| /* ----------------------------------------------------------------------------- |
| 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): Josef Hoepfl |
| |
| Description: perceptual noise substitution tool |
| |
| *******************************************************************************/ |
| |
| #include "aacdec_pns.h" |
| |
| #include "aac_ram.h" |
| #include "aac_rom.h" |
| #include "channelinfo.h" |
| #include "block.h" |
| #include "FDK_bitstream.h" |
| |
| #include "genericStds.h" |
| |
| #define NOISE_OFFSET 90 /* cf. ISO 14496-3 p. 175 */ |
| |
| /*! |
| \brief Reset InterChannel and PNS data |
| |
| The function resets the InterChannel and PNS data |
| */ |
| void CPns_ResetData(CPnsData *pPnsData, |
| CPnsInterChannelData *pPnsInterChannelData) { |
| FDK_ASSERT(pPnsData != NULL); |
| FDK_ASSERT(pPnsInterChannelData != NULL); |
| /* Assign pointer always, since pPnsData is not persistent data */ |
| pPnsData->pPnsInterChannelData = pPnsInterChannelData; |
| pPnsData->PnsActive = 0; |
| pPnsData->CurrentEnergy = 0; |
| |
| FDKmemclear(pPnsData->pnsUsed, (8 * 16) * sizeof(UCHAR)); |
| FDKmemclear(pPnsInterChannelData->correlated, (8 * 16) * sizeof(UCHAR)); |
| } |
| |
| /*! |
| \brief Update PNS noise generator state. |
| |
| The function sets the seed for PNS noise generation. |
| It can be used to link two or more channels in terms of PNS. |
| */ |
| void CPns_UpdateNoiseState(CPnsData *pPnsData, INT *currentSeed, |
| INT *randomSeed) { |
| /* use pointer because seed has to be |
| same, left and right channel ! */ |
| pPnsData->currentSeed = currentSeed; |
| pPnsData->randomSeed = randomSeed; |
| } |
| |
| /*! |
| \brief Indicates if PNS is used |
| |
| The function returns a value indicating whether PNS is used or not |
| acordding to the noise energy |
| |
| \return PNS used |
| */ |
| int CPns_IsPnsUsed(const CPnsData *pPnsData, const int group, const int band) { |
| unsigned pns_band = group * 16 + band; |
| |
| return pPnsData->pnsUsed[pns_band] & (UCHAR)1; |
| } |
| |
| /*! |
| \brief Set correlation |
| |
| The function activates the noise correlation between the channel pair |
| */ |
| void CPns_SetCorrelation(CPnsData *pPnsData, const int group, const int band, |
| const int outofphase) { |
| CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData; |
| unsigned pns_band = group * 16 + band; |
| |
| pInterChannelData->correlated[pns_band] = (outofphase) ? 3 : 1; |
| } |
| |
| /*! |
| \brief Indicates if correlation is used |
| |
| The function indicates if the noise correlation between the channel pair |
| is activated |
| |
| \return PNS is correlated |
| */ |
| static int CPns_IsCorrelated(const CPnsData *pPnsData, const int group, |
| const int band) { |
| CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData; |
| unsigned pns_band = group * 16 + band; |
| |
| return (pInterChannelData->correlated[pns_band] & 0x01) ? 1 : 0; |
| } |
| |
| /*! |
| \brief Indicates if correlated out of phase mode is used. |
| |
| The function indicates if the noise correlation between the channel pair |
| is activated in out-of-phase mode. |
| |
| \return PNS is out-of-phase |
| */ |
| static int CPns_IsOutOfPhase(const CPnsData *pPnsData, const int group, |
| const int band) { |
| CPnsInterChannelData *pInterChannelData = pPnsData->pPnsInterChannelData; |
| unsigned pns_band = group * 16 + band; |
| |
| return (pInterChannelData->correlated[pns_band] & 0x02) ? 1 : 0; |
| } |
| |
| /*! |
| \brief Read PNS information |
| |
| The function reads the PNS information from the bitstream |
| */ |
| void CPns_Read(CPnsData *pPnsData, HANDLE_FDK_BITSTREAM bs, |
| const CodeBookDescription *hcb, SHORT *pScaleFactor, |
| UCHAR global_gain, int band, int group /* = 0 */) { |
| int delta; |
| UINT pns_band = group * 16 + band; |
| |
| if (pPnsData->PnsActive) { |
| /* Next PNS band case */ |
| delta = CBlock_DecodeHuffmanWord(bs, hcb) - 60; |
| } else { |
| /* First PNS band case */ |
| int noiseStartValue = FDKreadBits(bs, 9); |
| |
| delta = noiseStartValue - 256; |
| pPnsData->PnsActive = 1; |
| pPnsData->CurrentEnergy = global_gain - NOISE_OFFSET; |
| } |
| |
| pPnsData->CurrentEnergy += delta; |
| pScaleFactor[pns_band] = pPnsData->CurrentEnergy; |
| |
| pPnsData->pnsUsed[pns_band] = 1; |
| } |
| |
| /** |
| * \brief Generate a vector of noise of given length. The noise values are |
| * scaled in order to yield a noise energy of 1.0 |
| * \param spec pointer to were the noise values will be written to. |
| * \param size amount of noise values to be generated. |
| * \param pRandomState pointer to the state of the random generator being used. |
| * \return exponent of generated noise vector. |
| */ |
| static int GenerateRandomVector(FIXP_DBL *RESTRICT spec, int size, |
| int *pRandomState) { |
| int i, invNrg_e = 0, nrg_e = 0; |
| FIXP_DBL invNrg_m, nrg_m = FL2FXCONST_DBL(0.0f); |
| FIXP_DBL *RESTRICT ptr = spec; |
| int randomState = *pRandomState; |
| |
| #define GEN_NOISE_NRG_SCALE 7 |
| |
| /* Generate noise and calculate energy. */ |
| for (i = 0; i < size; i++) { |
| randomState = |
| (((INT64)1664525 * randomState) + (INT64)1013904223) & 0xFFFFFFFF; |
| nrg_m = fPow2AddDiv2(nrg_m, (FIXP_DBL)randomState >> GEN_NOISE_NRG_SCALE); |
| *ptr++ = (FIXP_DBL)randomState; |
| } |
| nrg_e = GEN_NOISE_NRG_SCALE * 2 + 1; |
| |
| /* weight noise with = 1 / sqrt_nrg; */ |
| invNrg_m = invSqrtNorm2(nrg_m << 1, &invNrg_e); |
| invNrg_e += -((nrg_e - 1) >> 1); |
| |
| for (i = size; i--;) { |
| spec[i] = fMult(spec[i], invNrg_m); |
| } |
| |
| /* Store random state */ |
| *pRandomState = randomState; |
| |
| return invNrg_e; |
| } |
| |
| static void ScaleBand(FIXP_DBL *RESTRICT spec, int size, int scaleFactor, |
| int specScale, int noise_e, int out_of_phase) { |
| int i, shift, sfExponent; |
| FIXP_DBL sfMatissa; |
| |
| /* Get gain from scale factor value = 2^(scaleFactor * 0.25) */ |
| sfMatissa = MantissaTable[scaleFactor & 0x03][0]; |
| /* sfExponent = (scaleFactor >> 2) + ExponentTable[scaleFactor & 0x03][0]; */ |
| /* Note: ExponentTable[scaleFactor & 0x03][0] is always 1. */ |
| sfExponent = (scaleFactor >> 2) + 1; |
| |
| if (out_of_phase != 0) { |
| sfMatissa = -sfMatissa; |
| } |
| |
| /* +1 because of fMultDiv2 below. */ |
| shift = sfExponent - specScale + 1 + noise_e; |
| |
| /* Apply gain to noise values */ |
| if (shift >= 0) { |
| shift = fixMin(shift, DFRACT_BITS - 1); |
| for (i = size; i-- != 0;) { |
| spec[i] = fMultDiv2(spec[i], sfMatissa) << shift; |
| } |
| } else { |
| shift = fixMin(-shift, DFRACT_BITS - 1); |
| for (i = size; i-- != 0;) { |
| spec[i] = fMultDiv2(spec[i], sfMatissa) >> shift; |
| } |
| } |
| } |
| |
| /*! |
| \brief Apply PNS |
| |
| The function applies PNS (i.e. it generates noise) on the bands |
| flagged as noisy bands |
| |
| */ |
| void CPns_Apply(const CPnsData *pPnsData, const CIcsInfo *pIcsInfo, |
| SPECTRAL_PTR pSpectrum, const SHORT *pSpecScale, |
| const SHORT *pScaleFactor, |
| const SamplingRateInfo *pSamplingRateInfo, |
| const INT granuleLength, const int channel) { |
| if (pPnsData->PnsActive) { |
| const short *BandOffsets = |
| GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo); |
| |
| int ScaleFactorBandsTransmitted = GetScaleFactorBandsTransmitted(pIcsInfo); |
| |
| for (int window = 0, group = 0; group < GetWindowGroups(pIcsInfo); |
| group++) { |
| for (int groupwin = 0; groupwin < GetWindowGroupLength(pIcsInfo, group); |
| groupwin++, window++) { |
| FIXP_DBL *spectrum = SPEC(pSpectrum, window, granuleLength); |
| |
| for (int band = 0; band < ScaleFactorBandsTransmitted; band++) { |
| if (CPns_IsPnsUsed(pPnsData, group, band)) { |
| UINT pns_band = window * 16 + band; |
| |
| int bandWidth = BandOffsets[band + 1] - BandOffsets[band]; |
| int noise_e; |
| |
| FDK_ASSERT(bandWidth >= 0); |
| |
| if (channel > 0 && CPns_IsCorrelated(pPnsData, group, band)) { |
| noise_e = |
| GenerateRandomVector(spectrum + BandOffsets[band], bandWidth, |
| &pPnsData->randomSeed[pns_band]); |
| } else { |
| pPnsData->randomSeed[pns_band] = *pPnsData->currentSeed; |
| |
| noise_e = GenerateRandomVector(spectrum + BandOffsets[band], |
| bandWidth, pPnsData->currentSeed); |
| } |
| |
| int outOfPhase = CPns_IsOutOfPhase(pPnsData, group, band); |
| |
| ScaleBand(spectrum + BandOffsets[band], bandWidth, |
| pScaleFactor[group * 16 + band], pSpecScale[window], |
| noise_e, outOfPhase); |
| } |
| } |
| } |
| } |
| } |
| } |