
 236 void
 237 qmfChangeOutScalefactor (HANDLE_QMF_FILTER_BANK synQmf,     /*!< Handle of Qmf Synthesis Bank */
 238                          int outScalefactor                 /*!< New scaling factor for output data */
 239                         );
 240
 241 void
 242 qmfChangeOutGain (HANDLE_QMF_FILTER_BANK synQmf,     /*!< Handle of Qmf Synthesis Bank */
 243                   FIXP_DBL outputGain                /*!< New gain for output data */
 244                  );
 245
 246
 247
 248 #endif /* __QMF_H */