| |
| /* ----------------------------------------------------------------------------------------------------------- |
| 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 Decoder ************************** |
| |
| 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 |
| ) |
| { |
| /* 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 Initialize PNS data |
| |
| The function initializes the PNS data |
| */ |
| void CPns_InitPns( |
| CPnsData *pPnsData, |
| CPnsInterChannelData *pPnsInterChannelData, |
| INT* currentSeed, INT* randomSeed) |
| { |
| /* save pointer to inter channel data */ |
| pPnsData->pPnsInterChannelData = pPnsInterChannelData; |
| |
| /* 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 = (1664525L * randomState) + 1013904223L; // Numerical Recipes |
| 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 = group*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[pns_band], |
| pSpecScale[window], noise_e, outOfPhase) ; |
| } |
| } |
| } |
| } |
| } |
| } |