| |
| /* ----------------------------------------------------------------------------------------------------------- |
| 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; |
| } |
| |
