/* -----------------------------------------------------------------------------
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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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/******************* Library for basic calculation routines ********************
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Author(s): M. Lohwasser
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Description: auto-correlation functions
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*******************************************************************************/
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#include "autocorr2nd.h"
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/* If the accumulator does not provide enough overflow bits,
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products have to be shifted down in the autocorrelation below. */
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#define SHIFT_FACTOR (5)
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#define SHIFT >> (SHIFT_FACTOR)
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/*!
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*
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* \brief Calculate second order autocorrelation using 2 accumulators
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*
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*/
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#if !defined(FUNCTION_autoCorr2nd_real)
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INT autoCorr2nd_real(
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ACORR_COEFS *ac, /*!< Pointer to autocorrelation coeffs */
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const FIXP_DBL *reBuffer, /*!< Pointer to to real part of input samples */
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const int len /*!< Number input samples */
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) {
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int j, autoCorrScaling, mScale;
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FIXP_DBL accu1, accu2, accu3, accu4, accu5;
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const FIXP_DBL *pReBuf;
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const FIXP_DBL *realBuf = reBuffer;
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/*
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r11r,r22r
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r01r,r12r
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r02r
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*/
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pReBuf = realBuf - 2;
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accu5 = ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3]))
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SHIFT);
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pReBuf++;
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/* len must be even */
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accu1 = fPow2Div2(pReBuf[0]) SHIFT;
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accu3 = fMultDiv2(pReBuf[0], pReBuf[1]) SHIFT;
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pReBuf++;
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for (j = (len - 2) >> 1; j != 0; j--, pReBuf += 2) {
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accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pReBuf[1])) SHIFT);
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accu3 += ((fMultDiv2(pReBuf[0], pReBuf[1]) +
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fMultDiv2(pReBuf[1], pReBuf[2])) SHIFT);
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accu5 += ((fMultDiv2(pReBuf[0], pReBuf[2]) +
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fMultDiv2(pReBuf[1], pReBuf[3])) SHIFT);
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}
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accu2 = (fPow2Div2(realBuf[-2]) SHIFT);
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accu2 += accu1;
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accu1 += (fPow2Div2(realBuf[len - 2]) SHIFT);
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accu4 = (fMultDiv2(realBuf[-1], realBuf[-2]) SHIFT);
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accu4 += accu3;
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accu3 += (fMultDiv2(realBuf[len - 1], realBuf[len - 2]) SHIFT);
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mScale = CntLeadingZeros(
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(accu1 | accu2 | fAbs(accu3) | fAbs(accu4) | fAbs(accu5))) -
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1;
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autoCorrScaling = mScale - 1 - SHIFT_FACTOR; /* -1 because of fMultDiv2*/
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/* Scale to common scale factor */
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ac->r11r = accu1 << mScale;
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ac->r22r = accu2 << mScale;
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ac->r01r = accu3 << mScale;
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ac->r12r = accu4 << mScale;
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ac->r02r = accu5 << mScale;
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ac->det = (fMultDiv2(ac->r11r, ac->r22r) - fMultDiv2(ac->r12r, ac->r12r));
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mScale = CountLeadingBits(fAbs(ac->det));
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ac->det <<= mScale;
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ac->det_scale = mScale - 1;
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return autoCorrScaling;
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}
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#endif
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#if !defined(FUNCTION_autoCorr2nd_cplx)
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INT autoCorr2nd_cplx(
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ACORR_COEFS *ac, /*!< Pointer to autocorrelation coeffs */
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const FIXP_DBL *reBuffer, /*!< Pointer to real part of input samples */
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const FIXP_DBL *imBuffer, /*!< Pointer to imag part of input samples */
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const int len /*!< Number of input samples (should be smaller than 128) */
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) {
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int j, autoCorrScaling, mScale, len_scale;
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FIXP_DBL accu0, accu1, accu2, accu3, accu4, accu5, accu6, accu7, accu8;
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const FIXP_DBL *pReBuf, *pImBuf;
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const FIXP_DBL *realBuf = reBuffer;
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const FIXP_DBL *imagBuf = imBuffer;
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(len > 64) ? (len_scale = 6) : (len_scale = 5);
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/*
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r00r,
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r11r,r22r
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r01r,r12r
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r01i,r12i
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r02r,r02i
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*/
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accu1 = accu3 = accu5 = accu7 = accu8 = FL2FXCONST_DBL(0.0f);
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pReBuf = realBuf - 2, pImBuf = imagBuf - 2;
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accu7 +=
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((fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >>
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len_scale);
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accu8 +=
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((fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >>
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len_scale);
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pReBuf = realBuf - 1, pImBuf = imagBuf - 1;
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for (j = (len - 1); j != 0; j--, pReBuf++, pImBuf++) {
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accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pImBuf[0])) >> len_scale);
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accu3 +=
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((fMultDiv2(pReBuf[0], pReBuf[1]) + fMultDiv2(pImBuf[0], pImBuf[1])) >>
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len_scale);
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accu5 +=
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((fMultDiv2(pImBuf[1], pReBuf[0]) - fMultDiv2(pReBuf[1], pImBuf[0])) >>
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len_scale);
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accu7 +=
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((fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >>
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len_scale);
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accu8 +=
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((fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >>
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len_scale);
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}
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accu2 = ((fPow2Div2(realBuf[-2]) + fPow2Div2(imagBuf[-2])) >> len_scale);
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accu2 += accu1;
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accu1 += ((fPow2Div2(realBuf[len - 2]) + fPow2Div2(imagBuf[len - 2])) >>
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len_scale);
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accu0 = ((fPow2Div2(realBuf[len - 1]) + fPow2Div2(imagBuf[len - 1])) >>
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len_scale) -
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((fPow2Div2(realBuf[-1]) + fPow2Div2(imagBuf[-1])) >> len_scale);
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accu0 += accu1;
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accu4 = ((fMultDiv2(realBuf[-1], realBuf[-2]) +
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fMultDiv2(imagBuf[-1], imagBuf[-2])) >>
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len_scale);
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accu4 += accu3;
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accu3 += ((fMultDiv2(realBuf[len - 1], realBuf[len - 2]) +
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fMultDiv2(imagBuf[len - 1], imagBuf[len - 2])) >>
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len_scale);
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accu6 = ((fMultDiv2(imagBuf[-1], realBuf[-2]) -
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fMultDiv2(realBuf[-1], imagBuf[-2])) >>
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len_scale);
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accu6 += accu5;
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accu5 += ((fMultDiv2(imagBuf[len - 1], realBuf[len - 2]) -
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fMultDiv2(realBuf[len - 1], imagBuf[len - 2])) >>
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len_scale);
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mScale =
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CntLeadingZeros((accu0 | accu1 | accu2 | fAbs(accu3) | fAbs(accu4) |
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fAbs(accu5) | fAbs(accu6) | fAbs(accu7) | fAbs(accu8))) -
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1;
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autoCorrScaling = mScale - 1 - len_scale; /* -1 because of fMultDiv2*/
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/* Scale to common scale factor */
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ac->r00r = (FIXP_DBL)accu0 << mScale;
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ac->r11r = (FIXP_DBL)accu1 << mScale;
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ac->r22r = (FIXP_DBL)accu2 << mScale;
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ac->r01r = (FIXP_DBL)accu3 << mScale;
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ac->r12r = (FIXP_DBL)accu4 << mScale;
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ac->r01i = (FIXP_DBL)accu5 << mScale;
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ac->r12i = (FIXP_DBL)accu6 << mScale;
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ac->r02r = (FIXP_DBL)accu7 << mScale;
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ac->r02i = (FIXP_DBL)accu8 << mScale;
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ac->det =
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(fMultDiv2(ac->r11r, ac->r22r) >> 1) -
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((fMultDiv2(ac->r12r, ac->r12r) + fMultDiv2(ac->r12i, ac->r12i)) >> 1);
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mScale = CntLeadingZeros(fAbs(ac->det)) - 1;
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ac->det <<= mScale;
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ac->det_scale = mScale - 2;
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return autoCorrScaling;
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}
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#endif /* FUNCTION_autoCorr2nd_cplx */
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