Coverage Report

Created: 2025-07-01 06:21

/src/aac/libAACdec/src/usacdec_fac.cpp
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/* -----------------------------------------------------------------------------
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Software License for The Fraunhofer FDK AAC Codec Library for Android
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© Copyright  1995 - 2019 Fraunhofer-Gesellschaft zur Förderung der angewandten
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Forschung e.V. All rights reserved.
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 1.    INTRODUCTION
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The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
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that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
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scheme for digital audio. This FDK AAC Codec software is intended to be used on
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a wide variety of Android devices.
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AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
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general perceptual audio codecs. AAC-ELD is considered the best-performing
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full-bandwidth communications codec by independent studies and is widely
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deployed. AAC has been standardized by ISO and IEC as part of the MPEG
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specifications.
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Patent licenses for necessary patent claims for the FDK AAC Codec (including
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those of Fraunhofer) may be obtained through Via Licensing
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(www.vialicensing.com) or through the respective patent owners individually for
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the purpose of encoding or decoding bit streams in products that are compliant
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with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
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Android devices already license these patent claims through Via Licensing or
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directly from the patent owners, and therefore FDK AAC Codec software may
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already be covered under those patent licenses when it is used for those
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licensed purposes only.
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Commercially-licensed AAC software libraries, including floating-point versions
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with enhanced sound quality, are also available from Fraunhofer. Users are
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encouraged to check the Fraunhofer website for additional applications
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information and documentation.
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2.    COPYRIGHT LICENSE
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Redistribution and use in source and binary forms, with or without modification,
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are permitted without payment of copyright license fees provided that you
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satisfy the following conditions:
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You must retain the complete text of this software license in redistributions of
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the FDK AAC Codec or your modifications thereto in source code form.
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You must retain the complete text of this software license in the documentation
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and/or other materials provided with redistributions of the FDK AAC Codec or
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your modifications thereto in binary form. You must make available free of
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charge copies of the complete source code of the FDK AAC Codec and your
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modifications thereto to recipients of copies in binary form.
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The name of Fraunhofer may not be used to endorse or promote products derived
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from this library without prior written permission.
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You may not charge copyright license fees for anyone to use, copy or distribute
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the FDK AAC Codec software or your modifications thereto.
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Your modified versions of the FDK AAC Codec must carry prominent notices stating
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that you changed the software and the date of any change. For modified versions
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of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
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must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
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AAC Codec Library for Android."
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3.    NO PATENT LICENSE
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NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
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limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
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Fraunhofer provides no warranty of patent non-infringement with respect to this
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software.
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You may use this FDK AAC Codec software or modifications thereto only for
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purposes that are authorized by appropriate patent licenses.
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4.    DISCLAIMER
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
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holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
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including but not limited to the implied warranties of merchantability and
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fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
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or consequential damages, including but not limited to procurement of substitute
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goods or services; loss of use, data, or profits, or business interruption,
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however caused and on any theory of liability, whether in contract, strict
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liability, or tort (including negligence), arising in any way out of the use of
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this software, even if advised of the possibility of such damage.
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5.    CONTACT INFORMATION
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Fraunhofer Institute for Integrated Circuits IIS
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Attention: Audio and Multimedia Departments - FDK AAC LL
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Am Wolfsmantel 33
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91058 Erlangen, Germany
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www.iis.fraunhofer.de/amm
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amm-info@iis.fraunhofer.de
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----------------------------------------------------------------------------- */
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/**************************** AAC decoder library ******************************
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   Author(s):   Manuel Jander
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   Description: USAC FAC
100
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*******************************************************************************/
102
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#include "usacdec_fac.h"
104
105
#include "usacdec_const.h"
106
#include "usacdec_lpc.h"
107
#include "usacdec_acelp.h"
108
#include "usacdec_rom.h"
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#include "dct.h"
110
#include "FDK_tools_rom.h"
111
#include "mdct.h"
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113
0
#define SPEC_FAC(ptr, i, gl) ((ptr) + ((i) * (gl)))
114
115
FIXP_DBL *CLpd_FAC_GetMemory(CAacDecoderChannelInfo *pAacDecoderChannelInfo,
116
0
                             UCHAR mod[NB_DIV], int *pState) {
117
0
  FIXP_DBL *ptr;
118
0
  int i;
119
0
  int k = 0;
120
0
  int max_windows = 8;
121
122
0
  FDK_ASSERT(*pState >= 0 && *pState < max_windows);
123
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  /* Look for free space to store FAC data. 2 FAC data blocks fit into each TCX
125
   * spectral data block. */
126
0
  for (i = *pState; i < max_windows; i++) {
127
0
    if (mod[i >> 1] == 0) {
128
0
      break;
129
0
    }
130
0
  }
131
132
0
  *pState = i + 1;
133
134
0
  if (i == max_windows) {
135
0
    ptr = pAacDecoderChannelInfo->data.usac.fac_data0;
136
0
  } else {
137
0
    FDK_ASSERT(mod[(i >> 1)] == 0);
138
0
    ptr = SPEC_FAC(pAacDecoderChannelInfo->pSpectralCoefficient, i,
139
0
                   pAacDecoderChannelInfo->granuleLength << k);
140
0
  }
141
142
0
  return ptr;
143
0
}
144
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int CLpd_FAC_Read(HANDLE_FDK_BITSTREAM hBs, FIXP_DBL *pFac, SCHAR *pFacScale,
146
0
                  int length, int use_gain, int frame) {
147
0
  FIXP_DBL fac_gain;
148
0
  int fac_gain_e = 0;
149
150
0
  if (use_gain) {
151
0
    CLpd_DecodeGain(&fac_gain, &fac_gain_e, FDKreadBits(hBs, 7));
152
0
  }
153
154
0
  if (CLpc_DecodeAVQ(hBs, pFac, 1, 1, length) != 0) {
155
0
    return -1;
156
0
  }
157
158
0
  {
159
0
    int scale;
160
161
0
    scale = getScalefactor(pFac, length);
162
0
    scaleValues(pFac, length, scale);
163
0
    pFacScale[frame] = DFRACT_BITS - 1 - scale;
164
0
  }
165
166
0
  if (use_gain) {
167
0
    int i;
168
169
0
    pFacScale[frame] += fac_gain_e;
170
171
0
    for (i = 0; i < length; i++) {
172
0
      pFac[i] = fMult(pFac[i], fac_gain);
173
0
    }
174
0
  }
175
0
  return 0;
176
0
}
177
178
/**
179
 * \brief Apply synthesis filter with zero input to x. The overall filter gain
180
 * is 1.0.
181
 * \param a LPC filter coefficients.
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 * \param length length of the input/output data vector x.
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 * \param x input/output vector, where the synthesis filter is applied in place.
184
 */
185
static void Syn_filt_zero(const FIXP_LPC a[], const INT a_exp, INT length,
186
0
                          FIXP_DBL x[]) {
187
0
  int i, j;
188
0
  FIXP_DBL L_tmp;
189
190
0
  for (i = 0; i < length; i++) {
191
0
    L_tmp = (FIXP_DBL)0;
192
193
0
    for (j = 0; j < fMin(i, M_LP_FILTER_ORDER); j++) {
194
0
      L_tmp -= fMultDiv2(a[j], x[i - (j + 1)]) >> (LP_FILTER_SCALE - 1);
195
0
    }
196
197
0
    L_tmp = scaleValue(L_tmp, a_exp + LP_FILTER_SCALE);
198
0
    x[i] = fAddSaturate(x[i], L_tmp);
199
0
  }
200
0
}
201
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/* Table is also correct for coreCoderFrameLength = 768. Factor 3/4 is canceled
203
   out: gainFac = 0.5 * sqrt(fac_length/lFrame)
204
*/
205
static const FIXP_DBL gainFac[4] = {0x40000000, 0x2d413ccd, 0x20000000,
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                                    0x16a09e66};
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void CFac_ApplyGains(FIXP_DBL fac_data[LFAC], const INT fac_length,
209
                     const FIXP_DBL tcx_gain, const FIXP_DBL alfd_gains[],
210
0
                     const INT mod) {
211
0
  FIXP_DBL facFactor;
212
0
  int i;
213
214
0
  FDK_ASSERT((fac_length == 128) || (fac_length == 96));
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  /* 2) Apply gain factor to FAC data */
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0
  facFactor = fMult(gainFac[mod], tcx_gain);
218
0
  for (i = 0; i < fac_length; i++) {
219
0
    fac_data[i] = fMult(fac_data[i], facFactor);
220
0
  }
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  /* 3) Apply spectrum deshaping using alfd_gains */
223
0
  for (i = 0; i < fac_length / 4; i++) {
224
0
    int k;
225
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0
    k = i >> (3 - mod);
227
0
    fac_data[i] = fMult(fac_data[i], alfd_gains[k])
228
0
                  << 1; /* alfd_gains is scaled by one bit. */
229
0
  }
230
0
}
231
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static void CFac_CalcFacSignal(FIXP_DBL *pOut, FIXP_DBL *pFac,
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                               const int fac_scale, const int fac_length,
234
                               const FIXP_LPC A[M_LP_FILTER_ORDER],
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                               const INT A_exp, const int fAddZir,
236
0
                               const int isFdFac) {
237
0
  FIXP_LPC wA[M_LP_FILTER_ORDER];
238
0
  FIXP_DBL tf_gain = (FIXP_DBL)0;
239
0
  int wlength;
240
0
  int scale = fac_scale;
241
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  /* obtain tranform gain. */
243
0
  imdct_gain(&tf_gain, &scale, isFdFac ? 0 : fac_length);
244
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  /* 4) Compute inverse DCT-IV of FAC data. Output scale of DCT IV is 16 bits.
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   */
247
0
  dct_IV(pFac, fac_length, &scale);
248
  /* dct_IV scale = log2(fac_length). "- 7" is a factor of 2/128 */
249
0
  if (tf_gain != (FIXP_DBL)0) { /* non-radix 2 transform gain */
250
0
    int i;
251
252
0
    for (i = 0; i < fac_length; i++) {
253
0
      pFac[i] = fMult(tf_gain, pFac[i]);
254
0
    }
255
0
  }
256
0
  scaleValuesSaturate(pOut, pFac, fac_length,
257
0
                      scale); /* Avoid overflow issues and saturate. */
258
259
0
  E_LPC_a_weight(wA, A, M_LP_FILTER_ORDER);
260
261
  /* We need the output of the IIR filter to be longer than "fac_length".
262
  For this reason we run it with zero input appended to the end of the input
263
  sequence, i.e. we generate its ZIR and extend the output signal.*/
264
0
  FDKmemclear(pOut + fac_length, fac_length * sizeof(FIXP_DBL));
265
0
  wlength = 2 * fac_length;
266
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  /* 5) Apply weighted synthesis filter to FAC data, including optional Zir (5.
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   * item 4). */
269
0
  Syn_filt_zero(wA, A_exp, wlength, pOut);
270
0
}
271
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INT CLpd_FAC_Mdct2Acelp(H_MDCT hMdct, FIXP_DBL *output, FIXP_DBL *pFac,
273
                        const int fac_scale, FIXP_LPC *A, INT A_exp,
274
                        INT nrOutSamples, const INT fac_length,
275
0
                        const INT isFdFac, UCHAR prevWindowShape) {
276
0
  FIXP_DBL *pOvl;
277
0
  FIXP_DBL *pOut0;
278
0
  const FIXP_WTP *pWindow;
279
0
  int i, fl, nrSamples = 0;
280
281
0
  FDK_ASSERT(fac_length <= 1024 / (4 * 2));
282
283
0
  fl = fac_length * 2;
284
285
0
  pWindow = FDKgetWindowSlope(fl, prevWindowShape);
286
287
  /* Adapt window slope length in case of frame loss. */
288
0
  if (hMdct->prev_fr != fl) {
289
0
    int nl = 0;
290
0
    imdct_adapt_parameters(hMdct, &fl, &nl, fac_length, pWindow, nrOutSamples);
291
0
    FDK_ASSERT(nl == 0);
292
0
  }
293
294
0
  if (nrSamples < nrOutSamples) {
295
0
    pOut0 = output;
296
0
    nrSamples += hMdct->ov_offset;
297
    /* Purge buffered output. */
298
0
    FDKmemcpy(pOut0, hMdct->overlap.time, hMdct->ov_offset * sizeof(pOut0[0]));
299
0
    hMdct->ov_offset = 0;
300
0
  }
301
302
0
  pOvl = hMdct->overlap.freq + hMdct->ov_size - 1;
303
304
0
  if (nrSamples >= nrOutSamples) {
305
0
    pOut0 = hMdct->overlap.time + hMdct->ov_offset;
306
0
    hMdct->ov_offset += hMdct->prev_nr + fl / 2;
307
0
  } else {
308
0
    pOut0 = output + nrSamples;
309
0
    nrSamples += hMdct->prev_nr + fl / 2;
310
0
  }
311
0
  if (hMdct->prevPrevAliasSymmetry == 0) {
312
0
    for (i = 0; i < hMdct->prev_nr; i++) {
313
0
      FIXP_DBL x = -(*pOvl--);
314
0
      *pOut0 = IMDCT_SCALE_DBL(x);
315
0
      pOut0++;
316
0
    }
317
0
  } else {
318
0
    for (i = 0; i < hMdct->prev_nr; i++) {
319
0
      FIXP_DBL x = (*pOvl--);
320
0
      *pOut0 = IMDCT_SCALE_DBL(x);
321
0
      pOut0++;
322
0
    }
323
0
  }
324
0
  hMdct->prev_nr = 0;
325
326
0
  {
327
0
    if (pFac != NULL) {
328
      /* Note: The FAC gain might have been applied directly after bit stream
329
       * parse in this case. */
330
0
      CFac_CalcFacSignal(pOut0, pFac, fac_scale, fac_length, A, A_exp, 0,
331
0
                         isFdFac);
332
0
    } else {
333
      /* Clear buffer because of the overlap and ADD! */
334
0
      FDKmemclear(pOut0, fac_length * sizeof(FIXP_DBL));
335
0
    }
336
0
  }
337
338
0
  i = 0;
339
340
0
  if (hMdct->prevPrevAliasSymmetry == 0) {
341
0
    for (; i < fl / 2; i++) {
342
0
      FIXP_DBL x0;
343
344
      /* Overlap Add */
345
0
      x0 = -fMult(*pOvl--, pWindow[i].v.re);
346
347
0
      *pOut0 = fAddSaturate(*pOut0, IMDCT_SCALE_DBL(x0));
348
0
      pOut0++;
349
0
    }
350
0
  } else {
351
0
    for (; i < fl / 2; i++) {
352
0
      FIXP_DBL x0;
353
354
      /* Overlap Add */
355
0
      x0 = fMult(*pOvl--, pWindow[i].v.re);
356
357
0
      *pOut0 = fAddSaturate(*pOut0, IMDCT_SCALE_DBL(x0));
358
0
      pOut0++;
359
0
    }
360
0
  }
361
0
  if (hMdct->pFacZir !=
362
0
      0) { /* this should only happen for ACELP -> TCX20 -> ACELP transition */
363
0
    FIXP_DBL *pOut = pOut0 - fl / 2; /* fl/2 == fac_length */
364
0
    for (i = 0; i < fl / 2; i++) {
365
0
      pOut[i] = fAddSaturate(pOut[i], IMDCT_SCALE_DBL(hMdct->pFacZir[i]));
366
0
    }
367
0
    hMdct->pFacZir = NULL;
368
0
  }
369
370
0
  hMdct->prev_fr = 0;
371
0
  hMdct->prev_nr = 0;
372
0
  hMdct->prev_tl = 0;
373
0
  hMdct->prevPrevAliasSymmetry = hMdct->prevAliasSymmetry;
374
375
0
  return nrSamples;
376
0
}
377
378
INT CLpd_FAC_Acelp2Mdct(H_MDCT hMdct, FIXP_DBL *output, FIXP_DBL *_pSpec,
379
                        const SHORT spec_scale[], const int nSpec,
380
                        FIXP_DBL *pFac, const int fac_scale,
381
                        const INT fac_length, INT noOutSamples, const INT tl,
382
                        const FIXP_WTP *wrs, const INT fr, FIXP_LPC A[16],
383
                        INT A_exp, CAcelpStaticMem *acelp_mem,
384
                        const FIXP_DBL gain, const int last_frame_lost,
385
                        const int isFdFac, const UCHAR last_lpd_mode,
386
0
                        const int k, int currAliasingSymmetry) {
387
0
  FIXP_DBL *pCurr, *pOvl, *pSpec;
388
0
  const FIXP_WTP *pWindow;
389
0
  const FIXP_WTB *FacWindowZir_conceal;
390
0
  UCHAR doFacZirConceal = 0;
391
0
  int doDeemph = 1;
392
0
  const FIXP_WTB *FacWindowZir, *FacWindowSynth;
393
0
  FIXP_DBL *pOut0 = output, *pOut1;
394
0
  int w, i, fl, nl, nr, f_len, nrSamples = 0, s = 0, scale, total_gain_e;
395
0
  FIXP_DBL *pF, *pFAC_and_FAC_ZIR = NULL;
396
0
  FIXP_DBL total_gain = gain;
397
398
0
  FDK_ASSERT(fac_length <= 1024 / (4 * 2));
399
0
  switch (fac_length) {
400
    /* coreCoderFrameLength = 1024 */
401
0
    case 128:
402
0
      pWindow = SineWindow256;
403
0
      FacWindowZir = FacWindowZir128;
404
0
      FacWindowSynth = FacWindowSynth128;
405
0
      break;
406
0
    case 64:
407
0
      pWindow = SineWindow128;
408
0
      FacWindowZir = FacWindowZir64;
409
0
      FacWindowSynth = FacWindowSynth64;
410
0
      break;
411
0
    case 32:
412
0
      pWindow = SineWindow64;
413
0
      FacWindowZir = FacWindowZir32;
414
0
      FacWindowSynth = FacWindowSynth32;
415
0
      break;
416
    /* coreCoderFrameLength = 768 */
417
0
    case 96:
418
0
      pWindow = SineWindow192;
419
0
      FacWindowZir = FacWindowZir96;
420
0
      FacWindowSynth = FacWindowSynth96;
421
0
      break;
422
0
    case 48:
423
0
      pWindow = SineWindow96;
424
0
      FacWindowZir = FacWindowZir48;
425
0
      FacWindowSynth = FacWindowSynth48;
426
0
      break;
427
0
    default:
428
0
      FDK_ASSERT(0);
429
0
      return 0;
430
0
  }
431
432
0
  FacWindowZir_conceal = FacWindowSynth;
433
  /* Derive NR and NL */
434
0
  fl = fac_length * 2;
435
0
  nl = (tl - fl) >> 1;
436
0
  nr = (tl - fr) >> 1;
437
438
0
  if (noOutSamples > nrSamples) {
439
    /* Purge buffered output. */
440
0
    FDKmemcpy(pOut0, hMdct->overlap.time, hMdct->ov_offset * sizeof(pOut0[0]));
441
0
    nrSamples = hMdct->ov_offset;
442
0
    hMdct->ov_offset = 0;
443
0
  }
444
445
0
  if (nrSamples >= noOutSamples) {
446
0
    pOut1 = hMdct->overlap.time + hMdct->ov_offset;
447
0
    if (hMdct->ov_offset < fac_length) {
448
0
      pOut0 = output + nrSamples;
449
0
    } else {
450
0
      pOut0 = pOut1;
451
0
    }
452
0
    hMdct->ov_offset += fac_length + nl;
453
0
  } else {
454
0
    pOut1 = output + nrSamples;
455
0
    pOut0 = output + nrSamples;
456
0
  }
457
458
0
  {
459
0
    pFAC_and_FAC_ZIR = CLpd_ACELP_GetFreeExcMem(acelp_mem, 2 * fac_length);
460
0
    {
461
0
      const FIXP_DBL *pTmp1, *pTmp2;
462
463
0
      doFacZirConceal |= ((last_frame_lost != 0) && (k == 0));
464
0
      doDeemph &= (last_lpd_mode != 4);
465
0
      if (doFacZirConceal) {
466
        /* ACELP contribution in concealment case:
467
           Use ZIR with a modified ZIR window to preserve some more energy.
468
           Dont use FAC, which contains wrong information for concealed frame
469
           Dont use last ACELP samples, but double ZIR, instead (afterwards) */
470
0
        FDKmemclear(pFAC_and_FAC_ZIR, 2 * fac_length * sizeof(FIXP_DBL));
471
0
        FacWindowSynth = (FIXP_WTB *)pFAC_and_FAC_ZIR;
472
0
        FacWindowZir = FacWindowZir_conceal;
473
0
      } else {
474
0
        CFac_CalcFacSignal(pFAC_and_FAC_ZIR, pFac, fac_scale + s, fac_length, A,
475
0
                           A_exp, 1, isFdFac);
476
0
      }
477
      /* 6) Get windowed past ACELP samples and ACELP ZIR signal */
478
479
      /*
480
       * Get ACELP ZIR (pFac[]) and ACELP past samples (pOut0[]) and add them
481
       * to the FAC synth signal contribution on pOut1[].
482
       */
483
0
      {
484
0
        {
485
0
          CLpd_Acelp_Zir(A, A_exp, acelp_mem, fac_length, pFac, doDeemph);
486
487
0
          pTmp1 = pOut0;
488
0
          pTmp2 = pFac;
489
0
        }
490
491
0
        for (i = 0, w = 0; i < fac_length; i++) {
492
0
          FIXP_DBL x;
493
          /* Div2 is compensated by table scaling */
494
0
          x = fMultDiv2(pTmp2[i], FacWindowZir[w]);
495
0
          x += fMultDiv2(pTmp1[-i - 1], FacWindowSynth[w]);
496
0
          pOut1[i] = fAddSaturate(x, pFAC_and_FAC_ZIR[i]);
497
0
          w++;
498
0
        }
499
0
      }
500
501
0
      if (doFacZirConceal) {
502
        /* ZIR is the only ACELP contribution, so double it */
503
0
        scaleValues(pOut1, fac_length, 1);
504
0
      }
505
0
    }
506
0
  }
507
508
0
  if (nrSamples < noOutSamples) {
509
0
    nrSamples += fac_length + nl;
510
0
  }
511
512
  /* Obtain transform gain */
513
0
  total_gain = gain;
514
0
  total_gain_e = 0;
515
0
  imdct_gain(&total_gain, &total_gain_e, tl);
516
517
  /* IMDCT overlap add */
518
0
  scale = total_gain_e;
519
0
  pSpec = _pSpec;
520
521
  /* Note:when comming from an LPD frame (TCX/ACELP) the previous alisaing
522
   * symmetry must always be 0 */
523
0
  if (currAliasingSymmetry == 0) {
524
0
    dct_IV(pSpec, tl, &scale);
525
0
  } else {
526
0
    FIXP_DBL _tmp[1024 + ALIGNMENT_DEFAULT / sizeof(FIXP_DBL)];
527
0
    FIXP_DBL *tmp = (FIXP_DBL *)ALIGN_PTR(_tmp);
528
0
    C_ALLOC_ALIGNED_REGISTER(tmp, sizeof(_tmp));
529
0
    dst_III(pSpec, tmp, tl, &scale);
530
0
    C_ALLOC_ALIGNED_UNREGISTER(tmp);
531
0
  }
532
533
  /* Optional scaling of time domain - no yet windowed - of current spectrum */
534
0
  if (total_gain != (FIXP_DBL)0) {
535
0
    for (i = 0; i < tl; i++) {
536
0
      pSpec[i] = fMult(pSpec[i], total_gain);
537
0
    }
538
0
  }
539
0
  int loc_scale = fixmin_I(spec_scale[0] + scale, (INT)DFRACT_BITS - 1);
540
0
  scaleValuesSaturate(pSpec, tl, loc_scale);
541
542
0
  pOut1 += fl / 2 - 1;
543
0
  pCurr = pSpec + tl - fl / 2;
544
545
0
  for (i = 0; i < fl / 2; i++) {
546
0
    FIXP_DBL x1;
547
548
    /* FAC signal is already on pOut1, because of that the += operator. */
549
0
    x1 = fMult(*pCurr++, pWindow[i].v.re);
550
0
    FDK_ASSERT((pOut1 >= hMdct->overlap.time &&
551
0
                pOut1 < hMdct->overlap.time + hMdct->ov_size) ||
552
0
               (pOut1 >= output && pOut1 < output + 1024));
553
0
    *pOut1 = fAddSaturate(*pOut1, IMDCT_SCALE_DBL(-x1));
554
0
    pOut1--;
555
0
  }
556
557
  /* NL output samples TL/2+FL/2..TL. - current[FL/2..0] */
558
0
  pOut1 += (fl / 2) + 1;
559
560
0
  pFAC_and_FAC_ZIR += fac_length; /* set pointer to beginning of FAC ZIR */
561
562
0
  if (nl == 0) {
563
    /* save pointer to write FAC ZIR data later */
564
0
    hMdct->pFacZir = pFAC_and_FAC_ZIR;
565
0
  } else {
566
0
    FDK_ASSERT(nl >= fac_length);
567
    /* FAC ZIR will be added now ... */
568
0
    hMdct->pFacZir = NULL;
569
0
  }
570
571
0
  pF = pFAC_and_FAC_ZIR;
572
0
  f_len = fac_length;
573
574
0
  pCurr = pSpec + tl - fl / 2 - 1;
575
0
  for (i = 0; i < nl; i++) {
576
0
    FIXP_DBL x = -(*pCurr--);
577
    /* 5) (item 4) Synthesis filter Zir component, FAC ZIR (another one). */
578
0
    if (i < f_len) {
579
0
      x = fAddSaturate(x, *pF++);
580
0
    }
581
582
0
    FDK_ASSERT((pOut1 >= hMdct->overlap.time &&
583
0
                pOut1 < hMdct->overlap.time + hMdct->ov_size) ||
584
0
               (pOut1 >= output && pOut1 < output + 1024));
585
0
    *pOut1 = IMDCT_SCALE_DBL(x);
586
0
    pOut1++;
587
0
  }
588
589
0
  hMdct->prev_nr = nr;
590
0
  hMdct->prev_fr = fr;
591
0
  hMdct->prev_wrs = wrs;
592
0
  hMdct->prev_tl = tl;
593
0
  hMdct->prevPrevAliasSymmetry = hMdct->prevAliasSymmetry;
594
0
  hMdct->prevAliasSymmetry = currAliasingSymmetry;
595
0
  fl = fr;
596
0
  nl = nr;
597
598
0
  pOvl = pSpec + tl / 2 - 1;
599
0
  pOut0 = pOut1;
600
601
0
  for (w = 1; w < nSpec; w++) /* for ACELP -> FD short */
602
0
  {
603
0
    const FIXP_WTP *pWindow_prev;
604
605
    /* Setup window pointers */
606
0
    pWindow_prev = hMdct->prev_wrs;
607
608
    /* Current spectrum */
609
0
    pSpec = _pSpec + w * tl;
610
611
0
    scale = total_gain_e;
612
613
    /* For the second, third, etc. short frames the alisaing symmetry is equal,
614
     * either (0,0) or (1,1) */
615
0
    if (currAliasingSymmetry == 0) {
616
      /* DCT IV of current spectrum */
617
0
      dct_IV(pSpec, tl, &scale);
618
0
    } else {
619
0
      dst_IV(pSpec, tl, &scale);
620
0
    }
621
622
    /* Optional scaling of time domain - no yet windowed - of current spectrum
623
     */
624
    /* and de-scale current spectrum signal (time domain, no yet windowed) */
625
0
    if (total_gain != (FIXP_DBL)0) {
626
0
      for (i = 0; i < tl; i++) {
627
0
        pSpec[i] = fMult(pSpec[i], total_gain);
628
0
      }
629
0
    }
630
0
    loc_scale = fixmin_I(spec_scale[w] + scale, (INT)DFRACT_BITS - 1);
631
0
    scaleValuesSaturate(pSpec, tl, loc_scale);
632
633
0
    if (noOutSamples <= nrSamples) {
634
      /* Divert output first half to overlap buffer if we already got enough
635
       * output samples. */
636
0
      pOut0 = hMdct->overlap.time + hMdct->ov_offset;
637
0
      hMdct->ov_offset += hMdct->prev_nr + fl / 2;
638
0
    } else {
639
      /* Account output samples */
640
0
      nrSamples += hMdct->prev_nr + fl / 2;
641
0
    }
642
643
    /* NR output samples 0 .. NR. -overlap[TL/2..TL/2-NR] */
644
0
    for (i = 0; i < hMdct->prev_nr; i++) {
645
0
      FIXP_DBL x = -(*pOvl--);
646
0
      *pOut0 = IMDCT_SCALE_DBL(x);
647
0
      pOut0++;
648
0
    }
649
650
0
    if (noOutSamples <= nrSamples) {
651
      /* Divert output second half to overlap buffer if we already got enough
652
       * output samples. */
653
0
      pOut1 = hMdct->overlap.time + hMdct->ov_offset + fl / 2 - 1;
654
0
      hMdct->ov_offset += fl / 2 + nl;
655
0
    } else {
656
0
      pOut1 = pOut0 + (fl - 1);
657
0
      nrSamples += fl / 2 + nl;
658
0
    }
659
660
    /* output samples before window crossing point NR .. TL/2.
661
     * -overlap[TL/2-NR..TL/2-NR-FL/2] + current[NR..TL/2] */
662
    /* output samples after window crossing point TL/2 .. TL/2+FL/2.
663
     * -overlap[0..FL/2] - current[TL/2..FL/2] */
664
0
    pCurr = pSpec + tl - fl / 2;
665
0
    if (currAliasingSymmetry == 0) {
666
0
      for (i = 0; i < fl / 2; i++) {
667
0
        FIXP_DBL x0, x1;
668
669
0
        cplxMultDiv2(&x1, &x0, *pCurr++, -*pOvl--, pWindow_prev[i]);
670
0
        *pOut0 = IMDCT_SCALE_DBL_LSH1(x0);
671
0
        *pOut1 = IMDCT_SCALE_DBL_LSH1(-x1);
672
0
        pOut0++;
673
0
        pOut1--;
674
0
      }
675
0
    } else {
676
0
      if (hMdct->prevPrevAliasSymmetry == 0) {
677
        /* Jump DST II -> DST IV for the second window */
678
0
        for (i = 0; i < fl / 2; i++) {
679
0
          FIXP_DBL x0, x1;
680
681
0
          cplxMultDiv2(&x1, &x0, *pCurr++, -*pOvl--, pWindow_prev[i]);
682
0
          *pOut0 = IMDCT_SCALE_DBL_LSH1(x0);
683
0
          *pOut1 = IMDCT_SCALE_DBL_LSH1(x1);
684
0
          pOut0++;
685
0
          pOut1--;
686
0
        }
687
0
      } else {
688
        /* Jump DST IV -> DST IV from the second window on */
689
0
        for (i = 0; i < fl / 2; i++) {
690
0
          FIXP_DBL x0, x1;
691
692
0
          cplxMultDiv2(&x1, &x0, *pCurr++, *pOvl--, pWindow_prev[i]);
693
0
          *pOut0 = IMDCT_SCALE_DBL_LSH1(x0);
694
0
          *pOut1 = IMDCT_SCALE_DBL_LSH1(x1);
695
0
          pOut0++;
696
0
          pOut1--;
697
0
        }
698
0
      }
699
0
    }
700
701
0
    if (hMdct->pFacZir != 0) {
702
      /* add FAC ZIR of previous ACELP -> mdct transition */
703
0
      FIXP_DBL *pOut = pOut0 - fl / 2;
704
0
      FDK_ASSERT(fl / 2 <= 128);
705
0
      for (i = 0; i < fl / 2; i++) {
706
0
        pOut[i] = fAddSaturate(pOut[i], IMDCT_SCALE_DBL(hMdct->pFacZir[i]));
707
0
      }
708
0
      hMdct->pFacZir = NULL;
709
0
    }
710
0
    pOut0 += (fl / 2);
711
712
    /* NL output samples TL/2+FL/2..TL. - current[FL/2..0] */
713
0
    pOut1 += (fl / 2) + 1;
714
0
    pCurr = pSpec + tl - fl / 2 - 1;
715
0
    for (i = 0; i < nl; i++) {
716
0
      FIXP_DBL x = -(*pCurr--);
717
0
      *pOut1 = IMDCT_SCALE_DBL(x);
718
0
      pOut1++;
719
0
    }
720
721
    /* Set overlap source pointer for next window pOvl = pSpec + tl/2 - 1; */
722
0
    pOvl = pSpec + tl / 2 - 1;
723
724
    /* Previous window values. */
725
0
    hMdct->prev_nr = nr;
726
0
    hMdct->prev_fr = fr;
727
0
    hMdct->prev_tl = tl;
728
0
    hMdct->prev_wrs = pWindow_prev;
729
0
    hMdct->prevPrevAliasSymmetry = hMdct->prevAliasSymmetry;
730
0
    hMdct->prevAliasSymmetry = currAliasingSymmetry;
731
0
  }
732
733
  /* Save overlap */
734
735
0
  pOvl = hMdct->overlap.freq + hMdct->ov_size - tl / 2;
736
0
  FDK_ASSERT(pOvl >= hMdct->overlap.time + hMdct->ov_offset);
737
0
  FDK_ASSERT(tl / 2 <= hMdct->ov_size);
738
0
  for (i = 0; i < tl / 2; i++) {
739
0
    pOvl[i] = _pSpec[i + (w - 1) * tl];
740
0
  }
741
742
0
  return nrSamples;
743
0
}