Coverage Report

Created: 2026-01-16 07:48

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/src/fdk-aac/libSBRdec/src/HFgen_preFlat.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
23
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
47
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
53
the FDK AAC Codec software or your modifications thereto.
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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
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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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/**************************** SBR decoder library ******************************
96
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   Author(s):   Oliver Moser, Manuel Jander, Matthias Hildenbrand
98
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   Description: QMF frequency pre-whitening for SBR.
100
                In the documentation the terms "scale factor" and "exponent"
101
                mean the same. Variables containing such information have
102
                the suffix "_sf".
103
104
*******************************************************************************/
105
106
#include "HFgen_preFlat.h"
107
108
4.33M
#define POLY_ORDER 3
109
#define MAXLOWBANDS 32
110
#define LOG10FAC 0.752574989159953f     /* == 10/log2(10) * 2^-2 */
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#define LOG10FAC_INV 0.664385618977472f /* == log2(10)/20 * 2^2  */
112
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#define FIXP_CHB FIXP_SGL /* STB sinus Tab used in transformation */
114
#define CHC(a) (FX_DBL2FXCONST_SGL(a))
115
254k
#define FX_CHB2FX_DBL(a) FX_SGL2FX_DBL(a)
116
117
typedef struct backsubst_data {
118
  FIXP_CHB Lnorm1d[3]; /*!< Normalized L matrix */
119
  SCHAR Lnorm1d_sf[3];
120
  FIXP_CHB Lnormii
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      [3]; /*!< The diagonal data points [i][i] of the normalized L matrix */
122
  SCHAR Lnormii_sf[3];
123
  FIXP_CHB Bmul0
124
      [4]; /*!< To normalize L*x=b, Bmul0 is what we need to multiply b with. */
125
  SCHAR Bmul0_sf[4];
126
  FIXP_CHB LnormInv1d[6]; /*!< Normalized inverted L matrix (L') */
127
  SCHAR LnormInv1d_sf[6];
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  FIXP_CHB
129
  Bmul1[4]; /*!< To normalize L'*x=b, Bmul1 is what we need to multiply b
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               with. */
131
  SCHAR Bmul1_sf[4];
132
} backsubst_data;
133
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/* for each element n do, f(n) = trunc(log2(n))+1  */
135
const UCHAR getLog2[32] = {0, 1, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4,
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                           5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5};
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/** \def  BSD_IDX_OFFSET
139
 *
140
 *  bsd[] begins at index 0 with data for numBands=5. The correct bsd[] is
141
 *  indexed like bsd[numBands-BSD_IDX_OFFSET].
142
 */
143
127k
#define BSD_IDX_OFFSET 5
144
145
#define N_NUMBANDS               \
146
  MAXLOWBANDS - BSD_IDX_OFFSET + \
147
      1 /*!< Number of backsubst_data elements in bsd */
148
149
const backsubst_data bsd[N_NUMBANDS] = {
150
    {
151
        /* numBands=5 */
152
        {CHC(0x66c85a52), CHC(0x4278e587), CHC(0x697dcaff)},
153
        {-1, 0, 0},
154
        {CHC(0x66a61789), CHC(0x5253b8e3), CHC(0x5addad81)},
155
        {3, 4, 1},
156
        {CHC(0x7525ee90), CHC(0x6e2a1210), CHC(0x6523bb40), CHC(0x59822ead)},
157
        {-6, -4, -2, 0},
158
        {CHC(0x609e4cad), CHC(0x59c7e312), CHC(0x681eecac), CHC(0x440ea893),
159
         CHC(0x4a214bb3), CHC(0x53c345a1)},
160
        {1, 0, -1, -1, -3, -5},
161
        {CHC(0x7525ee90), CHC(0x58587936), CHC(0x410d0b38), CHC(0x7f1519d6)},
162
        {-6, -1, 2, 0},
163
    },
164
    {
165
        /* numBands=6 */
166
        {CHC(0x68943285), CHC(0x4841d2c3), CHC(0x6a6214c7)},
167
        {-1, 0, 0},
168
        {CHC(0x63c5923e), CHC(0x4e906e18), CHC(0x6285af8a)},
169
        {3, 4, 1},
170
        {CHC(0x7263940b), CHC(0x424a69a5), CHC(0x4ae8383a), CHC(0x517b7730)},
171
        {-7, -4, -2, 0},
172
        {CHC(0x518aee5f), CHC(0x4823a096), CHC(0x43764a39), CHC(0x6e6faf23),
173
         CHC(0x61bba44f), CHC(0x59d8b132)},
174
        {1, 0, -1, -2, -4, -6},
175
        {CHC(0x7263940b), CHC(0x6757bff2), CHC(0x5bf40fe0), CHC(0x7d6f4292)},
176
        {-7, -2, 1, 0},
177
    },
178
    {
179
        /* numBands=7 */
180
        {CHC(0x699b4c3c), CHC(0x4b8b702f), CHC(0x6ae51a4f)},
181
        {-1, 0, 0},
182
        {CHC(0x623a7f49), CHC(0x4ccc91fc), CHC(0x68f048dd)},
183
        {3, 4, 1},
184
        {CHC(0x7e6ebe18), CHC(0x5701daf2), CHC(0x74a8198b), CHC(0x4b399aa1)},
185
        {-8, -5, -3, 0},
186
        {CHC(0x464a64a6), CHC(0x78e42633), CHC(0x5ee174ba), CHC(0x5d0008c8),
187
         CHC(0x455cff0f), CHC(0x6b9100e7)},
188
        {1, -1, -2, -2, -4, -7},
189
        {CHC(0x7e6ebe18), CHC(0x42c52efe), CHC(0x45fe401f), CHC(0x7b5808ef)},
190
        {-8, -2, 1, 0},
191
    },
192
    {
193
        /* numBands=8 */
194
        {CHC(0x6a3fd9b4), CHC(0x4d99823f), CHC(0x6b372a94)},
195
        {-1, 0, 0},
196
        {CHC(0x614c6ef7), CHC(0x4bd06699), CHC(0x6e59cfca)},
197
        {3, 4, 1},
198
        {CHC(0x4c389cc5), CHC(0x79686681), CHC(0x5e2544c2), CHC(0x46305b43)},
199
        {-8, -6, -3, 0},
200
        {CHC(0x7b4ca7c6), CHC(0x68270ac5), CHC(0x467c644c), CHC(0x505c1b0f),
201
         CHC(0x67a14778), CHC(0x45801767)},
202
        {0, -1, -2, -2, -5, -7},
203
        {CHC(0x4c389cc5), CHC(0x5c499ceb), CHC(0x6f863c9f), CHC(0x79059bfc)},
204
        {-8, -3, 0, 0},
205
    },
206
    {
207
        /* numBands=9 */
208
        {CHC(0x6aad9988), CHC(0x4ef8ac18), CHC(0x6b6df116)},
209
        {-1, 0, 0},
210
        {CHC(0x60b159b0), CHC(0x4b33f772), CHC(0x72f5573d)},
211
        {3, 4, 1},
212
        {CHC(0x6206cb18), CHC(0x58a7d8dc), CHC(0x4e0b2d0b), CHC(0x4207ad84)},
213
        {-9, -6, -3, 0},
214
        {CHC(0x6dadadae), CHC(0x5b8b2cfc), CHC(0x6cf61db2), CHC(0x46c3c90b),
215
         CHC(0x506314ea), CHC(0x5f034acd)},
216
        {0, -1, -3, -2, -5, -8},
217
        {CHC(0x6206cb18), CHC(0x42f8b8de), CHC(0x5bb4776f), CHC(0x769acc79)},
218
        {-9, -3, 0, 0},
219
    },
220
    {
221
        /* numBands=10 */
222
        {CHC(0x6afa7252), CHC(0x4feed3ed), CHC(0x6b94504d)},
223
        {-1, 0, 0},
224
        {CHC(0x60467899), CHC(0x4acbafba), CHC(0x76eb327f)},
225
        {3, 4, 1},
226
        {CHC(0x42415b15), CHC(0x431080da), CHC(0x420f1c32), CHC(0x7d0c1aeb)},
227
        {-9, -6, -3, -1},
228
        {CHC(0x62b2c7a4), CHC(0x51b040a6), CHC(0x56caddb4), CHC(0x7e74a2c8),
229
         CHC(0x4030adf5), CHC(0x43d1dc4f)},
230
        {0, -1, -3, -3, -5, -8},
231
        {CHC(0x42415b15), CHC(0x64e299b3), CHC(0x4d33b5e8), CHC(0x742cee5f)},
232
        {-9, -4, 0, 0},
233
    },
234
    {
235
        /* numBands=11 */
236
        {CHC(0x6b3258bb), CHC(0x50a21233), CHC(0x6bb03c19)},
237
        {-1, 0, 0},
238
        {CHC(0x5ff997c6), CHC(0x4a82706e), CHC(0x7a5aae36)},
239
        {3, 4, 1},
240
        {CHC(0x5d2fb4fb), CHC(0x685bddd8), CHC(0x71b5e983), CHC(0x7708c90b)},
241
        {-10, -7, -4, -1},
242
        {CHC(0x59aceea2), CHC(0x49c428a0), CHC(0x46ca5527), CHC(0x724be884),
243
         CHC(0x68e586da), CHC(0x643485b6)},
244
        {0, -1, -3, -3, -6, -9},
245
        {CHC(0x5d2fb4fb), CHC(0x4e3fad1a), CHC(0x42310ba2), CHC(0x71c8b3ce)},
246
        {-10, -4, 0, 0},
247
    },
248
    {
249
        /* numBands=12 */
250
        {CHC(0x6b5c4726), CHC(0x5128a4a8), CHC(0x6bc52ee1)},
251
        {-1, 0, 0},
252
        {CHC(0x5fc06618), CHC(0x4a4ce559), CHC(0x7d5c16e9)},
253
        {3, 4, 1},
254
        {CHC(0x43af8342), CHC(0x531533d3), CHC(0x633660a6), CHC(0x71ce6052)},
255
        {-10, -7, -4, -1},
256
        {CHC(0x522373d7), CHC(0x434150cb), CHC(0x75b58afc), CHC(0x68474f2d),
257
         CHC(0x575348a5), CHC(0x4c20973f)},
258
        {0, -1, -4, -3, -6, -9},
259
        {CHC(0x43af8342), CHC(0x7c4d3d11), CHC(0x732e13db), CHC(0x6f756ac4)},
260
        {-10, -5, -1, 0},
261
    },
262
    {
263
        /* numBands=13 */
264
        {CHC(0x6b7c8953), CHC(0x51903fcd), CHC(0x6bd54d2e)},
265
        {-1, 0, 0},
266
        {CHC(0x5f94abf0), CHC(0x4a2480fa), CHC(0x40013553)},
267
        {3, 4, 2},
268
        {CHC(0x6501236e), CHC(0x436b9c4e), CHC(0x578d7881), CHC(0x6d34f92e)},
269
        {-11, -7, -4, -1},
270
        {CHC(0x4bc0e2b2), CHC(0x7b9d12ac), CHC(0x636c1c1b), CHC(0x5fe15c2b),
271
         CHC(0x49d54879), CHC(0x7662cfa5)},
272
        {0, -2, -4, -3, -6, -10},
273
        {CHC(0x6501236e), CHC(0x64b059fe), CHC(0x656d8359), CHC(0x6d370900)},
274
        {-11, -5, -1, 0},
275
    },
276
    {
277
        /* numBands=14 */
278
        {CHC(0x6b95e276), CHC(0x51e1b637), CHC(0x6be1f7ed)},
279
        {-1, 0, 0},
280
        {CHC(0x5f727a1c), CHC(0x4a053e9c), CHC(0x412e528c)},
281
        {3, 4, 2},
282
        {CHC(0x4d178bd4), CHC(0x6f33b4e8), CHC(0x4e028f7f), CHC(0x691ee104)},
283
        {-11, -8, -4, -1},
284
        {CHC(0x46473d3f), CHC(0x725bd0a6), CHC(0x55199885), CHC(0x58bcc56b),
285
         CHC(0x7e7e6288), CHC(0x5ddef6eb)},
286
        {0, -2, -4, -3, -7, -10},
287
        {CHC(0x4d178bd4), CHC(0x52ebd467), CHC(0x5a395a6e), CHC(0x6b0f724f)},
288
        {-11, -5, -1, 0},
289
    },
290
    {
291
        /* numBands=15 */
292
        {CHC(0x6baa2a22), CHC(0x5222eb91), CHC(0x6bec1a86)},
293
        {-1, 0, 0},
294
        {CHC(0x5f57393b), CHC(0x49ec8934), CHC(0x423b5b58)},
295
        {3, 4, 2},
296
        {CHC(0x77fd2486), CHC(0x5cfbdf2c), CHC(0x46153bd1), CHC(0x65757ed9)},
297
        {-12, -8, -4, -1},
298
        {CHC(0x41888ee6), CHC(0x6a661db3), CHC(0x49abc8c8), CHC(0x52965848),
299
         CHC(0x6d9301b7), CHC(0x4bb04721)},
300
        {0, -2, -4, -3, -7, -10},
301
        {CHC(0x77fd2486), CHC(0x45424c68), CHC(0x50f33cc6), CHC(0x68ff43f0)},
302
        {-12, -5, -1, 0},
303
    },
304
    {
305
        /* numBands=16 */
306
        {CHC(0x6bbaa499), CHC(0x5257ed94), CHC(0x6bf456e4)},
307
        {-1, 0, 0},
308
        {CHC(0x5f412594), CHC(0x49d8a766), CHC(0x432d1dbd)},
309
        {3, 4, 2},
310
        {CHC(0x5ef5cfde), CHC(0x4eafcd2d), CHC(0x7ed36893), CHC(0x62274b45)},
311
        {-12, -8, -5, -1},
312
        {CHC(0x7ac438f5), CHC(0x637aab21), CHC(0x4067617a), CHC(0x4d3c6ec7),
313
         CHC(0x5fd6e0dd), CHC(0x7bd5f024)},
314
        {-1, -2, -4, -3, -7, -11},
315
        {CHC(0x5ef5cfde), CHC(0x751d0d4f), CHC(0x492b3c41), CHC(0x67065409)},
316
        {-12, -6, -1, 0},
317
    },
318
    {
319
        /* numBands=17 */
320
        {CHC(0x6bc836c9), CHC(0x5283997e), CHC(0x6bfb1f5e)},
321
        {-1, 0, 0},
322
        {CHC(0x5f2f02b6), CHC(0x49c868e9), CHC(0x44078151)},
323
        {3, 4, 2},
324
        {CHC(0x4c43b65a), CHC(0x4349dcf6), CHC(0x73799e2d), CHC(0x5f267274)},
325
        {-12, -8, -5, -1},
326
        {CHC(0x73726394), CHC(0x5d68511a), CHC(0x7191bbcc), CHC(0x48898c70),
327
         CHC(0x548956e1), CHC(0x66981ce8)},
328
        {-1, -2, -5, -3, -7, -11},
329
        {CHC(0x4c43b65a), CHC(0x64131116), CHC(0x429028e2), CHC(0x65240211)},
330
        {-12, -6, -1, 0},
331
    },
332
    {
333
        /* numBands=18 */
334
        {CHC(0x6bd3860d), CHC(0x52a80156), CHC(0x6c00c68d)},
335
        {-1, 0, 0},
336
        {CHC(0x5f1fed86), CHC(0x49baf636), CHC(0x44cdb9dc)},
337
        {3, 4, 2},
338
        {CHC(0x7c189389), CHC(0x742666d8), CHC(0x69b8c776), CHC(0x5c67e27d)},
339
        {-13, -9, -5, -1},
340
        {CHC(0x6cf1ea76), CHC(0x58095703), CHC(0x64e351a9), CHC(0x4460da90),
341
         CHC(0x4b1f8083), CHC(0x55f2d3e1)},
342
        {-1, -2, -5, -3, -7, -11},
343
        {CHC(0x7c189389), CHC(0x5651792a), CHC(0x79cb9b3d), CHC(0x635769c0)},
344
        {-13, -6, -2, 0},
345
    },
346
    {
347
        /* numBands=19 */
348
        {CHC(0x6bdd0c40), CHC(0x52c6abf6), CHC(0x6c058950)},
349
        {-1, 0, 0},
350
        {CHC(0x5f133f88), CHC(0x49afb305), CHC(0x45826d73)},
351
        {3, 4, 2},
352
        {CHC(0x6621a164), CHC(0x6512528e), CHC(0x61449fc8), CHC(0x59e2a0c0)},
353
        {-13, -9, -5, -1},
354
        {CHC(0x6721cadb), CHC(0x53404cd4), CHC(0x5a389e91), CHC(0x40abcbd2),
355
         CHC(0x43332f01), CHC(0x48b82e46)},
356
        {-1, -2, -5, -3, -7, -11},
357
        {CHC(0x6621a164), CHC(0x4b12cc28), CHC(0x6ffd4df8), CHC(0x619f835e)},
358
        {-13, -6, -2, 0},
359
    },
360
    {
361
        /* numBands=20 */
362
        {CHC(0x6be524c5), CHC(0x52e0beb3), CHC(0x6c099552)},
363
        {-1, 0, 0},
364
        {CHC(0x5f087c68), CHC(0x49a62bb5), CHC(0x4627d175)},
365
        {3, 4, 2},
366
        {CHC(0x54ec6afe), CHC(0x58991a42), CHC(0x59e23e8c), CHC(0x578f4ef4)},
367
        {-13, -9, -5, -1},
368
        {CHC(0x61e78f6f), CHC(0x4ef5e1e9), CHC(0x5129c3b8), CHC(0x7ab0f7b2),
369
         CHC(0x78efb076), CHC(0x7c2567ea)},
370
        {-1, -2, -5, -4, -8, -12},
371
        {CHC(0x54ec6afe), CHC(0x41c7812c), CHC(0x676f6f8d), CHC(0x5ffb383f)},
372
        {-13, -6, -2, 0},
373
    },
374
    {
375
        /* numBands=21 */
376
        {CHC(0x6bec1542), CHC(0x52f71929), CHC(0x6c0d0d5e)},
377
        {-1, 0, 0},
378
        {CHC(0x5eff45c5), CHC(0x499e092d), CHC(0x46bfc0c9)},
379
        {3, 4, 2},
380
        {CHC(0x47457a78), CHC(0x4e2d99b3), CHC(0x53637ea5), CHC(0x5567d0e9)},
381
        {-13, -9, -5, -1},
382
        {CHC(0x5d2dc61b), CHC(0x4b1760c8), CHC(0x4967cf39), CHC(0x74b113d8),
383
         CHC(0x6d6676b6), CHC(0x6ad114e9)},
384
        {-1, -2, -5, -4, -8, -12},
385
        {CHC(0x47457a78), CHC(0x740accaa), CHC(0x5feb6609), CHC(0x5e696f95)},
386
        {-13, -7, -2, 0},
387
    },
388
    {
389
        /* numBands=22 */
390
        {CHC(0x6bf21387), CHC(0x530a683c), CHC(0x6c100c59)},
391
        {-1, 0, 0},
392
        {CHC(0x5ef752ea), CHC(0x499708c6), CHC(0x474bcd1b)},
393
        {3, 4, 2},
394
        {CHC(0x78a21ab7), CHC(0x45658aec), CHC(0x4da3c4fe), CHC(0x5367094b)},
395
        {-14, -9, -5, -1},
396
        {CHC(0x58e2df6a), CHC(0x4795990e), CHC(0x42b5e0f7), CHC(0x6f408c64),
397
         CHC(0x6370bebf), CHC(0x5c91ca85)},
398
        {-1, -2, -5, -4, -8, -12},
399
        {CHC(0x78a21ab7), CHC(0x66f951d6), CHC(0x594605bb), CHC(0x5ce91657)},
400
        {-14, -7, -2, 0},
401
    },
402
    {
403
        /* numBands=23 */
404
        {CHC(0x6bf749b2), CHC(0x531b3348), CHC(0x6c12a750)},
405
        {-1, 0, 0},
406
        {CHC(0x5ef06b17), CHC(0x4990f6c9), CHC(0x47cd4c5b)},
407
        {3, 4, 2},
408
        {CHC(0x66dede36), CHC(0x7bdf90a9), CHC(0x4885b2b9), CHC(0x5188a6b7)},
409
        {-14, -10, -5, -1},
410
        {CHC(0x54f85812), CHC(0x446414ae), CHC(0x79c8d519), CHC(0x6a4c2f31),
411
         CHC(0x5ac8325f), CHC(0x50bf9200)},
412
        {-1, -2, -6, -4, -8, -12},
413
        {CHC(0x66dede36), CHC(0x5be0d90e), CHC(0x535cc453), CHC(0x5b7923f0)},
414
        {-14, -7, -2, 0},
415
    },
416
    {
417
        /* numBands=24 */
418
        {CHC(0x6bfbd91d), CHC(0x5329e580), CHC(0x6c14eeed)},
419
        {-1, 0, 0},
420
        {CHC(0x5eea6179), CHC(0x498baa90), CHC(0x4845635d)},
421
        {3, 4, 2},
422
        {CHC(0x58559b7e), CHC(0x6f1b231f), CHC(0x43f1789b), CHC(0x4fc8fcb8)},
423
        {-14, -10, -5, -1},
424
        {CHC(0x51621775), CHC(0x417881a3), CHC(0x6f9ba9b6), CHC(0x65c412b2),
425
         CHC(0x53352c61), CHC(0x46db9caf)},
426
        {-1, -2, -6, -4, -8, -12},
427
        {CHC(0x58559b7e), CHC(0x52636003), CHC(0x4e13b316), CHC(0x5a189cdf)},
428
        {-14, -7, -2, 0},
429
    },
430
    {
431
        /* numBands=25 */
432
        {CHC(0x6bffdc73), CHC(0x5336d4af), CHC(0x6c16f084)},
433
        {-1, 0, 0},
434
        {CHC(0x5ee51249), CHC(0x498703cc), CHC(0x48b50e4f)},
435
        {3, 4, 2},
436
        {CHC(0x4c5616cf), CHC(0x641b9fad), CHC(0x7fa735e0), CHC(0x4e24e57a)},
437
        {-14, -10, -6, -1},
438
        {CHC(0x4e15f47a), CHC(0x7d9481d6), CHC(0x66a82f8a), CHC(0x619ae971),
439
         CHC(0x4c8b2f5f), CHC(0x7d09ec11)},
440
        {-1, -3, -6, -4, -8, -13},
441
        {CHC(0x4c5616cf), CHC(0x4a3770fb), CHC(0x495402de), CHC(0x58c693fa)},
442
        {-14, -7, -2, 0},
443
    },
444
    {
445
        /* numBands=26 */
446
        {CHC(0x6c036943), CHC(0x53424625), CHC(0x6c18b6dc)},
447
        {-1, 0, 0},
448
        {CHC(0x5ee060aa), CHC(0x4982e88a), CHC(0x491d277f)},
449
        {3, 4, 2},
450
        {CHC(0x425ada5b), CHC(0x5a9368ac), CHC(0x78380a42), CHC(0x4c99aa05)},
451
        {-14, -10, -6, -1},
452
        {CHC(0x4b0b569c), CHC(0x78a420da), CHC(0x5ebdf203), CHC(0x5dc57e63),
453
         CHC(0x46a650ff), CHC(0x6ee13fb8)},
454
        {-1, -3, -6, -4, -8, -13},
455
        {CHC(0x425ada5b), CHC(0x4323073c), CHC(0x450ae92b), CHC(0x57822ad5)},
456
        {-14, -7, -2, 0},
457
    },
458
    {
459
        /* numBands=27 */
460
        {CHC(0x6c06911a), CHC(0x534c7261), CHC(0x6c1a4aba)},
461
        {-1, 0, 0},
462
        {CHC(0x5edc3524), CHC(0x497f43c0), CHC(0x497e6cd8)},
463
        {3, 4, 2},
464
        {CHC(0x73fb550e), CHC(0x5244894f), CHC(0x717aad78), CHC(0x4b24ef6c)},
465
        {-15, -10, -6, -1},
466
        {CHC(0x483aebe4), CHC(0x74139116), CHC(0x57b58037), CHC(0x5a3a4f3c),
467
         CHC(0x416950fe), CHC(0x62c7f4f2)},
468
        {-1, -3, -6, -4, -8, -13},
469
        {CHC(0x73fb550e), CHC(0x79efb994), CHC(0x4128cab7), CHC(0x564a919a)},
470
        {-15, -8, -2, 0},
471
    },
472
    {
473
        /* numBands=28 */
474
        {CHC(0x6c096264), CHC(0x535587cd), CHC(0x6c1bb355)},
475
        {-1, 0, 0},
476
        {CHC(0x5ed87c76), CHC(0x497c0439), CHC(0x49d98452)},
477
        {3, 4, 2},
478
        {CHC(0x65dec5bf), CHC(0x4afd1ba3), CHC(0x6b58b4b3), CHC(0x49c4a7b0)},
479
        {-15, -10, -6, -1},
480
        {CHC(0x459e6eb1), CHC(0x6fd850b7), CHC(0x516e7be9), CHC(0x56f13d05),
481
         CHC(0x79785594), CHC(0x58617de7)},
482
        {-1, -3, -6, -4, -9, -13},
483
        {CHC(0x65dec5bf), CHC(0x6f2168aa), CHC(0x7b41310f), CHC(0x551f0692)},
484
        {-15, -8, -3, 0},
485
    },
486
    {
487
        /* numBands=29 */
488
        {CHC(0x6c0be913), CHC(0x535dacd5), CHC(0x6c1cf6a3)},
489
        {-1, 0, 0},
490
        {CHC(0x5ed526b4), CHC(0x49791bc5), CHC(0x4a2eff99)},
491
        {3, 4, 2},
492
        {CHC(0x59e44afe), CHC(0x44949ada), CHC(0x65bf36f5), CHC(0x487705a0)},
493
        {-15, -10, -6, -1},
494
        {CHC(0x43307779), CHC(0x6be959c4), CHC(0x4bce2122), CHC(0x53e34d89),
495
         CHC(0x7115ff82), CHC(0x4f6421a1)},
496
        {-1, -3, -6, -4, -9, -13},
497
        {CHC(0x59e44afe), CHC(0x659eab7d), CHC(0x74cea459), CHC(0x53fed574)},
498
        {-15, -8, -3, 0},
499
    },
500
    {
501
        /* numBands=30 */
502
        {CHC(0x6c0e2f17), CHC(0x53650181), CHC(0x6c1e199d)},
503
        {-1, 0, 0},
504
        {CHC(0x5ed2269f), CHC(0x49767e9e), CHC(0x4a7f5f0b)},
505
        {3, 4, 2},
506
        {CHC(0x4faa4ae6), CHC(0x7dd3bf11), CHC(0x609e2732), CHC(0x473a72e9)},
507
        {-15, -11, -6, -1},
508
        {CHC(0x40ec57c6), CHC(0x683ee147), CHC(0x46be261d), CHC(0x510a7983),
509
         CHC(0x698a84cb), CHC(0x4794a927)},
510
        {-1, -3, -6, -4, -9, -13},
511
        {CHC(0x4faa4ae6), CHC(0x5d3615ad), CHC(0x6ee74773), CHC(0x52e956a1)},
512
        {-15, -8, -3, 0},
513
    },
514
    {
515
        /* numBands=31 */
516
        {CHC(0x6c103cc9), CHC(0x536ba0ac), CHC(0x6c1f2070)},
517
        {-1, 0, 0},
518
        {CHC(0x5ecf711e), CHC(0x497422ea), CHC(0x4acb1438)},
519
        {3, 4, 2},
520
        {CHC(0x46e322ad), CHC(0x73c32f3c), CHC(0x5be7d172), CHC(0x460d8800)},
521
        {-15, -11, -6, -1},
522
        {CHC(0x7d9bf8ad), CHC(0x64d22351), CHC(0x422bdc81), CHC(0x4e6184aa),
523
         CHC(0x62ba2375), CHC(0x40c325de)},
524
        {-2, -3, -6, -4, -9, -13},
525
        {CHC(0x46e322ad), CHC(0x55bef2a3), CHC(0x697b3135), CHC(0x51ddee4d)},
526
        {-15, -8, -3, 0},
527
    },
528
    {
529
        // numBands=32
530
        {CHC(0x6c121933), CHC(0x5371a104), CHC(0x6c200ea0)},
531
        {-1, 0, 0},
532
        {CHC(0x5eccfcd3), CHC(0x49720060), CHC(0x4b1283f0)},
533
        {3, 4, 2},
534
        {CHC(0x7ea12a52), CHC(0x6aca3303), CHC(0x579072bf), CHC(0x44ef056e)},
535
        {-16, -11, -6, -1},
536
        {CHC(0x79a3a9ab), CHC(0x619d38fc), CHC(0x7c0f0734), CHC(0x4be3dd5d),
537
         CHC(0x5c8d7163), CHC(0x7591065f)},
538
        {-2, -3, -7, -4, -9, -14},
539
        {CHC(0x7ea12a52), CHC(0x4f1782a6), CHC(0x647cbcb2), CHC(0x50dc0bb1)},
540
        {-16, -8, -3, 0},
541
    },
542
};
543
544
/** \def  SUM_SAFETY
545
 *
546
 *  SUM_SAFTEY defines the bits needed to right-shift every summand in
547
 *  order to be overflow-safe. In the two backsubst functions we sum up 4
548
 *  values. Since one of which is definitely not MAXVAL_DBL (the L[x][y]),
549
 *  we spare just 2 safety bits instead of 3.
550
 */
551
304k
#define SUM_SAFETY 2
552
553
/**
554
 * \brief  Solves L*x=b via backsubstitution according to the following
555
 * structure:
556
 *
557
 *  x[0] =  b[0];
558
 *  x[1] = (b[1]                               - x[0]) / L[1][1];
559
 *  x[2] = (b[2] - x[1]*L[2][1]                - x[0]) / L[2][2];
560
 *  x[3] = (b[3] - x[2]*L[3][2] - x[1]*L[3][1] - x[0]) / L[3][3];
561
 *
562
 * \param[in]  numBands  SBR crossover band index
563
 * \param[in]  b         the b in L*x=b (one-dimensional)
564
 * \param[out] x         output polynomial coefficients (mantissa)
565
 * \param[out] x_sf      exponents of x[]
566
 */
567
static void backsubst_fw(const int numBands, const FIXP_DBL *const b,
568
12.7k
                         FIXP_DBL *RESTRICT x, int *RESTRICT x_sf) {
569
12.7k
  int i, k;
570
12.7k
  int m; /* the trip counter that indexes incrementally through Lnorm1d[] */
571
572
12.7k
  const FIXP_CHB *RESTRICT pLnorm1d = bsd[numBands - BSD_IDX_OFFSET].Lnorm1d;
573
12.7k
  const SCHAR *RESTRICT pLnorm1d_sf = bsd[numBands - BSD_IDX_OFFSET].Lnorm1d_sf;
574
12.7k
  const FIXP_CHB *RESTRICT pLnormii = bsd[numBands - BSD_IDX_OFFSET].Lnormii;
575
12.7k
  const SCHAR *RESTRICT pLnormii_sf = bsd[numBands - BSD_IDX_OFFSET].Lnormii_sf;
576
577
12.7k
  x[0] = b[0];
578
579
50.8k
  for (i = 1, m = 0; i <= POLY_ORDER; ++i) {
580
38.1k
    FIXP_DBL sum = b[i] >> SUM_SAFETY;
581
38.1k
    int sum_sf = x_sf[i];
582
76.2k
    for (k = i - 1; k > 0; --k, ++m) {
583
38.1k
      int e;
584
38.1k
      FIXP_DBL mult = fMultNorm(FX_CHB2FX_DBL(pLnorm1d[m]), x[k], &e);
585
38.1k
      int mult_sf = pLnorm1d_sf[m] + x_sf[k] + e;
586
587
      /* check if the new summand mult has a different sf than the sum currently
588
       * has */
589
38.1k
      int diff = mult_sf - sum_sf;
590
591
38.1k
      if (diff > 0) {
592
        /* yes, and it requires the sum to be adjusted (scaled down) */
593
15.5k
        sum >>= diff;
594
15.5k
        sum_sf = mult_sf;
595
22.5k
      } else if (diff < 0) {
596
        /* yes, but here mult needs to be scaled down */
597
16.9k
        mult >>= -diff;
598
16.9k
      }
599
38.1k
      sum -= (mult >> SUM_SAFETY);
600
38.1k
    }
601
602
    /* - x[0] */
603
38.1k
    if (x_sf[0] > sum_sf) {
604
22.0k
      sum >>= (x_sf[0] - sum_sf);
605
22.0k
      sum_sf = x_sf[0];
606
22.0k
    }
607
38.1k
    sum -= (x[0] >> (sum_sf - x_sf[0] + SUM_SAFETY));
608
609
    /* instead of the division /L[i][i], we multiply by the inverse */
610
38.1k
    int e;
611
38.1k
    x[i] = fMultNorm(sum, FX_CHB2FX_DBL(pLnormii[i - 1]), &e);
612
38.1k
    x_sf[i] = sum_sf + pLnormii_sf[i - 1] + e + SUM_SAFETY;
613
38.1k
  }
614
12.7k
}
615
616
/**
617
 * \brief Solves L*x=b via backsubstitution according to the following
618
 * structure:
619
 *
620
 *  x[3] = b[3];
621
 *  x[2] = b[2] - L[2][3]*x[3];
622
 *  x[1] = b[1] - L[1][2]*x[2] - L[1][3]*x[3];
623
 *  x[0] = b[0] - L[0][1]*x[1] - L[0][2]*x[2] - L[0][3]*x[3];
624
 *
625
 * \param[in]  numBands  SBR crossover band index
626
 * \param[in]  b         the b in L*x=b (one-dimensional)
627
 * \param[out] x         solution vector
628
 * \param[out] x_sf      exponents of x[]
629
 */
630
static void backsubst_bw(const int numBands, const FIXP_DBL *const b,
631
12.7k
                         FIXP_DBL *RESTRICT x, int *RESTRICT x_sf) {
632
12.7k
  int i, k;
633
12.7k
  int m; /* the trip counter that indexes incrementally through LnormInv1d[] */
634
635
12.7k
  const FIXP_CHB *RESTRICT pLnormInv1d =
636
12.7k
      bsd[numBands - BSD_IDX_OFFSET].LnormInv1d;
637
12.7k
  const SCHAR *RESTRICT pLnormInv1d_sf =
638
12.7k
      bsd[numBands - BSD_IDX_OFFSET].LnormInv1d_sf;
639
640
12.7k
  x[POLY_ORDER] = b[POLY_ORDER];
641
642
50.8k
  for (i = POLY_ORDER - 1, m = 0; i >= 0; i--) {
643
38.1k
    FIXP_DBL sum = b[i] >> SUM_SAFETY;
644
38.1k
    int sum_sf = x_sf[i]; /* sum's sf but disregarding SUM_SAFETY (added at the
645
                             iteration's end) */
646
647
114k
    for (k = i + 1; k <= POLY_ORDER; ++k, ++m) {
648
76.2k
      int e;
649
76.2k
      FIXP_DBL mult = fMultNorm(FX_CHB2FX_DBL(pLnormInv1d[m]), x[k], &e);
650
76.2k
      int mult_sf = pLnormInv1d_sf[m] + x_sf[k] + e;
651
652
      /* check if the new summand mult has a different sf than sum currently has
653
       */
654
76.2k
      int diff = mult_sf - sum_sf;
655
656
76.2k
      if (diff > 0) {
657
        /* yes, and it requires the sum v to be adjusted (scaled down) */
658
27.5k
        sum >>= diff;
659
27.5k
        sum_sf = mult_sf;
660
48.6k
      } else if (diff < 0) {
661
        /* yes, but here mult needs to be scaled down */
662
32.6k
        mult >>= -diff;
663
32.6k
      }
664
665
      /* mult has now the same sf than what it is about to be added to. */
666
      /* scale mult down additionally so that building the sum is overflow-safe.
667
       */
668
76.2k
      sum -= (mult >> SUM_SAFETY);
669
76.2k
    }
670
671
38.1k
    x_sf[i] = sum_sf + SUM_SAFETY;
672
38.1k
    x[i] = sum;
673
38.1k
  }
674
12.7k
}
675
676
/**
677
 * \brief  Solves a system of linear equations (L*x=b) with the Cholesky
678
 * algorithm.
679
 *
680
 * \param[in]     numBands  SBR crossover band index
681
 * \param[in,out] b         input: vector b, output: solution vector p.
682
 * \param[in,out] b_sf      input: exponent of b; output: exponent of solution
683
 * p.
684
 */
685
static void choleskySolve(const int numBands, FIXP_DBL *RESTRICT b,
686
12.7k
                          int *RESTRICT b_sf) {
687
12.7k
  int i, e;
688
689
12.7k
  const FIXP_CHB *RESTRICT pBmul0 = bsd[numBands - BSD_IDX_OFFSET].Bmul0;
690
12.7k
  const SCHAR *RESTRICT pBmul0_sf = bsd[numBands - BSD_IDX_OFFSET].Bmul0_sf;
691
12.7k
  const FIXP_CHB *RESTRICT pBmul1 = bsd[numBands - BSD_IDX_OFFSET].Bmul1;
692
12.7k
  const SCHAR *RESTRICT pBmul1_sf = bsd[numBands - BSD_IDX_OFFSET].Bmul1_sf;
693
694
  /* normalize b */
695
12.7k
  FIXP_DBL bnormed[POLY_ORDER + 1];
696
63.5k
  for (i = 0; i <= POLY_ORDER; ++i) {
697
50.8k
    bnormed[i] = fMultNorm(b[i], FX_CHB2FX_DBL(pBmul0[i]), &e);
698
50.8k
    b_sf[i] += pBmul0_sf[i] + e;
699
50.8k
  }
700
701
12.7k
  backsubst_fw(numBands, bnormed, b, b_sf);
702
703
  /* normalize b again */
704
63.5k
  for (i = 0; i <= POLY_ORDER; ++i) {
705
50.8k
    bnormed[i] = fMultNorm(b[i], FX_CHB2FX_DBL(pBmul1[i]), &e);
706
50.8k
    b_sf[i] += pBmul1_sf[i] + e;
707
50.8k
  }
708
709
12.7k
  backsubst_bw(numBands, bnormed, b, b_sf);
710
12.7k
}
711
712
/**
713
 * \brief  Find polynomial approximation of vector y with implicit abscisas
714
 * x=0,1,2,3..n-1
715
 *
716
 *  The problem (V^T * V * p = V^T * y) is solved with Cholesky.
717
 *  V is the Vandermode Matrix constructed with x = 0...n-1;
718
 *  A = V^T * V; b = V^T * y;
719
 *
720
 * \param[in]  numBands  SBR crossover band index (BSD_IDX_OFFSET <= numBands <=
721
 * MAXLOWBANDS)
722
 * \param[in]  y         input vector (mantissa)
723
 * \param[in]  y_sf      exponents of y[]
724
 * \param[out] p         output polynomial coefficients (mantissa)
725
 * \param[out] p_sf      exponents of p[]
726
 */
727
static void polyfit(const int numBands, const FIXP_DBL *const y, const int y_sf,
728
12.7k
                    FIXP_DBL *RESTRICT p, int *RESTRICT p_sf) {
729
12.7k
  int i, k;
730
12.7k
  LONG v[POLY_ORDER + 1];
731
12.7k
  int sum_saftey = getLog2[numBands - 1];
732
733
12.7k
  FDK_ASSERT((numBands >= BSD_IDX_OFFSET) && (numBands <= MAXLOWBANDS));
734
735
  /* construct vector b[] temporarily stored in array p[] */
736
12.7k
  FDKmemclear(p, (POLY_ORDER + 1) * sizeof(FIXP_DBL));
737
738
  /* p[] are the sums over n values and each p[i] has its own sf */
739
63.5k
  for (i = 0; i <= POLY_ORDER; ++i) p_sf[i] = 1 - DFRACT_BITS;
740
741
203k
  for (k = 0; k < numBands; k++) {
742
191k
    v[0] = (LONG)1;
743
764k
    for (i = 1; i <= POLY_ORDER; i++) {
744
573k
      v[i] = k * v[i - 1];
745
573k
    }
746
747
955k
    for (i = 0; i <= POLY_ORDER; i++) {
748
764k
      if (v[POLY_ORDER - i] != 0 && y[k] != FIXP_DBL(0)) {
749
716k
        int e;
750
716k
        FIXP_DBL mult = fMultNorm((FIXP_DBL)v[POLY_ORDER - i], y[k], &e);
751
716k
        int sf = DFRACT_BITS - 1 + y_sf + e;
752
753
        /* check if the new summand has a different sf than the sum p[i]
754
         * currently has */
755
716k
        int diff = sf - p_sf[i];
756
757
716k
        if (diff > 0) {
758
          /* yes, and it requires the sum p[i] to be adjusted (scaled down) */
759
255k
          p[i] >>= fMin(DFRACT_BITS - 1, diff);
760
255k
          p_sf[i] = sf;
761
461k
        } else if (diff < 0) {
762
          /* yes, but here mult needs to be scaled down */
763
260k
          mult >>= -diff;
764
260k
        }
765
766
        /* mult has now the same sf than what it is about to be added to.
767
           scale mult down additionally so that building the sum is
768
           overflow-safe. */
769
716k
        p[i] += mult >> sum_saftey;
770
716k
      }
771
764k
    }
772
191k
  }
773
774
12.7k
  p_sf[0] += sum_saftey;
775
12.7k
  p_sf[1] += sum_saftey;
776
12.7k
  p_sf[2] += sum_saftey;
777
12.7k
  p_sf[3] += sum_saftey;
778
779
12.7k
  choleskySolve(numBands, p, p_sf);
780
12.7k
}
781
782
/**
783
 * \brief  Calculates the output of a POLY_ORDER-degree polynomial function
784
 *         with Horner scheme:
785
 *
786
 *         y(x) = p3 + p2*x + p1*x^2 + p0*x^3
787
 *              = p3 + x*(p2 + x*(p1 + x*p0))
788
 *
789
 *         The for loop iterates through the mult/add parts in y(x) as above,
790
 *         during which regular upscaling ensures a stable exponent of the
791
 *         result.
792
 *
793
 * \param[in]  p       coefficients as in y(x)
794
 * \param[in]  p_sf    exponents of p[]
795
 * \param[in]  x_int   non-fractional integer representation of x as in y(x)
796
 * \param[out] out_sf  exponent of return value
797
 *
798
 * \return             result y(x)
799
 */
800
static FIXP_DBL polyval(const FIXP_DBL *const p, const int *const p_sf,
801
191k
                        const int x_int, int *out_sf) {
802
191k
  FDK_ASSERT(x_int <= 31); /* otherwise getLog2[] needs more elements */
803
804
191k
  int k, x_sf;
805
191k
  int result_sf;   /* working space to compute return value *out_sf */
806
191k
  FIXP_DBL x;      /* fractional value of x_int */
807
191k
  FIXP_DBL result; /* return value */
808
809
  /* if x == 0, then y(x) is just p3 */
810
191k
  if (x_int != 0) {
811
178k
    x_sf = getLog2[x_int];
812
178k
    x = (FIXP_DBL)x_int << (DFRACT_BITS - 1 - x_sf);
813
178k
  } else {
814
12.7k
    *out_sf = p_sf[3];
815
12.7k
    return p[3];
816
12.7k
  }
817
818
178k
  result = p[0];
819
178k
  result_sf = p_sf[0];
820
821
713k
  for (k = 1; k <= POLY_ORDER; ++k) {
822
534k
    FIXP_DBL mult = fMult(x, result);
823
534k
    int mult_sf = x_sf + result_sf;
824
825
534k
    int room = CountLeadingBits(mult);
826
534k
    mult <<= room;
827
534k
    mult_sf -= room;
828
829
534k
    FIXP_DBL pp = p[k];
830
534k
    int pp_sf = p_sf[k];
831
832
    /* equalize the shift factors of pp and mult so that we can sum them up */
833
534k
    int diff = pp_sf - mult_sf;
834
835
534k
    if (diff > 0) {
836
431k
      diff = fMin(diff, DFRACT_BITS - 1);
837
431k
      mult >>= diff;
838
431k
    } else if (diff < 0) {
839
54.1k
      diff = fMax(diff, 1 - DFRACT_BITS);
840
54.1k
      pp >>= -diff;
841
54.1k
    }
842
843
    /* downshift by 1 to ensure safe summation */
844
534k
    mult >>= 1;
845
534k
    mult_sf++;
846
534k
    pp >>= 1;
847
534k
    pp_sf++;
848
849
534k
    result_sf = fMax(pp_sf, mult_sf);
850
851
534k
    result = mult + pp;
852
    /* rarely, mult and pp happen to be almost equal except their sign,
853
    and then upon summation, result becomes so small, that it is within
854
    the inaccuracy range of a few bits, and then the relative error
855
    produced by this function may become HUGE */
856
534k
  }
857
858
178k
  *out_sf = result_sf;
859
178k
  return result;
860
191k
}
861
862
void sbrDecoder_calculateGainVec(FIXP_DBL **sourceBufferReal,
863
                                 FIXP_DBL **sourceBufferImag,
864
                                 int sourceBuf_e_overlap,
865
                                 int sourceBuf_e_current, int overlap,
866
                                 FIXP_DBL *RESTRICT GainVec, int *GainVec_exp,
867
                                 int numBands, const int startSample,
868
12.7k
                                 const int stopSample) {
869
12.7k
  FIXP_DBL p[POLY_ORDER + 1];
870
12.7k
  FIXP_DBL meanNrg;
871
12.7k
  FIXP_DBL LowEnv[MAXLOWBANDS];
872
12.7k
  FIXP_DBL invNumBands = GetInvInt(numBands);
873
12.7k
  FIXP_DBL invNumSlots = GetInvInt(stopSample - startSample);
874
12.7k
  int i, loBand, exp, scale_nrg, scale_nrg_ov;
875
12.7k
  int sum_scale = 5, sum_scale_ov = 3;
876
877
12.7k
  if (overlap > 8) {
878
931
    FDK_ASSERT(overlap <= 16);
879
931
    sum_scale_ov += 1;
880
931
    sum_scale += 1;
881
931
  }
882
883
  /* exponents of energy values */
884
12.7k
  sourceBuf_e_overlap = sourceBuf_e_overlap * 2 + sum_scale_ov;
885
12.7k
  sourceBuf_e_current = sourceBuf_e_current * 2 + sum_scale;
886
12.7k
  exp = fMax(sourceBuf_e_overlap, sourceBuf_e_current);
887
12.7k
  scale_nrg = sourceBuf_e_current - exp;
888
12.7k
  scale_nrg_ov = sourceBuf_e_overlap - exp;
889
890
12.7k
  meanNrg = (FIXP_DBL)0;
891
  /* Calculate the spectral envelope in dB over the current copy-up frame. */
892
203k
  for (loBand = 0; loBand < numBands; loBand++) {
893
191k
    FIXP_DBL nrg_ov, nrg;
894
191k
    INT reserve = 0, exp_new;
895
191k
    FIXP_DBL maxVal = FL2FX_DBL(0.0f);
896
897
6.55M
    for (i = startSample; i < stopSample; i++) {
898
6.36M
      maxVal |=
899
6.36M
          (FIXP_DBL)((LONG)(sourceBufferReal[i][loBand]) ^
900
6.36M
                     ((LONG)sourceBufferReal[i][loBand] >> (DFRACT_BITS - 1)));
901
6.36M
      maxVal |=
902
6.36M
          (FIXP_DBL)((LONG)(sourceBufferImag[i][loBand]) ^
903
6.36M
                     ((LONG)sourceBufferImag[i][loBand] >> (DFRACT_BITS - 1)));
904
6.36M
    }
905
906
191k
    if (maxVal != FL2FX_DBL(0.0f)) {
907
187k
      reserve = CntLeadingZeros(maxVal) - 2;
908
187k
    }
909
910
191k
    nrg_ov = nrg = (FIXP_DBL)0;
911
191k
    if (scale_nrg_ov > -31) {
912
1.37M
      for (i = startSample; i < overlap; i++) {
913
1.18M
        nrg_ov +=
914
1.18M
            (fPow2Div2(scaleValue(sourceBufferReal[i][loBand], reserve)) +
915
1.18M
             fPow2Div2(scaleValue(sourceBufferImag[i][loBand], reserve))) >>
916
1.18M
            sum_scale_ov;
917
1.18M
      }
918
190k
    } else {
919
55
      scale_nrg_ov = 0;
920
55
    }
921
191k
    if (scale_nrg > -31) {
922
5.36M
      for (i = overlap; i < stopSample; i++) {
923
5.17M
        nrg += (fPow2Div2(scaleValue(sourceBufferReal[i][loBand], reserve)) +
924
5.17M
                fPow2Div2(scaleValue(sourceBufferImag[i][loBand], reserve))) >>
925
5.17M
               sum_scale;
926
5.17M
      }
927
190k
    } else {
928
19
      scale_nrg = 0;
929
19
    }
930
931
191k
    nrg = (scaleValue(nrg_ov, scale_nrg_ov) >> 1) +
932
191k
          (scaleValue(nrg, scale_nrg) >> 1);
933
191k
    nrg = fMult(nrg, invNumSlots);
934
935
191k
    exp_new =
936
191k
        exp - (2 * reserve) +
937
191k
        2; /* +1 for addition directly above, +1 for fPow2Div2 in loops above */
938
939
    /* LowEnv = 10*log10(nrg) = log2(nrg) * 10/log2(10) */
940
    /* exponent of logarithmic energy is 8 */
941
191k
    if (nrg > (FIXP_DBL)0) {
942
187k
      int exp_log2;
943
187k
      nrg = CalcLog2(nrg, exp_new, &exp_log2);
944
187k
      nrg = scaleValue(nrg, exp_log2 - 6);
945
187k
      nrg = fMult(FL2FXCONST_SGL(LOG10FAC), nrg);
946
187k
    } else {
947
3.75k
      nrg = (FIXP_DBL)0;
948
3.75k
    }
949
191k
    LowEnv[loBand] = nrg;
950
191k
    meanNrg += fMult(nrg, invNumBands);
951
191k
  }
952
12.7k
  exp = 6 + 2; /* exponent of LowEnv: +2 is exponent of LOG10FAC */
953
954
  /* subtract mean before polynomial approximation to reduce dynamic of p[] */
955
203k
  for (loBand = 0; loBand < numBands; loBand++) {
956
191k
    LowEnv[loBand] = meanNrg - LowEnv[loBand];
957
191k
  }
958
959
  /* For numBands < BSD_IDX_OFFSET (== POLY_ORDER+2) we dont get an
960
     overdetermined equation system. The calculated polynomial will exactly fit
961
     the input data and evaluating the polynomial will lead to the same vector
962
     than the original input vector: lowEnvSlope[] == lowEnv[]
963
  */
964
12.7k
  if (numBands > POLY_ORDER + 1) {
965
    /* Find polynomial approximation of LowEnv */
966
12.7k
    int p_sf[POLY_ORDER + 1];
967
968
12.7k
    polyfit(numBands, LowEnv, exp, p, p_sf);
969
970
203k
    for (i = 0; i < numBands; i++) {
971
191k
      int sf;
972
973
      /* lowBandEnvSlope[i] = tmp; */
974
191k
      FIXP_DBL tmp = polyval(p, p_sf, i, &sf);
975
976
      /* GainVec = 10^((mean(y)-y)/20) = 2^( (mean(y)-y) * log2(10)/20 ) */
977
191k
      tmp = fMult(tmp, FL2FXCONST_SGL(LOG10FAC_INV));
978
191k
      GainVec[i] = f2Pow(tmp, sf - 2,
979
191k
                         &GainVec_exp[i]); /* -2 is exponent of LOG10FAC_INV */
980
191k
    }
981
12.7k
  } else { /* numBands <= POLY_ORDER+1 */
982
0
    for (i = 0; i < numBands; i++) {
983
0
      int sf = exp; /* exponent of LowEnv[] */
984
985
      /* lowBandEnvSlope[i] = LowEnv[i]; */
986
0
      FIXP_DBL tmp = LowEnv[i];
987
988
      /* GainVec = 10^((mean(y)-y)/20) = 2^( (mean(y)-y) * log2(10)/20 ) */
989
0
      tmp = fMult(tmp, FL2FXCONST_SGL(LOG10FAC_INV));
990
0
      GainVec[i] = f2Pow(tmp, sf - 2,
991
0
                         &GainVec_exp[i]); /* -2 is exponent of LOG10FAC_INV */
992
0
    }
993
0
  }
994
12.7k
}