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authorMatthias P. Braendli <matthias.braendli@mpb.li>2020-03-31 10:03:58 +0200
committerMatthias P. Braendli <matthias.braendli@mpb.li>2020-03-31 10:03:58 +0200
commita1eb6cf861d3c1cbd4e6c016be3cbd2a1e3d797d (patch)
tree2b4790eec8f47fb086e645717f07c53b30ace919 /fdk-aac/libAACenc/src/block_switch.cpp
parent2f84a54ec1d10b10293c7b1f4ab9fee31f3c6327 (diff)
parentc6a73c219dbfdfe639372d9922f4eb512f06fa2f (diff)
downloadODR-AudioEnc-a1eb6cf861d3c1cbd4e6c016be3cbd2a1e3d797d.tar.gz
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+/* -----------------------------------------------------------------------------
+Software License for The Fraunhofer FDK AAC Codec Library for Android
+
+© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
+Forschung e.V. All rights reserved.
+
+ 1. INTRODUCTION
+The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
+that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
+scheme for digital audio. This FDK AAC Codec software is intended to be used on
+a wide variety of Android devices.
+
+AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
+general perceptual audio codecs. AAC-ELD is considered the best-performing
+full-bandwidth communications codec by independent studies and is widely
+deployed. AAC has been standardized by ISO and IEC as part of the MPEG
+specifications.
+
+Patent licenses for necessary patent claims for the FDK AAC Codec (including
+those of Fraunhofer) may be obtained through Via Licensing
+(www.vialicensing.com) or through the respective patent owners individually for
+the purpose of encoding or decoding bit streams in products that are compliant
+with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
+Android devices already license these patent claims through Via Licensing or
+directly from the patent owners, and therefore FDK AAC Codec software may
+already be covered under those patent licenses when it is used for those
+licensed purposes only.
+
+Commercially-licensed AAC software libraries, including floating-point versions
+with enhanced sound quality, are also available from Fraunhofer. Users are
+encouraged to check the Fraunhofer website for additional applications
+information and documentation.
+
+2. COPYRIGHT LICENSE
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted without payment of copyright license fees provided that you
+satisfy the following conditions:
+
+You must retain the complete text of this software license in redistributions of
+the FDK AAC Codec or your modifications thereto in source code form.
+
+You must retain the complete text of this software license in the documentation
+and/or other materials provided with redistributions of the FDK AAC Codec or
+your modifications thereto in binary form. You must make available free of
+charge copies of the complete source code of the FDK AAC Codec and your
+modifications thereto to recipients of copies in binary form.
+
+The name of Fraunhofer may not be used to endorse or promote products derived
+from this library without prior written permission.
+
+You may not charge copyright license fees for anyone to use, copy or distribute
+the FDK AAC Codec software or your modifications thereto.
+
+Your modified versions of the FDK AAC Codec must carry prominent notices stating
+that you changed the software and the date of any change. For modified versions
+of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
+must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
+AAC Codec Library for Android."
+
+3. NO PATENT LICENSE
+
+NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
+limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
+Fraunhofer provides no warranty of patent non-infringement with respect to this
+software.
+
+You may use this FDK AAC Codec software or modifications thereto only for
+purposes that are authorized by appropriate patent licenses.
+
+4. DISCLAIMER
+
+This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
+holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
+including but not limited to the implied warranties of merchantability and
+fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
+or consequential damages, including but not limited to procurement of substitute
+goods or services; loss of use, data, or profits, or business interruption,
+however caused and on any theory of liability, whether in contract, strict
+liability, or tort (including negligence), arising in any way out of the use of
+this software, even if advised of the possibility of such damage.
+
+5. CONTACT INFORMATION
+
+Fraunhofer Institute for Integrated Circuits IIS
+Attention: Audio and Multimedia Departments - FDK AAC LL
+Am Wolfsmantel 33
+91058 Erlangen, Germany
+
+www.iis.fraunhofer.de/amm
+amm-info@iis.fraunhofer.de
+----------------------------------------------------------------------------- */
+
+/**************************** AAC encoder library ******************************
+
+ Author(s): M. Werner, Tobias Chalupka
+
+ Description: Block switching
+
+*******************************************************************************/
+
+/****************** Includes *****************************/
+
+#include "block_switch.h"
+#include "genericStds.h"
+
+#define LOWOV_WINDOW _LOWOV_WINDOW
+
+/**************** internal function prototypes ***********/
+
+static FIXP_DBL FDKaacEnc_GetWindowEnergy(const FIXP_DBL in[],
+ const INT blSwWndIdx);
+
+static void FDKaacEnc_CalcWindowEnergy(
+ BLOCK_SWITCHING_CONTROL *RESTRICT blockSwitchingControl, INT windowLen,
+ const INT_PCM *pTimeSignal);
+
+/****************** Constants *****************************/
+/* LONG START
+ * SHORT STOP LOWOV */
+static const INT blockType2windowShape[2][5] = {
+ {SINE_WINDOW, KBD_WINDOW, WRONG_WINDOW, SINE_WINDOW, KBD_WINDOW}, /* LD */
+ {KBD_WINDOW, SINE_WINDOW, SINE_WINDOW, KBD_WINDOW, WRONG_WINDOW}}; /* LC */
+
+/* IIR high pass coeffs */
+
+#ifndef SINETABLE_16BIT
+
+static const FIXP_DBL hiPassCoeff[BLOCK_SWITCHING_IIR_LEN] = {
+ FL2FXCONST_DBL(-0.5095), FL2FXCONST_DBL(0.7548)};
+
+static const FIXP_DBL accWindowNrgFac =
+ FL2FXCONST_DBL(0.3f); /* factor for accumulating filtered window energies */
+static const FIXP_DBL oneMinusAccWindowNrgFac = FL2FXCONST_DBL(0.7f);
+/* static const float attackRatio = 10.0; */ /* lower ratio limit for attacks */
+static const FIXP_DBL invAttackRatio =
+ FL2FXCONST_DBL(0.1f); /* inverted lower ratio limit for attacks */
+
+/* The next constants are scaled, because they are used for comparison with
+ * scaled values*/
+/* minimum energy for attacks */
+static const FIXP_DBL minAttackNrg =
+ (FL2FXCONST_DBL(1e+6f * NORM_PCM_ENERGY) >>
+ BLOCK_SWITCH_ENERGY_SHIFT); /* minimum energy for attacks */
+
+#else
+
+static const FIXP_SGL hiPassCoeff[BLOCK_SWITCHING_IIR_LEN] = {
+ FL2FXCONST_SGL(-0.5095), FL2FXCONST_SGL(0.7548)};
+
+static const FIXP_DBL accWindowNrgFac =
+ FL2FXCONST_DBL(0.3f); /* factor for accumulating filtered window energies */
+static const FIXP_SGL oneMinusAccWindowNrgFac = FL2FXCONST_SGL(0.7f);
+/* static const float attackRatio = 10.0; */ /* lower ratio limit for attacks */
+static const FIXP_SGL invAttackRatio =
+ FL2FXCONST_SGL(0.1f); /* inverted lower ratio limit for attacks */
+/* minimum energy for attacks */
+static const FIXP_DBL minAttackNrg =
+ (FL2FXCONST_DBL(1e+6f * NORM_PCM_ENERGY) >>
+ BLOCK_SWITCH_ENERGY_SHIFT); /* minimum energy for attacks */
+
+#endif
+
+/**************** internal function prototypes ***********/
+
+/****************** Routines ****************************/
+void FDKaacEnc_InitBlockSwitching(
+ BLOCK_SWITCHING_CONTROL *blockSwitchingControl, INT isLowDelay) {
+ FDKmemclear(blockSwitchingControl, sizeof(BLOCK_SWITCHING_CONTROL));
+
+ if (isLowDelay) {
+ blockSwitchingControl->nBlockSwitchWindows = 4;
+ blockSwitchingControl->allowShortFrames = 0;
+ blockSwitchingControl->allowLookAhead = 0;
+ } else {
+ blockSwitchingControl->nBlockSwitchWindows = 8;
+ blockSwitchingControl->allowShortFrames = 1;
+ blockSwitchingControl->allowLookAhead = 1;
+ }
+
+ blockSwitchingControl->noOfGroups = MAX_NO_OF_GROUPS;
+
+ /* Initialize startvalue for blocktype */
+ blockSwitchingControl->lastWindowSequence = LONG_WINDOW;
+ blockSwitchingControl->windowShape =
+ blockType2windowShape[blockSwitchingControl->allowShortFrames]
+ [blockSwitchingControl->lastWindowSequence];
+}
+
+static const INT suggestedGroupingTable[TRANS_FAC][MAX_NO_OF_GROUPS] = {
+ /* Attack in Window 0 */ {1, 3, 3, 1},
+ /* Attack in Window 1 */ {1, 1, 3, 3},
+ /* Attack in Window 2 */ {2, 1, 3, 2},
+ /* Attack in Window 3 */ {3, 1, 3, 1},
+ /* Attack in Window 4 */ {3, 1, 1, 3},
+ /* Attack in Window 5 */ {3, 2, 1, 2},
+ /* Attack in Window 6 */ {3, 3, 1, 1},
+ /* Attack in Window 7 */ {3, 3, 1, 1}};
+
+/* change block type depending on current blocktype and whether there's an
+ * attack */
+/* assume no look-ahead */
+static const INT chgWndSq[2][N_BLOCKTYPES] = {
+ /* LONG WINDOW START_WINDOW SHORT_WINDOW STOP_WINDOW,
+ LOWOV_WINDOW, WRONG_WINDOW */
+ /*no attack*/ {LONG_WINDOW, STOP_WINDOW, WRONG_WINDOW, LONG_WINDOW,
+ STOP_WINDOW, WRONG_WINDOW},
+ /*attack */ {START_WINDOW, LOWOV_WINDOW, WRONG_WINDOW, START_WINDOW,
+ LOWOV_WINDOW, WRONG_WINDOW}};
+
+/* change block type depending on current blocktype and whether there's an
+ * attack */
+/* assume look-ahead */
+static const INT chgWndSqLkAhd[2][2][N_BLOCKTYPES] = {
+ /*attack LONG WINDOW START_WINDOW SHORT_WINDOW STOP_WINDOW LOWOV_WINDOW, WRONG_WINDOW */ /* last attack */
+ /*no attack*/ {
+ {LONG_WINDOW, SHORT_WINDOW, STOP_WINDOW, LONG_WINDOW, WRONG_WINDOW,
+ WRONG_WINDOW}, /* no attack */
+ /*attack */ {START_WINDOW, SHORT_WINDOW, SHORT_WINDOW, START_WINDOW,
+ WRONG_WINDOW, WRONG_WINDOW}}, /* no attack */
+ /*no attack*/ {{LONG_WINDOW, SHORT_WINDOW, SHORT_WINDOW, LONG_WINDOW,
+ WRONG_WINDOW, WRONG_WINDOW}, /* attack */
+ /*attack */ {START_WINDOW, SHORT_WINDOW, SHORT_WINDOW,
+ START_WINDOW, WRONG_WINDOW,
+ WRONG_WINDOW}} /* attack */
+};
+
+int FDKaacEnc_BlockSwitching(BLOCK_SWITCHING_CONTROL *blockSwitchingControl,
+ const INT granuleLength, const int isLFE,
+ const INT_PCM *pTimeSignal) {
+ UINT i;
+ FIXP_DBL enM1, enMax;
+
+ UINT nBlockSwitchWindows = blockSwitchingControl->nBlockSwitchWindows;
+
+ /* for LFE : only LONG window allowed */
+ if (isLFE) {
+ /* case LFE: */
+ /* only long blocks, always use sine windows (MPEG2 AAC, MPEG4 AAC) */
+ blockSwitchingControl->lastWindowSequence = LONG_WINDOW;
+ blockSwitchingControl->windowShape = SINE_WINDOW;
+ blockSwitchingControl->noOfGroups = 1;
+ blockSwitchingControl->groupLen[0] = 1;
+
+ return (0);
+ };
+
+ /* Save current attack index as last attack index */
+ blockSwitchingControl->lastattack = blockSwitchingControl->attack;
+ blockSwitchingControl->lastAttackIndex = blockSwitchingControl->attackIndex;
+
+ /* Save current window energy as last window energy */
+ FDKmemcpy(blockSwitchingControl->windowNrg[0],
+ blockSwitchingControl->windowNrg[1],
+ sizeof(blockSwitchingControl->windowNrg[0]));
+ FDKmemcpy(blockSwitchingControl->windowNrgF[0],
+ blockSwitchingControl->windowNrgF[1],
+ sizeof(blockSwitchingControl->windowNrgF[0]));
+
+ if (blockSwitchingControl->allowShortFrames) {
+ /* Calculate suggested grouping info for the last frame */
+
+ /* Reset grouping info */
+ FDKmemclear(blockSwitchingControl->groupLen,
+ sizeof(blockSwitchingControl->groupLen));
+
+ /* Set grouping info */
+ blockSwitchingControl->noOfGroups = MAX_NO_OF_GROUPS;
+
+ FDKmemcpy(blockSwitchingControl->groupLen,
+ suggestedGroupingTable[blockSwitchingControl->lastAttackIndex],
+ sizeof(blockSwitchingControl->groupLen));
+
+ if (blockSwitchingControl->attack == TRUE)
+ blockSwitchingControl->maxWindowNrg =
+ FDKaacEnc_GetWindowEnergy(blockSwitchingControl->windowNrg[0],
+ blockSwitchingControl->lastAttackIndex);
+ else
+ blockSwitchingControl->maxWindowNrg = FL2FXCONST_DBL(0.0);
+ }
+
+ /* Calculate unfiltered and filtered energies in subwindows and combine to
+ * segments */
+ FDKaacEnc_CalcWindowEnergy(
+ blockSwitchingControl,
+ granuleLength >> (nBlockSwitchWindows == 4 ? 2 : 3), pTimeSignal);
+
+ /* now calculate if there is an attack */
+
+ /* reset attack */
+ blockSwitchingControl->attack = FALSE;
+
+ /* look for attack */
+ enMax = FL2FXCONST_DBL(0.0f);
+ enM1 = blockSwitchingControl->windowNrgF[0][nBlockSwitchWindows - 1];
+
+ for (i = 0; i < nBlockSwitchWindows; i++) {
+ FIXP_DBL tmp =
+ fMultDiv2(oneMinusAccWindowNrgFac, blockSwitchingControl->accWindowNrg);
+ blockSwitchingControl->accWindowNrg = fMultAdd(tmp, accWindowNrgFac, enM1);
+
+ if (fMult(blockSwitchingControl->windowNrgF[1][i], invAttackRatio) >
+ blockSwitchingControl->accWindowNrg) {
+ blockSwitchingControl->attack = TRUE;
+ blockSwitchingControl->attackIndex = i;
+ }
+ enM1 = blockSwitchingControl->windowNrgF[1][i];
+ enMax = fixMax(enMax, enM1);
+ }
+
+ if (enMax < minAttackNrg) blockSwitchingControl->attack = FALSE;
+
+ /* Check if attack spreads over frame border */
+ if ((blockSwitchingControl->attack == FALSE) &&
+ (blockSwitchingControl->lastattack == TRUE)) {
+ /* if attack is in last window repeat SHORT_WINDOW */
+ if (((blockSwitchingControl->windowNrgF[0][nBlockSwitchWindows - 1] >> 4) >
+ fMult((FIXP_DBL)(10 << (DFRACT_BITS - 1 - 4)),
+ blockSwitchingControl->windowNrgF[1][1])) &&
+ (blockSwitchingControl->lastAttackIndex ==
+ (INT)nBlockSwitchWindows - 1)) {
+ blockSwitchingControl->attack = TRUE;
+ blockSwitchingControl->attackIndex = 0;
+ }
+ }
+
+ if (blockSwitchingControl->allowLookAhead) {
+ blockSwitchingControl->lastWindowSequence =
+ chgWndSqLkAhd[blockSwitchingControl->lastattack]
+ [blockSwitchingControl->attack]
+ [blockSwitchingControl->lastWindowSequence];
+ } else {
+ /* Low Delay */
+ blockSwitchingControl->lastWindowSequence =
+ chgWndSq[blockSwitchingControl->attack]
+ [blockSwitchingControl->lastWindowSequence];
+ }
+
+ /* update window shape */
+ blockSwitchingControl->windowShape =
+ blockType2windowShape[blockSwitchingControl->allowShortFrames]
+ [blockSwitchingControl->lastWindowSequence];
+
+ return (0);
+}
+
+static FIXP_DBL FDKaacEnc_GetWindowEnergy(const FIXP_DBL in[],
+ const INT blSwWndIdx) {
+ /* For coherency, change FDKaacEnc_GetWindowEnergy() to calcluate the energy
+ for a block switching analysis windows, not for a short block. The same is
+ done FDKaacEnc_CalcWindowEnergy(). The result of
+ FDKaacEnc_GetWindowEnergy() is used for a comparision of the max energy of
+ left/right channel. */
+
+ return in[blSwWndIdx];
+}
+
+static void FDKaacEnc_CalcWindowEnergy(
+ BLOCK_SWITCHING_CONTROL *RESTRICT blockSwitchingControl, INT windowLen,
+ const INT_PCM *pTimeSignal) {
+ INT i;
+ UINT w;
+
+#ifndef SINETABLE_16BIT
+ const FIXP_DBL hiPassCoeff0 = hiPassCoeff[0];
+ const FIXP_DBL hiPassCoeff1 = hiPassCoeff[1];
+#else
+ const FIXP_SGL hiPassCoeff0 = hiPassCoeff[0];
+ const FIXP_SGL hiPassCoeff1 = hiPassCoeff[1];
+#endif
+
+ FIXP_DBL temp_iirState0 = blockSwitchingControl->iirStates[0];
+ FIXP_DBL temp_iirState1 = blockSwitchingControl->iirStates[1];
+
+ /* sum up scalarproduct of timesignal as windowed Energies */
+ for (w = 0; w < blockSwitchingControl->nBlockSwitchWindows; w++) {
+ ULONG temp_windowNrg = 0x0;
+ ULONG temp_windowNrgF = 0x0;
+
+ /* windowNrg = sum(timesample^2) */
+ for (i = 0; i < windowLen; i++) {
+ FIXP_DBL tempUnfiltered, t1, t2;
+ /* tempUnfiltered is scaled with 1 to prevent overflows during calculation
+ * of tempFiltred */
+#if SAMPLE_BITS == DFRACT_BITS
+ tempUnfiltered = (FIXP_DBL)*pTimeSignal++ >> 1;
+#else
+ tempUnfiltered = (FIXP_DBL)*pTimeSignal++
+ << (DFRACT_BITS - SAMPLE_BITS - 1);
+#endif
+ t1 = fMultDiv2(hiPassCoeff1, tempUnfiltered - temp_iirState0);
+ t2 = fMultDiv2(hiPassCoeff0, temp_iirState1);
+ temp_iirState0 = tempUnfiltered;
+ temp_iirState1 = (t1 - t2) << 1;
+
+ temp_windowNrg += (LONG)fPow2Div2(temp_iirState0) >>
+ (BLOCK_SWITCH_ENERGY_SHIFT - 1 - 2);
+ temp_windowNrgF += (LONG)fPow2Div2(temp_iirState1) >>
+ (BLOCK_SWITCH_ENERGY_SHIFT - 1 - 2);
+ }
+ blockSwitchingControl->windowNrg[1][w] =
+ (LONG)fMin(temp_windowNrg, (UINT)MAXVAL_DBL);
+ blockSwitchingControl->windowNrgF[1][w] =
+ (LONG)fMin(temp_windowNrgF, (UINT)MAXVAL_DBL);
+ }
+ blockSwitchingControl->iirStates[0] = temp_iirState0;
+ blockSwitchingControl->iirStates[1] = temp_iirState1;
+}
+
+static const UCHAR synchronizedBlockTypeTable[5][5] = {
+ /* LONG_WINDOW START_WINDOW SHORT_WINDOW STOP_WINDOW
+ LOWOV_WINDOW*/
+ /* LONG_WINDOW */ {LONG_WINDOW, START_WINDOW, SHORT_WINDOW, STOP_WINDOW,
+ LOWOV_WINDOW},
+ /* START_WINDOW */
+ {START_WINDOW, START_WINDOW, SHORT_WINDOW, SHORT_WINDOW, LOWOV_WINDOW},
+ /* SHORT_WINDOW */
+ {SHORT_WINDOW, SHORT_WINDOW, SHORT_WINDOW, SHORT_WINDOW, WRONG_WINDOW},
+ /* STOP_WINDOW */
+ {STOP_WINDOW, SHORT_WINDOW, SHORT_WINDOW, STOP_WINDOW, LOWOV_WINDOW},
+ /* LOWOV_WINDOW */
+ {LOWOV_WINDOW, LOWOV_WINDOW, WRONG_WINDOW, LOWOV_WINDOW, LOWOV_WINDOW},
+};
+
+int FDKaacEnc_SyncBlockSwitching(
+ BLOCK_SWITCHING_CONTROL *blockSwitchingControlLeft,
+ BLOCK_SWITCHING_CONTROL *blockSwitchingControlRight, const INT nChannels,
+ const INT commonWindow) {
+ UCHAR patchType = LONG_WINDOW;
+
+ if (nChannels == 2 && commonWindow == TRUE) {
+ /* could be better with a channel loop (need a handle to psy_data) */
+ /* get suggested Block Types and synchronize */
+ patchType = synchronizedBlockTypeTable[patchType][blockSwitchingControlLeft
+ ->lastWindowSequence];
+ patchType = synchronizedBlockTypeTable[patchType][blockSwitchingControlRight
+ ->lastWindowSequence];
+
+ /* sanity check (no change from low overlap window to short winow and vice
+ * versa) */
+ if (patchType == WRONG_WINDOW) return -1; /* mixed up AAC-LC and AAC-LD */
+
+ /* Set synchronized Blocktype */
+ blockSwitchingControlLeft->lastWindowSequence = patchType;
+ blockSwitchingControlRight->lastWindowSequence = patchType;
+
+ /* update window shape */
+ blockSwitchingControlLeft->windowShape =
+ blockType2windowShape[blockSwitchingControlLeft->allowShortFrames]
+ [blockSwitchingControlLeft->lastWindowSequence];
+ blockSwitchingControlRight->windowShape =
+ blockType2windowShape[blockSwitchingControlLeft->allowShortFrames]
+ [blockSwitchingControlRight->lastWindowSequence];
+ }
+
+ if (blockSwitchingControlLeft->allowShortFrames) {
+ int i;
+
+ if (nChannels == 2) {
+ if (commonWindow == TRUE) {
+ /* Synchronize grouping info */
+ int windowSequenceLeftOld =
+ blockSwitchingControlLeft->lastWindowSequence;
+ int windowSequenceRightOld =
+ blockSwitchingControlRight->lastWindowSequence;
+
+ /* Long Blocks */
+ if (patchType != SHORT_WINDOW) {
+ /* Set grouping info */
+ blockSwitchingControlLeft->noOfGroups = 1;
+ blockSwitchingControlRight->noOfGroups = 1;
+ blockSwitchingControlLeft->groupLen[0] = 1;
+ blockSwitchingControlRight->groupLen[0] = 1;
+
+ for (i = 1; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlLeft->groupLen[i] = 0;
+ blockSwitchingControlRight->groupLen[i] = 0;
+ }
+ }
+
+ /* Short Blocks */
+ else {
+ /* in case all two channels were detected as short-blocks before
+ * syncing, use the grouping of channel with higher maxWindowNrg */
+ if ((windowSequenceLeftOld == SHORT_WINDOW) &&
+ (windowSequenceRightOld == SHORT_WINDOW)) {
+ if (blockSwitchingControlLeft->maxWindowNrg >
+ blockSwitchingControlRight->maxWindowNrg) {
+ /* Left Channel wins */
+ blockSwitchingControlRight->noOfGroups =
+ blockSwitchingControlLeft->noOfGroups;
+ for (i = 0; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlRight->groupLen[i] =
+ blockSwitchingControlLeft->groupLen[i];
+ }
+ } else {
+ /* Right Channel wins */
+ blockSwitchingControlLeft->noOfGroups =
+ blockSwitchingControlRight->noOfGroups;
+ for (i = 0; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlLeft->groupLen[i] =
+ blockSwitchingControlRight->groupLen[i];
+ }
+ }
+ } else if ((windowSequenceLeftOld == SHORT_WINDOW) &&
+ (windowSequenceRightOld != SHORT_WINDOW)) {
+ /* else use grouping of short-block channel */
+ blockSwitchingControlRight->noOfGroups =
+ blockSwitchingControlLeft->noOfGroups;
+ for (i = 0; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlRight->groupLen[i] =
+ blockSwitchingControlLeft->groupLen[i];
+ }
+ } else if ((windowSequenceRightOld == SHORT_WINDOW) &&
+ (windowSequenceLeftOld != SHORT_WINDOW)) {
+ blockSwitchingControlLeft->noOfGroups =
+ blockSwitchingControlRight->noOfGroups;
+ for (i = 0; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlLeft->groupLen[i] =
+ blockSwitchingControlRight->groupLen[i];
+ }
+ } else {
+ /* syncing a start and stop window ... */
+ blockSwitchingControlLeft->noOfGroups =
+ blockSwitchingControlRight->noOfGroups = 2;
+ blockSwitchingControlLeft->groupLen[0] =
+ blockSwitchingControlRight->groupLen[0] = 4;
+ blockSwitchingControlLeft->groupLen[1] =
+ blockSwitchingControlRight->groupLen[1] = 4;
+ }
+ } /* Short Blocks */
+ } else {
+ /* stereo, no common window */
+ if (blockSwitchingControlLeft->lastWindowSequence != SHORT_WINDOW) {
+ blockSwitchingControlLeft->noOfGroups = 1;
+ blockSwitchingControlLeft->groupLen[0] = 1;
+ for (i = 1; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlLeft->groupLen[i] = 0;
+ }
+ }
+ if (blockSwitchingControlRight->lastWindowSequence != SHORT_WINDOW) {
+ blockSwitchingControlRight->noOfGroups = 1;
+ blockSwitchingControlRight->groupLen[0] = 1;
+ for (i = 1; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlRight->groupLen[i] = 0;
+ }
+ }
+ } /* common window */
+ } else {
+ /* Mono */
+ if (blockSwitchingControlLeft->lastWindowSequence != SHORT_WINDOW) {
+ blockSwitchingControlLeft->noOfGroups = 1;
+ blockSwitchingControlLeft->groupLen[0] = 1;
+
+ for (i = 1; i < MAX_NO_OF_GROUPS; i++) {
+ blockSwitchingControlLeft->groupLen[i] = 0;
+ }
+ }
+ }
+ } /* allowShortFrames */
+
+ /* Translate LOWOV_WINDOW block type to a meaningful window shape. */
+ if (!blockSwitchingControlLeft->allowShortFrames) {
+ if (blockSwitchingControlLeft->lastWindowSequence != LONG_WINDOW &&
+ blockSwitchingControlLeft->lastWindowSequence != STOP_WINDOW) {
+ blockSwitchingControlLeft->lastWindowSequence = LONG_WINDOW;
+ blockSwitchingControlLeft->windowShape = LOL_WINDOW;
+ }
+ }
+ if (nChannels == 2) {
+ if (!blockSwitchingControlRight->allowShortFrames) {
+ if (blockSwitchingControlRight->lastWindowSequence != LONG_WINDOW &&
+ blockSwitchingControlRight->lastWindowSequence != STOP_WINDOW) {
+ blockSwitchingControlRight->lastWindowSequence = LONG_WINDOW;
+ blockSwitchingControlRight->windowShape = LOL_WINDOW;
+ }
+ }
+ }
+
+ return 0;
+}