Coverage Report

Created: 2025-07-12 07:06

/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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18.4M
#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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937k
#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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468k
#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 */
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        {CHC(0x68943285), CHC(0x4841d2c3), CHC(0x6a6214c7)},
167
        {-1, 0, 0},
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        {CHC(0x63c5923e), CHC(0x4e906e18), CHC(0x6285af8a)},
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        {3, 4, 1},
170
        {CHC(0x7263940b), CHC(0x424a69a5), CHC(0x4ae8383a), CHC(0x517b7730)},
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        {-7, -4, -2, 0},
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        {CHC(0x518aee5f), CHC(0x4823a096), CHC(0x43764a39), CHC(0x6e6faf23),
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         CHC(0x61bba44f), CHC(0x59d8b132)},
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        {1, 0, -1, -2, -4, -6},
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        {CHC(0x7263940b), CHC(0x6757bff2), CHC(0x5bf40fe0), CHC(0x7d6f4292)},
176
        {-7, -2, 1, 0},
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    },
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)},
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        {-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},
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        {CHC(0x4c389cc5), CHC(0x79686681), CHC(0x5e2544c2), CHC(0x46305b43)},
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        {-8, -6, -3, 0},
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        {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},
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        {CHC(0x4c389cc5), CHC(0x5c499ceb), CHC(0x6f863c9f), CHC(0x79059bfc)},
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        {-8, -3, 0, 0},
205
    },
206
    {
207
        /* numBands=9 */
208
        {CHC(0x6aad9988), CHC(0x4ef8ac18), CHC(0x6b6df116)},
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        {-1, 0, 0},
210
        {CHC(0x60b159b0), CHC(0x4b33f772), CHC(0x72f5573d)},
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        {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)},
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        {0, -1, -3, -2, -5, -8},
217
        {CHC(0x6206cb18), CHC(0x42f8b8de), CHC(0x5bb4776f), CHC(0x769acc79)},
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        {-9, -3, 0, 0},
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    },
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},
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        {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
1.12M
#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
46.8k
                         FIXP_DBL *RESTRICT x, int *RESTRICT x_sf) {
569
46.8k
  int i, k;
570
46.8k
  int m; /* the trip counter that indexes incrementally through Lnorm1d[] */
571
572
46.8k
  const FIXP_CHB *RESTRICT pLnorm1d = bsd[numBands - BSD_IDX_OFFSET].Lnorm1d;
573
46.8k
  const SCHAR *RESTRICT pLnorm1d_sf = bsd[numBands - BSD_IDX_OFFSET].Lnorm1d_sf;
574
46.8k
  const FIXP_CHB *RESTRICT pLnormii = bsd[numBands - BSD_IDX_OFFSET].Lnormii;
575
46.8k
  const SCHAR *RESTRICT pLnormii_sf = bsd[numBands - BSD_IDX_OFFSET].Lnormii_sf;
576
577
46.8k
  x[0] = b[0];
578
579
187k
  for (i = 1, m = 0; i <= POLY_ORDER; ++i) {
580
140k
    FIXP_DBL sum = b[i] >> SUM_SAFETY;
581
140k
    int sum_sf = x_sf[i];
582
281k
    for (k = i - 1; k > 0; --k, ++m) {
583
140k
      int e;
584
140k
      FIXP_DBL mult = fMultNorm(FX_CHB2FX_DBL(pLnorm1d[m]), x[k], &e);
585
140k
      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
140k
      int diff = mult_sf - sum_sf;
590
591
140k
      if (diff > 0) {
592
        /* yes, and it requires the sum to be adjusted (scaled down) */
593
61.2k
        sum >>= diff;
594
61.2k
        sum_sf = mult_sf;
595
79.3k
      } else if (diff < 0) {
596
        /* yes, but here mult needs to be scaled down */
597
72.9k
        mult >>= -diff;
598
72.9k
      }
599
140k
      sum -= (mult >> SUM_SAFETY);
600
140k
    }
601
602
    /* - x[0] */
603
140k
    if (x_sf[0] > sum_sf) {
604
38.9k
      sum >>= (x_sf[0] - sum_sf);
605
38.9k
      sum_sf = x_sf[0];
606
38.9k
    }
607
140k
    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
140k
    int e;
611
140k
    x[i] = fMultNorm(sum, FX_CHB2FX_DBL(pLnormii[i - 1]), &e);
612
140k
    x_sf[i] = sum_sf + pLnormii_sf[i - 1] + e + SUM_SAFETY;
613
140k
  }
614
46.8k
}
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
46.8k
                         FIXP_DBL *RESTRICT x, int *RESTRICT x_sf) {
632
46.8k
  int i, k;
633
46.8k
  int m; /* the trip counter that indexes incrementally through LnormInv1d[] */
634
635
46.8k
  const FIXP_CHB *RESTRICT pLnormInv1d =
636
46.8k
      bsd[numBands - BSD_IDX_OFFSET].LnormInv1d;
637
46.8k
  const SCHAR *RESTRICT pLnormInv1d_sf =
638
46.8k
      bsd[numBands - BSD_IDX_OFFSET].LnormInv1d_sf;
639
640
46.8k
  x[POLY_ORDER] = b[POLY_ORDER];
641
642
187k
  for (i = POLY_ORDER - 1, m = 0; i >= 0; i--) {
643
140k
    FIXP_DBL sum = b[i] >> SUM_SAFETY;
644
140k
    int sum_sf = x_sf[i]; /* sum's sf but disregarding SUM_SAFETY (added at the
645
                             iteration's end) */
646
647
421k
    for (k = i + 1; k <= POLY_ORDER; ++k, ++m) {
648
281k
      int e;
649
281k
      FIXP_DBL mult = fMultNorm(FX_CHB2FX_DBL(pLnormInv1d[m]), x[k], &e);
650
281k
      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
281k
      int diff = mult_sf - sum_sf;
655
656
281k
      if (diff > 0) {
657
        /* yes, and it requires the sum v to be adjusted (scaled down) */
658
137k
        sum >>= diff;
659
137k
        sum_sf = mult_sf;
660
143k
      } else if (diff < 0) {
661
        /* yes, but here mult needs to be scaled down */
662
114k
        mult >>= -diff;
663
114k
      }
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
281k
      sum -= (mult >> SUM_SAFETY);
669
281k
    }
670
671
140k
    x_sf[i] = sum_sf + SUM_SAFETY;
672
140k
    x[i] = sum;
673
140k
  }
674
46.8k
}
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
46.8k
                          int *RESTRICT b_sf) {
687
46.8k
  int i, e;
688
689
46.8k
  const FIXP_CHB *RESTRICT pBmul0 = bsd[numBands - BSD_IDX_OFFSET].Bmul0;
690
46.8k
  const SCHAR *RESTRICT pBmul0_sf = bsd[numBands - BSD_IDX_OFFSET].Bmul0_sf;
691
46.8k
  const FIXP_CHB *RESTRICT pBmul1 = bsd[numBands - BSD_IDX_OFFSET].Bmul1;
692
46.8k
  const SCHAR *RESTRICT pBmul1_sf = bsd[numBands - BSD_IDX_OFFSET].Bmul1_sf;
693
694
  /* normalize b */
695
46.8k
  FIXP_DBL bnormed[POLY_ORDER + 1];
696
234k
  for (i = 0; i <= POLY_ORDER; ++i) {
697
187k
    bnormed[i] = fMultNorm(b[i], FX_CHB2FX_DBL(pBmul0[i]), &e);
698
187k
    b_sf[i] += pBmul0_sf[i] + e;
699
187k
  }
700
701
46.8k
  backsubst_fw(numBands, bnormed, b, b_sf);
702
703
  /* normalize b again */
704
234k
  for (i = 0; i <= POLY_ORDER; ++i) {
705
187k
    bnormed[i] = fMultNorm(b[i], FX_CHB2FX_DBL(pBmul1[i]), &e);
706
187k
    b_sf[i] += pBmul1_sf[i] + e;
707
187k
  }
708
709
46.8k
  backsubst_bw(numBands, bnormed, b, b_sf);
710
46.8k
}
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
46.8k
                    FIXP_DBL *RESTRICT p, int *RESTRICT p_sf) {
729
46.8k
  int i, k;
730
46.8k
  LONG v[POLY_ORDER + 1];
731
46.8k
  int sum_saftey = getLog2[numBands - 1];
732
733
46.8k
  FDK_ASSERT((numBands >= BSD_IDX_OFFSET) && (numBands <= MAXLOWBANDS));
734
735
  /* construct vector b[] temporarily stored in array p[] */
736
46.8k
  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
234k
  for (i = 0; i <= POLY_ORDER; ++i) p_sf[i] = 1 - DFRACT_BITS;
740
741
909k
  for (k = 0; k < numBands; k++) {
742
863k
    v[0] = (LONG)1;
743
3.45M
    for (i = 1; i <= POLY_ORDER; i++) {
744
2.58M
      v[i] = k * v[i - 1];
745
2.58M
    }
746
747
4.31M
    for (i = 0; i <= POLY_ORDER; i++) {
748
3.45M
      if (v[POLY_ORDER - i] != 0 && y[k] != FIXP_DBL(0)) {
749
2.41M
        int e;
750
2.41M
        FIXP_DBL mult = fMultNorm((FIXP_DBL)v[POLY_ORDER - i], y[k], &e);
751
2.41M
        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
2.41M
        int diff = sf - p_sf[i];
756
757
2.41M
        if (diff > 0) {
758
          /* yes, and it requires the sum p[i] to be adjusted (scaled down) */
759
626k
          p[i] >>= fMin(DFRACT_BITS - 1, diff);
760
626k
          p_sf[i] = sf;
761
1.78M
        } else if (diff < 0) {
762
          /* yes, but here mult needs to be scaled down */
763
1.11M
          mult >>= -diff;
764
1.11M
        }
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
2.41M
        p[i] += mult >> sum_saftey;
770
2.41M
      }
771
3.45M
    }
772
863k
  }
773
774
46.8k
  p_sf[0] += sum_saftey;
775
46.8k
  p_sf[1] += sum_saftey;
776
46.8k
  p_sf[2] += sum_saftey;
777
46.8k
  p_sf[3] += sum_saftey;
778
779
46.8k
  choleskySolve(numBands, p, p_sf);
780
46.8k
}
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
863k
                        const int x_int, int *out_sf) {
802
863k
  FDK_ASSERT(x_int <= 31); /* otherwise getLog2[] needs more elements */
803
804
863k
  int k, x_sf;
805
863k
  int result_sf;   /* working space to compute return value *out_sf */
806
863k
  FIXP_DBL x;      /* fractional value of x_int */
807
863k
  FIXP_DBL result; /* return value */
808
809
  /* if x == 0, then y(x) is just p3 */
810
863k
  if (x_int != 0) {
811
816k
    x_sf = getLog2[x_int];
812
816k
    x = (FIXP_DBL)x_int << (DFRACT_BITS - 1 - x_sf);
813
816k
  } else {
814
46.8k
    *out_sf = p_sf[3];
815
46.8k
    return p[3];
816
46.8k
  }
817
818
816k
  result = p[0];
819
816k
  result_sf = p_sf[0];
820
821
3.26M
  for (k = 1; k <= POLY_ORDER; ++k) {
822
2.44M
    FIXP_DBL mult = fMult(x, result);
823
2.44M
    int mult_sf = x_sf + result_sf;
824
825
2.44M
    int room = CountLeadingBits(mult);
826
2.44M
    mult <<= room;
827
2.44M
    mult_sf -= room;
828
829
2.44M
    FIXP_DBL pp = p[k];
830
2.44M
    int pp_sf = p_sf[k];
831
832
    /* equalize the shift factors of pp and mult so that we can sum them up */
833
2.44M
    int diff = pp_sf - mult_sf;
834
835
2.44M
    if (diff > 0) {
836
1.38M
      diff = fMin(diff, DFRACT_BITS - 1);
837
1.38M
      mult >>= diff;
838
1.38M
    } else if (diff < 0) {
839
660k
      diff = fMax(diff, 1 - DFRACT_BITS);
840
660k
      pp >>= -diff;
841
660k
    }
842
843
    /* downshift by 1 to ensure safe summation */
844
2.44M
    mult >>= 1;
845
2.44M
    mult_sf++;
846
2.44M
    pp >>= 1;
847
2.44M
    pp_sf++;
848
849
2.44M
    result_sf = fMax(pp_sf, mult_sf);
850
851
2.44M
    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
2.44M
  }
857
858
816k
  *out_sf = result_sf;
859
816k
  return result;
860
863k
}
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
46.9k
                                 const int stopSample) {
869
46.9k
  FIXP_DBL p[POLY_ORDER + 1];
870
46.9k
  FIXP_DBL meanNrg;
871
46.9k
  FIXP_DBL LowEnv[MAXLOWBANDS];
872
46.9k
  FIXP_DBL invNumBands = GetInvInt(numBands);
873
46.9k
  FIXP_DBL invNumSlots = GetInvInt(stopSample - startSample);
874
46.9k
  int i, loBand, exp, scale_nrg, scale_nrg_ov;
875
46.9k
  int sum_scale = 5, sum_scale_ov = 3;
876
877
46.9k
  if (overlap > 8) {
878
11.4k
    FDK_ASSERT(overlap <= 16);
879
11.4k
    sum_scale_ov += 1;
880
11.4k
    sum_scale += 1;
881
11.4k
  }
882
883
  /* exponents of energy values */
884
46.9k
  sourceBuf_e_overlap = sourceBuf_e_overlap * 2 + sum_scale_ov;
885
46.9k
  sourceBuf_e_current = sourceBuf_e_current * 2 + sum_scale;
886
46.9k
  exp = fMax(sourceBuf_e_overlap, sourceBuf_e_current);
887
46.9k
  scale_nrg = sourceBuf_e_current - exp;
888
46.9k
  scale_nrg_ov = sourceBuf_e_overlap - exp;
889
890
46.9k
  meanNrg = (FIXP_DBL)0;
891
  /* Calculate the spectral envelope in dB over the current copy-up frame. */
892
910k
  for (loBand = 0; loBand < numBands; loBand++) {
893
863k
    FIXP_DBL nrg_ov, nrg;
894
863k
    INT reserve = 0, exp_new;
895
863k
    FIXP_DBL maxVal = FL2FX_DBL(0.0f);
896
897
33.5M
    for (i = startSample; i < stopSample; i++) {
898
32.6M
      maxVal |=
899
32.6M
          (FIXP_DBL)((LONG)(sourceBufferReal[i][loBand]) ^
900
32.6M
                     ((LONG)sourceBufferReal[i][loBand] >> (DFRACT_BITS - 1)));
901
32.6M
      maxVal |=
902
32.6M
          (FIXP_DBL)((LONG)(sourceBufferImag[i][loBand]) ^
903
32.6M
                     ((LONG)sourceBufferImag[i][loBand] >> (DFRACT_BITS - 1)));
904
32.6M
    }
905
906
863k
    if (maxVal != FL2FX_DBL(0.0f)) {
907
625k
      reserve = CntLeadingZeros(maxVal) - 2;
908
625k
    }
909
910
863k
    nrg_ov = nrg = (FIXP_DBL)0;
911
863k
    if (scale_nrg_ov > -31) {
912
5.62M
      for (i = startSample; i < overlap; i++) {
913
4.75M
        nrg_ov +=
914
4.75M
            (fPow2Div2(scaleValue(sourceBufferReal[i][loBand], reserve)) +
915
4.75M
             fPow2Div2(scaleValue(sourceBufferImag[i][loBand], reserve))) >>
916
4.75M
            sum_scale_ov;
917
4.75M
      }
918
862k
    } else {
919
1.55k
      scale_nrg_ov = 0;
920
1.55k
    }
921
863k
    if (scale_nrg > -31) {
922
28.6M
      for (i = overlap; i < stopSample; i++) {
923
27.8M
        nrg += (fPow2Div2(scaleValue(sourceBufferReal[i][loBand], reserve)) +
924
27.8M
                fPow2Div2(scaleValue(sourceBufferImag[i][loBand], reserve))) >>
925
27.8M
               sum_scale;
926
27.8M
      }
927
860k
    } else {
928
2.91k
      scale_nrg = 0;
929
2.91k
    }
930
931
863k
    nrg = (scaleValue(nrg_ov, scale_nrg_ov) >> 1) +
932
863k
          (scaleValue(nrg, scale_nrg) >> 1);
933
863k
    nrg = fMult(nrg, invNumSlots);
934
935
863k
    exp_new =
936
863k
        exp - (2 * reserve) +
937
863k
        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
863k
    if (nrg > (FIXP_DBL)0) {
942
606k
      int exp_log2;
943
606k
      nrg = CalcLog2(nrg, exp_new, &exp_log2);
944
606k
      nrg = scaleValue(nrg, exp_log2 - 6);
945
606k
      nrg = fMult(FL2FXCONST_SGL(LOG10FAC), nrg);
946
606k
    } else {
947
257k
      nrg = (FIXP_DBL)0;
948
257k
    }
949
863k
    LowEnv[loBand] = nrg;
950
863k
    meanNrg += fMult(nrg, invNumBands);
951
863k
  }
952
46.9k
  exp = 6 + 2; /* exponent of LowEnv: +2 is exponent of LOG10FAC */
953
954
  /* subtract mean before polynomial approximation to reduce dynamic of p[] */
955
910k
  for (loBand = 0; loBand < numBands; loBand++) {
956
863k
    LowEnv[loBand] = meanNrg - LowEnv[loBand];
957
863k
  }
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
46.9k
  if (numBands > POLY_ORDER + 1) {
965
    /* Find polynomial approximation of LowEnv */
966
46.8k
    int p_sf[POLY_ORDER + 1];
967
968
46.8k
    polyfit(numBands, LowEnv, exp, p, p_sf);
969
970
909k
    for (i = 0; i < numBands; i++) {
971
863k
      int sf;
972
973
      /* lowBandEnvSlope[i] = tmp; */
974
863k
      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
863k
      tmp = fMult(tmp, FL2FXCONST_SGL(LOG10FAC_INV));
978
863k
      GainVec[i] = f2Pow(tmp, sf - 2,
979
863k
                         &GainVec_exp[i]); /* -2 is exponent of LOG10FAC_INV */
980
863k
    }
981
46.8k
  } else { /* numBands <= POLY_ORDER+1 */
982
690
    for (i = 0; i < numBands; i++) {
983
552
      int sf = exp; /* exponent of LowEnv[] */
984
985
      /* lowBandEnvSlope[i] = LowEnv[i]; */
986
552
      FIXP_DBL tmp = LowEnv[i];
987
988
      /* GainVec = 10^((mean(y)-y)/20) = 2^( (mean(y)-y) * log2(10)/20 ) */
989
552
      tmp = fMult(tmp, FL2FXCONST_SGL(LOG10FAC_INV));
990
552
      GainVec[i] = f2Pow(tmp, sf - 2,
991
552
                         &GainVec_exp[i]); /* -2 is exponent of LOG10FAC_INV */
992
552
    }
993
138
  }
994
46.9k
}