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Any reproduction or distribution of this software and/or program, or any portion of it, may result in severe civil and criminal penalties, and will be prosecuted to the maximum extent possible under law. $Id$ *******************************************************************************/ /*! \file \brief FDK resampler tool box:$Revision: 11752 $ \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;iWc <= 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; nstates; 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; inoCoeffs; 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; inoCoeffs; 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; iratio) { *outSamples = AdvanceFilter(&(DownSampler->downFilter), &inSamples[i*inStride], DownSampler->ratio, inStride); outSamples += outStride; } *numOutSamples = numInSamples/DownSampler->ratio; return 0; }