text: /*
  ** FAAD2 - Freeware Advanced Audio (AAC) Decoder including SBR decoding
  ** Copyright (C) 2003-2005 M. Bakker, Nero AG, http://www.nero.com
  **  
  ** This program is free software; you can redistribute it and/or modify
  ** it under the terms of the GNU General Public License as published by
  ** the Free Software Foundation; either version 2 of the License, or
  ** (at your option) any later version.
  ** 
  ** This program is distributed in the hope that it will be useful,
  ** but WITHOUT ANY WARRANTY; without even the implied warranty of
  ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  ** GNU General Public License for more details.
  ** 
  ** You should have received a copy of the GNU General Public License
  ** along with this program; if not, write to the Free Software 
  ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  **
  ** Any non-GPL usage of this software or parts of this software is strictly
  ** forbidden.
  **
  ** The "appropriate copyright message" mentioned in section 2c of the GPLv2
  ** must read: "Code from FAAD2 is copyright (c) Nero AG, www.nero.com"
  **
  ** Commercial non-GPL licensing of this software is possible.
  ** For more info contact Nero AG through Mpeg4AAClicense@nero.com.
  **
  ** $Id: sbr_qmf.c,v 1.32 2007/11/01 12:33:36 menno Exp $
  **/
  
  #include "common.h"
  #include "structs.h"
  
  #ifdef SBR_DEC
  
  
  #include <stdlib.h>
  #include <string.h>
  #include "sbr_dct.h"
  #include "sbr_qmf.h"
  #include "sbr_qmf_c.h"
  #include "sbr_syntax.h"
  
  qmfa_info *qmfa_init(uint8_t channels)
  {
      qmfa_info *qmfa = (qmfa_info*)faad_malloc(sizeof(qmfa_info));
  
  	/* x is implemented as double ringbuffer */
      qmfa->x = (real_t*)faad_malloc(2 * channels * 10 * sizeof(real_t));
      memset(qmfa->x, 0, 2 * channels * 10 * sizeof(real_t));
  
  	/* ringbuffer index */
  	qmfa->x_index = 0;
  
      qmfa->channels = channels;
  
      return qmfa;
  }
  
  void qmfa_end(qmfa_info *qmfa)
  {
      if (qmfa)
      {
          if (qmfa->x) faad_free(qmfa->x);
          faad_free(qmfa);
      }
  }
  
  void sbr_qmf_analysis_32(sbr_info *sbr, qmfa_info *qmfa, const real_t *input,
                           qmf_t X[MAX_NTSRHFG][64], uint8_t offset, uint8_t kx)
  {
      ALIGN real_t u[64];
  #ifndef SBR_LOW_POWER
      ALIGN real_t in_real[32], in_imag[32], out_real[32], out_imag[32];
  #else
      ALIGN real_t y[32];
  #endif
      uint32_t in = 0;
      uint8_t l;
  
      /* qmf subsample l */
      for (l = 0; l < sbr->numTimeSlotsRate; l++)
      {
          int16_t n;
  
          /* shift input buffer x */
  		/* input buffer is not shifted anymore, x is implemented as double ringbuffer */
          //memmove(qmfa->x + 32, qmfa->x, (320-32)*sizeof(real_t));
  
          /* add new samples to input buffer x */
          for (n = 32 - 1; n >= 0; n--)
          {
  #ifdef FIXED_POINT
              qmfa->x[qmfa->x_index + n] = qmfa->x[qmfa->x_index + n + 320] = (input[in++]) >> 4;
  #else
              qmfa->x[qmfa->x_index + n] = qmfa->x[qmfa->x_index + n + 320] = input[in++];
  #endif
          }
  
          /* window and summation to create array u */
          for (n = 0; n < 64; n++)
          {
              u[n] = MUL_F(qmfa->x[qmfa->x_index + n], qmf_c[2*n]) +
                  MUL_F(qmfa->x[qmfa->x_index + n + 64], qmf_c[2*(n + 64)]) +
                  MUL_F(qmfa->x[qmfa->x_index + n + 128], qmf_c[2*(n + 128)]) +
                  MUL_F(qmfa->x[qmfa->x_index + n + 192], qmf_c[2*(n + 192)]) +
                  MUL_F(qmfa->x[qmfa->x_index + n + 256], qmf_c[2*(n + 256)]);
          }
  
  		/* update ringbuffer index */
  		qmfa->x_index -= 32;
  		if (qmfa->x_index < 0)
  			qmfa->x_index = (320-32);
  
          /* calculate 32 subband samples by introducing X */
  #ifdef SBR_LOW_POWER
          y[0] = u[48];
          for (n = 1; n < 16; n++)
              y[n] = u[n+48] + u[48-n];
          for (n = 16; n < 32; n++)
              y[n] = -u[n-16] + u[48-n];
  
          DCT3_32_unscaled(u, y);
  
          for (n = 0; n < 32; n++)
          {
              if (n < kx)
              {
  #ifdef FIXED_POINT
                  QMF_RE(X[l + offset][n]) = u[n] /*<< 1*/;
  #else
                  QMF_RE(X[l + offset][n]) = 2. * u[n];
  #endif
              } else {
                  QMF_RE(X[l + offset][n]) = 0;
              }
          }
  #else
  
          // Reordering of data moved from DCT_IV to here
          in_imag[31] = u[1];
          in_real[0] = u[0];
          for (n = 1; n < 31; n++)
          {
              in_imag[31 - n] = u[n+1];
              in_real[n] = -u[64-n];
          }
          in_imag[0] = u[32];
          in_real[31] = -u[33];
  
          // dct4_kernel is DCT_IV without reordering which is done before and after FFT
          dct4_kernel(in_real, in_imag, out_real, out_imag);
  
          // Reordering of data moved from DCT_IV to here
          for (n = 0; n < 16; n++) {
              if (2*n+1 < kx) {
  #ifdef FIXED_POINT
                  QMF_RE(X[l + offset][2*n])   = out_real[n];
                  QMF_IM(X[l + offset][2*n])   = out_imag[n];
                  QMF_RE(X[l + offset][2*n+1]) = -out_imag[31-n];
                  QMF_IM(X[l + offset][2*n+1]) = -out_real[31-n];
  #else
                  QMF_RE(X[l + offset][2*n])   = 2. * out_real[n];
                  QMF_IM(X[l + offset][2*n])   = 2. * out_imag[n];
                  QMF_RE(X[l + offset][2*n+1]) = -2. * out_imag[31-n];
                  QMF_IM(X[l + offset][2*n+1]) = -2. * out_real[31-n];
  #endif
              } else {
                  if (2*n < kx) {
  #ifdef FIXED_POINT
                      QMF_RE(X[l + offset][2*n])   = out_real[n];
                      QMF_IM(X[l + offset][2*n])   = out_imag[n];
  #else
                      QMF_RE(X[l + offset][2*n])   = 2. * out_real[n];
                      QMF_IM(X[l + offset][2*n])   = 2. * out_imag[n];
  #endif
                  }
                  else {
                      QMF_RE(X[l + offset][2*n]) = 0;
                      QMF_IM(X[l + offset][2*n]) = 0;
                  }
                  QMF_RE(X[l + offset][2*n+1]) = 0;
                  QMF_IM(X[l + offset][2*n+1]) = 0;
              }
          }
  #endif
      }
  }
  
  static const complex_t qmf32_pre_twiddle[] =
  {
      { FRAC_CONST(0.999924701839145), FRAC_CONST(-0.012271538285720) },
      { FRAC_CONST(0.999322384588350), FRAC_CONST(-0.036807222941359) },
      { FRAC_CONST(0.998118112900149), FRAC_CONST(-0.061320736302209) },
      { FRAC_CONST(0.996312612182778), FRAC_CONST(-0.085797312344440) },
      { FRAC_CONST(0.993906970002356), FRAC_CONST(-0.110222207293883) },
      { FRAC_CONST(0.990902635427780), FRAC_CONST(-0.134580708507126) },
      { FRAC_CONST(0.987301418157858), FRAC_CONST(-0.158858143333861) },
      { FRAC_CONST(0.983105487431216), FRAC_CONST(-0.183039887955141) },
      { FRAC_CONST(0.978317370719628), FRAC_CONST(-0.207111376192219) },
      { FRAC_CONST(0.972939952205560), FRAC_CONST(-0.231058108280671) },
      { FRAC_CONST(0.966976471044852), FRAC_CONST(-0.254865659604515) },
      { FRAC_CONST(0.960430519415566), FRAC_CONST(-0.278519689385053) },
      { FRAC_CONST(0.953306040354194), FRAC_CONST(-0.302005949319228) },
      { FRAC_CONST(0.945607325380521), FRAC_CONST(-0.325310292162263) },
      { FRAC_CONST(0.937339011912575), FRAC_CONST(-0.348418680249435) },
      { FRAC_CONST(0.928506080473216), FRAC_CONST(-0.371317193951838) },
      { FRAC_CONST(0.919113851690058), FRAC_CONST(-0.393992040061048) },
      { FRAC_CONST(0.909167983090522), FRAC_CONST(-0.416429560097637) },
      { FRAC_CONST(0.898674465693954), FRAC_CONST(-0.438616238538528) },
      { FRAC_CONST(0.887639620402854), FRAC_CONST(-0.460538710958240) },
      { FRAC_CONST(0.876070094195407), FRAC_CONST(-0.482183772079123) },
      { FRAC_CONST(0.863972856121587), FRAC_CONST(-0.503538383725718) },
      { FRAC_CONST(0.851355193105265), FRAC_CONST(-0.524589682678469) },
      { FRAC_CONST(0.838224705554838), FRAC_CONST(-0.545324988422046) },
      { FRAC_CONST(0.824589302785025), FRAC_CONST(-0.565731810783613) },
      { FRAC_CONST(0.810457198252595), FRAC_CONST(-0.585797857456439) },
      { FRAC_CONST(0.795836904608884), FRAC_CONST(-0.605511041404326) },
      { FRAC_CONST(0.780737228572094), FRAC_CONST(-0.624859488142386) },
      { FRAC_CONST(0.765167265622459), FRAC_CONST(-0.643831542889791) },
      { FRAC_CONST(0.749136394523459), FRAC_CONST(-0.662415777590172) },
      { FRAC_CONST(0.732654271672413), FRAC_CONST(-0.680600997795453) },
      { FRAC_CONST(0.715730825283819), FRAC_CONST(-0.698376249408973) }
  };
  
  qmfs_info *qmfs_init(uint8_t channels)
  {
      qmfs_info *qmfs = (qmfs_info*)faad_malloc(sizeof(qmfs_info));
  
  	/* v is a double ringbuffer */
      qmfs->v = (real_t*)faad_malloc(2 * channels * 20 * sizeof(real_t));
      memset(qmfs->v, 0, 2 * channels * 20 * sizeof(real_t));
  
      qmfs->v_index = 0;
  
      qmfs->channels = channels;
  
      return qmfs;
  }
  
  void qmfs_end(qmfs_info *qmfs)
  {
      if (qmfs)
      {
          if (qmfs->v) faad_free(qmfs->v);
          faad_free(qmfs);
      }
  }
  
  #ifdef SBR_LOW_POWER
  
  void sbr_qmf_synthesis_32(sbr_info *sbr, qmfs_info *qmfs, qmf_t X[MAX_NTSRHFG][64],
                            real_t *output)
  {
      ALIGN real_t x[16];
      ALIGN real_t y[16];
      int32_t n, k, out = 0;
      uint8_t l;
  
      /* qmf subsample l */
      for (l = 0; l < sbr->numTimeSlotsRate; l++)
      {
          /* shift buffers */
          /* we are not shifting v, it is a double ringbuffer */
          //memmove(qmfs->v + 64, qmfs->v, (640-64)*sizeof(real_t));
  
          /* calculate 64 samples */
          for (k = 0; k < 16; k++)
          {
  #ifdef FIXED_POINT
              y[k] = (QMF_RE(X[l][k]) - QMF_RE(X[l][31 - k]));
              x[k] = (QMF_RE(X[l][k]) + QMF_RE(X[l][31 - k]));
  #else
              y[k] = (QMF_RE(X[l][k]) - QMF_RE(X[l][31 - k])) / 32.0;
              x[k] = (QMF_RE(X[l][k]) + QMF_RE(X[l][31 - k])) / 32.0;
  #endif
          }
  
          /* even n samples */
          DCT2_16_unscaled(x, x);
          /* odd n samples */
          DCT4_16(y, y);
  
          for (n = 8; n < 24; n++)
          {
              qmfs->v[qmfs->v_index + n*2] = qmfs->v[qmfs->v_index + 640 + n*2] = x[n-8];
              qmfs->v[qmfs->v_index + n*2+1] = qmfs->v[qmfs->v_index + 640 + n*2+1] = y[n-8];
          }
          for (n = 0; n < 16; n++)
          {
              qmfs->v[qmfs->v_index + n] = qmfs->v[qmfs->v_index + 640 + n] = qmfs->v[qmfs->v_index + 32-n];
          }
          qmfs->v[qmfs->v_index + 48] = qmfs->v[qmfs->v_index + 640 + 48] = 0;
          for (n = 1; n < 16; n++)
          {
              qmfs->v[qmfs->v_index + 48+n] = qmfs->v[qmfs->v_index + 640 + 48+n] = -qmfs->v[qmfs->v_index + 48-n];
          }
  
          /* calculate 32 output samples and window */
          for (k = 0; k < 32; k++)
          {
              output[out++] = MUL_F(qmfs->v[qmfs->v_index + k], qmf_c[2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 96 + k], qmf_c[64 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 128 + k], qmf_c[128 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 224 + k], qmf_c[192 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 256 + k], qmf_c[256 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 352 + k], qmf_c[320 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 384 + k], qmf_c[384 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 480 + k], qmf_c[448 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 512 + k], qmf_c[512 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 608 + k], qmf_c[576 + 2*k]);
          }
  
          /* update the ringbuffer index */
          qmfs->v_index -= 64;
          if (qmfs->v_index < 0)
              qmfs->v_index = (640-64);
      }
  }
  
  void sbr_qmf_synthesis_64(sbr_info *sbr, qmfs_info *qmfs, qmf_t X[MAX_NTSRHFG][64],
                            real_t *output)
  {
      ALIGN real_t x[64];
      ALIGN real_t y[64];
      int32_t n, k, out = 0;
      uint8_t l;
  
  
      /* qmf subsample l */
      for (l = 0; l < sbr->numTimeSlotsRate; l++)
      {
          /* shift buffers */
          /* we are not shifting v, it is a double ringbuffer */
          //memmove(qmfs->v + 128, qmfs->v, (1280-128)*sizeof(real_t));
  
          /* calculate 128 samples */
          for (k = 0; k < 32; k++)
          {
  #ifdef FIXED_POINT
              y[k] = (QMF_RE(X[l][k]) - QMF_RE(X[l][63 - k]));
              x[k] = (QMF_RE(X[l][k]) + QMF_RE(X[l][63 - k]));
  #else
              y[k] = (QMF_RE(X[l][k]) - QMF_RE(X[l][63 - k])) / 32.0;
              x[k] = (QMF_RE(X[l][k]) + QMF_RE(X[l][63 - k])) / 32.0;
  #endif
          }
  
          /* even n samples */
          DCT2_32_unscaled(x, x);
          /* odd n samples */
          DCT4_32(y, y);
  
          for (n = 16; n < 48; n++)
          {
              qmfs->v[qmfs->v_index + n*2]   = qmfs->v[qmfs->v_index + 1280 + n*2]   = x[n-16];
              qmfs->v[qmfs->v_index + n*2+1] = qmfs->v[qmfs->v_index + 1280 + n*2+1] = y[n-16];
          }
          for (n = 0; n < 32; n++)
          {
              qmfs->v[qmfs->v_index + n] = qmfs->v[qmfs->v_index + 1280 + n] = qmfs->v[qmfs->v_index + 64-n];
          }
          qmfs->v[qmfs->v_index + 96] = qmfs->v[qmfs->v_index + 1280 + 96] = 0;
          for (n = 1; n < 32; n++)
          {
              qmfs->v[qmfs->v_index + 96+n] = qmfs->v[qmfs->v_index + 1280 + 96+n] = -qmfs->v[qmfs->v_index + 96-n];
          }
  
          /* calculate 64 output samples and window */
          for (k = 0; k < 64; k++)
          {
              output[out++] = MUL_F(qmfs->v[qmfs->v_index + k], qmf_c[k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 192 + k], qmf_c[64 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 256 + k], qmf_c[128 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 256 + 192 + k], qmf_c[128 + 64 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 512 + k], qmf_c[256 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 512 + 192 + k], qmf_c[256 + 64 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 768 + k], qmf_c[384 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 768 + 192 + k], qmf_c[384 + 64 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 1024 + k], qmf_c[512 + k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 1024 + 192 + k], qmf_c[512 + 64 + k]);
          }
  
          /* update the ringbuffer index */
          qmfs->v_index -= 128;
          if (qmfs->v_index < 0)
              qmfs->v_index = (1280-128);
      }
  }
  #else
  void sbr_qmf_synthesis_32(sbr_info *sbr, qmfs_info *qmfs, qmf_t X[MAX_NTSRHFG][64],
                            real_t *output)
  {
      ALIGN real_t x1[32], x2[32];
  #ifndef FIXED_POINT
      real_t scale = 1.f/64.f;
  #endif
      int32_t n, k, out = 0;
      uint8_t l;
  
  
      /* qmf subsample l */
      for (l = 0; l < sbr->numTimeSlotsRate; l++)
      {
          /* shift buffer v */
          /* buffer is not shifted, we are using a ringbuffer */
          //memmove(qmfs->v + 64, qmfs->v, (640-64)*sizeof(real_t));
  
          /* calculate 64 samples */
          /* complex pre-twiddle */
          for (k = 0; k < 32; k++)
          {
              x1[k] = MUL_F(QMF_RE(X[l][k]), RE(qmf32_pre_twiddle[k])) - MUL_F(QMF_IM(X[l][k]), IM(qmf32_pre_twiddle[k]));
              x2[k] = MUL_F(QMF_IM(X[l][k]), RE(qmf32_pre_twiddle[k])) + MUL_F(QMF_RE(X[l][k]), IM(qmf32_pre_twiddle[k]));
  
  #ifndef FIXED_POINT
              x1[k] *= scale;
              x2[k] *= scale;
  #else
              x1[k] >>= 1;
              x2[k] >>= 1;
  #endif
          }
  
          /* transform */
          DCT4_32(x1, x1);
          DST4_32(x2, x2);
  
          for (n = 0; n < 32; n++)
          {
              qmfs->v[qmfs->v_index + n]      = qmfs->v[qmfs->v_index + 640 + n]      = -x1[n] + x2[n];
              qmfs->v[qmfs->v_index + 63 - n] = qmfs->v[qmfs->v_index + 640 + 63 - n] =  x1[n] + x2[n];
          }
  
          /* calculate 32 output samples and window */
          for (k = 0; k < 32; k++)
          {
              output[out++] = MUL_F(qmfs->v[qmfs->v_index + k], qmf_c[2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 96 + k], qmf_c[64 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 128 + k], qmf_c[128 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 224 + k], qmf_c[192 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 256 + k], qmf_c[256 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 352 + k], qmf_c[320 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 384 + k], qmf_c[384 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 480 + k], qmf_c[448 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 512 + k], qmf_c[512 + 2*k]) +
                  MUL_F(qmfs->v[qmfs->v_index + 608 + k], qmf_c[576 + 2*k]);
          }
  
          /* update ringbuffer index */
          qmfs->v_index -= 64;
          if (qmfs->v_index < 0)
              qmfs->v_index = (640 - 64);
      }
  }
  
  void sbr_qmf_synthesis_64(sbr_info *sbr, qmfs_info *qmfs, qmf_t X[MAX_NTSRHFG][64],
                            real_t *output)
  {
  //    ALIGN real_t x1[64], x2[64];
  #ifndef SBR_LOW_POWER
      ALIGN real_t in_real1[32], in_imag1[32], out_real1[32], out_imag1[32];
      ALIGN real_t in_real2[32], in_imag2[32], out_real2[32], out_imag2[32];
  #endif
      qmf_t * pX;
      real_t * pring_buffer_1, * pring_buffer_3;
  //    real_t * ptemp_1, * ptemp_2;
  #ifdef PREFER_POINTERS
      // These pointers are used if target platform has autoinc address generators
      real_t * pring_buffer_2, * pring_buffer_4;
      real_t * pring_buffer_5, * pring_buffer_6;
      real_t * pring_buffer_7, * pring_buffer_8;
      real_t * pring_buffer_9, * pring_buffer_10;
      const real_t * pqmf_c_1, * pqmf_c_2, * pqmf_c_3, * pqmf_c_4;
      const real_t * pqmf_c_5, * pqmf_c_6, * pqmf_c_7, * pqmf_c_8;
      const real_t * pqmf_c_9, * pqmf_c_10;
  #endif // #ifdef PREFER_POINTERS
  #ifndef FIXED_POINT
      real_t scale = 1.f/64.f;
  #endif
      int32_t n, k, out = 0;
      uint8_t l;
  
  
      /* qmf subsample l */
      for (l = 0; l < sbr->numTimeSlotsRate; l++)
      {
          /* shift buffer v */
  		/* buffer is not shifted, we use double ringbuffer */
  		//memmove(qmfs->v + 128, qmfs->v, (1280-128)*sizeof(real_t));
  
          /* calculate 128 samples */
  #ifndef FIXED_POINT
  
          pX = X[l];
  
          in_imag1[31] = scale*QMF_RE(pX[1]);
          in_real1[0]  = scale*QMF_RE(pX[0]);
          in_imag2[31] = scale*QMF_IM(pX[63-1]);
          in_real2[0]  = scale*QMF_IM(pX[63-0]);
          for (k = 1; k < 31; k++)
          {
              in_imag1[31 - k] = scale*QMF_RE(pX[2*k + 1]);
              in_real1[     k] = scale*QMF_RE(pX[2*k    ]);
              in_imag2[31 - k] = scale*QMF_IM(pX[63 - (2*k + 1)]);
              in_real2[     k] = scale*QMF_IM(pX[63 - (2*k    )]);
          }
          in_imag1[0]  = scale*QMF_RE(pX[63]);
          in_real1[31] = scale*QMF_RE(pX[62]);
          in_imag2[0]  = scale*QMF_IM(pX[63-63]);
          in_real2[31] = scale*QMF_IM(pX[63-62]);
  
  #else
  
          pX = X[l];
  
          in_imag1[31] = QMF_RE(pX[1]) >> 1;
          in_real1[0]  = QMF_RE(pX[0]) >> 1;
          in_imag2[31] = QMF_IM(pX[62]) >> 1;
          in_real2[0]  = QMF_IM(pX[63]) >> 1;
          for (k = 1; k < 31; k++)
          {
              in_imag1[31 - k] = QMF_RE(pX[2*k + 1]) >> 1;
              in_real1[     k] = QMF_RE(pX[2*k    ]) >> 1;
              in_imag2[31 - k] = QMF_IM(pX[63 - (2*k + 1)]) >> 1;
              in_real2[     k] = QMF_IM(pX[63 - (2*k    )]) >> 1;
          }
          in_imag1[0]  = QMF_RE(pX[63]) >> 1;
          in_real1[31] = QMF_RE(pX[62]) >> 1;
          in_imag2[0]  = QMF_IM(pX[0]) >> 1;
          in_real2[31] = QMF_IM(pX[1]) >> 1;
  
  #endif
  
  
          // dct4_kernel is DCT_IV without reordering which is done before and after FFT
          dct4_kernel(in_real1, in_imag1, out_real1, out_imag1);
          dct4_kernel(in_real2, in_imag2, out_real2, out_imag2);
  
  
          pring_buffer_1 = qmfs->v + qmfs->v_index;
          pring_buffer_3 = pring_buffer_1 + 1280;
  #ifdef PREFER_POINTERS
          pring_buffer_2 = pring_buffer_1 + 127;
          pring_buffer_4 = pring_buffer_1 + (1280 + 127);
  #endif // #ifdef PREFER_POINTERS
  //        ptemp_1 = x1;
  //        ptemp_2 = x2;
  #ifdef PREFER_POINTERS
          for (n = 0; n < 32; n ++)
          {
              //real_t x1 = *ptemp_1++;
              //real_t x2 = *ptemp_2++;
              // pring_buffer_3 and pring_buffer_4 are needed only for double ring buffer
              *pring_buffer_1++ = *pring_buffer_3++ = out_real2[n] - out_real1[n];
              *pring_buffer_2-- = *pring_buffer_4-- = out_real2[n] + out_real1[n];
              //x1 = *ptemp_1++;
              //x2 = *ptemp_2++;
              *pring_buffer_1++ = *pring_buffer_3++ = out_imag2[31-n] + out_imag1[31-n];
              *pring_buffer_2-- = *pring_buffer_4-- = out_imag2[31-n] - out_imag1[31-n];
          }
  #else // #ifdef PREFER_POINTERS
  
          for (n = 0; n < 32; n++)
          {
              // pring_buffer_3 and pring_buffer_4 are needed only for double ring buffer
              pring_buffer_1[2*n]         = pring_buffer_3[2*n]         = out_real2[n] - out_real1[n];
              pring_buffer_1[127-2*n]     = pring_buffer_3[127-2*n]     = out_real2[n] + out_real1[n];
              pring_buffer_1[2*n+1]       = pring_buffer_3[2*n+1]       = out_imag2[31-n] + out_imag1[31-n];
              pring_buffer_1[127-(2*n+1)] = pring_buffer_3[127-(2*n+1)] = out_imag2[31-n] - out_imag1[31-n];
          }
  
  #endif // #ifdef PREFER_POINTERS
  
          pring_buffer_1 = qmfs->v + qmfs->v_index;
  #ifdef PREFER_POINTERS
          pring_buffer_2 = pring_buffer_1 + 192;
          pring_buffer_3 = pring_buffer_1 + 256;
          pring_buffer_4 = pring_buffer_1 + (256 + 192);
          pring_buffer_5 = pring_buffer_1 + 512;
          pring_buffer_6 = pring_buffer_1 + (512 + 192);
          pring_buffer_7 = pring_buffer_1 + 768;
          pring_buffer_8 = pring_buffer_1 + (768 + 192);
          pring_buffer_9 = pring_buffer_1 + 1024;
          pring_buffer_10 = pring_buffer_1 + (1024 + 192);
          pqmf_c_1 = qmf_c;
          pqmf_c_2 = qmf_c + 64;
          pqmf_c_3 = qmf_c + 128;
          pqmf_c_4 = qmf_c + 192;
          pqmf_c_5 = qmf_c + 256;
          pqmf_c_6 = qmf_c + 320;
          pqmf_c_7 = qmf_c + 384;
          pqmf_c_8 = qmf_c + 448;
          pqmf_c_9 = qmf_c + 512;
          pqmf_c_10 = qmf_c + 576;
  #endif // #ifdef PREFER_POINTERS
  
          /* calculate 64 output samples and window */
          for (k = 0; k < 64; k++)
          {
  #ifdef PREFER_POINTERS
              output[out++] =
                  MUL_F(*pring_buffer_1++,  *pqmf_c_1++) +
                  MUL_F(*pring_buffer_2++,  *pqmf_c_2++) +
                  MUL_F(*pring_buffer_3++,  *pqmf_c_3++) +
                  MUL_F(*pring_buffer_4++,  *pqmf_c_4++) +
                  MUL_F(*pring_buffer_5++,  *pqmf_c_5++) +
                  MUL_F(*pring_buffer_6++,  *pqmf_c_6++) +
                  MUL_F(*pring_buffer_7++,  *pqmf_c_7++) +
                  MUL_F(*pring_buffer_8++,  *pqmf_c_8++) +
                  MUL_F(*pring_buffer_9++,  *pqmf_c_9++) +
                  MUL_F(*pring_buffer_10++, *pqmf_c_10++);
  #else // #ifdef PREFER_POINTERS
              output[out++] =
                  MUL_F(pring_buffer_1[k+0],          qmf_c[k+0])   +
                  MUL_F(pring_buffer_1[k+192],        qmf_c[k+64])  +
                  MUL_F(pring_buffer_1[k+256],        qmf_c[k+128]) +
                  MUL_F(pring_buffer_1[k+(256+192)],  qmf_c[k+192]) +
                  MUL_F(pring_buffer_1[k+512],        qmf_c[k+256]) +
                  MUL_F(pring_buffer_1[k+(512+192)],  qmf_c[k+320]) +
                  MUL_F(pring_buffer_1[k+768],        qmf_c[k+384]) +
                  MUL_F(pring_buffer_1[k+(768+192)],  qmf_c[k+448]) +
                  MUL_F(pring_buffer_1[k+1024],       qmf_c[k+512]) +
                  MUL_F(pring_buffer_1[k+(1024+192)], qmf_c[k+576]);
  #endif // #ifdef PREFER_POINTERS
          }
  
          /* update ringbuffer index */
          qmfs->v_index -= 128;
          if (qmfs->v_index < 0)
              qmfs->v_index = (1280 - 128);
      }
  }
  #endif
  
  #endif
  