/* -----------------------------------------------------------------------------
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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, M. Gayer
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Description:
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*******************************************************************************/
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#include "fft_rad2.h"
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#include "scramble.h"
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#define __FFT_RAD2_CPP__
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#if defined(__arm__)
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#include "arm/fft_rad2_arm.cpp"
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#elif defined(__GNUC__) && defined(__mips__) && defined(__mips_dsp)
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#include "mips/fft_rad2_mips.cpp"
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#endif
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/*****************************************************************************
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functionname: dit_fft (analysis)
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description: dit-tukey-algorithm
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scrambles data at entry
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i.e. loop is made with scrambled data
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returns:
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input:
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output:
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*****************************************************************************/
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#ifndef FUNCTION_dit_fft
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void dit_fft(FIXP_DBL *x, const INT ldn, const FIXP_STP *trigdata,
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const INT trigDataSize) {
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const INT n = 1 << ldn;
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INT trigstep, i, ldm;
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C_ALLOC_ALIGNED_CHECK(x);
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scramble(x, n);
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/*
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* 1+2 stage radix 4
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*/
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for (i = 0; i < n * 2; i += 8) {
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FIXP_DBL a00, a10, a20, a30;
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a00 = (x[i + 0] + x[i + 2]) >> 1; /* Re A + Re B */
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a10 = (x[i + 4] + x[i + 6]) >> 1; /* Re C + Re D */
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a20 = (x[i + 1] + x[i + 3]) >> 1; /* Im A + Im B */
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a30 = (x[i + 5] + x[i + 7]) >> 1; /* Im C + Im D */
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x[i + 0] = a00 + a10; /* Re A' = Re A + Re B + Re C + Re D */
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x[i + 4] = a00 - a10; /* Re C' = Re A + Re B - Re C - Re D */
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x[i + 1] = a20 + a30; /* Im A' = Im A + Im B + Im C + Im D */
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x[i + 5] = a20 - a30; /* Im C' = Im A + Im B - Im C - Im D */
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a00 = a00 - x[i + 2]; /* Re A - Re B */
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a10 = a10 - x[i + 6]; /* Re C - Re D */
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a20 = a20 - x[i + 3]; /* Im A - Im B */
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a30 = a30 - x[i + 7]; /* Im C - Im D */
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x[i + 2] = a00 + a30; /* Re B' = Re A - Re B + Im C - Im D */
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x[i + 6] = a00 - a30; /* Re D' = Re A - Re B - Im C + Im D */
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x[i + 3] = a20 - a10; /* Im B' = Im A - Im B - Re C + Re D */
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x[i + 7] = a20 + a10; /* Im D' = Im A - Im B + Re C - Re D */
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}
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for (ldm = 3; ldm <= ldn; ++ldm) {
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INT m = (1 << ldm);
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INT mh = (m >> 1);
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INT j, r;
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trigstep = ((trigDataSize << 2) >> ldm);
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FDK_ASSERT(trigstep > 0);
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/* Do first iteration with c=1.0 and s=0.0 separately to avoid loosing to
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much precision. Beware: The impact on the overal FFT precision is rather
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large. */
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{ /* block 1 */
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j = 0;
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for (r = 0; r < n; r += m) {
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INT t1 = (r + j) << 1;
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INT t2 = t1 + (mh << 1);
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FIXP_DBL vr, vi, ur, ui;
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// cplxMultDiv2(&vi, &vr, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
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vi = x[t2 + 1] >> 1;
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vr = x[t2] >> 1;
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui + vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui - vi;
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t1 += mh;
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t2 = t1 + (mh << 1);
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// cplxMultDiv2(&vr, &vi, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
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vr = x[t2 + 1] >> 1;
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vi = x[t2] >> 1;
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui - vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui + vi;
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}
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} /* end of block 1 */
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for (j = 1; j < mh / 4; ++j) {
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FIXP_STP cs;
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cs = trigdata[j * trigstep];
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for (r = 0; r < n; r += m) {
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INT t1 = (r + j) << 1;
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INT t2 = t1 + (mh << 1);
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FIXP_DBL vr, vi, ur, ui;
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cplxMultDiv2(&vi, &vr, x[t2 + 1], x[t2], cs);
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui + vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui - vi;
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t1 += mh;
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t2 = t1 + (mh << 1);
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cplxMultDiv2(&vr, &vi, x[t2 + 1], x[t2], cs);
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui - vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui + vi;
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/* Same as above but for t1,t2 with j>mh/4 and thus cs swapped */
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t1 = (r + mh / 2 - j) << 1;
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t2 = t1 + (mh << 1);
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cplxMultDiv2(&vi, &vr, x[t2], x[t2 + 1], cs);
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui - vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui + vi;
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t1 += mh;
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t2 = t1 + (mh << 1);
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cplxMultDiv2(&vr, &vi, x[t2], x[t2 + 1], cs);
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur - vr;
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x[t1 + 1] = ui - vi;
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x[t2] = ur + vr;
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x[t2 + 1] = ui + vi;
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}
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}
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{ /* block 2 */
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j = mh / 4;
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for (r = 0; r < n; r += m) {
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INT t1 = (r + j) << 1;
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INT t2 = t1 + (mh << 1);
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FIXP_DBL vr, vi, ur, ui;
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cplxMultDiv2(&vi, &vr, x[t2 + 1], x[t2], STC(0x5a82799a),
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STC(0x5a82799a));
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui + vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui - vi;
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t1 += mh;
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t2 = t1 + (mh << 1);
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cplxMultDiv2(&vr, &vi, x[t2 + 1], x[t2], STC(0x5a82799a),
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STC(0x5a82799a));
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ur = x[t1] >> 1;
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ui = x[t1 + 1] >> 1;
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x[t1] = ur + vr;
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x[t1 + 1] = ui - vi;
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x[t2] = ur - vr;
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x[t2 + 1] = ui + vi;
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}
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} /* end of block 2 */
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}
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}
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#endif
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