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Diffstat (limited to 'fdk-aac/libAACenc/src/aacenc_tns.cpp')
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diff --git a/fdk-aac/libAACenc/src/aacenc_tns.cpp b/fdk-aac/libAACenc/src/aacenc_tns.cpp new file mode 100644 index 0000000..3436150 --- /dev/null +++ b/fdk-aac/libAACenc/src/aacenc_tns.cpp @@ -0,0 +1,1210 @@ +/* ----------------------------------------------------------------------------- +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): Alex Groeschel, Tobias Chalupka + + Description: Temporal noise shaping + +*******************************************************************************/ + +#include "aacenc_tns.h" +#include "psy_const.h" +#include "psy_configuration.h" +#include "tns_func.h" +#include "aacEnc_rom.h" +#include "aacenc_tns.h" +#include "FDK_lpc.h" + +#define FILTER_DIRECTION 0 /* 0 = up, 1 = down */ + +static const FIXP_DBL acfWindowLong[12 + 3 + 1] = { + 0x7fffffff, 0x7fb80000, 0x7ee00000, 0x7d780000, 0x7b800000, 0x78f80000, + 0x75e00000, 0x72380000, 0x6e000000, 0x69380000, 0x63e00000, 0x5df80000, + 0x57800000, 0x50780000, 0x48e00000, 0x40b80000}; + +static const FIXP_DBL acfWindowShort[4 + 3 + 1] = { + 0x7fffffff, 0x7e000000, 0x78000000, 0x6e000000, + 0x60000000, 0x4e000000, 0x38000000, 0x1e000000}; + +typedef struct { + INT bitRateFrom[2]; /* noneSbr=0, useSbr=1 */ + INT bitRateTo[2]; /* noneSbr=0, useSbr=1 */ + TNS_PARAMETER_TABULATED paramTab[2]; /* mono=0, stereo=1 */ + +} TNS_INFO_TAB; + +#define TNS_TIMERES_SCALE (1) +#define FL2_TIMERES_FIX(a) (FL2FXCONST_DBL(a / (float)(1 << TNS_TIMERES_SCALE))) + +static const TNS_INFO_TAB tnsInfoTab[] = { + {{16000, 13500}, + {32000, 28000}, + {{{1, 1}, + {1437, 1500}, + {1400, 600}, + {12, 12}, + {FILTER_DIRECTION, FILTER_DIRECTION}, + {3, 1}, + {FL2_TIMERES_FIX(0.4f), FL2_TIMERES_FIX(1.2f)}, + 1}, + {{1, 1}, + {1437, 1500}, + {1400, 600}, + {12, 12}, + {FILTER_DIRECTION, FILTER_DIRECTION}, + {3, 1}, + {FL2_TIMERES_FIX(0.4f), FL2_TIMERES_FIX(1.2f)}, + 1}}}, + {{32001, 28001}, + {60000, 52000}, + {{{1, 1}, + {1437, 1500}, + {1400, 600}, + {12, 10}, + {FILTER_DIRECTION, FILTER_DIRECTION}, + {3, 1}, + {FL2_TIMERES_FIX(0.4f), FL2_TIMERES_FIX(1.0f)}, + 1}, + {{1, 1}, + {1437, 1500}, + {1400, 600}, + {12, 10}, + {FILTER_DIRECTION, FILTER_DIRECTION}, + {3, 1}, + {FL2_TIMERES_FIX(0.4f), FL2_TIMERES_FIX(1.0f)}, + 1}}}, + {{60001, 52001}, + {384000, 384000}, + {{{1, 1}, + {1437, 1500}, + {1400, 600}, + {12, 8}, + {FILTER_DIRECTION, FILTER_DIRECTION}, + {3, 1}, + {FL2_TIMERES_FIX(0.4f), FL2_TIMERES_FIX(1.0f)}, + 1}, + {{1, 1}, + {1437, 1500}, + {1400, 600}, + {12, 8}, + {FILTER_DIRECTION, FILTER_DIRECTION}, + {3, 1}, + {FL2_TIMERES_FIX(0.4f), FL2_TIMERES_FIX(1.0f)}, + 1}}}}; + +typedef struct { + INT samplingRate; + SCHAR maxBands[2]; /* long=0; short=1 */ + +} TNS_MAX_TAB_ENTRY; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab1024[] = { + {96000, {31, 9}}, {88200, {31, 9}}, {64000, {34, 10}}, {48000, {40, 14}}, + {44100, {42, 14}}, {32000, {51, 14}}, {24000, {46, 14}}, {22050, {46, 14}}, + {16000, {42, 14}}, {12000, {42, 14}}, {11025, {42, 14}}, {8000, {39, 14}}}; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab960[] = +{ + { 96000, { 31, 9}}, + { 88200, { 31, 9}}, + { 64000, { 34, 10}}, + { 48000, { 49, 14}}, + { 44100, { 49, 14}}, + { 32000, { 49, 14}}, + { 24000, { 46, 15}}, + { 22050, { 46, 14}}, + { 16000, { 46, 15}}, + { 12000, { 42, 15}}, + { 11025, { 42, 15}}, + { 8000, { 40, 15}} +}; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab120[] = { + {48000, {12, -1}}, /* 48000 */ + {44100, {12, -1}}, /* 44100 */ + {32000, {15, -1}}, /* 32000 */ + {24000, {15, -1}}, /* 24000 */ + {22050, {15, -1}} /* 22050 */ +}; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab128[] = { + {48000, {12, -1}}, /* 48000 */ + {44100, {12, -1}}, /* 44100 */ + {32000, {15, -1}}, /* 32000 */ + {24000, {15, -1}}, /* 24000 */ + {22050, {15, -1}} /* 22050 */ +}; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab240[] = { + {96000, {22, -1}}, /* 96000 */ + {48000, {22, -1}}, /* 48000 */ + {44100, {22, -1}}, /* 44100 */ + {32000, {21, -1}}, /* 32000 */ + {24000, {21, -1}}, /* 24000 */ + {22050, {21, -1}} /* 22050 */ +}; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab256[] = { + {96000, {25, -1}}, /* 96000 */ + {48000, {25, -1}}, /* 48000 */ + {44100, {25, -1}}, /* 44100 */ + {32000, {24, -1}}, /* 32000 */ + {24000, {24, -1}}, /* 24000 */ + {22050, {24, -1}} /* 22050 */ +}; +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab480[] = {{48000, {31, -1}}, + {44100, {32, -1}}, + {32000, {37, -1}}, + {24000, {30, -1}}, + {22050, {30, -1}}}; + +static const TNS_MAX_TAB_ENTRY tnsMaxBandsTab512[] = {{48000, {31, -1}}, + {44100, {32, -1}}, + {32000, {37, -1}}, + {24000, {31, -1}}, + {22050, {31, -1}}}; + +static void FDKaacEnc_Parcor2Index(const FIXP_LPC *parcor, INT *RESTRICT index, + const INT order, const INT bitsPerCoeff); + +static void FDKaacEnc_Index2Parcor(const INT *index, FIXP_LPC *RESTRICT parcor, + const INT order, const INT bitsPerCoeff); + +static void FDKaacEnc_CalcGaussWindow(FIXP_DBL *win, const int winSize, + const INT samplingRate, + const INT transformResolution, + const FIXP_DBL timeResolution, + const INT timeResolution_e); + +static const TNS_PARAMETER_TABULATED *FDKaacEnc_GetTnsParam(const INT bitRate, + const INT channels, + const INT sbrLd) { + int i; + const TNS_PARAMETER_TABULATED *tnsConfigTab = NULL; + + for (i = 0; i < (int)(sizeof(tnsInfoTab) / sizeof(TNS_INFO_TAB)); i++) { + if ((bitRate >= tnsInfoTab[i].bitRateFrom[sbrLd ? 1 : 0]) && + bitRate <= tnsInfoTab[i].bitRateTo[sbrLd ? 1 : 0]) { + tnsConfigTab = &tnsInfoTab[i].paramTab[(channels == 1) ? 0 : 1]; + } + } + + return tnsConfigTab; +} + +static INT getTnsMaxBands(const INT sampleRate, const INT granuleLength, + const INT isShortBlock) { + int i; + INT numBands = -1; + const TNS_MAX_TAB_ENTRY *pMaxBandsTab = NULL; + int maxBandsTabSize = 0; + + switch (granuleLength) { + case 960: + pMaxBandsTab = tnsMaxBandsTab960; + maxBandsTabSize = sizeof(tnsMaxBandsTab960) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 1024: + pMaxBandsTab = tnsMaxBandsTab1024; + maxBandsTabSize = sizeof(tnsMaxBandsTab1024) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 120: + pMaxBandsTab = tnsMaxBandsTab120; + maxBandsTabSize = sizeof(tnsMaxBandsTab120) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 128: + pMaxBandsTab = tnsMaxBandsTab128; + maxBandsTabSize = sizeof(tnsMaxBandsTab128) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 240: + pMaxBandsTab = tnsMaxBandsTab240; + maxBandsTabSize = sizeof(tnsMaxBandsTab240) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 256: + pMaxBandsTab = tnsMaxBandsTab256; + maxBandsTabSize = sizeof(tnsMaxBandsTab256) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 480: + pMaxBandsTab = tnsMaxBandsTab480; + maxBandsTabSize = sizeof(tnsMaxBandsTab480) / sizeof(TNS_MAX_TAB_ENTRY); + break; + case 512: + pMaxBandsTab = tnsMaxBandsTab512; + maxBandsTabSize = sizeof(tnsMaxBandsTab512) / sizeof(TNS_MAX_TAB_ENTRY); + break; + default: + numBands = -1; + } + + if (pMaxBandsTab != NULL) { + for (i = 0; i < maxBandsTabSize; i++) { + numBands = pMaxBandsTab[i].maxBands[(!isShortBlock) ? 0 : 1]; + if (sampleRate >= pMaxBandsTab[i].samplingRate) { + break; + } + } + } + + return numBands; +} + +/***************************************************************************/ +/*! + \brief FDKaacEnc_FreqToBandWidthRounding + + Returns index of nearest band border + + \param frequency + \param sampling frequency + \param total number of bands + \param pointer to table of band borders + + \return band border +****************************************************************************/ + +INT FDKaacEnc_FreqToBandWidthRounding(const INT freq, const INT fs, + const INT numOfBands, + const INT *bandStartOffset) { + INT lineNumber, band; + + /* assert(freq >= 0); */ + lineNumber = (freq * bandStartOffset[numOfBands] * 4 / fs + 1) / 2; + + /* freq > fs/2 */ + if (lineNumber >= bandStartOffset[numOfBands]) return numOfBands; + + /* find band the line number lies in */ + for (band = 0; band < numOfBands; band++) { + if (bandStartOffset[band + 1] > lineNumber) break; + } + + /* round to nearest band border */ + if (lineNumber - bandStartOffset[band] > + bandStartOffset[band + 1] - lineNumber) { + band++; + } + + return (band); +} + +/***************************************************************************** + + functionname: FDKaacEnc_InitTnsConfiguration + description: fill TNS_CONFIG structure with sensible content + returns: + input: bitrate, samplerate, number of channels, + blocktype (long or short), + TNS Config struct (modified), + psy config struct, + tns active flag + output: + +*****************************************************************************/ +AAC_ENCODER_ERROR FDKaacEnc_InitTnsConfiguration( + INT bitRate, INT sampleRate, INT channels, INT blockType, INT granuleLength, + INT isLowDelay, INT ldSbrPresent, TNS_CONFIG *tC, PSY_CONFIGURATION *pC, + INT active, INT useTnsPeak) { + int i; + // float acfTimeRes = (blockType == SHORT_WINDOW) ? 0.125f : 0.046875f; + + if (channels <= 0) return (AAC_ENCODER_ERROR)1; + + tC->isLowDelay = isLowDelay; + + /* initialize TNS filter flag, order, and coefficient resolution (in bits per + * coeff) */ + tC->tnsActive = (active) ? TRUE : FALSE; + tC->maxOrder = (blockType == SHORT_WINDOW) ? 5 : 12; /* maximum: 7, 20 */ + if (bitRate < 16000) tC->maxOrder -= 2; + tC->coefRes = (blockType == SHORT_WINDOW) ? 3 : 4; + + /* LPC stop line: highest MDCT line to be coded, but do not go beyond + * TNS_MAX_BANDS! */ + tC->lpcStopBand = getTnsMaxBands(sampleRate, granuleLength, + (blockType == SHORT_WINDOW) ? 1 : 0); + + if (tC->lpcStopBand < 0) { + return (AAC_ENCODER_ERROR)1; + } + + tC->lpcStopBand = fMin(tC->lpcStopBand, pC->sfbActive); + tC->lpcStopLine = pC->sfbOffset[tC->lpcStopBand]; + + switch (granuleLength) { + case 960: + case 1024: + /* TNS start line: skip lower MDCT lines to prevent artifacts due to + * filter mismatch */ + if (blockType == SHORT_WINDOW) { + tC->lpcStartBand[LOFILT] = 0; + } else { + tC->lpcStartBand[LOFILT] = + (sampleRate < 9391) ? 2 : ((sampleRate < 18783) ? 4 : 8); + } + tC->lpcStartLine[LOFILT] = pC->sfbOffset[tC->lpcStartBand[LOFILT]]; + + i = tC->lpcStopBand; + while (pC->sfbOffset[i] > + (tC->lpcStartLine[LOFILT] + + (tC->lpcStopLine - tC->lpcStartLine[LOFILT]) / 4)) + i--; + tC->lpcStartBand[HIFILT] = i; + tC->lpcStartLine[HIFILT] = pC->sfbOffset[i]; + + tC->confTab.threshOn[HIFILT] = 1437; + tC->confTab.threshOn[LOFILT] = 1500; + + tC->confTab.tnsLimitOrder[HIFILT] = tC->maxOrder; + tC->confTab.tnsLimitOrder[LOFILT] = fMax(0, tC->maxOrder - 7); + + tC->confTab.tnsFilterDirection[HIFILT] = FILTER_DIRECTION; + tC->confTab.tnsFilterDirection[LOFILT] = FILTER_DIRECTION; + + tC->confTab.acfSplit[HIFILT] = + -1; /* signal Merged4to2QuartersAutoCorrelation in + FDKaacEnc_MergedAutoCorrelation*/ + tC->confTab.acfSplit[LOFILT] = + -1; /* signal Merged4to2QuartersAutoCorrelation in + FDKaacEnc_MergedAutoCorrelation */ + + tC->confTab.filterEnabled[HIFILT] = 1; + tC->confTab.filterEnabled[LOFILT] = 1; + tC->confTab.seperateFiltersAllowed = 1; + + /* compute autocorrelation window based on maximum filter order for given + * block type */ + /* for (i = 0; i <= tC->maxOrder + 3; i++) { + float acfWinTemp = acfTimeRes * i; + acfWindow[i] = FL2FXCONST_DBL(1.0f - acfWinTemp * acfWinTemp); + } + */ + if (blockType == SHORT_WINDOW) { + FDKmemcpy(tC->acfWindow[HIFILT], acfWindowShort, + fMin((LONG)sizeof(acfWindowShort), + (LONG)sizeof(tC->acfWindow[HIFILT]))); + FDKmemcpy(tC->acfWindow[LOFILT], acfWindowShort, + fMin((LONG)sizeof(acfWindowShort), + (LONG)sizeof(tC->acfWindow[HIFILT]))); + } else { + FDKmemcpy(tC->acfWindow[HIFILT], acfWindowLong, + fMin((LONG)sizeof(acfWindowLong), + (LONG)sizeof(tC->acfWindow[HIFILT]))); + FDKmemcpy(tC->acfWindow[LOFILT], acfWindowLong, + fMin((LONG)sizeof(acfWindowLong), + (LONG)sizeof(tC->acfWindow[HIFILT]))); + } + break; + case 480: + case 512: { + const TNS_PARAMETER_TABULATED *pCfg = + FDKaacEnc_GetTnsParam(bitRate, channels, ldSbrPresent); + if (pCfg != NULL) { + FDKmemcpy(&(tC->confTab), pCfg, sizeof(tC->confTab)); + + tC->lpcStartBand[HIFILT] = FDKaacEnc_FreqToBandWidthRounding( + pCfg->filterStartFreq[HIFILT], sampleRate, pC->sfbCnt, + pC->sfbOffset); + tC->lpcStartLine[HIFILT] = pC->sfbOffset[tC->lpcStartBand[HIFILT]]; + tC->lpcStartBand[LOFILT] = FDKaacEnc_FreqToBandWidthRounding( + pCfg->filterStartFreq[LOFILT], sampleRate, pC->sfbCnt, + pC->sfbOffset); + tC->lpcStartLine[LOFILT] = pC->sfbOffset[tC->lpcStartBand[LOFILT]]; + + FDKaacEnc_CalcGaussWindow( + tC->acfWindow[HIFILT], tC->maxOrder + 1, sampleRate, granuleLength, + pCfg->tnsTimeResolution[HIFILT], TNS_TIMERES_SCALE); + FDKaacEnc_CalcGaussWindow( + tC->acfWindow[LOFILT], tC->maxOrder + 1, sampleRate, granuleLength, + pCfg->tnsTimeResolution[LOFILT], TNS_TIMERES_SCALE); + } else { + tC->tnsActive = + FALSE; /* no configuration available, disable tns tool */ + } + } break; + default: + tC->tnsActive = FALSE; /* no configuration available, disable tns tool */ + } + + return AAC_ENC_OK; +} + +/***************************************************************************/ +/*! + \brief FDKaacEnc_ScaleUpSpectrum + + Scales up spectrum lines in a given frequency section + + \param scaled spectrum + \param original spectrum + \param frequency line to start scaling + \param frequency line to enc scaling + + \return scale factor + +****************************************************************************/ +static inline INT FDKaacEnc_ScaleUpSpectrum(FIXP_DBL *dest, const FIXP_DBL *src, + const INT startLine, + const INT stopLine) { + INT i, scale; + + FIXP_DBL maxVal = FL2FXCONST_DBL(0.f); + + /* Get highest value in given spectrum */ + for (i = startLine; i < stopLine; i++) { + maxVal = fixMax(maxVal, fixp_abs(src[i])); + } + scale = CountLeadingBits(maxVal); + + /* Scale spectrum according to highest value */ + for (i = startLine; i < stopLine; i++) { + dest[i] = src[i] << scale; + } + + return scale; +} + +/***************************************************************************/ +/*! + \brief FDKaacEnc_CalcAutoCorrValue + + Calculate autocorellation value for one lag + + \param pointer to spectrum + \param start line + \param stop line + \param lag to be calculated + \param scaling of the lag + +****************************************************************************/ +static inline FIXP_DBL FDKaacEnc_CalcAutoCorrValue(const FIXP_DBL *spectrum, + const INT startLine, + const INT stopLine, + const INT lag, + const INT scale) { + int i; + FIXP_DBL result = FL2FXCONST_DBL(0.f); + + /* This versions allows to save memory accesses, when computing pow2 */ + /* It is of interest for ARM, XTENSA without parallel memory access */ + if (lag == 0) { + for (i = startLine; i < stopLine; i++) { + result += (fPow2(spectrum[i]) >> scale); + } + } else { + for (i = startLine; i < (stopLine - lag); i++) { + result += (fMult(spectrum[i], spectrum[i + lag]) >> scale); + } + } + + return result; +} + +/***************************************************************************/ +/*! + \brief FDKaacEnc_AutoCorrNormFac + + Autocorrelation function for 1st and 2nd half of the spectrum + + \param pointer to spectrum + \param pointer to autocorrelation window + \param filter start line + +****************************************************************************/ +static inline FIXP_DBL FDKaacEnc_AutoCorrNormFac(const FIXP_DBL value, + const INT scale, INT *sc) { +#define HLM_MIN_NRG 0.0000000037252902984619140625f /* 2^-28 */ +#define MAX_INV_NRGFAC (1.f / HLM_MIN_NRG) + + FIXP_DBL retValue; + FIXP_DBL A, B; + + if (scale >= 0) { + A = value; + B = FL2FXCONST_DBL(HLM_MIN_NRG) >> fixMin(DFRACT_BITS - 1, scale); + } else { + A = value >> fixMin(DFRACT_BITS - 1, (-scale)); + B = FL2FXCONST_DBL(HLM_MIN_NRG); + } + + if (A > B) { + int shift = 0; + FIXP_DBL tmp = invSqrtNorm2(value, &shift); + + retValue = fMult(tmp, tmp); + *sc += (2 * shift); + } else { + /* MAX_INV_NRGFAC*FDKpow(2,-28) = 1/2^-28 * 2^-28 = 1.0 */ + retValue = + /*FL2FXCONST_DBL(MAX_INV_NRGFAC*FDKpow(2,-28))*/ (FIXP_DBL)MAXVAL_DBL; + *sc += scale + 28; + } + + return retValue; +} + +static void FDKaacEnc_MergedAutoCorrelation( + const FIXP_DBL *spectrum, const INT isLowDelay, + const FIXP_DBL acfWindow[MAX_NUM_OF_FILTERS][TNS_MAX_ORDER + 3 + 1], + const INT lpcStartLine[MAX_NUM_OF_FILTERS], const INT lpcStopLine, + const INT maxOrder, const INT acfSplit[MAX_NUM_OF_FILTERS], FIXP_DBL *_rxx1, + FIXP_DBL *_rxx2) { + int i, idx0, idx1, idx2, idx3, idx4, lag; + FIXP_DBL rxx1_0, rxx2_0, rxx3_0, rxx4_0; + + /* buffer for temporal spectrum */ + C_ALLOC_SCRATCH_START(pSpectrum, FIXP_DBL, (1024)) + + /* MDCT line indices separating the 1st, 2nd, 3rd, and 4th analysis quarters + */ + if ((acfSplit[LOFILT] == -1) || (acfSplit[HIFILT] == -1)) { + /* autocorrelation function for 1st, 2nd, 3rd, and 4th quarter of the + * spectrum */ + idx0 = lpcStartLine[LOFILT]; + i = lpcStopLine - lpcStartLine[LOFILT]; + idx1 = idx0 + i / 4; + idx2 = idx0 + i / 2; + idx3 = idx0 + i * 3 / 4; + idx4 = lpcStopLine; + } else { + FDK_ASSERT(acfSplit[LOFILT] == 1); + FDK_ASSERT(acfSplit[HIFILT] == 3); + i = (lpcStopLine - lpcStartLine[HIFILT]) / 3; + idx0 = lpcStartLine[LOFILT]; + idx1 = lpcStartLine[HIFILT]; + idx2 = idx1 + i; + idx3 = idx2 + i; + idx4 = lpcStopLine; + } + + /* copy spectrum to temporal buffer and scale up as much as possible */ + INT sc1 = FDKaacEnc_ScaleUpSpectrum(pSpectrum, spectrum, idx0, idx1); + INT sc2 = FDKaacEnc_ScaleUpSpectrum(pSpectrum, spectrum, idx1, idx2); + INT sc3 = FDKaacEnc_ScaleUpSpectrum(pSpectrum, spectrum, idx2, idx3); + INT sc4 = FDKaacEnc_ScaleUpSpectrum(pSpectrum, spectrum, idx3, idx4); + + /* get scaling values for summation */ + INT nsc1, nsc2, nsc3, nsc4; + for (nsc1 = 1; (1 << nsc1) < (idx1 - idx0); nsc1++) + ; + for (nsc2 = 1; (1 << nsc2) < (idx2 - idx1); nsc2++) + ; + for (nsc3 = 1; (1 << nsc3) < (idx3 - idx2); nsc3++) + ; + for (nsc4 = 1; (1 << nsc4) < (idx4 - idx3); nsc4++) + ; + + /* compute autocorrelation value at lag zero, i. e. energy, for each quarter + */ + rxx1_0 = FDKaacEnc_CalcAutoCorrValue(pSpectrum, idx0, idx1, 0, nsc1); + rxx2_0 = FDKaacEnc_CalcAutoCorrValue(pSpectrum, idx1, idx2, 0, nsc2); + rxx3_0 = FDKaacEnc_CalcAutoCorrValue(pSpectrum, idx2, idx3, 0, nsc3); + rxx4_0 = FDKaacEnc_CalcAutoCorrValue(pSpectrum, idx3, idx4, 0, nsc4); + + /* compute energy normalization factors, i. e. 1/energy (saves some divisions) + */ + if (rxx1_0 != FL2FXCONST_DBL(0.f)) { + INT sc_fac1 = -1; + FIXP_DBL fac1 = + FDKaacEnc_AutoCorrNormFac(rxx1_0, ((-2 * sc1) + nsc1), &sc_fac1); + _rxx1[0] = scaleValue(fMult(rxx1_0, fac1), sc_fac1); + + if (isLowDelay) { + for (lag = 1; lag <= maxOrder; lag++) { + /* compute energy-normalized and windowed autocorrelation values at this + * lag */ + FIXP_DBL x1 = + FDKaacEnc_CalcAutoCorrValue(pSpectrum, idx0, idx1, lag, nsc1); + _rxx1[lag] = + fMult(scaleValue(fMult(x1, fac1), sc_fac1), acfWindow[LOFILT][lag]); + } + } else { + for (lag = 1; lag <= maxOrder; lag++) { + if ((3 * lag) <= maxOrder + 3) { + FIXP_DBL x1 = + FDKaacEnc_CalcAutoCorrValue(pSpectrum, idx0, idx1, lag, nsc1); + _rxx1[lag] = fMult(scaleValue(fMult(x1, fac1), sc_fac1), + acfWindow[LOFILT][3 * lag]); + } + } + } + } + + /* auto corr over upper 3/4 of spectrum */ + if (!((rxx2_0 == FL2FXCONST_DBL(0.f)) && (rxx3_0 == FL2FXCONST_DBL(0.f)) && + (rxx4_0 == FL2FXCONST_DBL(0.f)))) { + FIXP_DBL fac2, fac3, fac4; + fac2 = fac3 = fac4 = FL2FXCONST_DBL(0.f); + INT sc_fac2, sc_fac3, sc_fac4; + sc_fac2 = sc_fac3 = sc_fac4 = 0; + + if (rxx2_0 != FL2FXCONST_DBL(0.f)) { + fac2 = FDKaacEnc_AutoCorrNormFac(rxx2_0, ((-2 * sc2) + nsc2), &sc_fac2); + sc_fac2 -= 2; + } + if (rxx3_0 != FL2FXCONST_DBL(0.f)) { + fac3 = FDKaacEnc_AutoCorrNormFac(rxx3_0, ((-2 * sc3) + nsc3), &sc_fac3); + sc_fac3 -= 2; + } + if (rxx4_0 != FL2FXCONST_DBL(0.f)) { + fac4 = FDKaacEnc_AutoCorrNormFac(rxx4_0, ((-2 * sc4) + nsc4), &sc_fac4); + sc_fac4 -= 2; + } + + _rxx2[0] = scaleValue(fMult(rxx2_0, fac2), sc_fac2) + + scaleValue(fMult(rxx3_0, fac3), sc_fac3) + + scaleValue(fMult(rxx4_0, fac4), sc_fac4); + + for (lag = 1; lag <= maxOrder; lag++) { + /* merge quarters 2, 3, 4 into one autocorrelation; quarter 1 stays + * separate */ + FIXP_DBL x2 = scaleValue(fMult(FDKaacEnc_CalcAutoCorrValue( + pSpectrum, idx1, idx2, lag, nsc2), + fac2), + sc_fac2) + + scaleValue(fMult(FDKaacEnc_CalcAutoCorrValue( + pSpectrum, idx2, idx3, lag, nsc3), + fac3), + sc_fac3) + + scaleValue(fMult(FDKaacEnc_CalcAutoCorrValue( + pSpectrum, idx3, idx4, lag, nsc4), + fac4), + sc_fac4); + + _rxx2[lag] = fMult(x2, acfWindow[HIFILT][lag]); + } + } + + C_ALLOC_SCRATCH_END(pSpectrum, FIXP_DBL, (1024)) +} + +/***************************************************************************** + functionname: FDKaacEnc_TnsDetect + description: do decision, if TNS shall be used or not + returns: + input: tns data structure (modified), + tns config structure, + scalefactor size and table, + spectrum, + subblock num, blocktype, + sfb-wise energy. + +*****************************************************************************/ +INT FDKaacEnc_TnsDetect(TNS_DATA *tnsData, const TNS_CONFIG *tC, + TNS_INFO *tnsInfo, INT sfbCnt, const FIXP_DBL *spectrum, + INT subBlockNumber, INT blockType) { + /* autocorrelation function for 1st, 2nd, 3rd, and 4th quarter of the + * spectrum. */ + FIXP_DBL rxx1[TNS_MAX_ORDER + 1]; /* higher part */ + FIXP_DBL rxx2[TNS_MAX_ORDER + 1]; /* lower part */ + FIXP_LPC parcor_tmp[TNS_MAX_ORDER]; + + int i; + + FDKmemclear(rxx1, sizeof(rxx1)); + FDKmemclear(rxx2, sizeof(rxx2)); + + TNS_SUBBLOCK_INFO *tsbi = + (blockType == SHORT_WINDOW) + ? &tnsData->dataRaw.Short.subBlockInfo[subBlockNumber] + : &tnsData->dataRaw.Long.subBlockInfo; + + tnsData->filtersMerged = FALSE; + + tsbi->tnsActive[HIFILT] = FALSE; + tsbi->predictionGain[HIFILT] = 1000; + tsbi->tnsActive[LOFILT] = FALSE; + tsbi->predictionGain[LOFILT] = 1000; + + tnsInfo->numOfFilters[subBlockNumber] = 0; + tnsInfo->coefRes[subBlockNumber] = tC->coefRes; + for (i = 0; i < tC->maxOrder; i++) { + tnsInfo->coef[subBlockNumber][HIFILT][i] = + tnsInfo->coef[subBlockNumber][LOFILT][i] = 0; + } + + tnsInfo->length[subBlockNumber][HIFILT] = + tnsInfo->length[subBlockNumber][LOFILT] = 0; + tnsInfo->order[subBlockNumber][HIFILT] = + tnsInfo->order[subBlockNumber][LOFILT] = 0; + + if ((tC->tnsActive) && (tC->maxOrder > 0)) { + int sumSqrCoef; + + FDKaacEnc_MergedAutoCorrelation( + spectrum, tC->isLowDelay, tC->acfWindow, tC->lpcStartLine, + tC->lpcStopLine, tC->maxOrder, tC->confTab.acfSplit, rxx1, rxx2); + + /* compute higher TNS filter coefficients in lattice form (ParCor) with + * LeRoux-Gueguen/Schur algorithm */ + { + FIXP_DBL predictionGain_m; + INT predictionGain_e; + + CLpc_AutoToParcor(rxx2, 0, parcor_tmp, tC->confTab.tnsLimitOrder[HIFILT], + &predictionGain_m, &predictionGain_e); + tsbi->predictionGain[HIFILT] = + (INT)fMultNorm(predictionGain_m, predictionGain_e, 1000, 31, 31); + } + + /* non-linear quantization of TNS lattice coefficients with given resolution + */ + FDKaacEnc_Parcor2Index(parcor_tmp, tnsInfo->coef[subBlockNumber][HIFILT], + tC->confTab.tnsLimitOrder[HIFILT], tC->coefRes); + + /* reduce filter order by truncating trailing zeros, compute sum(abs(coefs)) + */ + for (i = tC->confTab.tnsLimitOrder[HIFILT] - 1; i >= 0; i--) { + if (tnsInfo->coef[subBlockNumber][HIFILT][i] != 0) { + break; + } + } + + tnsInfo->order[subBlockNumber][HIFILT] = i + 1; + + sumSqrCoef = 0; + for (; i >= 0; i--) { + sumSqrCoef += tnsInfo->coef[subBlockNumber][HIFILT][i] * + tnsInfo->coef[subBlockNumber][HIFILT][i]; + } + + tnsInfo->direction[subBlockNumber][HIFILT] = + tC->confTab.tnsFilterDirection[HIFILT]; + tnsInfo->length[subBlockNumber][HIFILT] = sfbCnt - tC->lpcStartBand[HIFILT]; + + /* disable TNS if predictionGain is less than 3dB or sumSqrCoef is too small + */ + if ((tsbi->predictionGain[HIFILT] > tC->confTab.threshOn[HIFILT]) || + (sumSqrCoef > (tC->confTab.tnsLimitOrder[HIFILT] / 2 + 2))) { + tsbi->tnsActive[HIFILT] = TRUE; + tnsInfo->numOfFilters[subBlockNumber]++; + + /* compute second filter for lower quarter; only allowed for long windows! + */ + if ((blockType != SHORT_WINDOW) && (tC->confTab.filterEnabled[LOFILT]) && + (tC->confTab.seperateFiltersAllowed)) { + /* compute second filter for lower frequencies */ + + /* compute TNS filter in lattice (ParCor) form with LeRoux-Gueguen + * algorithm */ + INT predGain; + { + FIXP_DBL predictionGain_m; + INT predictionGain_e; + + CLpc_AutoToParcor(rxx1, 0, parcor_tmp, + tC->confTab.tnsLimitOrder[LOFILT], + &predictionGain_m, &predictionGain_e); + predGain = + (INT)fMultNorm(predictionGain_m, predictionGain_e, 1000, 31, 31); + } + + /* non-linear quantization of TNS lattice coefficients with given + * resolution */ + FDKaacEnc_Parcor2Index(parcor_tmp, + tnsInfo->coef[subBlockNumber][LOFILT], + tC->confTab.tnsLimitOrder[LOFILT], tC->coefRes); + + /* reduce filter order by truncating trailing zeros, compute + * sum(abs(coefs)) */ + for (i = tC->confTab.tnsLimitOrder[LOFILT] - 1; i >= 0; i--) { + if (tnsInfo->coef[subBlockNumber][LOFILT][i] != 0) { + break; + } + } + tnsInfo->order[subBlockNumber][LOFILT] = i + 1; + + sumSqrCoef = 0; + for (; i >= 0; i--) { + sumSqrCoef += tnsInfo->coef[subBlockNumber][LOFILT][i] * + tnsInfo->coef[subBlockNumber][LOFILT][i]; + } + + tnsInfo->direction[subBlockNumber][LOFILT] = + tC->confTab.tnsFilterDirection[LOFILT]; + tnsInfo->length[subBlockNumber][LOFILT] = + tC->lpcStartBand[HIFILT] - tC->lpcStartBand[LOFILT]; + + /* filter lower quarter if gain is high enough, but not if it's too high + */ + if (((predGain > tC->confTab.threshOn[LOFILT]) && + (predGain < (16000 * tC->confTab.tnsLimitOrder[LOFILT]))) || + ((sumSqrCoef > 9) && + (sumSqrCoef < 22 * tC->confTab.tnsLimitOrder[LOFILT]))) { + /* compare lower to upper filter; if they are very similar, merge them + */ + tsbi->tnsActive[LOFILT] = TRUE; + sumSqrCoef = 0; + for (i = 0; i < tC->confTab.tnsLimitOrder[LOFILT]; i++) { + sumSqrCoef += fAbs(tnsInfo->coef[subBlockNumber][HIFILT][i] - + tnsInfo->coef[subBlockNumber][LOFILT][i]); + } + if ((sumSqrCoef < 2) && + (tnsInfo->direction[subBlockNumber][LOFILT] == + tnsInfo->direction[subBlockNumber][HIFILT])) { + tnsData->filtersMerged = TRUE; + tnsInfo->length[subBlockNumber][HIFILT] = + sfbCnt - tC->lpcStartBand[LOFILT]; + for (; i < tnsInfo->order[subBlockNumber][HIFILT]; i++) { + if (fAbs(tnsInfo->coef[subBlockNumber][HIFILT][i]) > 1) { + break; + } + } + for (i--; i >= 0; i--) { + if (tnsInfo->coef[subBlockNumber][HIFILT][i] != 0) { + break; + } + } + if (i < tnsInfo->order[subBlockNumber][HIFILT]) { + tnsInfo->order[subBlockNumber][HIFILT] = i + 1; + } + } else { + tnsInfo->numOfFilters[subBlockNumber]++; + } + } /* filter lower part */ + tsbi->predictionGain[LOFILT] = predGain; + + } /* second filter allowed */ + } /* if predictionGain > 1437 ... */ + } /* maxOrder > 0 && tnsActive */ + + return 0; +} + +/***************************************************************************/ +/*! + \brief FDKaacLdEnc_TnsSync + + synchronize TNS parameters when TNS gain difference small (relative) + + \param pointer to TNS data structure (destination) + \param pointer to TNS data structure (source) + \param pointer to TNS config structure + \param number of sub-block + \param block type + + \return void +****************************************************************************/ +void FDKaacEnc_TnsSync(TNS_DATA *tnsDataDest, const TNS_DATA *tnsDataSrc, + TNS_INFO *tnsInfoDest, TNS_INFO *tnsInfoSrc, + const INT blockTypeDest, const INT blockTypeSrc, + const TNS_CONFIG *tC) { + int i, w, absDiff, nWindows; + TNS_SUBBLOCK_INFO *sbInfoDest; + const TNS_SUBBLOCK_INFO *sbInfoSrc; + + /* if one channel contains short blocks and the other not, do not synchronize + */ + if ((blockTypeSrc == SHORT_WINDOW && blockTypeDest != SHORT_WINDOW) || + (blockTypeDest == SHORT_WINDOW && blockTypeSrc != SHORT_WINDOW)) { + return; + } + + if (blockTypeDest != SHORT_WINDOW) { + sbInfoDest = &tnsDataDest->dataRaw.Long.subBlockInfo; + sbInfoSrc = &tnsDataSrc->dataRaw.Long.subBlockInfo; + nWindows = 1; + } else { + sbInfoDest = &tnsDataDest->dataRaw.Short.subBlockInfo[0]; + sbInfoSrc = &tnsDataSrc->dataRaw.Short.subBlockInfo[0]; + nWindows = 8; + } + + for (w = 0; w < nWindows; w++) { + const TNS_SUBBLOCK_INFO *pSbInfoSrcW = sbInfoSrc + w; + TNS_SUBBLOCK_INFO *pSbInfoDestW = sbInfoDest + w; + INT doSync = 1, absDiffSum = 0; + + /* if TNS is active in at least one channel, check if ParCor coefficients of + * higher filter are similar */ + if (pSbInfoDestW->tnsActive[HIFILT] || pSbInfoSrcW->tnsActive[HIFILT]) { + for (i = 0; i < tC->maxOrder; i++) { + absDiff = fAbs(tnsInfoDest->coef[w][HIFILT][i] - + tnsInfoSrc->coef[w][HIFILT][i]); + absDiffSum += absDiff; + /* if coefficients diverge too much between channels, do not synchronize + */ + if ((absDiff > 1) || (absDiffSum > 2)) { + doSync = 0; + break; + } + } + + if (doSync) { + /* if no significant difference was detected, synchronize coefficient + * sets */ + if (pSbInfoSrcW->tnsActive[HIFILT]) { + /* no dest filter, or more dest than source filters: use one dest + * filter */ + if ((!pSbInfoDestW->tnsActive[HIFILT]) || + ((pSbInfoDestW->tnsActive[HIFILT]) && + (tnsInfoDest->numOfFilters[w] > tnsInfoSrc->numOfFilters[w]))) { + pSbInfoDestW->tnsActive[HIFILT] = tnsInfoDest->numOfFilters[w] = 1; + } + tnsDataDest->filtersMerged = tnsDataSrc->filtersMerged; + tnsInfoDest->order[w][HIFILT] = tnsInfoSrc->order[w][HIFILT]; + tnsInfoDest->length[w][HIFILT] = tnsInfoSrc->length[w][HIFILT]; + tnsInfoDest->direction[w][HIFILT] = tnsInfoSrc->direction[w][HIFILT]; + tnsInfoDest->coefCompress[w][HIFILT] = + tnsInfoSrc->coefCompress[w][HIFILT]; + + for (i = 0; i < tC->maxOrder; i++) { + tnsInfoDest->coef[w][HIFILT][i] = tnsInfoSrc->coef[w][HIFILT][i]; + } + } else + pSbInfoDestW->tnsActive[HIFILT] = tnsInfoDest->numOfFilters[w] = 0; + } + } + } +} + +/***************************************************************************/ +/*! + \brief FDKaacEnc_TnsEncode + + perform TNS encoding + + \param pointer to TNS info structure + \param pointer to TNS data structure + \param number of sfbs + \param pointer to TNS config structure + \param low-pass line + \param pointer to spectrum + \param number of sub-block + \param block type + + \return ERROR STATUS +****************************************************************************/ +INT FDKaacEnc_TnsEncode(TNS_INFO *tnsInfo, TNS_DATA *tnsData, + const INT numOfSfb, const TNS_CONFIG *tC, + const INT lowPassLine, FIXP_DBL *spectrum, + const INT subBlockNumber, const INT blockType) { + INT i, startLine, stopLine; + + if (((blockType == SHORT_WINDOW) && + (!tnsData->dataRaw.Short.subBlockInfo[subBlockNumber] + .tnsActive[HIFILT])) || + ((blockType != SHORT_WINDOW) && + (!tnsData->dataRaw.Long.subBlockInfo.tnsActive[HIFILT]))) { + return 1; + } + + startLine = (tnsData->filtersMerged) ? tC->lpcStartLine[LOFILT] + : tC->lpcStartLine[HIFILT]; + stopLine = tC->lpcStopLine; + + for (i = 0; i < tnsInfo->numOfFilters[subBlockNumber]; i++) { + INT lpcGainFactor; + FIXP_LPC LpcCoeff[TNS_MAX_ORDER]; + FIXP_DBL workBuffer[TNS_MAX_ORDER]; + FIXP_LPC parcor_tmp[TNS_MAX_ORDER]; + + FDKaacEnc_Index2Parcor(tnsInfo->coef[subBlockNumber][i], parcor_tmp, + tnsInfo->order[subBlockNumber][i], tC->coefRes); + + lpcGainFactor = CLpc_ParcorToLpc( + parcor_tmp, LpcCoeff, tnsInfo->order[subBlockNumber][i], workBuffer); + + FDKmemclear(workBuffer, TNS_MAX_ORDER * sizeof(FIXP_DBL)); + CLpc_Analysis(&spectrum[startLine], stopLine - startLine, LpcCoeff, + lpcGainFactor, tnsInfo->order[subBlockNumber][i], workBuffer, + NULL); + + /* update for second filter */ + startLine = tC->lpcStartLine[LOFILT]; + stopLine = tC->lpcStartLine[HIFILT]; + } + + return (0); +} + +static void FDKaacEnc_CalcGaussWindow(FIXP_DBL *win, const int winSize, + const INT samplingRate, + const INT transformResolution, + const FIXP_DBL timeResolution, + const INT timeResolution_e) { +#define PI_E (2) +#define PI_M FL2FXCONST_DBL(3.1416f / (float)(1 << PI_E)) + +#define EULER_E (2) +#define EULER_M FL2FXCONST_DBL(2.7183 / (float)(1 << EULER_E)) + +#define COEFF_LOOP_SCALE (4) + + INT i, e1, e2, gaussExp_e; + FIXP_DBL gaussExp_m; + + /* calc. window exponent from time resolution: + * + * gaussExp = PI * samplingRate * 0.001f * timeResolution / + * transformResolution; gaussExp = -0.5f * gaussExp * gaussExp; + */ + gaussExp_m = fMultNorm( + timeResolution, + fMult(PI_M, + fDivNorm((FIXP_DBL)(samplingRate), + (FIXP_DBL)(LONG)(transformResolution * 1000.f), &e1)), + &e2); + gaussExp_m = -fPow2Div2(gaussExp_m); + gaussExp_e = 2 * (e1 + e2 + timeResolution_e + PI_E); + + FDK_ASSERT(winSize < (1 << COEFF_LOOP_SCALE)); + + /* calc. window coefficients + * win[i] = (float)exp( gaussExp * (i+0.5) * (i+0.5) ); + */ + for (i = 0; i < winSize; i++) { + win[i] = fPow( + EULER_M, EULER_E, + fMult(gaussExp_m, + fPow2((i * FL2FXCONST_DBL(1.f / (float)(1 << COEFF_LOOP_SCALE)) + + FL2FXCONST_DBL(.5f / (float)(1 << COEFF_LOOP_SCALE))))), + gaussExp_e + 2 * COEFF_LOOP_SCALE, &e1); + + win[i] = scaleValueSaturate(win[i], e1); + } +} + +static INT FDKaacEnc_Search3(FIXP_LPC parcor) { + INT i, index = 0; + + for (i = 0; i < 8; i++) { + if (parcor > FDKaacEnc_tnsCoeff3Borders[i]) index = i; + } + return (index - 4); +} + +static INT FDKaacEnc_Search4(FIXP_LPC parcor) { + INT i, index = 0; + + for (i = 0; i < 16; i++) { + if (parcor > FDKaacEnc_tnsCoeff4Borders[i]) index = i; + } + return (index - 8); +} + +/***************************************************************************** + + functionname: FDKaacEnc_Parcor2Index + +*****************************************************************************/ +static void FDKaacEnc_Parcor2Index(const FIXP_LPC *parcor, INT *RESTRICT index, + const INT order, const INT bitsPerCoeff) { + INT i; + for (i = 0; i < order; i++) { + if (bitsPerCoeff == 3) + index[i] = FDKaacEnc_Search3(parcor[i]); + else + index[i] = FDKaacEnc_Search4(parcor[i]); + } +} + +/***************************************************************************** + + functionname: FDKaacEnc_Index2Parcor + description: inverse quantization for reflection coefficients + returns: - + input: quantized values, ptr. to reflection coefficients, + no. of coefficients, resolution + output: reflection coefficients + +*****************************************************************************/ +static void FDKaacEnc_Index2Parcor(const INT *index, FIXP_LPC *RESTRICT parcor, + const INT order, const INT bitsPerCoeff) { + INT i; + for (i = 0; i < order; i++) + parcor[i] = bitsPerCoeff == 4 ? FDKaacEnc_tnsEncCoeff4[index[i] + 8] + : FDKaacEnc_tnsEncCoeff3[index[i] + 4]; +} |