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Diffstat (limited to 'libAACdec/src/aacdec_pns.cpp')
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diff --git a/libAACdec/src/aacdec_pns.cpp b/libAACdec/src/aacdec_pns.cpp new file mode 100644 index 0000000..a3f7a78 --- /dev/null +++ b/libAACdec/src/aacdec_pns.cpp @@ -0,0 +1,382 @@ + +/* ----------------------------------------------------------------------------------------------------------- +Software License for The Fraunhofer FDK AAC Codec Library for Android + +© Copyright 1995 - 2012 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) ; + } + } + } + } + } +} |