/* -----------------------------------------------------------------------------
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Software License for The Fraunhofer FDK AAC Codec Library for Android
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© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
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Forschung e.V. All rights reserved.
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1. INTRODUCTION
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The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
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that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
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scheme for digital audio. This FDK AAC Codec software is intended to be used on
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a wide variety of Android devices.
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AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
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general perceptual audio codecs. AAC-ELD is considered the best-performing
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full-bandwidth communications codec by independent studies and is widely
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deployed. AAC has been standardized by ISO and IEC as part of the MPEG
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specifications.
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Patent licenses for necessary patent claims for the FDK AAC Codec (including
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those of Fraunhofer) may be obtained through Via Licensing
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(www.vialicensing.com) or through the respective patent owners individually for
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the purpose of encoding or decoding bit streams in products that are compliant
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with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
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Android devices already license these patent claims through Via Licensing or
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directly from the patent owners, and therefore FDK AAC Codec software may
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already be covered under those patent licenses when it is used for those
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licensed purposes only.
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Commercially-licensed AAC software libraries, including floating-point versions
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with enhanced sound quality, are also available from Fraunhofer. Users are
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encouraged to check the Fraunhofer website for additional applications
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information and documentation.
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2. COPYRIGHT LICENSE
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Redistribution and use in source and binary forms, with or without modification,
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are permitted without payment of copyright license fees provided that you
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satisfy the following conditions:
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You must retain the complete text of this software license in redistributions of
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the FDK AAC Codec or your modifications thereto in source code form.
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You must retain the complete text of this software license in the documentation
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and/or other materials provided with redistributions of the FDK AAC Codec or
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your modifications thereto in binary form. You must make available free of
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charge copies of the complete source code of the FDK AAC Codec and your
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modifications thereto to recipients of copies in binary form.
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The name of Fraunhofer may not be used to endorse or promote products derived
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from this library without prior written permission.
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You may not charge copyright license fees for anyone to use, copy or distribute
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the FDK AAC Codec software or your modifications thereto.
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Your modified versions of the FDK AAC Codec must carry prominent notices stating
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that you changed the software and the date of any change. For modified versions
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of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
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must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
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AAC Codec Library for Android."
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3. NO PATENT LICENSE
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NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
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limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
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Fraunhofer provides no warranty of patent non-infringement with respect to this
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software.
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You may use this FDK AAC Codec software or modifications thereto only for
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purposes that are authorized by appropriate patent licenses.
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4. DISCLAIMER
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
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holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
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including but not limited to the implied warranties of merchantability and
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fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
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or consequential damages, including but not limited to procurement of substitute
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goods or services; loss of use, data, or profits, or business interruption,
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however caused and on any theory of liability, whether in contract, strict
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liability, or tort (including negligence), arising in any way out of the use of
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this software, even if advised of the possibility of such damage.
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5. CONTACT INFORMATION
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Fraunhofer Institute for Integrated Circuits IIS
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Attention: Audio and Multimedia Departments - FDK AAC LL
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Am Wolfsmantel 33
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91058 Erlangen, Germany
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www.iis.fraunhofer.de/amm
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amm-info@iis.fraunhofer.de
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----------------------------------------------------------------------------- */
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/**************************** AAC decoder library ******************************
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Author(s): Matthias Hildenbrand
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Description: USAC ACELP LTP filter
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*******************************************************************************/
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#include "usacdec_ace_ltp.h"
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#include "genericStds.h"
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#include "common_fix.h"
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#define UP_SAMP 4
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#define L_INTERPOL2 16
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#define L_SUBFR 64
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#define A2 FL2FX_SGL(2 * 0.18f)
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#define B FL2FX_SGL(0.64f)
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static const LONG Pred_lt4_inter4_2[UP_SAMP][L_INTERPOL2] = {
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{(LONG)0x0000FFFC, (LONG)0x0008FFFC, (LONG)0xFFEB004C, (LONG)0xFF50014A,
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(LONG)0xFDD90351, (LONG)0xFB2A06CD, (LONG)0xF6920D46, (LONG)0xEBB42B35,
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(LONG)0x6D9EEF39, (LONG)0x0618FE0F, (LONG)0xFFE00131, (LONG)0xFE5501C5,
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(LONG)0xFE5E015D, (LONG)0xFEF700B6, (LONG)0xFF920037, (LONG)0xFFEC0003},
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{(LONG)0x0002FFF2, (LONG)0x0026FFBD, (LONG)0x005DFF98, (LONG)0x0055FFEF,
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(LONG)0xFF89015F, (LONG)0xFD3A04E5, (LONG)0xF7D90DAA, (LONG)0xE67A50EE,
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(LONG)0x50EEE67A, (LONG)0x0DAAF7D9, (LONG)0x04E5FD3A, (LONG)0x015FFF89,
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(LONG)0xFFEF0055, (LONG)0xFF98005D, (LONG)0xFFBD0026, (LONG)0xFFF20002},
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{(LONG)0x0003FFEC, (LONG)0x0037FF92, (LONG)0x00B6FEF7, (LONG)0x015DFE5E,
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(LONG)0x01C5FE55, (LONG)0x0131FFE0, (LONG)0xFE0F0618, (LONG)0xEF396D9E,
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(LONG)0x2B35EBB4, (LONG)0x0D46F692, (LONG)0x06CDFB2A, (LONG)0x0351FDD9,
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(LONG)0x014AFF50, (LONG)0x004CFFEB, (LONG)0xFFFC0008, (LONG)0xFFFC0000},
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{(LONG)0x0002FFF2, (LONG)0x002BFF9E, (LONG)0x00B9FECE, (LONG)0x01CFFD75,
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(LONG)0x035EFBC1, (LONG)0x0521FA0C, (LONG)0x06AAF8C9, (LONG)0x07907852,
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(LONG)0x0790F8C9, (LONG)0x06AAFA0C, (LONG)0x0521FBC1, (LONG)0x035EFD75,
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(LONG)0x01CFFECE, (LONG)0x00B9FF9E, (LONG)0x002BFFF2, (LONG)0x00020000}};
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void Pred_lt4(FIXP_DBL exc[], /* in/out: excitation buffer */
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int T0, /* input : integer pitch lag */
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int frac /* input : fraction of lag in range 0..3 */
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) {
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int j;
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FIXP_DBL *x;
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const LONG *interpol;
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FIXP_DBL L_sumb, L_sumt;
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x = &exc[-T0 - L_INTERPOL2 + 1];
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/* remap frac and x:
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0 -> 3 x (unchanged)
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1 -> 0 x--
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2 -> 1 x--
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3 -> 2 x--
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*/
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if (--frac < 0)
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frac += UP_SAMP;
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else
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x--;
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j = L_SUBFR + 1;
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do {
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LONG filt;
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FIXP_DBL x0, x1;
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FIXP_DBL *xi = x++;
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interpol = Pred_lt4_inter4_2[frac];
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int i = 3;
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filt = *interpol++;
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x0 = *xi++;
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x1 = *xi++;
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L_sumt = fMultDiv2(x0, (FIXP_SGL)((SHORT)(filt >> 16)));
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L_sumb = fMultDiv2(x1, (FIXP_SGL)((SHORT)filt));
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do {
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filt = *interpol++;
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x0 = *xi++;
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x1 = *xi++;
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L_sumt = fMultAddDiv2(L_sumt, x0, (FIXP_SGL)((SHORT)(filt >> 16)));
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L_sumb = fMultAddDiv2(L_sumb, x1, (FIXP_SGL)((SHORT)filt));
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filt = *interpol++;
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x0 = *xi++;
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x1 = *xi++;
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L_sumt = fMultAddDiv2(L_sumt, x0, (FIXP_SGL)((SHORT)(filt >> 16)));
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L_sumb = fMultAddDiv2(L_sumb, x1, (FIXP_SGL)((SHORT)filt));
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filt = *interpol++;
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x0 = *xi++;
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x1 = *xi++;
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L_sumt = fMultAddDiv2(L_sumt, x0, (FIXP_SGL)((SHORT)(filt >> 16)));
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L_sumb = fMultAddDiv2(L_sumb, x1, (FIXP_SGL)((SHORT)filt));
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filt = *interpol++;
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x0 = *xi++;
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x1 = *xi++;
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L_sumt = fMultAddDiv2(L_sumt, x0, (FIXP_SGL)((SHORT)(filt >> 16)));
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L_sumb = fMultAddDiv2(L_sumb, x1, (FIXP_SGL)((SHORT)filt));
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filt = *interpol++;
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x0 = *xi++;
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x1 = *xi++;
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L_sumt = fMultAddDiv2(L_sumt, x0, (FIXP_SGL)((SHORT)(filt >> 16)));
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L_sumb = fMultAddDiv2(L_sumb, x1, (FIXP_SGL)((SHORT)filt));
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} while (--i != 0);
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L_sumb <<= 1;
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L_sumb = fAddSaturate(L_sumt << 1, L_sumb);
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*exc++ = L_sumb;
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} while (--j != 0);
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return;
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}
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void Pred_lt4_postfilter(FIXP_DBL exc[] /* in/out: excitation buffer */
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) {
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/*
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exc[i] = A*exc[i-1] + B*exc[i] + A*exc[i+1]
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exc[i+1] = A*exc[i] + B*exc[i+1] + A*exc[i+2] ; i = 0:2:62
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*/
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int i;
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FIXP_DBL sum0, sum1, a_exc0, a_exc1;
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a_exc0 = fMultDiv2(A2, exc[-1]);
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a_exc1 = fMultDiv2(A2, exc[0]);
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/* ARM926: 22 cycles/iteration */
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for (i = 0; i < L_SUBFR; i += 2) {
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sum0 = a_exc0 + fMult(B, exc[i]);
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sum1 = a_exc1 + fMult(B, exc[i + 1]);
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a_exc0 = fMultDiv2(A2, exc[i + 1]);
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a_exc1 = fMultDiv2(A2, exc[i + 2]);
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exc[i] = sum0 + a_exc0;
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exc[i + 1] = sum1 + a_exc1;
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}
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return;
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}
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