Home | History | Annotate | Download | only in src
      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 /******************* Library for basic calculation routines ********************
     96 
     97    Author(s):   Markus Lohwasser, Josef Hoepfl, Manuel Jander
     98 
     99    Description: QMF filterbank
    100 
    101 *******************************************************************************/
    102 
    103 /*!
    104   \file
    105   \brief  Complex qmf analysis/synthesis
    106   This module contains the qmf filterbank for analysis [
    107   cplxAnalysisQmfFiltering() ] and synthesis [ cplxSynthesisQmfFiltering() ]. It
    108   is a polyphase implementation of a complex exponential modulated filter bank.
    109   The analysis part usually runs at half the sample rate than the synthesis
    110   part. (So called "dual-rate" mode.)
    111 
    112   The coefficients of the prototype filter are specified in #qmf_pfilt640 (in
    113   sbr_rom.cpp). Thus only a 64 channel version (32 on the analysis side) with a
    114   640 tap prototype filter are used.
    115 
    116   \anchor PolyphaseFiltering <h2>About polyphase filtering</h2>
    117   The polyphase implementation of a filterbank requires filtering at the input
    118   and output. This is implemented as part of cplxAnalysisQmfFiltering() and
    119   cplxSynthesisQmfFiltering(). The implementation requires the filter
    120   coefficients in a specific structure as described in #sbr_qmf_64_640_qmf (in
    121   sbr_rom.cpp).
    122 
    123   This module comprises the computationally most expensive functions of the SBR
    124   decoder. The accuracy of computations is also important and has a direct
    125   impact on the overall sound quality. Therefore a special test program is
    126   available which can be used to only test the filterbank: main_audio.cpp
    127 
    128   This modules also uses scaling of data to provide better SNR on fixed-point
    129   processors. See #QMF_SCALE_FACTOR (in sbr_scale.h) for details. An interesting
    130   note: The function getScalefactor() can constitute a significant amount of
    131   computational complexity - very much depending on the bitrate. Since it is a
    132   rather small function, effective assembler optimization might be possible.
    133 
    134 */
    135 
    136 #include "qmf.h"
    137 
    138 #include "FDK_trigFcts.h"
    139 #include "fixpoint_math.h"
    140 #include "dct.h"
    141 
    142 #define QSSCALE (0)
    143 #define FX_DBL2FX_QSS(x) (x)
    144 #define FX_QSS2FX_DBL(x) (x)
    145 
    146 /* moved to qmf_pcm.h: -> qmfSynPrototypeFirSlot */
    147 /* moved to qmf_pcm.h: -> qmfSynPrototypeFirSlot_NonSymmetric */
    148 /* moved to qmf_pcm.h: -> qmfSynthesisFilteringSlot */
    149 
    150 #ifndef FUNCTION_qmfAnaPrototypeFirSlot
    151 /*!
    152   \brief Perform Analysis Prototype Filtering on a single slot of input data.
    153 */
    154 static void qmfAnaPrototypeFirSlot(
    155     FIXP_DBL *analysisBuffer,
    156     INT no_channels, /*!< Number channels of analysis filter */
    157     const FIXP_PFT *p_filter, INT p_stride, /*!< Stride of analysis filter    */
    158     FIXP_QAS *RESTRICT pFilterStates) {
    159   INT k;
    160 
    161   FIXP_DBL accu;
    162   const FIXP_PFT *RESTRICT p_flt = p_filter;
    163   FIXP_DBL *RESTRICT pData_0 = analysisBuffer + 2 * no_channels - 1;
    164   FIXP_DBL *RESTRICT pData_1 = analysisBuffer;
    165 
    166   FIXP_QAS *RESTRICT sta_0 = (FIXP_QAS *)pFilterStates;
    167   FIXP_QAS *RESTRICT sta_1 =
    168       (FIXP_QAS *)pFilterStates + (2 * QMF_NO_POLY * no_channels) - 1;
    169   INT pfltStep = QMF_NO_POLY * (p_stride);
    170   INT staStep1 = no_channels << 1;
    171   INT staStep2 = (no_channels << 3) - 1; /* Rewind one less */
    172 
    173   /* FIR filters 127..64 0..63 */
    174   for (k = 0; k < no_channels; k++) {
    175     accu = fMultDiv2(p_flt[0], *sta_1);
    176     sta_1 -= staStep1;
    177     accu += fMultDiv2(p_flt[1], *sta_1);
    178     sta_1 -= staStep1;
    179     accu += fMultDiv2(p_flt[2], *sta_1);
    180     sta_1 -= staStep1;
    181     accu += fMultDiv2(p_flt[3], *sta_1);
    182     sta_1 -= staStep1;
    183     accu += fMultDiv2(p_flt[4], *sta_1);
    184     *pData_1++ = (accu << 1);
    185     sta_1 += staStep2;
    186 
    187     p_flt += pfltStep;
    188     accu = fMultDiv2(p_flt[0], *sta_0);
    189     sta_0 += staStep1;
    190     accu += fMultDiv2(p_flt[1], *sta_0);
    191     sta_0 += staStep1;
    192     accu += fMultDiv2(p_flt[2], *sta_0);
    193     sta_0 += staStep1;
    194     accu += fMultDiv2(p_flt[3], *sta_0);
    195     sta_0 += staStep1;
    196     accu += fMultDiv2(p_flt[4], *sta_0);
    197     *pData_0-- = (accu << 1);
    198     sta_0 -= staStep2;
    199   }
    200 }
    201 #endif /* !defined(FUNCTION_qmfAnaPrototypeFirSlot) */
    202 
    203 #ifndef FUNCTION_qmfAnaPrototypeFirSlot_NonSymmetric
    204 /*!
    205   \brief Perform Analysis Prototype Filtering on a single slot of input data.
    206 */
    207 static void qmfAnaPrototypeFirSlot_NonSymmetric(
    208     FIXP_DBL *analysisBuffer,
    209     int no_channels, /*!< Number channels of analysis filter */
    210     const FIXP_PFT *p_filter, int p_stride, /*!< Stride of analysis filter    */
    211     FIXP_QAS *RESTRICT pFilterStates) {
    212   const FIXP_PFT *RESTRICT p_flt = p_filter;
    213   int p, k;
    214 
    215   for (k = 0; k < 2 * no_channels; k++) {
    216     FIXP_DBL accu = (FIXP_DBL)0;
    217 
    218     p_flt += QMF_NO_POLY * (p_stride - 1);
    219 
    220     /*
    221       Perform FIR-Filter
    222     */
    223     for (p = 0; p < QMF_NO_POLY; p++) {
    224       accu += fMultDiv2(*p_flt++, pFilterStates[2 * no_channels * p]);
    225     }
    226     analysisBuffer[2 * no_channels - 1 - k] = (accu << 1);
    227     pFilterStates++;
    228   }
    229 }
    230 #endif /* FUNCTION_qmfAnaPrototypeFirSlot_NonSymmetric */
    231 
    232 /*!
    233  *
    234  * \brief Perform real-valued forward modulation of the time domain
    235  *        data of timeIn and stores the real part of the subband
    236  *        samples in rSubband
    237  *
    238  */
    239 static void qmfForwardModulationLP_even(
    240     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Analysis Bank  */
    241     FIXP_DBL *timeIn,              /*!< Time Signal */
    242     FIXP_DBL *rSubband)            /*!< Real Output */
    243 {
    244   int i;
    245   int L = anaQmf->no_channels;
    246   int M = L >> 1;
    247   int scale;
    248   FIXP_DBL accu;
    249 
    250   const FIXP_DBL *timeInTmp1 = (FIXP_DBL *)&timeIn[3 * M];
    251   const FIXP_DBL *timeInTmp2 = timeInTmp1;
    252   FIXP_DBL *rSubbandTmp = rSubband;
    253 
    254   rSubband[0] = timeIn[3 * M] >> 1;
    255 
    256   for (i = M - 1; i != 0; i--) {
    257     accu = ((*--timeInTmp1) >> 1) + ((*++timeInTmp2) >> 1);
    258     *++rSubbandTmp = accu;
    259   }
    260 
    261   timeInTmp1 = &timeIn[2 * M];
    262   timeInTmp2 = &timeIn[0];
    263   rSubbandTmp = &rSubband[M];
    264 
    265   for (i = L - M; i != 0; i--) {
    266     accu = ((*timeInTmp1--) >> 1) - ((*timeInTmp2++) >> 1);
    267     *rSubbandTmp++ = accu;
    268   }
    269 
    270   dct_III(rSubband, timeIn, L, &scale);
    271 }
    272 
    273 #if !defined(FUNCTION_qmfForwardModulationLP_odd)
    274 static void qmfForwardModulationLP_odd(
    275     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Analysis Bank  */
    276     const FIXP_DBL *timeIn,        /*!< Time Signal */
    277     FIXP_DBL *rSubband)            /*!< Real Output */
    278 {
    279   int i;
    280   int L = anaQmf->no_channels;
    281   int M = L >> 1;
    282   int shift = (anaQmf->no_channels >> 6) + 1;
    283 
    284   for (i = 0; i < M; i++) {
    285     rSubband[M + i] = (timeIn[L - 1 - i] >> 1) - (timeIn[i] >> shift);
    286     rSubband[M - 1 - i] =
    287         (timeIn[L + i] >> 1) + (timeIn[2 * L - 1 - i] >> shift);
    288   }
    289 
    290   dct_IV(rSubband, L, &shift);
    291 }
    292 #endif /* !defined(FUNCTION_qmfForwardModulationLP_odd) */
    293 
    294 /*!
    295  *
    296  * \brief Perform complex-valued forward modulation of the time domain
    297  *        data of timeIn and stores the real part of the subband
    298  *        samples in rSubband, and the imaginary part in iSubband
    299  *
    300  *
    301  */
    302 #if !defined(FUNCTION_qmfForwardModulationHQ)
    303 static void qmfForwardModulationHQ(
    304     HANDLE_QMF_FILTER_BANK anaQmf,   /*!< Handle of Qmf Analysis Bank  */
    305     const FIXP_DBL *RESTRICT timeIn, /*!< Time Signal */
    306     FIXP_DBL *RESTRICT rSubband,     /*!< Real Output */
    307     FIXP_DBL *RESTRICT iSubband      /*!< Imaginary Output */
    308 ) {
    309   int i;
    310   int L = anaQmf->no_channels;
    311   int L2 = L << 1;
    312   int shift = 0;
    313 
    314   /* Time advance by one sample, which is equivalent to the complex
    315      rotation at the end of the analysis. Works only for STD mode. */
    316   if ((L == 64) && !(anaQmf->flags & (QMF_FLAG_CLDFB | QMF_FLAG_MPSLDFB))) {
    317     FIXP_DBL x, y;
    318 
    319     /*rSubband[0] = u[1] + u[0]*/
    320     /*iSubband[0] = u[1] - u[0]*/
    321     x = timeIn[1] >> 1;
    322     y = timeIn[0];
    323     rSubband[0] = x + (y >> 1);
    324     iSubband[0] = x - (y >> 1);
    325 
    326     /*rSubband[n] = u[n+1] - u[2M-n], n=1,...,M-1*/
    327     /*iSubband[n] = u[n+1] + u[2M-n], n=1,...,M-1*/
    328     for (i = 1; i < L; i++) {
    329       x = timeIn[i + 1] >> 1; /*u[n+1]  */
    330       y = timeIn[L2 - i];     /*u[2M-n] */
    331       rSubband[i] = x - (y >> 1);
    332       iSubband[i] = x + (y >> 1);
    333     }
    334   } else {
    335     for (i = 0; i < L; i += 2) {
    336       FIXP_DBL x0, x1, y0, y1;
    337 
    338       x0 = timeIn[i + 0] >> 1;
    339       x1 = timeIn[i + 1] >> 1;
    340       y0 = timeIn[L2 - 1 - i];
    341       y1 = timeIn[L2 - 2 - i];
    342 
    343       rSubband[i + 0] = x0 - (y0 >> 1);
    344       rSubband[i + 1] = x1 - (y1 >> 1);
    345       iSubband[i + 0] = x0 + (y0 >> 1);
    346       iSubband[i + 1] = x1 + (y1 >> 1);
    347     }
    348   }
    349 
    350   dct_IV(rSubband, L, &shift);
    351   dst_IV(iSubband, L, &shift);
    352 
    353   /* Do the complex rotation except for the case of 64 bands (in STD mode). */
    354   if ((L != 64) || (anaQmf->flags & (QMF_FLAG_CLDFB | QMF_FLAG_MPSLDFB))) {
    355     if (anaQmf->flags & QMF_FLAG_MPSLDFB_OPTIMIZE_MODULATION) {
    356       FIXP_DBL iBand;
    357       for (i = 0; i < fMin(anaQmf->lsb, L); i += 2) {
    358         iBand = rSubband[i];
    359         rSubband[i] = -iSubband[i];
    360         iSubband[i] = iBand;
    361 
    362         iBand = -rSubband[i + 1];
    363         rSubband[i + 1] = iSubband[i + 1];
    364         iSubband[i + 1] = iBand;
    365       }
    366     } else {
    367       const FIXP_QTW *sbr_t_cos;
    368       const FIXP_QTW *sbr_t_sin;
    369       const int len = L; /* was len = fMin(anaQmf->lsb, L) but in case of USAC
    370                             the signal above lsb is actually needed in some
    371                             cases (HBE?) */
    372       sbr_t_cos = anaQmf->t_cos;
    373       sbr_t_sin = anaQmf->t_sin;
    374 
    375       for (i = 0; i < len; i++) {
    376         cplxMult(&iSubband[i], &rSubband[i], iSubband[i], rSubband[i],
    377                  sbr_t_cos[i], sbr_t_sin[i]);
    378       }
    379     }
    380   }
    381 }
    382 #endif /* FUNCTION_qmfForwardModulationHQ */
    383 
    384 /*
    385  * \brief Perform one QMF slot analysis of the time domain data of timeIn
    386  *        with specified stride and stores the real part of the subband
    387  *        samples in rSubband, and the imaginary part in iSubband
    388  *
    389  *        Note: anaQmf->lsb can be greater than anaQmf->no_channels in case
    390  *        of implicit resampling (USAC with reduced 3/4 core frame length).
    391  */
    392 #if (SAMPLE_BITS != DFRACT_BITS) && (QAS_BITS == DFRACT_BITS)
    393 void qmfAnalysisFilteringSlot(
    394     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Synthesis Bank  */
    395     FIXP_DBL *qmfReal,             /*!< Low and High band, real */
    396     FIXP_DBL *qmfImag,             /*!< Low and High band, imag */
    397     const LONG *RESTRICT timeIn,   /*!< Pointer to input */
    398     const int stride,              /*!< stride factor of input */
    399     FIXP_DBL *pWorkBuffer          /*!< pointer to temporal working buffer */
    400 ) {
    401   int offset = anaQmf->no_channels * (QMF_NO_POLY * 2 - 1);
    402   /*
    403     Feed time signal into oldest anaQmf->no_channels states
    404   */
    405   {
    406     FIXP_DBL *FilterStatesAnaTmp = ((FIXP_DBL *)anaQmf->FilterStates) + offset;
    407 
    408     /* Feed and scale actual time in slot */
    409     for (int i = anaQmf->no_channels >> 1; i != 0; i--) {
    410       /* Place INT_PCM value left aligned in scaledTimeIn */
    411 
    412       *FilterStatesAnaTmp++ = (FIXP_QAS)*timeIn;
    413       timeIn += stride;
    414       *FilterStatesAnaTmp++ = (FIXP_QAS)*timeIn;
    415       timeIn += stride;
    416     }
    417   }
    418 
    419   if (anaQmf->flags & QMF_FLAG_NONSYMMETRIC) {
    420     qmfAnaPrototypeFirSlot_NonSymmetric(pWorkBuffer, anaQmf->no_channels,
    421                                         anaQmf->p_filter, anaQmf->p_stride,
    422                                         (FIXP_QAS *)anaQmf->FilterStates);
    423   } else {
    424     qmfAnaPrototypeFirSlot(pWorkBuffer, anaQmf->no_channels, anaQmf->p_filter,
    425                            anaQmf->p_stride, (FIXP_QAS *)anaQmf->FilterStates);
    426   }
    427 
    428   if (anaQmf->flags & QMF_FLAG_LP) {
    429     if (anaQmf->flags & QMF_FLAG_CLDFB)
    430       qmfForwardModulationLP_odd(anaQmf, pWorkBuffer, qmfReal);
    431     else
    432       qmfForwardModulationLP_even(anaQmf, pWorkBuffer, qmfReal);
    433 
    434   } else {
    435     qmfForwardModulationHQ(anaQmf, pWorkBuffer, qmfReal, qmfImag);
    436   }
    437   /*
    438     Shift filter states
    439 
    440     Should be realized with modulo adressing on a DSP instead of a true buffer
    441     shift
    442   */
    443   FDKmemmove(anaQmf->FilterStates,
    444              (FIXP_QAS *)anaQmf->FilterStates + anaQmf->no_channels,
    445              offset * sizeof(FIXP_QAS));
    446 }
    447 #endif
    448 
    449 void qmfAnalysisFilteringSlot(
    450     HANDLE_QMF_FILTER_BANK anaQmf,  /*!< Handle of Qmf Synthesis Bank  */
    451     FIXP_DBL *qmfReal,              /*!< Low and High band, real */
    452     FIXP_DBL *qmfImag,              /*!< Low and High band, imag */
    453     const INT_PCM *RESTRICT timeIn, /*!< Pointer to input */
    454     const int stride,               /*!< stride factor of input */
    455     FIXP_DBL *pWorkBuffer           /*!< pointer to temporal working buffer */
    456 ) {
    457   int offset = anaQmf->no_channels * (QMF_NO_POLY * 2 - 1);
    458   /*
    459     Feed time signal into oldest anaQmf->no_channels states
    460   */
    461   {
    462     FIXP_QAS *FilterStatesAnaTmp = ((FIXP_QAS *)anaQmf->FilterStates) + offset;
    463 
    464     /* Feed and scale actual time in slot */
    465     for (int i = anaQmf->no_channels >> 1; i != 0; i--) {
    466     /* Place INT_PCM value left aligned in scaledTimeIn */
    467 #if (QAS_BITS == SAMPLE_BITS)
    468       *FilterStatesAnaTmp++ = (FIXP_QAS)*timeIn;
    469       timeIn += stride;
    470       *FilterStatesAnaTmp++ = (FIXP_QAS)*timeIn;
    471       timeIn += stride;
    472 #elif (QAS_BITS > SAMPLE_BITS)
    473       *FilterStatesAnaTmp++ = ((FIXP_QAS)*timeIn) << (QAS_BITS - SAMPLE_BITS);
    474       timeIn += stride;
    475       *FilterStatesAnaTmp++ = ((FIXP_QAS)*timeIn) << (QAS_BITS - SAMPLE_BITS);
    476       timeIn += stride;
    477 #else
    478       *FilterStatesAnaTmp++ = (FIXP_QAS)((*timeIn) >> (SAMPLE_BITS - QAS_BITS));
    479       timeIn += stride;
    480       *FilterStatesAnaTmp++ = (FIXP_QAS)((*timeIn) >> (SAMPLE_BITS - QAS_BITS));
    481       timeIn += stride;
    482 #endif
    483     }
    484   }
    485 
    486   if (anaQmf->flags & QMF_FLAG_NONSYMMETRIC) {
    487     qmfAnaPrototypeFirSlot_NonSymmetric(pWorkBuffer, anaQmf->no_channels,
    488                                         anaQmf->p_filter, anaQmf->p_stride,
    489                                         (FIXP_QAS *)anaQmf->FilterStates);
    490   } else {
    491     qmfAnaPrototypeFirSlot(pWorkBuffer, anaQmf->no_channels, anaQmf->p_filter,
    492                            anaQmf->p_stride, (FIXP_QAS *)anaQmf->FilterStates);
    493   }
    494 
    495   if (anaQmf->flags & QMF_FLAG_LP) {
    496     if (anaQmf->flags & QMF_FLAG_CLDFB)
    497       qmfForwardModulationLP_odd(anaQmf, pWorkBuffer, qmfReal);
    498     else
    499       qmfForwardModulationLP_even(anaQmf, pWorkBuffer, qmfReal);
    500 
    501   } else {
    502     qmfForwardModulationHQ(anaQmf, pWorkBuffer, qmfReal, qmfImag);
    503   }
    504   /*
    505     Shift filter states
    506 
    507     Should be realized with modulo adressing on a DSP instead of a true buffer
    508     shift
    509   */
    510   FDKmemmove(anaQmf->FilterStates,
    511              (FIXP_QAS *)anaQmf->FilterStates + anaQmf->no_channels,
    512              offset * sizeof(FIXP_QAS));
    513 }
    514 
    515 /*!
    516  *
    517  * \brief Perform complex-valued subband filtering of the time domain
    518  *        data of timeIn and stores the real part of the subband
    519  *        samples in rAnalysis, and the imaginary part in iAnalysis
    520  * The qmf coefficient table is symmetric. The symmetry is expoited by
    521  * shrinking the coefficient table to half the size. The addressing mode
    522  * takes care of the symmetries.
    523  *
    524  *
    525  * \sa PolyphaseFiltering
    526  */
    527 #if (SAMPLE_BITS != DFRACT_BITS) && (QAS_BITS == DFRACT_BITS)
    528 void qmfAnalysisFiltering(
    529     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Analysis Bank */
    530     FIXP_DBL **qmfReal,            /*!< Pointer to real subband slots */
    531     FIXP_DBL **qmfImag,            /*!< Pointer to imag subband slots */
    532     QMF_SCALE_FACTOR *scaleFactor, const LONG *timeIn, /*!< Time signal */
    533     const int timeIn_e, const int stride,
    534     FIXP_DBL *pWorkBuffer /*!< pointer to temporal working buffer */
    535 ) {
    536   int i;
    537   int no_channels = anaQmf->no_channels;
    538 
    539   scaleFactor->lb_scale =
    540       -ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK - timeIn_e;
    541   scaleFactor->lb_scale -= anaQmf->filterScale;
    542 
    543   for (i = 0; i < anaQmf->no_col; i++) {
    544     FIXP_DBL *qmfImagSlot = NULL;
    545 
    546     if (!(anaQmf->flags & QMF_FLAG_LP)) {
    547       qmfImagSlot = qmfImag[i];
    548     }
    549 
    550     qmfAnalysisFilteringSlot(anaQmf, qmfReal[i], qmfImagSlot, timeIn, stride,
    551                              pWorkBuffer);
    552 
    553     timeIn += no_channels * stride;
    554 
    555   } /* no_col loop  i  */
    556 }
    557 #endif
    558 
    559 void qmfAnalysisFiltering(
    560     HANDLE_QMF_FILTER_BANK anaQmf, /*!< Handle of Qmf Analysis Bank */
    561     FIXP_DBL **qmfReal,            /*!< Pointer to real subband slots */
    562     FIXP_DBL **qmfImag,            /*!< Pointer to imag subband slots */
    563     QMF_SCALE_FACTOR *scaleFactor, const INT_PCM *timeIn, /*!< Time signal */
    564     const int timeIn_e, const int stride,
    565     FIXP_DBL *pWorkBuffer /*!< pointer to temporal working buffer */
    566 ) {
    567   int i;
    568   int no_channels = anaQmf->no_channels;
    569 
    570   scaleFactor->lb_scale =
    571       -ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK - timeIn_e;
    572   scaleFactor->lb_scale -= anaQmf->filterScale;
    573 
    574   for (i = 0; i < anaQmf->no_col; i++) {
    575     FIXP_DBL *qmfImagSlot = NULL;
    576 
    577     if (!(anaQmf->flags & QMF_FLAG_LP)) {
    578       qmfImagSlot = qmfImag[i];
    579     }
    580 
    581     qmfAnalysisFilteringSlot(anaQmf, qmfReal[i], qmfImagSlot, timeIn, stride,
    582                              pWorkBuffer);
    583 
    584     timeIn += no_channels * stride;
    585 
    586   } /* no_col loop  i  */
    587 }
    588 
    589 /*!
    590  *
    591  * \brief Perform low power inverse modulation of the subband
    592  *        samples stored in rSubband (real part) and iSubband (imaginary
    593  *        part) and stores the result in pWorkBuffer.
    594  *
    595  */
    596 inline static void qmfInverseModulationLP_even(
    597     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank  */
    598     const FIXP_DBL *qmfReal, /*!< Pointer to qmf real subband slot (input) */
    599     const int scaleFactorLowBand,  /*!< Scalefactor for Low band */
    600     const int scaleFactorHighBand, /*!< Scalefactor for High band */
    601     FIXP_DBL *pTimeOut             /*!< Pointer to qmf subband slot (output)*/
    602 ) {
    603   int i;
    604   int L = synQmf->no_channels;
    605   int M = L >> 1;
    606   int scale;
    607   FIXP_DBL tmp;
    608   FIXP_DBL *RESTRICT tReal = pTimeOut;
    609   FIXP_DBL *RESTRICT tImag = pTimeOut + L;
    610 
    611   /* Move input to output vector with offset */
    612   scaleValues(&tReal[0], &qmfReal[0], synQmf->lsb, (int)scaleFactorLowBand);
    613   scaleValues(&tReal[0 + synQmf->lsb], &qmfReal[0 + synQmf->lsb],
    614               synQmf->usb - synQmf->lsb, (int)scaleFactorHighBand);
    615   FDKmemclear(&tReal[0 + synQmf->usb], (L - synQmf->usb) * sizeof(FIXP_DBL));
    616 
    617   /* Dct type-2 transform */
    618   dct_II(tReal, tImag, L, &scale);
    619 
    620   /* Expand output and replace inplace the output buffers */
    621   tImag[0] = tReal[M];
    622   tImag[M] = (FIXP_DBL)0;
    623   tmp = tReal[0];
    624   tReal[0] = tReal[M];
    625   tReal[M] = tmp;
    626 
    627   for (i = 1; i < M / 2; i++) {
    628     /* Imag */
    629     tmp = tReal[L - i];
    630     tImag[M - i] = tmp;
    631     tImag[i + M] = -tmp;
    632 
    633     tmp = tReal[M + i];
    634     tImag[i] = tmp;
    635     tImag[L - i] = -tmp;
    636 
    637     /* Real */
    638     tReal[M + i] = tReal[i];
    639     tReal[L - i] = tReal[M - i];
    640     tmp = tReal[i];
    641     tReal[i] = tReal[M - i];
    642     tReal[M - i] = tmp;
    643   }
    644   /* Remaining odd terms */
    645   tmp = tReal[M + M / 2];
    646   tImag[M / 2] = tmp;
    647   tImag[M / 2 + M] = -tmp;
    648 
    649   tReal[M + M / 2] = tReal[M / 2];
    650 }
    651 
    652 inline static void qmfInverseModulationLP_odd(
    653     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank  */
    654     const FIXP_DBL *qmfReal, /*!< Pointer to qmf real subband slot (input) */
    655     const int scaleFactorLowBand,  /*!< Scalefactor for Low band */
    656     const int scaleFactorHighBand, /*!< Scalefactor for High band */
    657     FIXP_DBL *pTimeOut             /*!< Pointer to qmf subband slot (output)*/
    658 ) {
    659   int i;
    660   int L = synQmf->no_channels;
    661   int M = L >> 1;
    662   int shift = 0;
    663 
    664   /* Move input to output vector with offset */
    665   scaleValues(pTimeOut + M, qmfReal, synQmf->lsb, scaleFactorLowBand);
    666   scaleValues(pTimeOut + M + synQmf->lsb, qmfReal + synQmf->lsb,
    667               synQmf->usb - synQmf->lsb, scaleFactorHighBand);
    668   FDKmemclear(pTimeOut + M + synQmf->usb, (L - synQmf->usb) * sizeof(FIXP_DBL));
    669 
    670   dct_IV(pTimeOut + M, L, &shift);
    671   for (i = 0; i < M; i++) {
    672     pTimeOut[i] = pTimeOut[L - 1 - i];
    673     pTimeOut[2 * L - 1 - i] = -pTimeOut[L + i];
    674   }
    675 }
    676 
    677 #ifndef FUNCTION_qmfInverseModulationHQ
    678 /*!
    679  *
    680  * \brief Perform complex-valued inverse modulation of the subband
    681  *        samples stored in rSubband (real part) and iSubband (imaginary
    682  *        part) and stores the result in pWorkBuffer.
    683  *
    684  */
    685 inline static void qmfInverseModulationHQ(
    686     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank     */
    687     const FIXP_DBL *qmfReal,       /*!< Pointer to qmf real subband slot */
    688     const FIXP_DBL *qmfImag,       /*!< Pointer to qmf imag subband slot */
    689     const int scaleFactorLowBand,  /*!< Scalefactor for Low band         */
    690     const int scaleFactorHighBand, /*!< Scalefactor for High band        */
    691     FIXP_DBL *pWorkBuffer          /*!< WorkBuffer (output)              */
    692 ) {
    693   int i;
    694   int L = synQmf->no_channels;
    695   int M = L >> 1;
    696   int shift = 0;
    697   FIXP_DBL *RESTRICT tReal = pWorkBuffer;
    698   FIXP_DBL *RESTRICT tImag = pWorkBuffer + L;
    699 
    700   if (synQmf->flags & QMF_FLAG_CLDFB) {
    701     for (i = 0; i < synQmf->lsb; i++) {
    702       cplxMult(&tImag[i], &tReal[i], scaleValue(qmfImag[i], scaleFactorLowBand),
    703                scaleValue(qmfReal[i], scaleFactorLowBand), synQmf->t_cos[i],
    704                synQmf->t_sin[i]);
    705     }
    706     for (; i < synQmf->usb; i++) {
    707       cplxMult(&tImag[i], &tReal[i],
    708                scaleValue(qmfImag[i], scaleFactorHighBand),
    709                scaleValue(qmfReal[i], scaleFactorHighBand), synQmf->t_cos[i],
    710                synQmf->t_sin[i]);
    711     }
    712   }
    713 
    714   if ((synQmf->flags & QMF_FLAG_CLDFB) == 0) {
    715     scaleValues(&tReal[0], &qmfReal[0], synQmf->lsb, (int)scaleFactorLowBand);
    716     scaleValues(&tReal[0 + synQmf->lsb], &qmfReal[0 + synQmf->lsb],
    717                 synQmf->usb - synQmf->lsb, (int)scaleFactorHighBand);
    718     scaleValues(&tImag[0], &qmfImag[0], synQmf->lsb, (int)scaleFactorLowBand);
    719     scaleValues(&tImag[0 + synQmf->lsb], &qmfImag[0 + synQmf->lsb],
    720                 synQmf->usb - synQmf->lsb, (int)scaleFactorHighBand);
    721   }
    722 
    723   FDKmemclear(&tReal[synQmf->usb],
    724               (synQmf->no_channels - synQmf->usb) * sizeof(FIXP_DBL));
    725   FDKmemclear(&tImag[synQmf->usb],
    726               (synQmf->no_channels - synQmf->usb) * sizeof(FIXP_DBL));
    727 
    728   dct_IV(tReal, L, &shift);
    729   dst_IV(tImag, L, &shift);
    730 
    731   if (synQmf->flags & QMF_FLAG_CLDFB) {
    732     for (i = 0; i < M; i++) {
    733       FIXP_DBL r1, i1, r2, i2;
    734       r1 = tReal[i];
    735       i2 = tImag[L - 1 - i];
    736       r2 = tReal[L - i - 1];
    737       i1 = tImag[i];
    738 
    739       tReal[i] = (r1 - i1) >> 1;
    740       tImag[L - 1 - i] = -(r1 + i1) >> 1;
    741       tReal[L - i - 1] = (r2 - i2) >> 1;
    742       tImag[i] = -(r2 + i2) >> 1;
    743     }
    744   } else {
    745     /* The array accesses are negative to compensate the missing minus sign in
    746      * the low and hi band gain. */
    747     /* 26 cycles on ARM926 */
    748     for (i = 0; i < M; i++) {
    749       FIXP_DBL r1, i1, r2, i2;
    750       r1 = -tReal[i];
    751       i2 = -tImag[L - 1 - i];
    752       r2 = -tReal[L - i - 1];
    753       i1 = -tImag[i];
    754 
    755       tReal[i] = (r1 - i1) >> 1;
    756       tImag[L - 1 - i] = -(r1 + i1) >> 1;
    757       tReal[L - i - 1] = (r2 - i2) >> 1;
    758       tImag[i] = -(r2 + i2) >> 1;
    759     }
    760   }
    761 }
    762 #endif /* #ifndef FUNCTION_qmfInverseModulationHQ */
    763 
    764 /*!
    765  *
    766  * \brief Create QMF filter bank instance
    767  *
    768  * \return 0 if successful
    769  *
    770  */
    771 static int qmfInitFilterBank(
    772     HANDLE_QMF_FILTER_BANK h_Qmf, /*!< Handle to return */
    773     void *pFilterStates,          /*!< Handle to filter states */
    774     int noCols,                   /*!< Number of timeslots per frame */
    775     int lsb,                      /*!< Lower end of QMF frequency range */
    776     int usb,                      /*!< Upper end of QMF frequency range */
    777     int no_channels,              /*!< Number of channels (bands) */
    778     UINT flags,                   /*!< flags */
    779     int synflag)                  /*!< 1: synthesis; 0: analysis */
    780 {
    781   FDKmemclear(h_Qmf, sizeof(QMF_FILTER_BANK));
    782 
    783   if (flags & QMF_FLAG_MPSLDFB) {
    784     flags |= QMF_FLAG_NONSYMMETRIC;
    785     flags |= QMF_FLAG_MPSLDFB_OPTIMIZE_MODULATION;
    786 
    787     h_Qmf->t_cos = NULL;
    788     h_Qmf->t_sin = NULL;
    789     h_Qmf->filterScale = QMF_MPSLDFB_PFT_SCALE;
    790     h_Qmf->p_stride = 1;
    791 
    792     switch (no_channels) {
    793       case 64:
    794         h_Qmf->p_filter = qmf_mpsldfb_640;
    795         h_Qmf->FilterSize = 640;
    796         break;
    797       case 32:
    798         h_Qmf->p_filter = qmf_mpsldfb_320;
    799         h_Qmf->FilterSize = 320;
    800         break;
    801       default:
    802         return -1;
    803     }
    804   }
    805 
    806   if (!(flags & QMF_FLAG_MPSLDFB) && (flags & QMF_FLAG_CLDFB)) {
    807     flags |= QMF_FLAG_NONSYMMETRIC;
    808     h_Qmf->filterScale = QMF_CLDFB_PFT_SCALE;
    809 
    810     h_Qmf->p_stride = 1;
    811     switch (no_channels) {
    812       case 64:
    813         h_Qmf->t_cos = qmf_phaseshift_cos64_cldfb;
    814         h_Qmf->t_sin = qmf_phaseshift_sin64_cldfb;
    815         h_Qmf->p_filter = qmf_cldfb_640;
    816         h_Qmf->FilterSize = 640;
    817         break;
    818       case 32:
    819         h_Qmf->t_cos = (synflag) ? qmf_phaseshift_cos32_cldfb_syn
    820                                  : qmf_phaseshift_cos32_cldfb_ana;
    821         h_Qmf->t_sin = qmf_phaseshift_sin32_cldfb;
    822         h_Qmf->p_filter = qmf_cldfb_320;
    823         h_Qmf->FilterSize = 320;
    824         break;
    825       case 16:
    826         h_Qmf->t_cos = (synflag) ? qmf_phaseshift_cos16_cldfb_syn
    827                                  : qmf_phaseshift_cos16_cldfb_ana;
    828         h_Qmf->t_sin = qmf_phaseshift_sin16_cldfb;
    829         h_Qmf->p_filter = qmf_cldfb_160;
    830         h_Qmf->FilterSize = 160;
    831         break;
    832       case 8:
    833         h_Qmf->t_cos = (synflag) ? qmf_phaseshift_cos8_cldfb_syn
    834                                  : qmf_phaseshift_cos8_cldfb_ana;
    835         h_Qmf->t_sin = qmf_phaseshift_sin8_cldfb;
    836         h_Qmf->p_filter = qmf_cldfb_80;
    837         h_Qmf->FilterSize = 80;
    838         break;
    839       default:
    840         return -1;
    841     }
    842   }
    843 
    844   if (!(flags & QMF_FLAG_MPSLDFB) && ((flags & QMF_FLAG_CLDFB) == 0)) {
    845     switch (no_channels) {
    846       case 64:
    847         h_Qmf->p_filter = qmf_pfilt640;
    848         h_Qmf->t_cos = qmf_phaseshift_cos64;
    849         h_Qmf->t_sin = qmf_phaseshift_sin64;
    850         h_Qmf->p_stride = 1;
    851         h_Qmf->FilterSize = 640;
    852         h_Qmf->filterScale = 0;
    853         break;
    854       case 40:
    855         if (synflag) {
    856           break;
    857         } else {
    858           h_Qmf->p_filter = qmf_pfilt400; /* Scaling factor 0.8 */
    859           h_Qmf->t_cos = qmf_phaseshift_cos40;
    860           h_Qmf->t_sin = qmf_phaseshift_sin40;
    861           h_Qmf->filterScale = 1;
    862           h_Qmf->p_stride = 1;
    863           h_Qmf->FilterSize = no_channels * 10;
    864         }
    865         break;
    866       case 32:
    867         h_Qmf->p_filter = qmf_pfilt640;
    868         if (flags & QMF_FLAG_DOWNSAMPLED) {
    869           h_Qmf->t_cos = qmf_phaseshift_cos_downsamp32;
    870           h_Qmf->t_sin = qmf_phaseshift_sin_downsamp32;
    871         } else {
    872           h_Qmf->t_cos = qmf_phaseshift_cos32;
    873           h_Qmf->t_sin = qmf_phaseshift_sin32;
    874         }
    875         h_Qmf->p_stride = 2;
    876         h_Qmf->FilterSize = 640;
    877         h_Qmf->filterScale = 0;
    878         break;
    879       case 20:
    880         h_Qmf->p_filter = qmf_pfilt200;
    881         h_Qmf->p_stride = 1;
    882         h_Qmf->FilterSize = 200;
    883         h_Qmf->filterScale = 0;
    884         break;
    885       case 12:
    886         h_Qmf->p_filter = qmf_pfilt120;
    887         h_Qmf->p_stride = 1;
    888         h_Qmf->FilterSize = 120;
    889         h_Qmf->filterScale = 0;
    890         break;
    891       case 8:
    892         h_Qmf->p_filter = qmf_pfilt640;
    893         h_Qmf->p_stride = 8;
    894         h_Qmf->FilterSize = 640;
    895         h_Qmf->filterScale = 0;
    896         break;
    897       case 16:
    898         h_Qmf->p_filter = qmf_pfilt640;
    899         h_Qmf->t_cos = qmf_phaseshift_cos16;
    900         h_Qmf->t_sin = qmf_phaseshift_sin16;
    901         h_Qmf->p_stride = 4;
    902         h_Qmf->FilterSize = 640;
    903         h_Qmf->filterScale = 0;
    904         break;
    905       case 24:
    906         h_Qmf->p_filter = qmf_pfilt240;
    907         h_Qmf->t_cos = qmf_phaseshift_cos24;
    908         h_Qmf->t_sin = qmf_phaseshift_sin24;
    909         h_Qmf->p_stride = 1;
    910         h_Qmf->FilterSize = 240;
    911         h_Qmf->filterScale = 1;
    912         break;
    913       default:
    914         return -1;
    915     }
    916   }
    917 
    918   h_Qmf->synScalefactor = h_Qmf->filterScale;
    919   // DCT|DST dependency
    920   switch (no_channels) {
    921     case 128:
    922       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK + 1;
    923       break;
    924     case 40: {
    925       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK - 1;
    926     } break;
    927     case 64:
    928       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK;
    929       break;
    930     case 8:
    931       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK - 3;
    932       break;
    933     case 12:
    934       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK;
    935       break;
    936     case 20:
    937       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK + 1;
    938       break;
    939     case 32:
    940       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK - 1;
    941       break;
    942     case 16:
    943       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK - 2;
    944       break;
    945     case 24:
    946       h_Qmf->synScalefactor += ALGORITHMIC_SCALING_IN_SYNTHESIS_FILTERBANK - 1;
    947       break;
    948     default:
    949       return -1;
    950   }
    951 
    952   h_Qmf->flags = flags;
    953 
    954   h_Qmf->no_channels = no_channels;
    955   h_Qmf->no_col = noCols;
    956 
    957   h_Qmf->lsb = fMin(lsb, h_Qmf->no_channels);
    958   h_Qmf->usb = synflag
    959                    ? fMin(usb, h_Qmf->no_channels)
    960                    : usb; /* was: h_Qmf->usb = fMin(usb, h_Qmf->no_channels); */
    961 
    962   h_Qmf->FilterStates = (void *)pFilterStates;
    963 
    964   h_Qmf->outScalefactor =
    965       (ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK + h_Qmf->filterScale) +
    966       h_Qmf->synScalefactor;
    967 
    968   h_Qmf->outGain_m =
    969       (FIXP_DBL)0x80000000; /* default init value will be not applied */
    970   h_Qmf->outGain_e = 0;
    971 
    972   return (0);
    973 }
    974 
    975 /*!
    976  *
    977  * \brief Adjust synthesis qmf filter states
    978  *
    979  * \return void
    980  *
    981  */
    982 static inline void qmfAdaptFilterStates(
    983     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Filter Bank */
    984     int scaleFactorDiff)           /*!< Scale factor difference to be applied */
    985 {
    986   if (synQmf == NULL || synQmf->FilterStates == NULL) {
    987     return;
    988   }
    989   if (scaleFactorDiff > 0) {
    990     scaleValuesSaturate((FIXP_QSS *)synQmf->FilterStates,
    991                         synQmf->no_channels * (QMF_NO_POLY * 2 - 1),
    992                         scaleFactorDiff);
    993   } else {
    994     scaleValues((FIXP_QSS *)synQmf->FilterStates,
    995                 synQmf->no_channels * (QMF_NO_POLY * 2 - 1), scaleFactorDiff);
    996   }
    997 }
    998 
    999 /*!
   1000  *
   1001  * \brief Create QMF filter bank instance
   1002  *
   1003  *
   1004  * \return 0 if succesful
   1005  *
   1006  */
   1007 int qmfInitAnalysisFilterBank(
   1008     HANDLE_QMF_FILTER_BANK h_Qmf, /*!< Returns handle */
   1009     FIXP_QAS *pFilterStates,      /*!< Handle to filter states */
   1010     int noCols,                   /*!< Number of timeslots per frame */
   1011     int lsb,                      /*!< lower end of QMF */
   1012     int usb,                      /*!< upper end of QMF */
   1013     int no_channels,              /*!< Number of channels (bands) */
   1014     int flags)                    /*!< Low Power flag */
   1015 {
   1016   int err = qmfInitFilterBank(h_Qmf, pFilterStates, noCols, lsb, usb,
   1017                               no_channels, flags, 0);
   1018   if (!(flags & QMF_FLAG_KEEP_STATES) && (h_Qmf->FilterStates != NULL)) {
   1019     FDKmemclear(h_Qmf->FilterStates,
   1020                 (2 * QMF_NO_POLY - 1) * h_Qmf->no_channels * sizeof(FIXP_QAS));
   1021   }
   1022 
   1023   FDK_ASSERT(h_Qmf->no_channels >= h_Qmf->lsb);
   1024 
   1025   return err;
   1026 }
   1027 
   1028 /*!
   1029  *
   1030  * \brief Create QMF filter bank instance
   1031  *
   1032  *
   1033  * \return 0 if succesful
   1034  *
   1035  */
   1036 int qmfInitSynthesisFilterBank(
   1037     HANDLE_QMF_FILTER_BANK h_Qmf, /*!< Returns handle */
   1038     FIXP_QSS *pFilterStates,      /*!< Handle to filter states */
   1039     int noCols,                   /*!< Number of timeslots per frame */
   1040     int lsb,                      /*!< lower end of QMF */
   1041     int usb,                      /*!< upper end of QMF */
   1042     int no_channels,              /*!< Number of channels (bands) */
   1043     int flags)                    /*!< Low Power flag */
   1044 {
   1045   int oldOutScale = h_Qmf->outScalefactor;
   1046   int err = qmfInitFilterBank(h_Qmf, pFilterStates, noCols, lsb, usb,
   1047                               no_channels, flags, 1);
   1048   if (h_Qmf->FilterStates != NULL) {
   1049     if (!(flags & QMF_FLAG_KEEP_STATES)) {
   1050       FDKmemclear(
   1051           h_Qmf->FilterStates,
   1052           (2 * QMF_NO_POLY - 1) * h_Qmf->no_channels * sizeof(FIXP_QSS));
   1053     } else {
   1054       qmfAdaptFilterStates(h_Qmf, oldOutScale - h_Qmf->outScalefactor);
   1055     }
   1056   }
   1057 
   1058   FDK_ASSERT(h_Qmf->no_channels >= h_Qmf->lsb);
   1059   FDK_ASSERT(h_Qmf->no_channels >= h_Qmf->usb);
   1060 
   1061   return err;
   1062 }
   1063 
   1064 /*!
   1065  *
   1066  * \brief Change scale factor for output data and adjust qmf filter states
   1067  *
   1068  * \return void
   1069  *
   1070  */
   1071 void qmfChangeOutScalefactor(
   1072     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank */
   1073     int outScalefactor             /*!< New scaling factor for output data */
   1074 ) {
   1075   if (synQmf == NULL) {
   1076     return;
   1077   }
   1078 
   1079   /* Add internal filterbank scale */
   1080   outScalefactor +=
   1081       (ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK + synQmf->filterScale) +
   1082       synQmf->synScalefactor;
   1083 
   1084   /* adjust filter states when scale factor has been changed */
   1085   if (synQmf->outScalefactor != outScalefactor) {
   1086     int diff;
   1087 
   1088     diff = synQmf->outScalefactor - outScalefactor;
   1089 
   1090     qmfAdaptFilterStates(synQmf, diff);
   1091 
   1092     /* save new scale factor */
   1093     synQmf->outScalefactor = outScalefactor;
   1094   }
   1095 }
   1096 
   1097 /*!
   1098  *
   1099  * \brief Get scale factor change which was set by qmfChangeOutScalefactor()
   1100  *
   1101  * \return scaleFactor
   1102  *
   1103  */
   1104 int qmfGetOutScalefactor(
   1105     HANDLE_QMF_FILTER_BANK synQmf) /*!< Handle of Qmf Synthesis Bank */
   1106 {
   1107   int scaleFactor = synQmf->outScalefactor
   1108                         ? (synQmf->outScalefactor -
   1109                            (ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK +
   1110                             synQmf->filterScale + synQmf->synScalefactor))
   1111                         : 0;
   1112   return scaleFactor;
   1113 }
   1114 
   1115 /*!
   1116  *
   1117  * \brief Change gain for output data
   1118  *
   1119  * \return void
   1120  *
   1121  */
   1122 void qmfChangeOutGain(
   1123     HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank */
   1124     FIXP_DBL outputGain,           /*!< New gain for output data (mantissa) */
   1125     int outputGainScale            /*!< New gain for output data (exponent) */
   1126 ) {
   1127   synQmf->outGain_m = outputGain;
   1128   synQmf->outGain_e = outputGainScale;
   1129 }
   1130 
   1131 /* When QMF_16IN_32OUT is set, synthesis functions for 16 and 32 bit parallel
   1132  * output is compiled */
   1133 #define INT_PCM_QMFOUT INT_PCM
   1134 #define SAMPLE_BITS_QMFOUT SAMPLE_BITS
   1135 #include "qmf_pcm.h"
   1136