Coverage Report

Created: 2025-07-23 06:43

/src/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
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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
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
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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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/**************************** SBR decoder library ******************************
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   Author(s):   Oliver Moser, Manuel Jander, Matthias Hildenbrand
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   Description: QMF frequency pre-whitening for SBR.
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                In the documentation the terms "scale factor" and "exponent"
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                mean the same. Variables containing such information have
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                the suffix "_sf".
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*******************************************************************************/
105
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#include "HFgen_preFlat.h"
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19.2M
#define POLY_ORDER 3
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#define MAXLOWBANDS 32
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#define LOG10FAC 0.752574989159953f     /* == 10/log2(10) * 2^-2 */
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#define LOG10FAC_INV 0.664385618977472f /* == log2(10)/20 * 2^2  */
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#define FIXP_CHB FIXP_SGL /* STB sinus Tab used in transformation */
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#define CHC(a) (FX_DBL2FXCONST_SGL(a))
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975k
#define FX_CHB2FX_DBL(a) FX_SGL2FX_DBL(a)
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typedef struct backsubst_data {
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  FIXP_CHB Lnorm1d[3]; /*!< Normalized L matrix */
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  SCHAR Lnorm1d_sf[3];
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  FIXP_CHB Lnormii
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      [3]; /*!< The diagonal data points [i][i] of the normalized L matrix */
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  SCHAR Lnormii_sf[3];
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  FIXP_CHB Bmul0
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      [4]; /*!< To normalize L*x=b, Bmul0 is what we need to multiply b with. */
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  SCHAR Bmul0_sf[4];
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  FIXP_CHB LnormInv1d[6]; /*!< Normalized inverted L matrix (L') */
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  SCHAR LnormInv1d_sf[6];
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  FIXP_CHB
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  Bmul1[4]; /*!< To normalize L'*x=b, Bmul1 is what we need to multiply b
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               with. */
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  SCHAR Bmul1_sf[4];
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} backsubst_data;
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/* for each element n do, f(n) = trunc(log2(n))+1  */
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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
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 *
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 *  bsd[] begins at index 0 with data for numBands=5. The correct bsd[] is
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 *  indexed like bsd[numBands-BSD_IDX_OFFSET].
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 */
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487k
#define BSD_IDX_OFFSET 5
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#define N_NUMBANDS               \
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  MAXLOWBANDS - BSD_IDX_OFFSET + \
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      1 /*!< Number of backsubst_data elements in bsd */
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const backsubst_data bsd[N_NUMBANDS] = {
150
    {
151
        /* numBands=5 */
152
        {CHC(0x66c85a52), CHC(0x4278e587), CHC(0x697dcaff)},
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        {-1, 0, 0},
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        {CHC(0x66a61789), CHC(0x5253b8e3), CHC(0x5addad81)},
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        {3, 4, 1},
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        {CHC(0x7525ee90), CHC(0x6e2a1210), CHC(0x6523bb40), CHC(0x59822ead)},
157
        {-6, -4, -2, 0},
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        {CHC(0x609e4cad), CHC(0x59c7e312), CHC(0x681eecac), CHC(0x440ea893),
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         CHC(0x4a214bb3), CHC(0x53c345a1)},
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        {1, 0, -1, -1, -3, -5},
161
        {CHC(0x7525ee90), CHC(0x58587936), CHC(0x410d0b38), CHC(0x7f1519d6)},
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        {-6, -1, 2, 0},
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    },
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),
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         CHC(0x61bba44f), CHC(0x59d8b132)},
174
        {1, 0, -1, -2, -4, -6},
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        {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),
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         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)},
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        {-8, -6, -3, 0},
200
        {CHC(0x7b4ca7c6), CHC(0x68270ac5), CHC(0x467c644c), CHC(0x505c1b0f),
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         CHC(0x67a14778), CHC(0x45801767)},
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        {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
1.17M
#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
48.7k
                         FIXP_DBL *RESTRICT x, int *RESTRICT x_sf) {
569
48.7k
  int i, k;
570
48.7k
  int m; /* the trip counter that indexes incrementally through Lnorm1d[] */
571
572
48.7k
  const FIXP_CHB *RESTRICT pLnorm1d = bsd[numBands - BSD_IDX_OFFSET].Lnorm1d;
573
48.7k
  const SCHAR *RESTRICT pLnorm1d_sf = bsd[numBands - BSD_IDX_OFFSET].Lnorm1d_sf;
574
48.7k
  const FIXP_CHB *RESTRICT pLnormii = bsd[numBands - BSD_IDX_OFFSET].Lnormii;
575
48.7k
  const SCHAR *RESTRICT pLnormii_sf = bsd[numBands - BSD_IDX_OFFSET].Lnormii_sf;
576
577
48.7k
  x[0] = b[0];
578
579
195k
  for (i = 1, m = 0; i <= POLY_ORDER; ++i) {
580
146k
    FIXP_DBL sum = b[i] >> SUM_SAFETY;
581
146k
    int sum_sf = x_sf[i];
582
292k
    for (k = i - 1; k > 0; --k, ++m) {
583
146k
      int e;
584
146k
      FIXP_DBL mult = fMultNorm(FX_CHB2FX_DBL(pLnorm1d[m]), x[k], &e);
585
146k
      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
146k
      int diff = mult_sf - sum_sf;
590
591
146k
      if (diff > 0) {
592
        /* yes, and it requires the sum to be adjusted (scaled down) */
593
63.1k
        sum >>= diff;
594
63.1k
        sum_sf = mult_sf;
595
83.1k
      } else if (diff < 0) {
596
        /* yes, but here mult needs to be scaled down */
597
76.9k
        mult >>= -diff;
598
76.9k
      }
599
146k
      sum -= (mult >> SUM_SAFETY);
600
146k
    }
601
602
    /* - x[0] */
603
146k
    if (x_sf[0] > sum_sf) {
604
40.2k
      sum >>= (x_sf[0] - sum_sf);
605
40.2k
      sum_sf = x_sf[0];
606
40.2k
    }
607
146k
    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
146k
    int e;
611
146k
    x[i] = fMultNorm(sum, FX_CHB2FX_DBL(pLnormii[i - 1]), &e);
612
146k
    x_sf[i] = sum_sf + pLnormii_sf[i - 1] + e + SUM_SAFETY;
613
146k
  }
614
48.7k
}
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
48.7k
                         FIXP_DBL *RESTRICT x, int *RESTRICT x_sf) {
632
48.7k
  int i, k;
633
48.7k
  int m; /* the trip counter that indexes incrementally through LnormInv1d[] */
634
635
48.7k
  const FIXP_CHB *RESTRICT pLnormInv1d =
636
48.7k
      bsd[numBands - BSD_IDX_OFFSET].LnormInv1d;
637
48.7k
  const SCHAR *RESTRICT pLnormInv1d_sf =
638
48.7k
      bsd[numBands - BSD_IDX_OFFSET].LnormInv1d_sf;
639
640
48.7k
  x[POLY_ORDER] = b[POLY_ORDER];
641
642
195k
  for (i = POLY_ORDER - 1, m = 0; i >= 0; i--) {
643
146k
    FIXP_DBL sum = b[i] >> SUM_SAFETY;
644
146k
    int sum_sf = x_sf[i]; /* sum's sf but disregarding SUM_SAFETY (added at the
645
                             iteration's end) */
646
647
438k
    for (k = i + 1; k <= POLY_ORDER; ++k, ++m) {
648
292k
      int e;
649
292k
      FIXP_DBL mult = fMultNorm(FX_CHB2FX_DBL(pLnormInv1d[m]), x[k], &e);
650
292k
      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
292k
      int diff = mult_sf - sum_sf;
655
656
292k
      if (diff > 0) {
657
        /* yes, and it requires the sum v to be adjusted (scaled down) */
658
143k
        sum >>= diff;
659
143k
        sum_sf = mult_sf;
660
149k
      } else if (diff < 0) {
661
        /* yes, but here mult needs to be scaled down */
662
119k
        mult >>= -diff;
663
119k
      }
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
292k
      sum -= (mult >> SUM_SAFETY);
669
292k
    }
670
671
146k
    x_sf[i] = sum_sf + SUM_SAFETY;
672
146k
    x[i] = sum;
673
146k
  }
674
48.7k
}
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
48.7k
                          int *RESTRICT b_sf) {
687
48.7k
  int i, e;
688
689
48.7k
  const FIXP_CHB *RESTRICT pBmul0 = bsd[numBands - BSD_IDX_OFFSET].Bmul0;
690
48.7k
  const SCHAR *RESTRICT pBmul0_sf = bsd[numBands - BSD_IDX_OFFSET].Bmul0_sf;
691
48.7k
  const FIXP_CHB *RESTRICT pBmul1 = bsd[numBands - BSD_IDX_OFFSET].Bmul1;
692
48.7k
  const SCHAR *RESTRICT pBmul1_sf = bsd[numBands - BSD_IDX_OFFSET].Bmul1_sf;
693
694
  /* normalize b */
695
48.7k
  FIXP_DBL bnormed[POLY_ORDER + 1];
696
243k
  for (i = 0; i <= POLY_ORDER; ++i) {
697
195k
    bnormed[i] = fMultNorm(b[i], FX_CHB2FX_DBL(pBmul0[i]), &e);
698
195k
    b_sf[i] += pBmul0_sf[i] + e;
699
195k
  }
700
701
48.7k
  backsubst_fw(numBands, bnormed, b, b_sf);
702
703
  /* normalize b again */
704
243k
  for (i = 0; i <= POLY_ORDER; ++i) {
705
195k
    bnormed[i] = fMultNorm(b[i], FX_CHB2FX_DBL(pBmul1[i]), &e);
706
195k
    b_sf[i] += pBmul1_sf[i] + e;
707
195k
  }
708
709
48.7k
  backsubst_bw(numBands, bnormed, b, b_sf);
710
48.7k
}
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
48.7k
                    FIXP_DBL *RESTRICT p, int *RESTRICT p_sf) {
729
48.7k
  int i, k;
730
48.7k
  LONG v[POLY_ORDER + 1];
731
48.7k
  int sum_saftey = getLog2[numBands - 1];
732
733
48.7k
  FDK_ASSERT((numBands >= BSD_IDX_OFFSET) && (numBands <= MAXLOWBANDS));
734
735
  /* construct vector b[] temporarily stored in array p[] */
736
48.7k
  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
243k
  for (i = 0; i <= POLY_ORDER; ++i) p_sf[i] = 1 - DFRACT_BITS;
740
741
949k
  for (k = 0; k < numBands; k++) {
742
900k
    v[0] = (LONG)1;
743
3.60M
    for (i = 1; i <= POLY_ORDER; i++) {
744
2.70M
      v[i] = k * v[i - 1];
745
2.70M
    }
746
747
4.50M
    for (i = 0; i <= POLY_ORDER; i++) {
748
3.60M
      if (v[POLY_ORDER - i] != 0 && y[k] != FIXP_DBL(0)) {
749
2.51M
        int e;
750
2.51M
        FIXP_DBL mult = fMultNorm((FIXP_DBL)v[POLY_ORDER - i], y[k], &e);
751
2.51M
        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
2.51M
        int diff = sf - p_sf[i];
756
757
2.51M
        if (diff > 0) {
758
          /* yes, and it requires the sum p[i] to be adjusted (scaled down) */
759
656k
          p[i] >>= fMin(DFRACT_BITS - 1, diff);
760
656k
          p_sf[i] = sf;
761
1.85M
        } else if (diff < 0) {
762
          /* yes, but here mult needs to be scaled down */
763
1.14M
          mult >>= -diff;
764
1.14M
        }
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
2.51M
        p[i] += mult >> sum_saftey;
770
2.51M
      }
771
3.60M
    }
772
900k
  }
773
774
48.7k
  p_sf[0] += sum_saftey;
775
48.7k
  p_sf[1] += sum_saftey;
776
48.7k
  p_sf[2] += sum_saftey;
777
48.7k
  p_sf[3] += sum_saftey;
778
779
48.7k
  choleskySolve(numBands, p, p_sf);
780
48.7k
}
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
900k
                        const int x_int, int *out_sf) {
802
900k
  FDK_ASSERT(x_int <= 31); /* otherwise getLog2[] needs more elements */
803
804
900k
  int k, x_sf;
805
900k
  int result_sf;   /* working space to compute return value *out_sf */
806
900k
  FIXP_DBL x;      /* fractional value of x_int */
807
900k
  FIXP_DBL result; /* return value */
808
809
  /* if x == 0, then y(x) is just p3 */
810
900k
  if (x_int != 0) {
811
851k
    x_sf = getLog2[x_int];
812
851k
    x = (FIXP_DBL)x_int << (DFRACT_BITS - 1 - x_sf);
813
851k
  } else {
814
48.7k
    *out_sf = p_sf[3];
815
48.7k
    return p[3];
816
48.7k
  }
817
818
851k
  result = p[0];
819
851k
  result_sf = p_sf[0];
820
821
3.40M
  for (k = 1; k <= POLY_ORDER; ++k) {
822
2.55M
    FIXP_DBL mult = fMult(x, result);
823
2.55M
    int mult_sf = x_sf + result_sf;
824
825
2.55M
    int room = CountLeadingBits(mult);
826
2.55M
    mult <<= room;
827
2.55M
    mult_sf -= room;
828
829
2.55M
    FIXP_DBL pp = p[k];
830
2.55M
    int pp_sf = p_sf[k];
831
832
    /* equalize the shift factors of pp and mult so that we can sum them up */
833
2.55M
    int diff = pp_sf - mult_sf;
834
835
2.55M
    if (diff > 0) {
836
1.43M
      diff = fMin(diff, DFRACT_BITS - 1);
837
1.43M
      mult >>= diff;
838
1.43M
    } else if (diff < 0) {
839
694k
      diff = fMax(diff, 1 - DFRACT_BITS);
840
694k
      pp >>= -diff;
841
694k
    }
842
843
    /* downshift by 1 to ensure safe summation */
844
2.55M
    mult >>= 1;
845
2.55M
    mult_sf++;
846
2.55M
    pp >>= 1;
847
2.55M
    pp_sf++;
848
849
2.55M
    result_sf = fMax(pp_sf, mult_sf);
850
851
2.55M
    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
2.55M
  }
857
858
851k
  *out_sf = result_sf;
859
851k
  return result;
860
900k
}
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
48.9k
                                 const int stopSample) {
869
48.9k
  FIXP_DBL p[POLY_ORDER + 1];
870
48.9k
  FIXP_DBL meanNrg;
871
48.9k
  FIXP_DBL LowEnv[MAXLOWBANDS];
872
48.9k
  FIXP_DBL invNumBands = GetInvInt(numBands);
873
48.9k
  FIXP_DBL invNumSlots = GetInvInt(stopSample - startSample);
874
48.9k
  int i, loBand, exp, scale_nrg, scale_nrg_ov;
875
48.9k
  int sum_scale = 5, sum_scale_ov = 3;
876
877
48.9k
  if (overlap > 8) {
878
12.5k
    FDK_ASSERT(overlap <= 16);
879
12.5k
    sum_scale_ov += 1;
880
12.5k
    sum_scale += 1;
881
12.5k
  }
882
883
  /* exponents of energy values */
884
48.9k
  sourceBuf_e_overlap = sourceBuf_e_overlap * 2 + sum_scale_ov;
885
48.9k
  sourceBuf_e_current = sourceBuf_e_current * 2 + sum_scale;
886
48.9k
  exp = fMax(sourceBuf_e_overlap, sourceBuf_e_current);
887
48.9k
  scale_nrg = sourceBuf_e_current - exp;
888
48.9k
  scale_nrg_ov = sourceBuf_e_overlap - exp;
889
890
48.9k
  meanNrg = (FIXP_DBL)0;
891
  /* Calculate the spectral envelope in dB over the current copy-up frame. */
892
950k
  for (loBand = 0; loBand < numBands; loBand++) {
893
901k
    FIXP_DBL nrg_ov, nrg;
894
901k
    INT reserve = 0, exp_new;
895
901k
    FIXP_DBL maxVal = FL2FX_DBL(0.0f);
896
897
35.4M
    for (i = startSample; i < stopSample; i++) {
898
34.4M
      maxVal |=
899
34.4M
          (FIXP_DBL)((LONG)(sourceBufferReal[i][loBand]) ^
900
34.4M
                     ((LONG)sourceBufferReal[i][loBand] >> (DFRACT_BITS - 1)));
901
34.4M
      maxVal |=
902
34.4M
          (FIXP_DBL)((LONG)(sourceBufferImag[i][loBand]) ^
903
34.4M
                     ((LONG)sourceBufferImag[i][loBand] >> (DFRACT_BITS - 1)));
904
34.4M
    }
905
906
901k
    if (maxVal != FL2FX_DBL(0.0f)) {
907
651k
      reserve = CntLeadingZeros(maxVal) - 2;
908
651k
    }
909
910
901k
    nrg_ov = nrg = (FIXP_DBL)0;
911
901k
    if (scale_nrg_ov > -31) {
912
6.02M
      for (i = startSample; i < overlap; i++) {
913
5.12M
        nrg_ov +=
914
5.12M
            (fPow2Div2(scaleValue(sourceBufferReal[i][loBand], reserve)) +
915
5.12M
             fPow2Div2(scaleValue(sourceBufferImag[i][loBand], reserve))) >>
916
5.12M
            sum_scale_ov;
917
5.12M
      }
918
899k
    } else {
919
1.95k
      scale_nrg_ov = 0;
920
1.95k
    }
921
901k
    if (scale_nrg > -31) {
922
30.1M
      for (i = overlap; i < stopSample; i++) {
923
29.2M
        nrg += (fPow2Div2(scaleValue(sourceBufferReal[i][loBand], reserve)) +
924
29.2M
                fPow2Div2(scaleValue(sourceBufferImag[i][loBand], reserve))) >>
925
29.2M
               sum_scale;
926
29.2M
      }
927
898k
    } else {
928
3.00k
      scale_nrg = 0;
929
3.00k
    }
930
931
901k
    nrg = (scaleValue(nrg_ov, scale_nrg_ov) >> 1) +
932
901k
          (scaleValue(nrg, scale_nrg) >> 1);
933
901k
    nrg = fMult(nrg, invNumSlots);
934
935
901k
    exp_new =
936
901k
        exp - (2 * reserve) +
937
901k
        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
901k
    if (nrg > (FIXP_DBL)0) {
942
628k
      int exp_log2;
943
628k
      nrg = CalcLog2(nrg, exp_new, &exp_log2);
944
628k
      nrg = scaleValue(nrg, exp_log2 - 6);
945
628k
      nrg = fMult(FL2FXCONST_SGL(LOG10FAC), nrg);
946
628k
    } else {
947
272k
      nrg = (FIXP_DBL)0;
948
272k
    }
949
901k
    LowEnv[loBand] = nrg;
950
901k
    meanNrg += fMult(nrg, invNumBands);
951
901k
  }
952
48.9k
  exp = 6 + 2; /* exponent of LowEnv: +2 is exponent of LOG10FAC */
953
954
  /* subtract mean before polynomial approximation to reduce dynamic of p[] */
955
950k
  for (loBand = 0; loBand < numBands; loBand++) {
956
901k
    LowEnv[loBand] = meanNrg - LowEnv[loBand];
957
901k
  }
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
48.9k
  if (numBands > POLY_ORDER + 1) {
965
    /* Find polynomial approximation of LowEnv */
966
48.7k
    int p_sf[POLY_ORDER + 1];
967
968
48.7k
    polyfit(numBands, LowEnv, exp, p, p_sf);
969
970
949k
    for (i = 0; i < numBands; i++) {
971
900k
      int sf;
972
973
      /* lowBandEnvSlope[i] = tmp; */
974
900k
      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
900k
      tmp = fMult(tmp, FL2FXCONST_SGL(LOG10FAC_INV));
978
900k
      GainVec[i] = f2Pow(tmp, sf - 2,
979
900k
                         &GainVec_exp[i]); /* -2 is exponent of LOG10FAC_INV */
980
900k
    }
981
48.7k
  } else { /* numBands <= POLY_ORDER+1 */
982
800
    for (i = 0; i < numBands; i++) {
983
640
      int sf = exp; /* exponent of LowEnv[] */
984
985
      /* lowBandEnvSlope[i] = LowEnv[i]; */
986
640
      FIXP_DBL tmp = LowEnv[i];
987
988
      /* GainVec = 10^((mean(y)-y)/20) = 2^( (mean(y)-y) * log2(10)/20 ) */
989
640
      tmp = fMult(tmp, FL2FXCONST_SGL(LOG10FAC_INV));
990
640
      GainVec[i] = f2Pow(tmp, sf - 2,
991
640
                         &GainVec_exp[i]); /* -2 is exponent of LOG10FAC_INV */
992
640
    }
993
160
  }
994
48.9k
}