mirror of https://github.com/mstorsjo/fdk-aac.git
544 lines
18 KiB
C++
544 lines
18 KiB
C++
/* -----------------------------------------------------------------------------
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Software License for The Fraunhofer FDK AAC Codec Library for Android
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© Copyright 1995 - 2020 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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/**************************** SBR decoder library ******************************
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Author(s): Christian Griebel
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Description: Dynamic range control (DRC) decoder tool for SBR
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*******************************************************************************/
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#include "sbrdec_drc.h"
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/* DRC - Offset table for QMF interpolation. Shifted by one index position.
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The table defines the (short) window borders rounded to the nearest QMF
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timeslot. It has the size 16 because it is accessed with the
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drcInterpolationScheme that is read from the bitstream with 4 bit. */
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static const UCHAR winBorderToColMappingTab[2][16] = {
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/*-1, 0, 1, 2, 3, 4, 5, 6, 7, 8 */
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{0, 0, 4, 8, 12, 16, 20, 24, 28, 32, 32, 32, 32, 32, 32,
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32}, /* 1024 framing */
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{0, 0, 4, 8, 11, 15, 19, 23, 26, 30, 30, 30, 30, 30, 30,
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30} /* 960 framing */
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};
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/*!
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\brief Initialize DRC QMF factors
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\hDrcData Handle to DRC channel data.
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\return none
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*/
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void sbrDecoder_drcInitChannel(HANDLE_SBR_DRC_CHANNEL hDrcData) {
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int band;
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if (hDrcData == NULL) {
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return;
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}
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for (band = 0; band < (64); band++) {
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hDrcData->prevFact_mag[band] = FL2FXCONST_DBL(0.5f);
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}
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for (band = 0; band < SBRDEC_MAX_DRC_BANDS; band++) {
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hDrcData->currFact_mag[band] = FL2FXCONST_DBL(0.5f);
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hDrcData->nextFact_mag[band] = FL2FXCONST_DBL(0.5f);
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}
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hDrcData->prevFact_exp = 1;
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hDrcData->currFact_exp = 1;
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hDrcData->nextFact_exp = 1;
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hDrcData->numBandsCurr = 1;
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hDrcData->numBandsNext = 1;
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hDrcData->winSequenceCurr = 0;
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hDrcData->winSequenceNext = 0;
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hDrcData->drcInterpolationSchemeCurr = 0;
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hDrcData->drcInterpolationSchemeNext = 0;
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hDrcData->enable = 0;
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}
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/*!
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\brief Swap DRC QMF scaling factors after they have been applied.
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\hDrcData Handle to DRC channel data.
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\return none
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*/
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void sbrDecoder_drcUpdateChannel(HANDLE_SBR_DRC_CHANNEL hDrcData) {
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if (hDrcData == NULL) {
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return;
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}
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if (hDrcData->enable != 1) {
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return;
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}
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/* swap previous data */
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FDKmemcpy(hDrcData->currFact_mag, hDrcData->nextFact_mag,
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SBRDEC_MAX_DRC_BANDS * sizeof(FIXP_DBL));
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hDrcData->currFact_exp = hDrcData->nextFact_exp;
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hDrcData->numBandsCurr = hDrcData->numBandsNext;
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FDKmemcpy(hDrcData->bandTopCurr, hDrcData->bandTopNext,
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SBRDEC_MAX_DRC_BANDS * sizeof(USHORT));
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hDrcData->drcInterpolationSchemeCurr = hDrcData->drcInterpolationSchemeNext;
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hDrcData->winSequenceCurr = hDrcData->winSequenceNext;
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}
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/*!
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\brief Apply DRC factors slot based.
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\hDrcData Handle to DRC channel data.
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\qmfRealSlot Pointer to real valued QMF data of one time slot.
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\qmfImagSlot Pointer to the imaginary QMF data of one time slot.
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\col Number of the time slot.
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\numQmfSubSamples Total number of time slots for one frame.
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\scaleFactor Pointer to the out scale factor of the time slot.
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\return None.
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*/
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void sbrDecoder_drcApplySlot(HANDLE_SBR_DRC_CHANNEL hDrcData,
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FIXP_DBL *qmfRealSlot, FIXP_DBL *qmfImagSlot,
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int col, int numQmfSubSamples, int maxShift) {
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const UCHAR *winBorderToColMap;
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int band, bottomMdct, topMdct, bin, useLP;
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int indx = numQmfSubSamples - (numQmfSubSamples >> 1) - 10; /* l_border */
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int frameLenFlag = (numQmfSubSamples == 30) ? 1 : 0;
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int frameSize = (frameLenFlag == 1) ? 960 : 1024;
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const FIXP_DBL *fact_mag = NULL;
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INT fact_exp = 0;
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UINT numBands = 0;
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USHORT *bandTop = NULL;
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int shortDrc = 0;
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FIXP_DBL alphaValue = FL2FXCONST_DBL(0.0f);
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if (hDrcData == NULL) {
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return;
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}
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if (hDrcData->enable != 1) {
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return;
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}
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winBorderToColMap = winBorderToColMappingTab[frameLenFlag];
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useLP = (qmfImagSlot == NULL) ? 1 : 0;
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col += indx;
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bottomMdct = 0;
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/* get respective data and calc interpolation factor */
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if (col < (numQmfSubSamples >> 1)) { /* first half of current frame */
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if (hDrcData->winSequenceCurr != 2) { /* long window */
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int j = col + (numQmfSubSamples >> 1);
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if (j < winBorderToColMap[15]) {
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if (hDrcData->drcInterpolationSchemeCurr == 0) {
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INT k = (frameLenFlag) ? 0x4444445 : 0x4000000;
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alphaValue = (FIXP_DBL)(j * k);
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} else {
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if (j >=
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(int)winBorderToColMap[hDrcData->drcInterpolationSchemeCurr]) {
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alphaValue = (FIXP_DBL)MAXVAL_DBL;
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}
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}
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} else {
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alphaValue = (FIXP_DBL)MAXVAL_DBL;
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}
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} else { /* short windows */
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shortDrc = 1;
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}
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fact_mag = hDrcData->currFact_mag;
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fact_exp = hDrcData->currFact_exp;
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numBands = hDrcData->numBandsCurr;
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bandTop = hDrcData->bandTopCurr;
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} else if (col < numQmfSubSamples) { /* second half of current frame */
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if (hDrcData->winSequenceNext != 2) { /* next: long window */
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int j = col - (numQmfSubSamples >> 1);
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if (j < winBorderToColMap[15]) {
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if (hDrcData->drcInterpolationSchemeNext == 0) {
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INT k = (frameLenFlag) ? 0x4444445 : 0x4000000;
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alphaValue = (FIXP_DBL)(j * k);
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} else {
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if (j >=
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(int)winBorderToColMap[hDrcData->drcInterpolationSchemeNext]) {
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alphaValue = (FIXP_DBL)MAXVAL_DBL;
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}
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}
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} else {
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alphaValue = (FIXP_DBL)MAXVAL_DBL;
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}
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fact_mag = hDrcData->nextFact_mag;
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fact_exp = hDrcData->nextFact_exp;
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numBands = hDrcData->numBandsNext;
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bandTop = hDrcData->bandTopNext;
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} else { /* next: short windows */
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if (hDrcData->winSequenceCurr != 2) { /* current: long window */
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alphaValue = (FIXP_DBL)0;
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fact_mag = hDrcData->nextFact_mag;
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fact_exp = hDrcData->nextFact_exp;
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numBands = hDrcData->numBandsNext;
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bandTop = hDrcData->bandTopNext;
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} else { /* current: short windows */
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shortDrc = 1;
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fact_mag = hDrcData->currFact_mag;
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fact_exp = hDrcData->currFact_exp;
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numBands = hDrcData->numBandsCurr;
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bandTop = hDrcData->bandTopCurr;
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}
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}
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} else { /* first half of next frame */
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if (hDrcData->winSequenceNext != 2) { /* long window */
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int j = col - (numQmfSubSamples >> 1);
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if (j < winBorderToColMap[15]) {
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if (hDrcData->drcInterpolationSchemeNext == 0) {
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INT k = (frameLenFlag) ? 0x4444445 : 0x4000000;
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alphaValue = (FIXP_DBL)(j * k);
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} else {
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if (j >=
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(int)winBorderToColMap[hDrcData->drcInterpolationSchemeNext]) {
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alphaValue = (FIXP_DBL)MAXVAL_DBL;
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}
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}
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} else {
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alphaValue = (FIXP_DBL)MAXVAL_DBL;
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}
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} else { /* short windows */
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shortDrc = 1;
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}
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fact_mag = hDrcData->nextFact_mag;
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fact_exp = hDrcData->nextFact_exp;
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numBands = hDrcData->numBandsNext;
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bandTop = hDrcData->bandTopNext;
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col -= numQmfSubSamples;
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}
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/* process bands */
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for (band = 0; band < (int)numBands; band++) {
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int bottomQmf, topQmf;
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FIXP_DBL drcFact_mag = (FIXP_DBL)MAXVAL_DBL;
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topMdct = (bandTop[band] + 1) << 2;
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if (!shortDrc) { /* long window */
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if (frameLenFlag) {
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/* 960 framing */
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bottomQmf = fMultIfloor((FIXP_DBL)0x4444445, bottomMdct);
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topQmf = fMultIfloor((FIXP_DBL)0x4444445, topMdct);
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topMdct = 30 * topQmf;
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} else {
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/* 1024 framing */
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topMdct &= ~0x1f;
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bottomQmf = bottomMdct >> 5;
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topQmf = topMdct >> 5;
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}
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if (band == ((int)numBands - 1)) {
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topQmf = (64);
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}
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for (bin = bottomQmf; bin < topQmf; bin++) {
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FIXP_DBL drcFact1_mag = hDrcData->prevFact_mag[bin];
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FIXP_DBL drcFact2_mag = fact_mag[band];
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/* normalize scale factors */
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if (hDrcData->prevFact_exp < maxShift) {
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drcFact1_mag >>= maxShift - hDrcData->prevFact_exp;
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}
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if (fact_exp < maxShift) {
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drcFact2_mag >>= maxShift - fact_exp;
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}
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/* interpolate */
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if (alphaValue == (FIXP_DBL)0) {
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drcFact_mag = drcFact1_mag;
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} else if (alphaValue == (FIXP_DBL)MAXVAL_DBL) {
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drcFact_mag = drcFact2_mag;
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} else {
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drcFact_mag =
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fMult(alphaValue, drcFact2_mag) +
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fMult(((FIXP_DBL)MAXVAL_DBL - alphaValue), drcFact1_mag);
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}
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/* apply scaling */
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qmfRealSlot[bin] = fMult(qmfRealSlot[bin], drcFact_mag);
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if (!useLP) {
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qmfImagSlot[bin] = fMult(qmfImagSlot[bin], drcFact_mag);
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}
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/* save previous factors */
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if (col == (numQmfSubSamples >> 1) - 1) {
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hDrcData->prevFact_mag[bin] = fact_mag[band];
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}
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}
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} else { /* short windows */
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unsigned startWinIdx, stopWinIdx;
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int startCol, stopCol;
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FIXP_DBL invFrameSizeDiv8 =
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(frameLenFlag) ? (FIXP_DBL)0x1111112 : (FIXP_DBL)0x1000000;
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/* limit top at the frame borders */
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if (topMdct < 0) {
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topMdct = 0;
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}
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if (topMdct >= frameSize) {
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topMdct = frameSize - 1;
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}
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if (frameLenFlag) {
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/* 960 framing */
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topMdct = fMultIfloor((FIXP_DBL)0x78000000,
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fMultIfloor((FIXP_DBL)0x22222223, topMdct) << 2);
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startWinIdx = fMultIfloor(invFrameSizeDiv8, bottomMdct) +
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1; /* winBorderToColMap table has offset of 1 */
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stopWinIdx = fMultIceil(invFrameSizeDiv8 - (FIXP_DBL)1, topMdct) + 1;
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} else {
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/* 1024 framing */
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topMdct &= ~0x03;
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startWinIdx = fMultIfloor(invFrameSizeDiv8, bottomMdct) + 1;
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stopWinIdx = fMultIceil(invFrameSizeDiv8, topMdct) + 1;
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}
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/* startCol is truncated to the nearest corresponding start subsample in
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the QMF of the short window bottom is present in:*/
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startCol = (int)winBorderToColMap[startWinIdx];
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/* stopCol is rounded upwards to the nearest corresponding stop subsample
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in the QMF of the short window top is present in. */
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stopCol = (int)winBorderToColMap[stopWinIdx];
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bottomQmf = fMultIfloor(invFrameSizeDiv8,
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((bottomMdct % (numQmfSubSamples << 2)) << 5));
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topQmf = fMultIfloor(invFrameSizeDiv8,
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((topMdct % (numQmfSubSamples << 2)) << 5));
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/* extend last band */
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if (band == ((int)numBands - 1)) {
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topQmf = (64);
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stopCol = numQmfSubSamples;
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stopWinIdx = 10;
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}
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if (topQmf == 0) {
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if (frameLenFlag) {
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FIXP_DBL rem = fMult(invFrameSizeDiv8,
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(FIXP_DBL)(topMdct << (DFRACT_BITS - 12)));
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if ((LONG)rem & (LONG)0x1F) {
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stopWinIdx -= 1;
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stopCol = (int)winBorderToColMap[stopWinIdx];
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}
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}
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topQmf = (64);
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}
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/* save previous factors */
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if (stopCol == numQmfSubSamples) {
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int tmpBottom = bottomQmf;
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if ((int)winBorderToColMap[8] > startCol) {
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tmpBottom = 0; /* band starts in previous short window */
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}
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for (bin = tmpBottom; bin < topQmf; bin++) {
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hDrcData->prevFact_mag[bin] = fact_mag[band];
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}
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}
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/* apply */
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if ((col >= startCol) && (col < stopCol)) {
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if (col >= (int)winBorderToColMap[startWinIdx + 1]) {
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bottomQmf = 0; /* band starts in previous short window */
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}
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if (col < (int)winBorderToColMap[stopWinIdx - 1]) {
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topQmf = (64); /* band ends in next short window */
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}
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drcFact_mag = fact_mag[band];
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/* normalize scale factor */
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if (fact_exp < maxShift) {
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drcFact_mag >>= maxShift - fact_exp;
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}
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/* apply scaling */
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for (bin = bottomQmf; bin < topQmf; bin++) {
|
|
qmfRealSlot[bin] = fMult(qmfRealSlot[bin], drcFact_mag);
|
|
if (!useLP) {
|
|
qmfImagSlot[bin] = fMult(qmfImagSlot[bin], drcFact_mag);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
bottomMdct = topMdct;
|
|
} /* end of bands loop */
|
|
|
|
if (col == (numQmfSubSamples >> 1) - 1) {
|
|
hDrcData->prevFact_exp = fact_exp;
|
|
}
|
|
}
|
|
|
|
/*!
|
|
\brief Apply DRC factors frame based.
|
|
|
|
\hDrcData Handle to DRC channel data.
|
|
\qmfRealSlot Pointer to real valued QMF data of the whole frame.
|
|
\qmfImagSlot Pointer to the imaginary QMF data of the whole frame.
|
|
\numQmfSubSamples Total number of time slots for one frame.
|
|
\scaleFactor Pointer to the out scale factor of the frame.
|
|
|
|
\return None.
|
|
*/
|
|
void sbrDecoder_drcApply(HANDLE_SBR_DRC_CHANNEL hDrcData,
|
|
FIXP_DBL **QmfBufferReal, FIXP_DBL **QmfBufferImag,
|
|
int numQmfSubSamples, int *scaleFactor) {
|
|
int col;
|
|
int maxShift = 0;
|
|
|
|
if (hDrcData == NULL) {
|
|
return;
|
|
}
|
|
if (hDrcData->enable == 0) {
|
|
return; /* Avoid changing the scaleFactor even though the processing is
|
|
disabled. */
|
|
}
|
|
|
|
/* get max scale factor */
|
|
if (hDrcData->prevFact_exp > maxShift) {
|
|
maxShift = hDrcData->prevFact_exp;
|
|
}
|
|
if (hDrcData->currFact_exp > maxShift) {
|
|
maxShift = hDrcData->currFact_exp;
|
|
}
|
|
if (hDrcData->nextFact_exp > maxShift) {
|
|
maxShift = hDrcData->nextFact_exp;
|
|
}
|
|
|
|
for (col = 0; col < numQmfSubSamples; col++) {
|
|
FIXP_DBL *qmfSlotReal = QmfBufferReal[col];
|
|
FIXP_DBL *qmfSlotImag = (QmfBufferImag == NULL) ? NULL : QmfBufferImag[col];
|
|
|
|
sbrDecoder_drcApplySlot(hDrcData, qmfSlotReal, qmfSlotImag, col,
|
|
numQmfSubSamples, maxShift);
|
|
}
|
|
|
|
*scaleFactor += maxShift;
|
|
}
|