/* ----------------------------------------------------------------------------- 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 decoder library ****************************** Author(s): Description: *******************************************************************************/ /*! \file \brief rvlc concealment \author Josef Hoepfl */ #include "rvlcconceal.h" #include "block.h" #include "rvlc.h" /*--------------------------------------------------------------------------------------------- function: calcRefValFwd description: The function determines the scalefactor which is closed to the scalefactorband conceal_min. The same is done for intensity data and noise energies. ----------------------------------------------------------------------------------------------- output: - reference value scf - reference value internsity data - reference value noise energy ----------------------------------------------------------------------------------------------- return: - -------------------------------------------------------------------------------------------- */ static void calcRefValFwd(CErRvlcInfo *pRvlc, CAacDecoderChannelInfo *pAacDecoderChannelInfo, int *refIsFwd, int *refNrgFwd, int *refScfFwd) { int band, bnds, group, startBand; int idIs, idNrg, idScf; int conceal_min, conceal_group_min; int MaximumScaleFactorBands; if (GetWindowSequence(&pAacDecoderChannelInfo->icsInfo) == BLOCK_SHORT) MaximumScaleFactorBands = 16; else MaximumScaleFactorBands = 64; conceal_min = pRvlc->conceal_min % MaximumScaleFactorBands; conceal_group_min = pRvlc->conceal_min / MaximumScaleFactorBands; /* calculate first reference value for approach in forward direction */ idIs = idNrg = idScf = 1; /* set reference values */ *refIsFwd = -SF_OFFSET; *refNrgFwd = pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain - SF_OFFSET - 90 - 256; *refScfFwd = pAacDecoderChannelInfo->pDynData->RawDataInfo.GlobalGain - SF_OFFSET; startBand = conceal_min - 1; for (group = conceal_group_min; group >= 0; group--) { for (band = startBand; band >= 0; band--) { bnds = 16 * group + band; switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: break; case INTENSITY_HCB: case INTENSITY_HCB2: if (idIs) { *refIsFwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; idIs = 0; /* reference value has been set */ } break; case NOISE_HCB: if (idNrg) { *refNrgFwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; idNrg = 0; /* reference value has been set */ } break; default: if (idScf) { *refScfFwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; idScf = 0; /* reference value has been set */ } break; } } startBand = pRvlc->maxSfbTransmitted - 1; } } /*--------------------------------------------------------------------------------------------- function: calcRefValBwd description: The function determines the scalefactor which is closed to the scalefactorband conceal_max. The same is done for intensity data and noise energies. ----------------------------------------------------------------------------------------------- output: - reference value scf - reference value internsity data - reference value noise energy ----------------------------------------------------------------------------------------------- return: - -------------------------------------------------------------------------------------------- */ static void calcRefValBwd(CErRvlcInfo *pRvlc, CAacDecoderChannelInfo *pAacDecoderChannelInfo, int *refIsBwd, int *refNrgBwd, int *refScfBwd) { int band, bnds, group, startBand; int idIs, idNrg, idScf; int conceal_max, conceal_group_max; int MaximumScaleFactorBands; if (GetWindowSequence(&pAacDecoderChannelInfo->icsInfo) == BLOCK_SHORT) MaximumScaleFactorBands = 16; else MaximumScaleFactorBands = 64; conceal_max = pRvlc->conceal_max % MaximumScaleFactorBands; conceal_group_max = pRvlc->conceal_max / MaximumScaleFactorBands; /* calculate first reference value for approach in backward direction */ idIs = idNrg = idScf = 1; /* set reference values */ *refIsBwd = pRvlc->dpcm_is_last_position - SF_OFFSET; *refNrgBwd = pRvlc->rev_global_gain + pRvlc->dpcm_noise_last_position - SF_OFFSET - 90 - 256 + pRvlc->dpcm_noise_nrg; *refScfBwd = pRvlc->rev_global_gain - SF_OFFSET; startBand = conceal_max + 1; /* if needed, re-set reference values */ for (group = conceal_group_max; group < pRvlc->numWindowGroups; group++) { for (band = startBand; band < pRvlc->maxSfbTransmitted; band++) { bnds = 16 * group + band; switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: break; case INTENSITY_HCB: case INTENSITY_HCB2: if (idIs) { *refIsBwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; idIs = 0; /* reference value has been set */ } break; case NOISE_HCB: if (idNrg) { *refNrgBwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; idNrg = 0; /* reference value has been set */ } break; default: if (idScf) { *refScfBwd = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; idScf = 0; /* reference value has been set */ } break; } } startBand = 0; } } /*--------------------------------------------------------------------------------------------- function: BidirectionalEstimation_UseLowerScfOfCurrentFrame description: This approach by means of bidirectional estimation is generally performed when a single bit error has been detected, the bit error can be isolated between 'conceal_min' and 'conceal_max' and the 'sf_concealment' flag is not set. The sets of scalefactors decoded in forward and backward direction are compared with each other. The smaller scalefactor will be considered as the correct one respectively. The reconstruction of the scalefactors with this approach archieve good results in audio quality. The strategy must be applied to scalefactors, intensity data and noise energy seperately. ----------------------------------------------------------------------------------------------- output: Concealed scalefactor, noise energy and intensity data between conceal_min and conceal_max ----------------------------------------------------------------------------------------------- return: - -------------------------------------------------------------------------------------------- */ void BidirectionalEstimation_UseLowerScfOfCurrentFrame( CAacDecoderChannelInfo *pAacDecoderChannelInfo) { CErRvlcInfo *pRvlc = &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo; int band, bnds, startBand, endBand, group; int conceal_min, conceal_max; int conceal_group_min, conceal_group_max; int MaximumScaleFactorBands; if (GetWindowSequence(&pAacDecoderChannelInfo->icsInfo) == BLOCK_SHORT) { MaximumScaleFactorBands = 16; } else { MaximumScaleFactorBands = 64; } /* If an error was detected just in forward or backward direction, set the corresponding border for concealment to a appropriate scalefactor band. The border is set to first or last sfb respectively, because the error will possibly not follow directly after the corrupt bit but just after decoding some more (wrong) scalefactors. */ if (pRvlc->conceal_min == CONCEAL_MIN_INIT) pRvlc->conceal_min = 0; if (pRvlc->conceal_max == CONCEAL_MAX_INIT) pRvlc->conceal_max = (pRvlc->numWindowGroups - 1) * 16 + pRvlc->maxSfbTransmitted - 1; conceal_min = pRvlc->conceal_min % MaximumScaleFactorBands; conceal_group_min = pRvlc->conceal_min / MaximumScaleFactorBands; conceal_max = pRvlc->conceal_max % MaximumScaleFactorBands; conceal_group_max = pRvlc->conceal_max / MaximumScaleFactorBands; if (pRvlc->conceal_min == pRvlc->conceal_max) { int refIsFwd, refNrgFwd, refScfFwd; int refIsBwd, refNrgBwd, refScfBwd; bnds = pRvlc->conceal_min; calcRefValFwd(pRvlc, pAacDecoderChannelInfo, &refIsFwd, &refNrgFwd, &refScfFwd); calcRefValBwd(pRvlc, pAacDecoderChannelInfo, &refIsBwd, &refNrgBwd, &refScfBwd); switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: break; case INTENSITY_HCB: case INTENSITY_HCB2: if (refIsFwd < refIsBwd) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = refIsFwd; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = refIsBwd; break; case NOISE_HCB: if (refNrgFwd < refNrgBwd) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = refNrgFwd; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = refNrgBwd; break; default: if (refScfFwd < refScfBwd) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = refScfFwd; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = refScfBwd; break; } } else { pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfFwd[pRvlc->conceal_max] = pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[pRvlc->conceal_max]; pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[pRvlc->conceal_min] = pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfFwd[pRvlc->conceal_min]; /* consider the smaller of the forward and backward decoded value as the * correct one */ startBand = conceal_min; if (conceal_group_min == conceal_group_max) endBand = conceal_max; else endBand = pRvlc->maxSfbTransmitted - 1; for (group = conceal_group_min; group <= conceal_group_max; group++) { for (band = startBand; band <= endBand; band++) { bnds = 16 * group + band; if (pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds] < pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; } startBand = 0; if ((group + 1) == conceal_group_max) endBand = conceal_max; } } /* now copy all data to the output buffer which needs not to be concealed */ if (conceal_group_min == 0) endBand = conceal_min; else endBand = pRvlc->maxSfbTransmitted; for (group = 0; group <= conceal_group_min; group++) { for (band = 0; band < endBand; band++) { bnds = 16 * group + band; pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; } if ((group + 1) == conceal_group_min) endBand = conceal_min; } startBand = conceal_max + 1; for (group = conceal_group_max; group < pRvlc->numWindowGroups; group++) { for (band = startBand; band < pRvlc->maxSfbTransmitted; band++) { bnds = 16 * group + band; pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; } startBand = 0; } } /*--------------------------------------------------------------------------------------------- function: BidirectionalEstimation_UseScfOfPrevFrameAsReference description: This approach by means of bidirectional estimation is generally performed when a single bit error has been detected, the bit error can be isolated between 'conceal_min' and 'conceal_max', the 'sf_concealment' flag is set and the previous frame has the same block type as the current frame. The scalefactor decoded in forward and backward direction and the scalefactor of the previous frame are compared with each other. The smaller scalefactor will be considered as the correct one. At this the codebook of the previous and current frame must be of the same set (scf, nrg, is) in each scalefactorband. Otherwise the scalefactor of the previous frame is not considered in the minimum calculation. The reconstruction of the scalefactors with this approach archieve good results in audio quality. The strategy must be applied to scalefactors, intensity data and noise energy seperately. ----------------------------------------------------------------------------------------------- output: Concealed scalefactor, noise energy and intensity data between conceal_min and conceal_max ----------------------------------------------------------------------------------------------- return: - -------------------------------------------------------------------------------------------- */ void BidirectionalEstimation_UseScfOfPrevFrameAsReference( CAacDecoderChannelInfo *pAacDecoderChannelInfo, CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo) { CErRvlcInfo *pRvlc = &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo; int band, bnds, startBand, endBand, group; int conceal_min, conceal_max; int conceal_group_min, conceal_group_max; int MaximumScaleFactorBands; SHORT commonMin; if (GetWindowSequence(&pAacDecoderChannelInfo->icsInfo) == BLOCK_SHORT) { MaximumScaleFactorBands = 16; } else { MaximumScaleFactorBands = 64; } /* If an error was detected just in forward or backward direction, set the corresponding border for concealment to a appropriate scalefactor band. The border is set to first or last sfb respectively, because the error will possibly not follow directly after the corrupt bit but just after decoding some more (wrong) scalefactors. */ if (pRvlc->conceal_min == CONCEAL_MIN_INIT) pRvlc->conceal_min = 0; if (pRvlc->conceal_max == CONCEAL_MAX_INIT) pRvlc->conceal_max = (pRvlc->numWindowGroups - 1) * 16 + pRvlc->maxSfbTransmitted - 1; conceal_min = pRvlc->conceal_min % MaximumScaleFactorBands; conceal_group_min = pRvlc->conceal_min / MaximumScaleFactorBands; conceal_max = pRvlc->conceal_max % MaximumScaleFactorBands; conceal_group_max = pRvlc->conceal_max / MaximumScaleFactorBands; pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfFwd[pRvlc->conceal_max] = pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[pRvlc->conceal_max]; pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[pRvlc->conceal_min] = pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfFwd[pRvlc->conceal_min]; /* consider the smaller of the forward and backward decoded value as the * correct one */ startBand = conceal_min; if (conceal_group_min == conceal_group_max) endBand = conceal_max; else endBand = pRvlc->maxSfbTransmitted - 1; for (group = conceal_group_min; group <= conceal_group_max; group++) { for (band = startBand; band <= endBand; band++) { bnds = 16 * group + band; switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = 0; break; case INTENSITY_HCB: case INTENSITY_HCB2: if ((pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] == INTENSITY_HCB) || (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] == INTENSITY_HCB2)) { commonMin = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin(commonMin, pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousScaleFactor[bnds]); } else { pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); } break; case NOISE_HCB: if (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] == NOISE_HCB) { commonMin = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin(commonMin, pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousScaleFactor[bnds]); } else { pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); } break; default: if ((pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != ZERO_HCB) && (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != NOISE_HCB) && (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != INTENSITY_HCB) && (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != INTENSITY_HCB2)) { commonMin = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin(commonMin, pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousScaleFactor[bnds]); } else { pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); } break; } } startBand = 0; if ((group + 1) == conceal_group_max) endBand = conceal_max; } /* now copy all data to the output buffer which needs not to be concealed */ if (conceal_group_min == 0) endBand = conceal_min; else endBand = pRvlc->maxSfbTransmitted; for (group = 0; group <= conceal_group_min; group++) { for (band = 0; band < endBand; band++) { bnds = 16 * group + band; pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; } if ((group + 1) == conceal_group_min) endBand = conceal_min; } startBand = conceal_max + 1; for (group = conceal_group_max; group < pRvlc->numWindowGroups; group++) { for (band = startBand; band < pRvlc->maxSfbTransmitted; band++) { bnds = 16 * group + band; pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; } startBand = 0; } } /*--------------------------------------------------------------------------------------------- function: StatisticalEstimation description: This approach by means of statistical estimation is generally performed when both the start value and the end value are different and no further errors have been detected. Considering the forward and backward decoded scalefactors, the set with the lower scalefactors in sum will be considered as the correct one. The scalefactors are differentially encoded. Normally it would reach to compare one pair of the forward and backward decoded scalefactors to specify the lower set. But having detected no further errors does not necessarily mean the absence of errors. Therefore all scalefactors decoded in forward and backward direction are summed up seperately. The set with the lower sum will be used. The strategy must be applied to scalefactors, intensity data and noise energy seperately. ----------------------------------------------------------------------------------------------- output: Concealed scalefactor, noise energy and intensity data ----------------------------------------------------------------------------------------------- return: - -------------------------------------------------------------------------------------------- */ void StatisticalEstimation(CAacDecoderChannelInfo *pAacDecoderChannelInfo) { CErRvlcInfo *pRvlc = &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo; int band, bnds, group; int sumIsFwd, sumIsBwd; /* sum of intensity data forward/backward */ int sumNrgFwd, sumNrgBwd; /* sum of noise energy data forward/backward */ int sumScfFwd, sumScfBwd; /* sum of scalefactor data forward/backward */ int useIsFwd, useNrgFwd, useScfFwd; /* the flags signals the elements which are used for the final result */ sumIsFwd = sumIsBwd = sumNrgFwd = sumNrgBwd = sumScfFwd = sumScfBwd = 0; useIsFwd = useNrgFwd = useScfFwd = 0; /* calculate sum of each group (scf,nrg,is) of forward and backward direction */ for (group = 0; group < pRvlc->numWindowGroups; group++) { for (band = 0; band < pRvlc->maxSfbTransmitted; band++) { bnds = 16 * group + band; switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: break; case INTENSITY_HCB: case INTENSITY_HCB2: sumIsFwd += pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; sumIsBwd += pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; break; case NOISE_HCB: sumNrgFwd += pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; sumNrgBwd += pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; break; default: sumScfFwd += pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; sumScfBwd += pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; break; } } } /* find for each group (scf,nrg,is) the correct direction */ if (sumIsFwd < sumIsBwd) useIsFwd = 1; if (sumNrgFwd < sumNrgBwd) useNrgFwd = 1; if (sumScfFwd < sumScfBwd) useScfFwd = 1; /* conceal each group (scf,nrg,is) */ for (group = 0; group < pRvlc->numWindowGroups; group++) { for (band = 0; band < pRvlc->maxSfbTransmitted; band++) { bnds = 16 * group + band; switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: break; case INTENSITY_HCB: case INTENSITY_HCB2: if (useIsFwd) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; break; case NOISE_HCB: if (useNrgFwd) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; break; default: if (useScfFwd) pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds]; else pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfBwd[bnds]; break; } } } } /*--------------------------------------------------------------------------------------------- description: Approach by means of predictive interpolation This approach by means of predictive estimation is generally performed when the error cannot be isolated between 'conceal_min' and 'conceal_max', the 'sf_concealment' flag is set and the previous frame has the same block type as the current frame. Check for each scalefactorband if the same type of data (scalefactor, internsity data, noise energies) is transmitted. If so use the scalefactor (intensity data, noise energy) in the current frame. Otherwise set the scalefactor (intensity data, noise energy) for this scalefactorband to zero. ----------------------------------------------------------------------------------------------- output: Concealed scalefactor, noise energy and intensity data ----------------------------------------------------------------------------------------------- return: - -------------------------------------------------------------------------------------------- */ void PredictiveInterpolation( CAacDecoderChannelInfo *pAacDecoderChannelInfo, CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo) { CErRvlcInfo *pRvlc = &pAacDecoderChannelInfo->pComData->overlay.aac.erRvlcInfo; int band, bnds, group; SHORT commonMin; for (group = 0; group < pRvlc->numWindowGroups; group++) { for (band = 0; band < pRvlc->maxSfbTransmitted; band++) { bnds = 16 * group + band; switch (pAacDecoderChannelInfo->pDynData->aCodeBook[bnds]) { case ZERO_HCB: pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = 0; break; case INTENSITY_HCB: case INTENSITY_HCB2: if ((pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] == INTENSITY_HCB) || (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] == INTENSITY_HCB2)) { commonMin = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin(commonMin, pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousScaleFactor[bnds]); } else { pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = -110; } break; case NOISE_HCB: if (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] == NOISE_HCB) { commonMin = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin(commonMin, pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousScaleFactor[bnds]); } else { pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = -110; } break; default: if ((pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != ZERO_HCB) && (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != NOISE_HCB) && (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != INTENSITY_HCB) && (pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousCodebook[bnds] != INTENSITY_HCB2)) { commonMin = fMin( pAacDecoderChannelInfo->pComData->overlay.aac.aRvlcScfFwd[bnds], pAacDecoderChannelInfo->pComData->overlay.aac .aRvlcScfBwd[bnds]); pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = fMin(commonMin, pAacDecoderStaticChannelInfo->concealmentInfo .aRvlcPreviousScaleFactor[bnds]); } else { pAacDecoderChannelInfo->pDynData->aScaleFactor[bnds] = 0; } break; } } } }