1/* -----------------------------------------------------------------------------
2Software License for The Fraunhofer FDK AAC Codec Library for Android
3
4© Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
5Forschung e.V. All rights reserved.
6
7 1.    INTRODUCTION
8The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10scheme for digital audio. This FDK AAC Codec software is intended to be used on
11a wide variety of Android devices.
12
13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14general perceptual audio codecs. AAC-ELD is considered the best-performing
15full-bandwidth communications codec by independent studies and is widely
16deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17specifications.
18
19Patent licenses for necessary patent claims for the FDK AAC Codec (including
20those of Fraunhofer) may be obtained through Via Licensing
21(www.vialicensing.com) or through the respective patent owners individually for
22the purpose of encoding or decoding bit streams in products that are compliant
23with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24Android devices already license these patent claims through Via Licensing or
25directly from the patent owners, and therefore FDK AAC Codec software may
26already be covered under those patent licenses when it is used for those
27licensed purposes only.
28
29Commercially-licensed AAC software libraries, including floating-point versions
30with enhanced sound quality, are also available from Fraunhofer. Users are
31encouraged to check the Fraunhofer website for additional applications
32information and documentation.
33
342.    COPYRIGHT LICENSE
35
36Redistribution and use in source and binary forms, with or without modification,
37are permitted without payment of copyright license fees provided that you
38satisfy the following conditions:
39
40You must retain the complete text of this software license in redistributions of
41the FDK AAC Codec or your modifications thereto in source code form.
42
43You must retain the complete text of this software license in the documentation
44and/or other materials provided with redistributions of the FDK AAC Codec or
45your modifications thereto in binary form. You must make available free of
46charge copies of the complete source code of the FDK AAC Codec and your
47modifications thereto to recipients of copies in binary form.
48
49The name of Fraunhofer may not be used to endorse or promote products derived
50from this library without prior written permission.
51
52You may not charge copyright license fees for anyone to use, copy or distribute
53the FDK AAC Codec software or your modifications thereto.
54
55Your modified versions of the FDK AAC Codec must carry prominent notices stating
56that you changed the software and the date of any change. For modified versions
57of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59AAC Codec Library for Android."
60
613.    NO PATENT LICENSE
62
63NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65Fraunhofer provides no warranty of patent non-infringement with respect to this
66software.
67
68You may use this FDK AAC Codec software or modifications thereto only for
69purposes that are authorized by appropriate patent licenses.
70
714.    DISCLAIMER
72
73This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75including but not limited to the implied warranties of merchantability and
76fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78or consequential damages, including but not limited to procurement of substitute
79goods or services; loss of use, data, or profits, or business interruption,
80however caused and on any theory of liability, whether in contract, strict
81liability, or tort (including negligence), arising in any way out of the use of
82this software, even if advised of the possibility of such damage.
83
845.    CONTACT INFORMATION
85
86Fraunhofer Institute for Integrated Circuits IIS
87Attention: Audio and Multimedia Departments - FDK AAC LL
88Am Wolfsmantel 33
8991058 Erlangen, Germany
90
91www.iis.fraunhofer.de/amm
92amm-info@iis.fraunhofer.de
93----------------------------------------------------------------------------- */
94
95/**************************** AAC encoder library ******************************
96
97   Author(s):   M. Werner
98
99   Description: Band/Line energy calculations
100
101*******************************************************************************/
102
103#include "band_nrg.h"
104
105/*****************************************************************************
106  functionname: FDKaacEnc_CalcSfbMaxScaleSpec
107  description:
108  input:
109  output:
110*****************************************************************************/
111void FDKaacEnc_CalcSfbMaxScaleSpec(const FIXP_DBL *RESTRICT mdctSpectrum,
112                                   const INT *RESTRICT bandOffset,
113                                   INT *RESTRICT sfbMaxScaleSpec,
114                                   const INT numBands) {
115  INT i, j;
116  FIXP_DBL maxSpc, tmp;
117
118  for (i = 0; i < numBands; i++) {
119    maxSpc = (FIXP_DBL)0;
120
121    DWORD_ALIGNED(mdctSpectrum);
122
123    for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
124      tmp = fixp_abs(mdctSpectrum[j]);
125      maxSpc = fixMax(maxSpc, tmp);
126    }
127    j = CntLeadingZeros(maxSpc) - 1;
128    sfbMaxScaleSpec[i] = fixMin((DFRACT_BITS - 2), j);
129    /* CountLeadingBits() is not necessary here since test value is always > 0
130     */
131  }
132}
133
134/*****************************************************************************
135  functionname: FDKaacEnc_CheckBandEnergyOptim
136  description:
137  input:
138  output:
139*****************************************************************************/
140FIXP_DBL
141FDKaacEnc_CheckBandEnergyOptim(const FIXP_DBL *const RESTRICT mdctSpectrum,
142                               const INT *const RESTRICT sfbMaxScaleSpec,
143                               const INT *const RESTRICT bandOffset,
144                               const INT numBands,
145                               FIXP_DBL *RESTRICT bandEnergy,
146                               FIXP_DBL *RESTRICT bandEnergyLdData,
147                               const INT minSpecShift) {
148  INT i, j, scale, nr = 0;
149  FIXP_DBL maxNrgLd = FL2FXCONST_DBL(-1.0f);
150  FIXP_DBL maxNrg = 0;
151  FIXP_DBL spec;
152
153  for (i = 0; i < numBands; i++) {
154    scale = fixMax(0, sfbMaxScaleSpec[i] - 4);
155    FIXP_DBL tmp = 0;
156
157    DWORD_ALIGNED(mdctSpectrum);
158
159    for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
160      spec = mdctSpectrum[j] << scale;
161      tmp = fPow2AddDiv2(tmp, spec);
162    }
163    bandEnergy[i] = tmp << 1;
164
165    /* calculate ld of bandNrg, subtract scaling */
166    bandEnergyLdData[i] = CalcLdData(bandEnergy[i]);
167    if (bandEnergyLdData[i] != FL2FXCONST_DBL(-1.0f)) {
168      bandEnergyLdData[i] -= scale * FL2FXCONST_DBL(2.0 / 64);
169    }
170    /* find index of maxNrg */
171    if (bandEnergyLdData[i] > maxNrgLd) {
172      maxNrgLd = bandEnergyLdData[i];
173      nr = i;
174    }
175  }
176
177  /* return unscaled maxNrg*/
178  scale = fixMax(0, sfbMaxScaleSpec[nr] - 4);
179  scale = fixMax(2 * (minSpecShift - scale), -(DFRACT_BITS - 1));
180
181  maxNrg = scaleValue(bandEnergy[nr], scale);
182
183  return maxNrg;
184}
185
186/*****************************************************************************
187  functionname: FDKaacEnc_CalcBandEnergyOptimLong
188  description:
189  input:
190  output:
191*****************************************************************************/
192INT FDKaacEnc_CalcBandEnergyOptimLong(const FIXP_DBL *RESTRICT mdctSpectrum,
193                                      INT *RESTRICT sfbMaxScaleSpec,
194                                      const INT *RESTRICT bandOffset,
195                                      const INT numBands,
196                                      FIXP_DBL *RESTRICT bandEnergy,
197                                      FIXP_DBL *RESTRICT bandEnergyLdData) {
198  INT i, j, shiftBits = 0;
199  FIXP_DBL maxNrgLd = FL2FXCONST_DBL(0.0f);
200
201  FIXP_DBL spec;
202
203  for (i = 0; i < numBands; i++) {
204    INT leadingBits = sfbMaxScaleSpec[i] -
205                      4; /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */
206    FIXP_DBL tmp = FL2FXCONST_DBL(0.0);
207    /* don't use scaleValue() here, it increases workload quite sufficiently...
208     */
209    if (leadingBits >= 0) {
210      for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
211        spec = mdctSpectrum[j] << leadingBits;
212        tmp = fPow2AddDiv2(tmp, spec);
213      }
214    } else {
215      INT shift = -leadingBits;
216      for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
217        spec = mdctSpectrum[j] >> shift;
218        tmp = fPow2AddDiv2(tmp, spec);
219      }
220    }
221    bandEnergy[i] = tmp << 1;
222  }
223
224  /* calculate ld of bandNrg, subtract scaling */
225  LdDataVector(bandEnergy, bandEnergyLdData, numBands);
226  for (i = numBands; i-- != 0;) {
227    FIXP_DBL scaleDiff = (sfbMaxScaleSpec[i] - 4) * FL2FXCONST_DBL(2.0 / 64);
228
229    bandEnergyLdData[i] = (bandEnergyLdData[i] >=
230                           ((FL2FXCONST_DBL(-1.f) >> 1) + (scaleDiff >> 1)))
231                              ? bandEnergyLdData[i] - scaleDiff
232                              : FL2FXCONST_DBL(-1.f);
233    /* find maxNrgLd */
234    maxNrgLd = fixMax(maxNrgLd, bandEnergyLdData[i]);
235  }
236
237  if (maxNrgLd <= (FIXP_DBL)0) {
238    for (i = numBands; i-- != 0;) {
239      INT scale = fixMin((sfbMaxScaleSpec[i] - 4) << 1, (DFRACT_BITS - 1));
240      bandEnergy[i] = scaleValue(bandEnergy[i], -scale);
241    }
242    return 0;
243  } else { /* scale down NRGs */
244    while (maxNrgLd > FL2FXCONST_DBL(0.0f)) {
245      maxNrgLd -= FL2FXCONST_DBL(2.0 / 64);
246      shiftBits++;
247    }
248    for (i = numBands; i-- != 0;) {
249      INT scale = fixMin(((sfbMaxScaleSpec[i] - 4) + shiftBits) << 1,
250                         (DFRACT_BITS - 1));
251      bandEnergyLdData[i] -= shiftBits * FL2FXCONST_DBL(2.0 / 64);
252      bandEnergy[i] = scaleValue(bandEnergy[i], -scale);
253    }
254    return shiftBits;
255  }
256}
257
258/*****************************************************************************
259  functionname: FDKaacEnc_CalcBandEnergyOptimShort
260  description:
261  input:
262  output:
263*****************************************************************************/
264void FDKaacEnc_CalcBandEnergyOptimShort(const FIXP_DBL *RESTRICT mdctSpectrum,
265                                        INT *RESTRICT sfbMaxScaleSpec,
266                                        const INT *RESTRICT bandOffset,
267                                        const INT numBands,
268                                        FIXP_DBL *RESTRICT bandEnergy) {
269  INT i, j;
270
271  for (i = 0; i < numBands; i++) {
272    int leadingBits = sfbMaxScaleSpec[i] -
273                      3; /* max sfbWidth = 36 ; 2^6=64 => 6/2 = 3 (spc*spc) */
274    FIXP_DBL tmp = FL2FXCONST_DBL(0.0);
275    for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
276      FIXP_DBL spec = scaleValue(mdctSpectrum[j], leadingBits);
277      tmp = fPow2AddDiv2(tmp, spec);
278    }
279    bandEnergy[i] = tmp;
280  }
281
282  for (i = 0; i < numBands; i++) {
283    INT scale = (2 * (sfbMaxScaleSpec[i] - 3)) -
284                1; /* max sfbWidth = 36 ; 2^6=64 => 6/2 = 3 (spc*spc) */
285    scale = fixMax(fixMin(scale, (DFRACT_BITS - 1)), -(DFRACT_BITS - 1));
286    bandEnergy[i] = scaleValueSaturate(bandEnergy[i], -scale);
287  }
288}
289
290/*****************************************************************************
291  functionname: FDKaacEnc_CalcBandNrgMSOpt
292  description:
293  input:
294  output:
295*****************************************************************************/
296void FDKaacEnc_CalcBandNrgMSOpt(
297    const FIXP_DBL *RESTRICT mdctSpectrumLeft,
298    const FIXP_DBL *RESTRICT mdctSpectrumRight,
299    INT *RESTRICT sfbMaxScaleSpecLeft, INT *RESTRICT sfbMaxScaleSpecRight,
300    const INT *RESTRICT bandOffset, const INT numBands,
301    FIXP_DBL *RESTRICT bandEnergyMid, FIXP_DBL *RESTRICT bandEnergySide,
302    INT calcLdData, FIXP_DBL *RESTRICT bandEnergyMidLdData,
303    FIXP_DBL *RESTRICT bandEnergySideLdData) {
304  INT i, j, minScale;
305  FIXP_DBL NrgMid, NrgSide, specm, specs;
306
307  for (i = 0; i < numBands; i++) {
308    NrgMid = NrgSide = FL2FXCONST_DBL(0.0);
309    minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]) - 4;
310    minScale = fixMax(0, minScale);
311
312    if (minScale > 0) {
313      for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
314        FIXP_DBL specL = mdctSpectrumLeft[j] << (minScale - 1);
315        FIXP_DBL specR = mdctSpectrumRight[j] << (minScale - 1);
316        specm = specL + specR;
317        specs = specL - specR;
318        NrgMid = fPow2AddDiv2(NrgMid, specm);
319        NrgSide = fPow2AddDiv2(NrgSide, specs);
320      }
321    } else {
322      for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) {
323        FIXP_DBL specL = mdctSpectrumLeft[j] >> 1;
324        FIXP_DBL specR = mdctSpectrumRight[j] >> 1;
325        specm = specL + specR;
326        specs = specL - specR;
327        NrgMid = fPow2AddDiv2(NrgMid, specm);
328        NrgSide = fPow2AddDiv2(NrgSide, specs);
329      }
330    }
331    bandEnergyMid[i] = fMin(NrgMid, (FIXP_DBL)MAXVAL_DBL >> 1) << 1;
332    bandEnergySide[i] = fMin(NrgSide, (FIXP_DBL)MAXVAL_DBL >> 1) << 1;
333  }
334
335  if (calcLdData) {
336    LdDataVector(bandEnergyMid, bandEnergyMidLdData, numBands);
337    LdDataVector(bandEnergySide, bandEnergySideLdData, numBands);
338  }
339
340  for (i = 0; i < numBands; i++) {
341    minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]);
342    INT scale = fixMax(0, 2 * (minScale - 4));
343
344    if (calcLdData) {
345      /* using the minimal scaling of left and right channel can cause very
346      small energies; check ldNrg before subtract scaling multiplication:
347      fract*INT we don't need fMult */
348
349      int minus = scale * FL2FXCONST_DBL(1.0 / 64);
350
351      if (bandEnergyMidLdData[i] != FL2FXCONST_DBL(-1.0f))
352        bandEnergyMidLdData[i] -= minus;
353
354      if (bandEnergySideLdData[i] != FL2FXCONST_DBL(-1.0f))
355        bandEnergySideLdData[i] -= minus;
356    }
357    scale = fixMin(scale, (DFRACT_BITS - 1));
358    bandEnergyMid[i] >>= scale;
359    bandEnergySide[i] >>= scale;
360  }
361}
362