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diff --git a/libSBRenc/src/resampler.cpp b/libSBRenc/src/resampler.cpp new file mode 100644 index 0000000..e8ab263 --- /dev/null +++ b/libSBRenc/src/resampler.cpp @@ -0,0 +1,507 @@ + +/* ----------------------------------------------------------------------------------------------------------- +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 +----------------------------------------------------------------------------------------------------------- */ + +/*! + \file + \brief FDK resampler tool box: + \author M. Werner +*/ + +#include "resampler.h" + +#include "genericStds.h" + + +/**************************************************************************/ +/* BIQUAD Filter Specifications */ +/**************************************************************************/ + +#define B1 0 +#define B2 1 +#define A1 2 +#define A2 3 + +#define BQC(x) FL2FXCONST_SGL(x/2) + + +struct FILTER_PARAM { + const FIXP_SGL *coeffa; /*! SOS matrix One row/section. Scaled using BQC(). Order of coefficients: B1,B2,A1,A2. B0=A0=1.0 */ + FIXP_DBL g; /*! overall gain */ + int Wc; /*! normalized passband bandwidth at input samplerate * 1000 */ + int noCoeffs; /*! number of filter coeffs */ + int delay; /*! delay in samples at input samplerate */ +}; + +#define BIQUAD_COEFSTEP 4 + +/** + *\brief Low Pass + Wc = 0,5, order 30, Stop Band -96dB. Wc criteria is "almost 0dB passband", not the usual -3db gain point. + [b,a]=cheby2(30,96,0.505) + [sos,g]=tf2sos(b,a) + bandwidth 0.48 + */ +static const FIXP_SGL sos48[] = { + BQC(1.98941075681938), BQC(0.999999996890811), BQC(0.863264527201963), BQC( 0.189553799960663), + BQC(1.90733804822445), BQC(1.00000001736189), BQC(0.836321575841691), BQC( 0.203505809266564), + BQC(1.75616665495325), BQC(0.999999946079721), BQC(0.784699225121588), BQC( 0.230471265506986), + BQC(1.55727745512726), BQC(1.00000011737815), BQC(0.712515423588351), BQC( 0.268752723900498), + BQC(1.33407591943643), BQC(0.999999795953228), BQC(0.625059117330989), BQC( 0.316194685288965), + BQC(1.10689898412458), BQC(1.00000035057114), BQC(0.52803514366398), BQC( 0.370517843224669), + BQC(0.89060371078454), BQC(0.999999343962822), BQC(0.426920462165257), BQC( 0.429608200207746), + BQC(0.694438261209433), BQC( 1.0000008629792), BQC(0.326530699561716), BQC( 0.491714450654174), + BQC(0.523237800935322), BQC(1.00000101349782), BQC(0.230829556274851), BQC( 0.555559034843281), + BQC(0.378631165929563), BQC(0.99998986482665), BQC(0.142906422036095), BQC( 0.620338874442411), + BQC(0.260786911308437), BQC(1.00003261460178), BQC(0.0651008576256505), BQC( 0.685759923926262), + BQC(0.168409429188098), BQC(0.999933049695828), BQC(-0.000790067789975562), BQC( 0.751905896602325), + BQC(0.100724533818628), BQC(1.00009472669872), BQC(-0.0533772830257041), BQC( 0.81930744384525), + BQC(0.0561434357867363), BQC(0.999911636304276), BQC(-0.0913550299236405), BQC( 0.88883625875915), + BQC(0.0341680678662057), BQC(1.00003667508676), BQC(-0.113405185536697), BQC( 0.961756638268446) +}; + +#ifdef RS_BIQUAD_SCATTERGAIN +static const FIXP_DBL g48 = FL2FXCONST_DBL(0.67436532061161992682404480717671 - 0.001); +#else +static const FIXP_DBL g48 = FL2FXCONST_DBL(0.002712866530047) - (FIXP_DBL)0x8000; +#endif + +static const struct FILTER_PARAM param_set48 = { + sos48, + g48, + 480, + 15, + 4 /* LF 2 */ +}; + +/** + *\brief Low Pass + Wc = 0,5, order 24, Stop Band -96dB. Wc criteria is "almost 0dB passband", not the usual -3db gain point. + [b,a]=cheby2(24,96,0.5) + [sos,g]=tf2sos(b,a) + bandwidth 0.45 + */ +static const FIXP_SGL sos45[] = { + BQC(1.982962601444), BQC(1.00000000007504), BQC(0.646113303737836), BQC( 0.10851149979981), + BQC(1.85334094281111), BQC(0.999999999677192), BQC(0.612073220102006), BQC( 0.130022141698044), + BQC(1.62541051415425), BQC(1.00000000080398), BQC(0.547879702855959), BQC( 0.171165825133192), + BQC(1.34554656923247), BQC(0.9999999980169), BQC(0.460373914508491), BQC( 0.228677463376354), + BQC(1.05656568503116), BQC(1.00000000569363), BQC(0.357891894038287), BQC( 0.298676843912185), + BQC(0.787967587877312), BQC(0.999999984415017), BQC(0.248826893211877), BQC( 0.377441803512978), + BQC(0.555480971120497), BQC(1.00000003583307), BQC(0.140614263345315), BQC( 0.461979302213679), + BQC(0.364986207070964), BQC(0.999999932084303), BQC(0.0392669446074516), BQC( 0.55033451180825), + BQC(0.216827267631558), BQC(1.00000010534682), BQC(-0.0506232228865103), BQC( 0.641691581560946), + BQC(0.108951672277119), BQC(0.999999871167516), BQC(-0.125584840183225), BQC( 0.736367748771803), + BQC(0.0387988607229035), BQC(1.00000011205574), BQC(-0.182814849097974), BQC( 0.835802108714964), + BQC(0.0042866175809225), BQC(0.999999954830813), BQC(-0.21965740617151), BQC( 0.942623047782363) +}; + +#ifdef RS_BIQUAD_SCATTERGAIN +static const FIXP_DBL g45 = FL2FXCONST_DBL(0.60547428891341319051142629706723 - 0.001); +#else +static const FIXP_DBL g45 = FL2FXCONST_DBL(0.00242743980909524) - (FIXP_DBL)0x8000; +#endif + +static const struct FILTER_PARAM param_set45 = { + sos45, + g45, + 450, + 12, + 4 /* LF 2 */ +}; + +/* + Created by Octave 2.1.73, Mon Oct 13 17:31:32 2008 CEST + Wc = 0,5, order 16, Stop Band -96dB damping. + [b,a]=cheby2(16,96,0.5) + [sos,g]=tf2sos(b,a) + bandwidth = 0.41 + */ + +static const FIXP_SGL sos41[] = +{ + BQC(1.96193625292), BQC(0.999999999999964), BQC(0.169266178786789), BQC(0.0128823300475907), + BQC(1.68913437662092), BQC(1.00000000000053), BQC(0.124751503206552), BQC(0.0537472273950989), + BQC(1.27274692366017), BQC(0.999999999995674), BQC(0.0433108625178357), BQC(0.131015753236317), + BQC(0.85214175088395), BQC(1.00000000001813), BQC(-0.0625658152550408), BQC(0.237763778993806), + BQC(0.503841579939009), BQC(0.999999999953223), BQC(-0.179176128722865), BQC(0.367475236424474), + BQC(0.249990711986162), BQC(1.00000000007952), BQC(-0.294425165824676), BQC(0.516594857170212), + BQC(0.087971668680286), BQC(0.999999999915528), BQC(-0.398956566777928), BQC(0.686417767801123), + BQC(0.00965373325350294), BQC(1.00000000003744), BQC(-0.48579173764817), BQC(0.884931534239068) +}; + +#ifdef RS_BIQUAD_SCATTERGAIN +static const FIXP_DBL g41 = FL2FXCONST_DBL(0.44578514476476679750811222123569); +#else +static const FIXP_DBL g41 = FL2FXCONST_DBL(0.00155956951169248); +#endif + +static const struct FILTER_PARAM param_set41 = { + sos41, + g41, + 410, + 8, + 5 /* LF 3 */ +}; + +/* + # Created by Octave 2.1.73, Mon Oct 13 17:55:33 2008 CEST + Wc = 0,5, order 12, Stop Band -96dB damping. + [b,a]=cheby2(12,96,0.5); + [sos,g]=tf2sos(b,a) +*/ +static const FIXP_SGL sos35[] = +{ + BQC(1.93299325235762), BQC(0.999999999999985), BQC(-0.140733187246596), BQC(0.0124139497836062), + BQC(1.4890416764109), BQC(1.00000000000011), BQC(-0.198215402588504), BQC(0.0746730616584138), + BQC(0.918450161309795), BQC(0.999999999999619), BQC(-0.30133912791941), BQC(0.192276468839529), + BQC(0.454877024246818), BQC(1.00000000000086), BQC(-0.432337328809815), BQC(0.356852933642815), + BQC(0.158017147118507), BQC(0.999999999998876), BQC(-0.574817494249777), BQC(0.566380436970833), + BQC(0.0171834649478749), BQC(1.00000000000055), BQC(-0.718581178041165), BQC(0.83367484487889) +}; + +#ifdef RS_BIQUAD_SCATTERGAIN +static const FIXP_DBL g35 = FL2FXCONST_DBL(0.34290853574973898694521267606792); +#else +static const FIXP_DBL g35 = FL2FXCONST_DBL(0.00162580994125131); +#endif + +static const struct FILTER_PARAM param_set35 = { + sos35, + g35, + 350, + 6, + 4 +}; + +/* + # Created by Octave 2.1.73, Mon Oct 13 18:15:38 2008 CEST + Wc = 0,5, order 8, Stop Band -96dB damping. + [b,a]=cheby2(8,96,0.5); + [sos,g]=tf2sos(b,a) +*/ +static const FIXP_SGL sos25[] = +{ + BQC(1.85334094301225), BQC(1.0), BQC(-0.702127214212663), BQC(0.132452403998767), + BQC(1.056565682167), BQC(0.999999999999997), BQC(-0.789503667880785), BQC(0.236328693569128), + BQC(0.364986307455489), BQC(0.999999999999996), BQC(-0.955191189843375), BQC(0.442966457936379), + BQC(0.0387985751642125), BQC(1.0), BQC(-1.19817786088084), BQC(0.770493895456328) +}; + +#ifdef RS_BIQUAD_SCATTERGAIN +static const FIXP_DBL g25 = FL2FXCONST_DBL(0.17533917408936346960080259950471); +#else +static const FIXP_DBL g25 = FL2FXCONST_DBL(0.000945182835294559); +#endif + +static const struct FILTER_PARAM param_set25 = { + sos25, + g25, + 250, + 4, + 5 +}; + +/* Must be sorted in descending order */ +static const struct FILTER_PARAM *const filter_paramSet[] = { + ¶m_set48, + ¶m_set45, + ¶m_set41, + ¶m_set35, + ¶m_set25 +}; + + +/**************************************************************************/ +/* Resampler Functions */ +/**************************************************************************/ + + +/*! + \brief Reset downsampler instance and clear delay lines + + \return success of operation +*/ + +INT FDKaacEnc_InitDownsampler(DOWNSAMPLER *DownSampler, /*!< pointer to downsampler instance */ + int Wc, /*!< normalized cutoff freq * 1000* */ + int ratio) /*!< downsampler ratio (only 2 supported at the momment) */ + +{ + UINT i; + const struct FILTER_PARAM *currentSet=NULL; + + FDK_ASSERT(ratio == 2); + FDKmemclear(DownSampler->downFilter.states, sizeof(DownSampler->downFilter.states)); + DownSampler->downFilter.ptr = 0; + + /* + find applicable parameter set + */ + currentSet = filter_paramSet[0]; + for(i=1;i<sizeof(filter_paramSet)/sizeof(struct FILTER_PARAM *);i++){ + if (filter_paramSet[i]->Wc <= Wc) { + break; + } + currentSet = filter_paramSet[i]; + } + + DownSampler->downFilter.coeffa = currentSet->coeffa; + + + DownSampler->downFilter.gain = currentSet->g; + FDK_ASSERT(currentSet->noCoeffs <= MAXNR_SECTIONS*2); + + DownSampler->downFilter.noCoeffs = currentSet->noCoeffs; + DownSampler->delay = currentSet->delay; + DownSampler->downFilter.Wc = currentSet->Wc; + + DownSampler->ratio = ratio; + DownSampler->pending = ratio-1; + return(1); +} + + +/*! + \brief faster simple folding operation + Filter: + H(z) = A(z)/B(z) + with + A(z) = a[0]*z^0 + a[1]*z^1 + a[2]*z^2 ... a[n]*z^n + + \return filtered value +*/ + +static inline INT_PCM AdvanceFilter(LP_FILTER *downFilter, /*!< pointer to iir filter instance */ + INT_PCM *pInput, /*!< input of filter */ + int downRatio, + int inStride) +{ + INT_PCM output; + int i, n; + + +#ifdef RS_BIQUAD_SCATTERGAIN +#define BIQUAD_SCALE 3 +#else +#define BIQUAD_SCALE 12 +#endif + + FIXP_DBL y = FL2FXCONST_DBL(0.0f); + FIXP_DBL input; + + for (n=0; n<downRatio; n++) + { + FIXP_BQS (*states)[2] = downFilter->states; + const FIXP_SGL *coeff = downFilter->coeffa; + int s1,s2; + + s1 = downFilter->ptr; + s2 = s1 ^ 1; + +#if (SAMPLE_BITS == 16) + input = ((FIXP_DBL)pInput[n*inStride]) << (DFRACT_BITS-SAMPLE_BITS-BIQUAD_SCALE); +#elif (SAMPLE_BITS == 32) + input = pInput[n*inStride] >> BIQUAD_SCALE; +#else +#error NOT IMPLEMENTED +#endif + +#ifndef RS_BIQUAD_SCATTERGAIN /* Merged Direct form I */ + + FIXP_BQS state1, state2, state1b, state2b; + + state1 = states[0][s1]; + state2 = states[0][s2]; + + /* Loop over sections */ + for (i=0; i<downFilter->noCoeffs; i++) + { + FIXP_DBL state0; + + /* Load merged states (from next section) */ + state1b = states[i+1][s1]; + state2b = states[i+1][s2]; + + state0 = input + fMult(state1, coeff[B1]) + fMult(state2, coeff[B2]); + y = state0 - fMult(state1b, coeff[A1]) - fMult(state2b, coeff[A2]); + + /* Store new feed forward merge state */ + states[i+1][s2] = y<<1; + /* Store new feed backward state */ + states[i][s2] = input<<1; + + /* Feedback output to next section. */ + input = y; + + /* Transfer merged states */ + state1 = state1b; + state2 = state2b; + + /* Step to next coef set */ + coeff += BIQUAD_COEFSTEP; + } + downFilter->ptr ^= 1; + } + /* Apply global gain */ + y = fMult(y, downFilter->gain); + +#else /* Direct form II */ + + /* Loop over sections */ + for (i=0; i<downFilter->noCoeffs; i++) + { + FIXP_BQS state1, state2; + FIXP_DBL state0; + + /* Load states */ + state1 = states[i][s1]; + state2 = states[i][s2]; + + state0 = input - fMult(state1, coeff[A1]) - fMult(state2, coeff[A2]); + y = state0 + fMult(state1, coeff[B1]) + fMult(state2, coeff[B2]); + /* Apply scattered gain */ + y = fMult(y, downFilter->gain); + + /* Store new state in normalized form */ +#ifdef RS_BIQUAD_STATES16 + /* Do not saturate any state value ! The result would be unacceptable. Rounding makes SNR around 10dB better. */ + states[i][s2] = (FIXP_BQS)(LONG)((state0 + (FIXP_DBL)(1<<(DFRACT_BITS-FRACT_BITS-2))) >> (DFRACT_BITS-FRACT_BITS-1)); +#else + states[i][s2] = state0<<1; +#endif + + /* Feedback output to next section. */ + input=y; + + /* Step to next coef set */ + coeff += BIQUAD_COEFSTEP; + } + downFilter->ptr ^= 1; + } + +#endif + + /* Apply final gain/scaling to output */ +#if (SAMPLE_BITS == 16) + output = (INT_PCM) SATURATE_RIGHT_SHIFT(y+(FIXP_DBL)(1<<(DFRACT_BITS-SAMPLE_BITS-BIQUAD_SCALE-1)), DFRACT_BITS-SAMPLE_BITS-BIQUAD_SCALE, SAMPLE_BITS); + //output = (INT_PCM) SATURATE_RIGHT_SHIFT(y, DFRACT_BITS-SAMPLE_BITS-BIQUAD_SCALE, SAMPLE_BITS); +#else + output = SATURATE_LEFT_SHIFT(y, BIQUAD_SCALE, SAMPLE_BITS); +#endif + + + return output; +} + + + + +/*! + \brief FDKaacEnc_Downsample numInSamples of type INT_PCM + Returns number of output samples in numOutSamples + + \return success of operation +*/ + +INT FDKaacEnc_Downsample(DOWNSAMPLER *DownSampler, /*!< pointer to downsampler instance */ + INT_PCM *inSamples, /*!< pointer to input samples */ + INT numInSamples, /*!< number of input samples */ + INT inStride, /*!< increment of input samples */ + INT_PCM *outSamples, /*!< pointer to output samples */ + INT *numOutSamples, /*!< pointer tp number of output samples */ + INT outStride /*!< increment of output samples */ + ) +{ + INT i; + *numOutSamples=0; + + for(i=0; i<numInSamples; i+=DownSampler->ratio) + { + *outSamples = AdvanceFilter(&(DownSampler->downFilter), &inSamples[i*inStride], DownSampler->ratio, inStride); + outSamples += outStride; + } + *numOutSamples = numInSamples/DownSampler->ratio; + + return 0; +} + |