diff options
Diffstat (limited to 'libAACenc/src/block_switch.cpp')
| -rw-r--r-- | libAACenc/src/block_switch.cpp | 545 |
1 files changed, 0 insertions, 545 deletions
diff --git a/libAACenc/src/block_switch.cpp b/libAACenc/src/block_switch.cpp deleted file mode 100644 index 7b3e275..0000000 --- a/libAACenc/src/block_switch.cpp +++ /dev/null @@ -1,545 +0,0 @@ - -/* ----------------------------------------------------------------------------------------------------------- -Software License for The Fraunhofer FDK AAC Codec Library for Android - -© Copyright 1995 - 2013 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 ------------------------------------------------------------------------------------------------------------ */ - -/***************************** MPEG-4 AAC Encoder ************************** - - 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; - - FIXP_SGL hiPassCoeff0 = hiPassCoeff[0]; - FIXP_SGL hiPassCoeff1 = hiPassCoeff[1]; - - /* sum up scalarproduct of timesignal as windowed Energies */ - for (w=0; w < blockSwitchingControl->nBlockSwitchWindows; w++) { - - FIXP_DBL temp_windowNrg = FL2FXCONST_DBL(0.0f); - FIXP_DBL temp_windowNrgF = FL2FXCONST_DBL(0.0f); - FIXP_DBL temp_iirState0 = blockSwitchingControl->iirStates[0]; - FIXP_DBL temp_iirState1 = blockSwitchingControl->iirStates[1]; - - /* windowNrg = sum(timesample^2) */ - for(i=0;i<windowLen;i++) - { - - FIXP_DBL tempUnfiltered, tempFiltred, 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); - tempFiltred = (t1 - t2) << 1; - - temp_iirState0 = tempUnfiltered; - temp_iirState1 = tempFiltred; - - /* subtract 2 from overallscaling (BLOCK_SWITCH_ENERGY_SHIFT) - * because tempUnfiltered was already scaled with 1 (is 2 after squaring) - * subtract 1 from overallscaling (BLOCK_SWITCH_ENERGY_SHIFT) - * because of fMultDiv2 is doing a scaling by one */ - temp_windowNrg += fPow2Div2(tempUnfiltered) >> (BLOCK_SWITCH_ENERGY_SHIFT - 1 - 2); - temp_windowNrgF += fPow2Div2(tempFiltred) >> (BLOCK_SWITCH_ENERGY_SHIFT - 1 - 2); - } - blockSwitchingControl->windowNrg[1][w] = temp_windowNrg; - blockSwitchingControl->windowNrgF[1][w] = temp_windowNrgF; - 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; -} - - |