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Diffstat (limited to 'libFDK/src/FDK_hybrid.cpp')
| -rw-r--r-- | libFDK/src/FDK_hybrid.cpp | 766 |
1 files changed, 766 insertions, 0 deletions
diff --git a/libFDK/src/FDK_hybrid.cpp b/libFDK/src/FDK_hybrid.cpp new file mode 100644 index 0000000..d66e534 --- /dev/null +++ b/libFDK/src/FDK_hybrid.cpp @@ -0,0 +1,766 @@ +/*************************** Fraunhofer IIS FDK Tools ********************** + + (C) Copyright Fraunhofer IIS (2011) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + $Id$ + Author(s): Markus Lohwasser + Description: FDK Tools Hybrid Filterbank + + This software and/or program is protected by copyright law and international + treaties. 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. + +******************************************************************************/ + +#include "FDK_hybrid.h" + + +#include "fft.h" + +/*--------------- defines -----------------------------*/ +#define FFT_IDX_R(a) (2*a) +#define FFT_IDX_I(a) (2*a+1) + +#define HYB_COEF8_0 ( 0.00746082949812f ) +#define HYB_COEF8_1 ( 0.02270420949825f ) +#define HYB_COEF8_2 ( 0.04546865930473f ) +#define HYB_COEF8_3 ( 0.07266113929591f ) +#define HYB_COEF8_4 ( 0.09885108575264f ) +#define HYB_COEF8_5 ( 0.11793710567217f ) +#define HYB_COEF8_6 ( 0.12500000000000f ) +#define HYB_COEF8_7 ( HYB_COEF8_5 ) +#define HYB_COEF8_8 ( HYB_COEF8_4 ) +#define HYB_COEF8_9 ( HYB_COEF8_3 ) +#define HYB_COEF8_10 ( HYB_COEF8_2 ) +#define HYB_COEF8_11 ( HYB_COEF8_1 ) +#define HYB_COEF8_12 ( HYB_COEF8_0 ) + + +/*--------------- structure definitions ---------------*/ + +#if defined(ARCH_PREFER_MULT_32x16) + #define FIXP_HTB FIXP_SGL /* SGL data type. */ + #define FIXP_HTP FIXP_SPK /* Packed SGL data type. */ + #define HTC(a) (FX_DBL2FXCONST_SGL(a)) /* Cast to SGL */ + #define FL2FXCONST_HTB FL2FXCONST_SGL +#else + #define FIXP_HTB FIXP_DBL /* SGL data type. */ + #define FIXP_HTP FIXP_DPK /* Packed DBL data type. */ + #define HTC(a) ((FIXP_DBL)(LONG)(a)) /* Cast to DBL */ + #define FL2FXCONST_HTB FL2FXCONST_DBL +#endif + +#define HTCP(real,imag) { { HTC(real), HTC(imag) } } /* How to arrange the packed values. */ + + +struct FDK_HYBRID_SETUP +{ + UCHAR nrQmfBands; /*!< Number of QMF bands to be converted to hybrid. */ + UCHAR nHybBands[3]; /*!< Number of Hybrid bands generated by nrQmfBands. */ + SCHAR kHybrid[3]; /*!< Filter configuration of each QMF band. */ + UCHAR protoLen; /*!< Prototype filter length. */ + UCHAR filterDelay; /*!< Delay caused by hybrid filter. */ + const INT *pReadIdxTable; /*!< Helper table to access input data ringbuffer. */ + +}; + +/*--------------- constants ---------------------------*/ +static const INT ringbuffIdxTab[2*13] = { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 }; + +static const FDK_HYBRID_SETUP setup_3_16 = { 3, { 8, 4, 4}, { 8, 4, 4}, 13, (13-1)/2, ringbuffIdxTab}; +static const FDK_HYBRID_SETUP setup_3_12 = { 3, { 8, 2, 2}, { 8, 2, 2}, 13, (13-1)/2, ringbuffIdxTab}; +static const FDK_HYBRID_SETUP setup_3_10 = { 3, { 6, 2, 2}, { -8, -2, 2}, 13, (13-1)/2, ringbuffIdxTab}; + + +static const FIXP_HTP HybFilterCoef8[] = { + HTCP(0x10000000, 0x00000000), HTCP(0x0df26407, 0xfa391882), HTCP(0xff532109, 0x00acdef7), HTCP(0x08f26d36, 0xf70d92ca), + HTCP(0xfee34b5f, 0x02af570f), HTCP(0x038f276e, 0xf7684793), HTCP(0x00000000, 0x05d1eac2), HTCP(0x00000000, 0x05d1eac2), + HTCP(0x038f276e, 0x0897b86d), HTCP(0xfee34b5f, 0xfd50a8f1), HTCP(0x08f26d36, 0x08f26d36), HTCP(0xff532109, 0xff532109), + HTCP(0x0df26407, 0x05c6e77e) +}; + +static const FIXP_HTB HybFilterCoef2[13] = { + FL2FXCONST_HTB( 0.00000000000000f), FL2FXCONST_HTB( 0.01899487526049f), FL2FXCONST_HTB( 0.00000000000000f), FL2FXCONST_HTB(-0.07293139167538f), FL2FXCONST_HTB( 0.00000000000000f), FL2FXCONST_HTB( 0.30596630545168f), + FL2FXCONST_HTB( 0.50000000000000f), FL2FXCONST_HTB( 0.30596630545168f), FL2FXCONST_HTB( 0.00000000000000f), FL2FXCONST_HTB(-0.07293139167538f), FL2FXCONST_HTB( 0.00000000000000f), FL2FXCONST_HTB( 0.01899487526049f), + FL2FXCONST_HTB( 0.00000000000000f) +}; + +static const FIXP_HTB HybFilterCoef4[13] = { + FL2FXCONST_HTB(-0.00305151927305f), FL2FXCONST_HTB(-0.00794862316203f), FL2FXCONST_HTB( 0.0f), FL2FXCONST_HTB( 0.04318924038756f), FL2FXCONST_HTB( 0.12542448210445f), FL2FXCONST_HTB( 0.21227807049160f), + FL2FXCONST_HTB( 0.25f), FL2FXCONST_HTB( 0.21227807049160f), FL2FXCONST_HTB( 0.12542448210445f), FL2FXCONST_HTB( 0.04318924038756f), FL2FXCONST_HTB( 0.0f), FL2FXCONST_HTB(-0.00794862316203f), + FL2FXCONST_HTB(-0.00305151927305f) +}; + +/*--------------- function declarations ---------------*/ +static INT kChannelFiltering( + const FIXP_DBL *const pQmfReal, + const FIXP_DBL *const pQmfImag, + const INT *const pReadIdx, + FIXP_DBL *const mHybridReal, + FIXP_DBL *const mHybridImag, + const SCHAR hybridConfig + ); + + +/*--------------- function definitions ----------------*/ + +INT FDKhybridAnalysisOpen( + HANDLE_FDK_ANA_HYB_FILTER hAnalysisHybFilter, + FIXP_DBL *const pLFmemory, + const UINT LFmemorySize, + FIXP_DBL *const pHFmemory, + const UINT HFmemorySize + ) +{ + INT err = 0; + + /* Save pointer to extern memory. */ + hAnalysisHybFilter->pLFmemory = pLFmemory; + hAnalysisHybFilter->LFmemorySize = LFmemorySize; + + hAnalysisHybFilter->pHFmemory = pHFmemory; + hAnalysisHybFilter->HFmemorySize = HFmemorySize; + + return err; +} + +INT FDKhybridAnalysisInit( + HANDLE_FDK_ANA_HYB_FILTER hAnalysisHybFilter, + const FDK_HYBRID_MODE mode, + const INT qmfBands, + const INT cplxBands, + const INT initStatesFlag + ) +{ + int k; + INT err = 0; + FIXP_DBL *pMem = NULL; + HANDLE_FDK_HYBRID_SETUP setup = NULL; + + switch (mode) { + case THREE_TO_TEN: setup = (HANDLE_FDK_HYBRID_SETUP)&setup_3_10; break; + case THREE_TO_TWELVE: setup = (HANDLE_FDK_HYBRID_SETUP)&setup_3_12; break; + case THREE_TO_SIXTEEN: setup = (HANDLE_FDK_HYBRID_SETUP)&setup_3_16; break; + default: err = -1; goto bail; + } + + /* Initialize handle. */ + hAnalysisHybFilter->pSetup = setup; + hAnalysisHybFilter->bufferLFpos = setup->protoLen-1; + hAnalysisHybFilter->bufferHFpos = 0; + hAnalysisHybFilter->nrBands = qmfBands; + hAnalysisHybFilter->cplxBands = cplxBands; + hAnalysisHybFilter->hfMode = 0; + + /* Check available memory. */ + if ( ((2*setup->nrQmfBands*setup->protoLen*sizeof(FIXP_DBL)) > hAnalysisHybFilter->LFmemorySize) + || ((setup->filterDelay*((qmfBands-setup->nrQmfBands)+(cplxBands-setup->nrQmfBands))*sizeof(FIXP_DBL)) > hAnalysisHybFilter->HFmemorySize) ) + { + err = -2; + goto bail; + } + + /* Distribut LF memory. */ + pMem = hAnalysisHybFilter->pLFmemory; + for (k=0; k<setup->nrQmfBands; k++) { + hAnalysisHybFilter->bufferLFReal[k] = pMem; pMem += setup->protoLen; + hAnalysisHybFilter->bufferLFImag[k] = pMem; pMem += setup->protoLen; + } + + /* Distribut HF memory. */ + pMem = hAnalysisHybFilter->pHFmemory; + for (k=0; k<setup->filterDelay; k++) { + hAnalysisHybFilter->bufferHFReal[k] = pMem; pMem += (qmfBands-setup->nrQmfBands); + hAnalysisHybFilter->bufferHFImag[k] = pMem; pMem += (cplxBands-setup->nrQmfBands); + } + + if (initStatesFlag) { + /* Clear LF buffer */ + for (k=0; k<setup->nrQmfBands; k++) { + FDKmemclear(hAnalysisHybFilter->bufferLFReal[k], setup->protoLen*sizeof(FIXP_DBL)); + FDKmemclear(hAnalysisHybFilter->bufferLFImag[k], setup->protoLen*sizeof(FIXP_DBL)); + } + + if (qmfBands > setup->nrQmfBands) { + /* Clear HF buffer */ + for (k=0; k<setup->filterDelay; k++) { + FDKmemclear(hAnalysisHybFilter->bufferHFReal[k], (qmfBands-setup->nrQmfBands)*sizeof(FIXP_DBL)); + FDKmemclear(hAnalysisHybFilter->bufferHFImag[k], (cplxBands-setup->nrQmfBands)*sizeof(FIXP_DBL)); + } + } + } + +bail: + return err; +} + +INT FDKhybridAnalysisScaleStates( + HANDLE_FDK_ANA_HYB_FILTER hAnalysisHybFilter, + const INT scalingValue + ) +{ + INT err = 0; + + if (hAnalysisHybFilter==NULL) { + err = 1; /* invalid handle */ + } + else { + int k; + HANDLE_FDK_HYBRID_SETUP setup = hAnalysisHybFilter->pSetup; + + /* Scale LF buffer */ + for (k=0; k<setup->nrQmfBands; k++) { + scaleValues(hAnalysisHybFilter->bufferLFReal[k], setup->protoLen, scalingValue); + scaleValues(hAnalysisHybFilter->bufferLFImag[k], setup->protoLen, scalingValue); + } + if (hAnalysisHybFilter->nrBands > setup->nrQmfBands) { + /* Scale HF buffer */ + for (k=0; k<setup->filterDelay; k++) { + scaleValues(hAnalysisHybFilter->bufferHFReal[k], (hAnalysisHybFilter->nrBands-setup->nrQmfBands), scalingValue); + scaleValues(hAnalysisHybFilter->bufferHFImag[k], (hAnalysisHybFilter->cplxBands-setup->nrQmfBands), scalingValue); + } + } + } + return err; +} + +INT FDKhybridAnalysisApply( + HANDLE_FDK_ANA_HYB_FILTER hAnalysisHybFilter, + const FIXP_DBL *const pQmfReal, + const FIXP_DBL *const pQmfImag, + FIXP_DBL *const pHybridReal, + FIXP_DBL *const pHybridImag) +{ + int k, hybOffset = 0; + INT err = 0; + const int nrQmfBandsLF = hAnalysisHybFilter->pSetup->nrQmfBands; /* number of QMF bands to be converted to hybrid */ + + const int writIndex = hAnalysisHybFilter->bufferLFpos; + int readIndex = hAnalysisHybFilter->bufferLFpos; + + if (++readIndex>=hAnalysisHybFilter->pSetup->protoLen) readIndex = 0; + const INT* pBufferLFreadIdx = &hAnalysisHybFilter->pSetup->pReadIdxTable[readIndex]; + + /* + * LF buffer. + */ + for (k=0; k<nrQmfBandsLF; k++) { + /* New input sample. */ + hAnalysisHybFilter->bufferLFReal[k][writIndex] = pQmfReal[k]; + hAnalysisHybFilter->bufferLFImag[k][writIndex] = pQmfImag[k]; + + /* Perform hybrid filtering. */ + kChannelFiltering( + hAnalysisHybFilter->bufferLFReal[k], + hAnalysisHybFilter->bufferLFImag[k], + pBufferLFreadIdx, + pHybridReal+hybOffset, + pHybridImag+hybOffset, + hAnalysisHybFilter->pSetup->kHybrid[k]); + + hybOffset += hAnalysisHybFilter->pSetup->nHybBands[k]; + } + + hAnalysisHybFilter->bufferLFpos = readIndex; /* Index where to write next input sample. */ + + if (hAnalysisHybFilter->nrBands > nrQmfBandsLF) { + /* + * HF buffer. + */ + if (hAnalysisHybFilter->hfMode!=0) { + /* HF delay compensation was applied outside. */ + FDKmemcpy(pHybridReal+hybOffset, &pQmfReal[nrQmfBandsLF], (hAnalysisHybFilter->nrBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + FDKmemcpy(pHybridImag+hybOffset, &pQmfImag[nrQmfBandsLF], (hAnalysisHybFilter->cplxBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + } + else { + /* HF delay compensation, filterlength/2. */ + FDKmemcpy(pHybridReal+hybOffset, hAnalysisHybFilter->bufferHFReal[hAnalysisHybFilter->bufferHFpos], (hAnalysisHybFilter->nrBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + FDKmemcpy(pHybridImag+hybOffset, hAnalysisHybFilter->bufferHFImag[hAnalysisHybFilter->bufferHFpos], (hAnalysisHybFilter->cplxBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + + FDKmemcpy(hAnalysisHybFilter->bufferHFReal[hAnalysisHybFilter->bufferHFpos], &pQmfReal[nrQmfBandsLF], (hAnalysisHybFilter->nrBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + FDKmemcpy(hAnalysisHybFilter->bufferHFImag[hAnalysisHybFilter->bufferHFpos], &pQmfImag[nrQmfBandsLF], (hAnalysisHybFilter->cplxBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + + if (++hAnalysisHybFilter->bufferHFpos>=hAnalysisHybFilter->pSetup->filterDelay) hAnalysisHybFilter->bufferHFpos = 0; + } + } /* process HF part*/ + + return err; +} + +INT FDKhybridAnalysisClose( + HANDLE_FDK_ANA_HYB_FILTER hAnalysisHybFilter + ) +{ + INT err = 0; + + if (hAnalysisHybFilter != NULL) { + hAnalysisHybFilter->pLFmemory = NULL; + hAnalysisHybFilter->pHFmemory = NULL; + hAnalysisHybFilter->LFmemorySize = 0; + hAnalysisHybFilter->HFmemorySize = 0; + } + + return err; +} + +INT FDKhybridSynthesisInit( + HANDLE_FDK_SYN_HYB_FILTER hSynthesisHybFilter, + const FDK_HYBRID_MODE mode, + const INT qmfBands, + const INT cplxBands + ) +{ + INT err = 0; + HANDLE_FDK_HYBRID_SETUP setup = NULL; + + switch (mode) { + case THREE_TO_TEN: setup = (HANDLE_FDK_HYBRID_SETUP)&setup_3_10; break; + case THREE_TO_TWELVE: setup = (HANDLE_FDK_HYBRID_SETUP)&setup_3_12; break; + case THREE_TO_SIXTEEN: setup = (HANDLE_FDK_HYBRID_SETUP)&setup_3_16; break; + default: err = -1; goto bail; + } + + hSynthesisHybFilter->pSetup = setup; + hSynthesisHybFilter->nrBands = qmfBands; + hSynthesisHybFilter->cplxBands = cplxBands; + +bail: + return err; +} + + +INT FDKhybridSynthesisApply( + HANDLE_FDK_SYN_HYB_FILTER hSynthesisHybFilter, + const FIXP_DBL *const pHybridReal, + const FIXP_DBL *const pHybridImag, + FIXP_DBL *const pQmfReal, + FIXP_DBL *const pQmfImag + ) +{ + int k, n, hybOffset=0; + INT err = 0; + const INT nrQmfBandsLF = hSynthesisHybFilter->pSetup->nrQmfBands; + + /* + * LF buffer. + */ + for (k=0; k<nrQmfBandsLF; k++) { + const int nHybBands = hSynthesisHybFilter->pSetup->nHybBands[k]; + + FIXP_DBL accu1 = FL2FXCONST_DBL(0.f); + FIXP_DBL accu2 = FL2FXCONST_DBL(0.f); + + /* Perform hybrid filtering. */ + for (n=0; n<nHybBands; n++) { + accu1 += pHybridReal[hybOffset+n]; + accu2 += pHybridImag[hybOffset+n]; + } + pQmfReal[k] = accu1; + pQmfImag[k] = accu2; + + hybOffset += nHybBands; + } + + if (hSynthesisHybFilter->nrBands > nrQmfBandsLF) { + /* + * HF buffer. + */ + FDKmemcpy(&pQmfReal[nrQmfBandsLF], &pHybridReal[hybOffset], (hSynthesisHybFilter->nrBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + FDKmemcpy(&pQmfImag[nrQmfBandsLF], &pHybridImag[hybOffset], (hSynthesisHybFilter->cplxBands-nrQmfBandsLF)*sizeof(FIXP_DBL)); + } + + return err; +} + +/*****************************************************************************/ +/* **** FILTERBANK **** */ + +/* + 2 channel filter + Filter Coefs: + 0.0, + 0.01899487526049, + 0.0, + -0.07293139167538, + 0.0, + 0.30596630545168, + 0.5, + 0.30596630545168, + 0.0, + -0.07293139167538, + 0.0, + 0.01899487526049, + 0.0 + + + Filter design: + h[q,n] = g[n] * cos(2pi/2 * q * (n-6) ); n = 0..12, q = 0,1; + + -> h[0,n] = g[n] * 1; + -> h[1,n] = g[n] * pow(-1,n); +*/ +static void dualChannelFiltering( + const FIXP_DBL *const pQmfReal, + const FIXP_DBL *const pQmfImag, + const INT *const pReadIdx, + FIXP_DBL *const mHybridReal, + FIXP_DBL *const mHybridImag, + const INT invert + ) +{ + const FIXP_HTB *p = HybFilterCoef2; + + FIXP_DBL r1, r6; + FIXP_DBL i1, i6; + + /* symmetric filter coefficients */ + r1 = fMultDiv2(p[1], pQmfReal[pReadIdx[1]]) + fMultDiv2(p[1], pQmfReal[pReadIdx[11]]) ; + i1 = fMultDiv2(p[1], pQmfImag[pReadIdx[1]]) + fMultDiv2(p[1], pQmfImag[pReadIdx[11]]) ; + r1 += fMultDiv2(p[3], pQmfReal[pReadIdx[3]]) + fMultDiv2(p[3], pQmfReal[pReadIdx[ 9]]) ; + i1 += fMultDiv2(p[3], pQmfImag[pReadIdx[3]]) + fMultDiv2(p[3], pQmfImag[pReadIdx[ 9]]) ; + r1 += fMultDiv2(p[5], pQmfReal[pReadIdx[5]]) + fMultDiv2(p[5], pQmfReal[pReadIdx[ 7]]) ; + i1 += fMultDiv2(p[5], pQmfImag[pReadIdx[5]]) + fMultDiv2(p[5], pQmfImag[pReadIdx[ 7]]) ; + r6 = fMultDiv2(p[6], pQmfReal[pReadIdx[6]]) ; + i6 = fMultDiv2(p[6], pQmfImag[pReadIdx[6]]) ; + + if (invert) { + mHybridReal[1] = (r1 + r6) << 1; + mHybridImag[1] = (i1 + i6) << 1; + + mHybridReal[0] = (r6 - r1) << 1; + mHybridImag[0] = (i6 - i1) << 1; + } + else { + mHybridReal[0] = (r1 + r6) << 1; + mHybridImag[0] = (i1 + i6) << 1; + + mHybridReal[1] = (r6 - r1) << 1; + mHybridImag[1] = (i6 - i1) << 1; + } +} + +static void fourChannelFiltering( + const FIXP_DBL *const pQmfReal, + const FIXP_DBL *const pQmfImag, + const INT *const pReadIdx, + FIXP_DBL *const mHybridReal, + FIXP_DBL *const mHybridImag, + const INT invert + ) +{ + const FIXP_HTB *p = HybFilterCoef4; + + FIXP_DBL fft[8]; + + static const FIXP_DBL cr[13] = { + FL2FXCONST_DBL( 0.f), FL2FXCONST_DBL(-0.70710678118655f), FL2FXCONST_DBL( -1.f), + FL2FXCONST_DBL(-0.70710678118655f), FL2FXCONST_DBL( 0.f), FL2FXCONST_DBL( 0.70710678118655f), + FL2FXCONST_DBL( 1.f), + FL2FXCONST_DBL( 0.70710678118655f), FL2FXCONST_DBL( 0.f), FL2FXCONST_DBL(-0.70710678118655f), + FL2FXCONST_DBL( -1.f), FL2FXCONST_DBL(-0.70710678118655f), FL2FXCONST_DBL( 0.f) + }; + static const FIXP_DBL ci[13] = { + FL2FXCONST_DBL( -1.f), FL2FXCONST_DBL(-0.70710678118655f), FL2FXCONST_DBL( 0.f), + FL2FXCONST_DBL( 0.70710678118655f), FL2FXCONST_DBL( 1.f), FL2FXCONST_DBL( 0.70710678118655f), + FL2FXCONST_DBL( 0.f), + FL2FXCONST_DBL(-0.70710678118655f), FL2FXCONST_DBL( -1.f), FL2FXCONST_DBL(-0.70710678118655f), + FL2FXCONST_DBL( 0.f), FL2FXCONST_DBL( 0.70710678118655f), FL2FXCONST_DBL( 1.f) + }; + + + /* FIR filter. */ + /* pre twiddeling with pre-twiddling coefficients c[n] */ + /* multiplication with filter coefficients p[n] */ + /* hint: (a + ib)*(c + id) = (a*c - b*d) + i(a*d + b*c) */ + /* write to fft coefficient n' */ + fft[FFT_IDX_R(0)] = ( fMult(p[10], ( fMultSub(fMultDiv2(cr[ 2], pQmfReal[pReadIdx[ 2]]), ci[ 2], pQmfImag[pReadIdx[ 2]]))) + + fMult(p[ 6], ( fMultSub(fMultDiv2(cr[ 6], pQmfReal[pReadIdx[ 6]]), ci[ 6], pQmfImag[pReadIdx[ 6]]))) + + fMult(p[ 2], ( fMultSub(fMultDiv2(cr[10], pQmfReal[pReadIdx[10]]), ci[10], pQmfImag[pReadIdx[10]]))) ); + fft[FFT_IDX_I(0)] = ( fMult(p[10], ( fMultAdd(fMultDiv2(ci[ 2], pQmfReal[pReadIdx[ 2]]), cr[ 2], pQmfImag[pReadIdx[ 2]]))) + + fMult(p[ 6], ( fMultAdd(fMultDiv2(ci[ 6], pQmfReal[pReadIdx[ 6]]), cr[ 6], pQmfImag[pReadIdx[ 6]]))) + + fMult(p[ 2], ( fMultAdd(fMultDiv2(ci[10], pQmfReal[pReadIdx[10]]), cr[10], pQmfImag[pReadIdx[10]]))) ); + + /* twiddle dee dum */ + fft[FFT_IDX_R(1)] = ( fMult(p[ 9], ( fMultSub(fMultDiv2(cr[ 3], pQmfReal[pReadIdx[ 3]]), ci[ 3], pQmfImag[pReadIdx[ 3]]))) + + fMult(p[ 5], ( fMultSub(fMultDiv2(cr[ 7], pQmfReal[pReadIdx[ 7]]), ci[ 7], pQmfImag[pReadIdx[ 7]]))) + + fMult(p[ 1], ( fMultSub(fMultDiv2(cr[11], pQmfReal[pReadIdx[11]]), ci[11], pQmfImag[pReadIdx[11]]))) ); + fft[FFT_IDX_I(1)] = ( fMult(p[ 9], ( fMultAdd(fMultDiv2(ci[ 3], pQmfReal[pReadIdx[ 3]]), cr[ 3], pQmfImag[pReadIdx[ 3]]))) + + fMult(p[ 5], ( fMultAdd(fMultDiv2(ci[ 7], pQmfReal[pReadIdx[ 7]]), cr[ 7], pQmfImag[pReadIdx[ 7]]))) + + fMult(p[ 1], ( fMultAdd(fMultDiv2(ci[11], pQmfReal[pReadIdx[11]]), cr[11], pQmfImag[pReadIdx[11]]))) ); + + /* twiddle dee dee */ + fft[FFT_IDX_R(2)] = ( fMult(p[12], ( fMultSub(fMultDiv2(cr[ 0], pQmfReal[pReadIdx[ 0]]), ci[ 0], pQmfImag[pReadIdx[ 0]]))) + + fMult(p[ 8], ( fMultSub(fMultDiv2(cr[ 4], pQmfReal[pReadIdx[ 4]]), ci[ 4], pQmfImag[pReadIdx[ 4]]))) + + fMult(p[ 4], ( fMultSub(fMultDiv2(cr[ 8], pQmfReal[pReadIdx[ 8]]), ci[ 8], pQmfImag[pReadIdx[ 8]]))) + + fMult(p[ 0], ( fMultSub(fMultDiv2(cr[12], pQmfReal[pReadIdx[12]]), ci[12], pQmfImag[pReadIdx[12]]))) ); + fft[FFT_IDX_I(2)] = ( fMult(p[12], ( fMultAdd(fMultDiv2(ci[ 0], pQmfReal[pReadIdx[ 0]]), cr[ 0], pQmfImag[pReadIdx[ 0]]))) + + fMult(p[ 8], ( fMultAdd(fMultDiv2(ci[ 4], pQmfReal[pReadIdx[ 4]]), cr[ 4], pQmfImag[pReadIdx[ 4]]))) + + fMult(p[ 4], ( fMultAdd(fMultDiv2(ci[ 8], pQmfReal[pReadIdx[ 8]]), cr[ 8], pQmfImag[pReadIdx[ 8]]))) + + fMult(p[ 0], ( fMultAdd(fMultDiv2(ci[12], pQmfReal[pReadIdx[12]]), cr[12], pQmfImag[pReadIdx[12]]))) ); + + fft[FFT_IDX_R(3)] = ( fMult(p[11], ( fMultSub(fMultDiv2(cr[ 1], pQmfReal[pReadIdx[ 1]]), ci[ 1], pQmfImag[pReadIdx[ 1]]))) + + fMult(p[ 7], ( fMultSub(fMultDiv2(cr[ 5], pQmfReal[pReadIdx[ 5]]), ci[ 5], pQmfImag[pReadIdx[ 5]]))) + + fMult(p[ 3], ( fMultSub(fMultDiv2(cr[ 9], pQmfReal[pReadIdx[ 9]]), ci[ 9], pQmfImag[pReadIdx[ 9]]))) ); + fft[FFT_IDX_I(3)] = ( fMult(p[11], ( fMultAdd(fMultDiv2(ci[ 1], pQmfReal[pReadIdx[ 1]]), cr[ 1], pQmfImag[pReadIdx[ 1]]))) + + fMult(p[ 7], ( fMultAdd(fMultDiv2(ci[ 5], pQmfReal[pReadIdx[ 5]]), cr[ 5], pQmfImag[pReadIdx[ 5]]))) + + fMult(p[ 3], ( fMultAdd(fMultDiv2(ci[ 9], pQmfReal[pReadIdx[ 9]]), cr[ 9], pQmfImag[pReadIdx[ 9]]))) ); + + /* fft modulation */ + /* here: fast manual fft modulation for a fft of length M=4 */ + /* fft_4{x[n]} = x[0]*exp(-i*2*pi/4*m*0) + x[1]*exp(-i*2*pi/4*m*1) + + x[2]*exp(-i*2*pi/4*m*2) + x[3]*exp(-i*2*pi/4*m*3) */ + + /* + fft bin m=0: + X[0, n] = x[0] + x[1] + x[2] + x[3] + */ + mHybridReal[0] = fft[FFT_IDX_R(0)] + fft[FFT_IDX_R(1)] + fft[FFT_IDX_R(2)] + fft[FFT_IDX_R(3)]; + mHybridImag[0] = fft[FFT_IDX_I(0)] + fft[FFT_IDX_I(1)] + fft[FFT_IDX_I(2)] + fft[FFT_IDX_I(3)]; + + /* + fft bin m=1: + X[1, n] = x[0] - i*x[1] - x[2] + i*x[3] + */ + mHybridReal[1] = fft[FFT_IDX_R(0)] + fft[FFT_IDX_I(1)] - fft[FFT_IDX_R(2)] - fft[FFT_IDX_I(3)]; + mHybridImag[1] = fft[FFT_IDX_I(0)] - fft[FFT_IDX_R(1)] - fft[FFT_IDX_I(2)] + fft[FFT_IDX_R(3)]; + + /* + fft bin m=2: + X[2, n] = x[0] - x[1] + x[2] - x[3] + */ + mHybridReal[2] = fft[FFT_IDX_R(0)] - fft[FFT_IDX_R(1)] + fft[FFT_IDX_R(2)] - fft[FFT_IDX_R(3)]; + mHybridImag[2] = fft[FFT_IDX_I(0)] - fft[FFT_IDX_I(1)] + fft[FFT_IDX_I(2)] - fft[FFT_IDX_I(3)]; + + /* + fft bin m=3: + X[3, n] = x[0] + j*x[1] - x[2] - j*x[3] + */ + mHybridReal[3] = fft[FFT_IDX_R(0)] - fft[FFT_IDX_I(1)] - fft[FFT_IDX_R(2)] + fft[FFT_IDX_I(3)]; + mHybridImag[3] = fft[FFT_IDX_I(0)] + fft[FFT_IDX_R(1)] - fft[FFT_IDX_I(2)] - fft[FFT_IDX_R(3)]; +} + + + +/* + 8 channel filter + + Implementation using a FFT of length 8 + + prototype filter coefficients: + 0.00746082949812 0.02270420949825 0.04546865930473 0.07266113929591 0.09885108575264 0.11793710567217 + 0.125 + 0.11793710567217 0.09885108575264 0.07266113929591 0.04546865930473 0.02270420949825 0.00746082949812 + + Filter design: + N = 13; Q = 8; + h[q,n] = g[n] * exp(j * 2 * pi / Q * (q + .5) * (n - 6)); n = 0..(N-1), q = 0..(Q-1); + + Time Signal: x[t]; + Filter Bank Output + y[q,t] = conv(x[t],h[q,t]) = conv(h[q,t],x[t]) = sum(x[k] * h[q, t - k] ) = sum(h[q, k] * x[t - k] ); k = 0..(N-1); + + y[q,t] = x[t - 12]*h[q, 12] + x[t - 11]*h[q, 11] + x[t - 10]*h[q, 10] + x[t - 9]*h[q, 9] + + x[t - 8]*h[q, 8] + x[t - 7]*h[q, 7] + + x[t - 6]*h[q, 6] + + x[t - 5]*h[q, 5] + x[t - 4]*h[q, 4] + + x[t - 3]*h[q, 3] + x[t - 2]*h[q, 2] + x[t - 1]*h[q, 1] + x[t - 0]*h[q, 0]; + + h'[q, n] = h[q,(N-1)-n] = g[n] * exp(j * 2 * pi / Q * (q + .5) * (6 - n)); n = 0..(N-1), q = 0..(Q-1); + + y[q,t] = x[t - 12]*h'[q, 0] + x[t - 11]*h'[q, 1] + x[t - 10]*h'[q, 2] + x[t - 9]*h'[q, 3] + + x[t - 8]*h'[q, 4] + x[t - 7]*h'[q, 5] + + x[t - 6]*h'[q, 6] + + x[t - 5]*h'[q, 7] + x[t - 4]*h'[q, 8] + + x[t - 3]*h'[q, 9] + x[t - 2]*h'[q, 10] + x[t - 1]*h'[q, 11] + x[t - 0]*h'[q, 12]; + + Try to split off FFT Modulation Term: + FFT(x[t], q) = sum(x[t+k]*exp(-j*2*pi/N *q * k)) + c m + Step 1: h'[q,n] = g[n] * ( exp(j * 2 * pi / 8 * .5 * (6 - n)) ) * ( exp (j * 2 * pi / 8 * q * (6 - n)) ); + + h'[q,n] = g[n] *c[n] * m[q,n]; (see above) + c[n] = exp( j * 2 * pi / 8 * .5 * (6 - n) ); + m[q,n] = exp( j * 2 * pi / 8 * q * (6 - n) ); + + y[q,t] = x[t - 0]*g[0]*c[0]*m[q,0] + x[t - 1]*g[1]*c[ 1]*m[q, 1] + ... + ... + x[t - 12]*g[2]*c[12]*m[q,12]; + + | + n m *exp(-j*2*pi) | n' fft +------------------------------------------------------------------------------------------------------------------------- + 0 exp( j * 2 * pi / 8 * q * 6) -> exp(-j * 2 * pi / 8 * q * 2) | 2 exp(-j * 2 * pi / 8 * q * 0) + 1 exp( j * 2 * pi / 8 * q * 5) -> exp(-j * 2 * pi / 8 * q * 3) | 3 exp(-j * 2 * pi / 8 * q * 1) + 2 exp( j * 2 * pi / 8 * q * 4) -> exp(-j * 2 * pi / 8 * q * 4) | 4 exp(-j * 2 * pi / 8 * q * 2) + 3 exp( j * 2 * pi / 8 * q * 3) -> exp(-j * 2 * pi / 8 * q * 5) | 5 exp(-j * 2 * pi / 8 * q * 3) + 4 exp( j * 2 * pi / 8 * q * 2) -> exp(-j * 2 * pi / 8 * q * 6) | 6 exp(-j * 2 * pi / 8 * q * 4) + 5 exp( j * 2 * pi / 8 * q * 1) -> exp(-j * 2 * pi / 8 * q * 7) | 7 exp(-j * 2 * pi / 8 * q * 5) + 6 exp( j * 2 * pi / 8 * q * 0) | 0 exp(-j * 2 * pi / 8 * q * 6) + 7 exp(-j * 2 * pi / 8 * q * 1) | 1 exp(-j * 2 * pi / 8 * q * 7) + 8 exp(-j * 2 * pi / 8 * q * 2) | 2 + 9 exp(-j * 2 * pi / 8 * q * 3) | 3 + 10 exp(-j * 2 * pi / 8 * q * 4) | 4 + 11 exp(-j * 2 * pi / 8 * q * 5) | 5 + 12 exp(-j * 2 * pi / 8 * q * 6) | 6 + + + now use fft modulation coefficients + m[6] = = fft[0] + m[7] = = fft[1] + m[8] = m[ 0] = fft[2] + m[9] = m[ 1] = fft[3] + m[10] = m[ 2] = fft[4] + m[11] = m[ 3] = fft[5] + m[12] = m[ 4] = fft[6] + m[ 5] = fft[7] + + y[q,t] = ( x[t- 6]*g[ 6]*c[ 6] ) * fft[q,0] + + ( x[t- 7]*g[ 7]*c[ 7] ) * fft[q,1] + + ( x[t- 0]*g[ 0]*c[ 0] + x[t- 8]*g[ 8]*c[ 8] ) * fft[q,2] + + ( x[t- 1]*g[ 1]*c[ 1] + x[t- 9]*g[ 9]*c[ 9] ) * fft[q,3] + + ( x[t- 2]*g[ 2]*c[ 2] + x[t-10]*g[10]*c[10] ) * fft[q,4] + + ( x[t- 3]*g[ 3]*c[ 3] + x[t-11]*g[11]*c[11] ) * fft[q,5] + + ( x[t- 4]*g[ 4]*c[ 4] + x[t-12]*g[12]*c[12] ) * fft[q,6] + + ( x[t- 5]*g[ 5]*c[ 5] ) * fft[q,7]; + + pre twiddle factors c[n] = exp(j * 2 * pi / 8 * .5 * (6 - n)); + n c] | n c[n] | n c[n] +--------------------------------------------------------------------------------------------------- + 0 exp( j * 6 * pi / 8) | 1 exp( j * 5 * pi / 8) | 2 exp( j * 4 * pi / 8) + 3 exp( j * 3 * pi / 8) | 4 exp( j * 2 * pi / 8) | 5 exp( j * 1 * pi / 8) + 6 exp( j * 0 * pi / 8) | 7 exp(-j * 1 * pi / 8) | 8 exp(-j * 2 * pi / 8) + 9 exp(-j * 3 * pi / 8) | 10 exp(-j * 4 * pi / 8) | 11 exp(-j * 5 * pi / 8) + 12 exp(-j * 6 * pi / 8) | | + +*/ +static void eightChannelFiltering( + const FIXP_DBL *const pQmfReal, + const FIXP_DBL *const pQmfImag, + const INT *const pReadIdx, + FIXP_DBL *const mHybridReal, + FIXP_DBL *const mHybridImag, + const INT invert + ) +{ + const FIXP_HTP *p = HybFilterCoef8; + INT k, sc; + + FIXP_DBL mfft[16+ALIGNMENT_DEFAULT]; + FIXP_DBL *pfft = (FIXP_DBL*)ALIGN_PTR(mfft); + + FIXP_DBL accu1, accu2, accu3, accu4; + + /* pre twiddeling */ + pfft[FFT_IDX_R(0)] = fMultDiv2(p[0].v.re, pQmfReal[pReadIdx[6]]); + pfft[FFT_IDX_I(0)] = fMultDiv2(p[0].v.re, pQmfImag[pReadIdx[6]]); + + cplxMultDiv2(&accu1, &accu2, pQmfReal[pReadIdx[7]], pQmfImag[pReadIdx[7]], p[1]); + pfft[FFT_IDX_R(1)] = accu1; + pfft[FFT_IDX_I(1)] = accu2; + + cplxMultDiv2(&accu1, &accu2, pQmfReal[pReadIdx[0]], pQmfImag[pReadIdx[0]], p[2]); + cplxMultDiv2(&accu3, &accu4, pQmfReal[pReadIdx[8]], pQmfImag[pReadIdx[8]], p[3]); + pfft[FFT_IDX_R(2)] = accu1 + accu3; + pfft[FFT_IDX_I(2)] = accu2 + accu4; + + cplxMultDiv2(&accu1, &accu2, pQmfReal[pReadIdx[1]], pQmfImag[pReadIdx[1]], p[4]); + cplxMultDiv2(&accu3, &accu4, pQmfReal[pReadIdx[9]], pQmfImag[pReadIdx[9]], p[5]); + pfft[FFT_IDX_R(3)] = accu1 + accu3; + pfft[FFT_IDX_I(3)] = accu2 + accu4; + + pfft[FFT_IDX_R(4)] = fMultDiv2(pQmfImag[pReadIdx[10]], p[7].v.im) - fMultDiv2(pQmfImag[pReadIdx[ 2]], p[6].v.im); + pfft[FFT_IDX_I(4)] = fMultDiv2(pQmfReal[pReadIdx[ 2]], p[6].v.im) - fMultDiv2(pQmfReal[pReadIdx[10]], p[7].v.im); + + cplxMultDiv2(&accu1, &accu2, pQmfReal[pReadIdx[ 3]], pQmfImag[pReadIdx[ 3]], p[8]); + cplxMultDiv2(&accu3, &accu4, pQmfReal[pReadIdx[11]], pQmfImag[pReadIdx[11]], p[9]); + pfft[FFT_IDX_R(5)] = accu1 + accu3; + pfft[FFT_IDX_I(5)] = accu2 + accu4; + + cplxMultDiv2(&accu1, &accu2, pQmfReal[pReadIdx[ 4]], pQmfImag[pReadIdx[ 4]], p[10]); + cplxMultDiv2(&accu3, &accu4, pQmfReal[pReadIdx[12]], pQmfImag[pReadIdx[12]], p[11]); + pfft[FFT_IDX_R(6)] = accu1 + accu3; + pfft[FFT_IDX_I(6)] = accu2 + accu4; + + cplxMultDiv2(&accu1, &accu2, pQmfReal[pReadIdx[ 5]], pQmfImag[pReadIdx[ 5]], p[12]); + pfft[FFT_IDX_R(7)] = accu1; + pfft[FFT_IDX_I(7)] = accu2; + + /* fft modulation */ + fft_8 (pfft); + sc = 1 + 2; + + if (invert) { + mHybridReal[0] = pfft[FFT_IDX_R(7)] << sc; + mHybridImag[0] = pfft[FFT_IDX_I(7)] << sc; + mHybridReal[1] = pfft[FFT_IDX_R(0)] << sc; + mHybridImag[1] = pfft[FFT_IDX_I(0)] << sc; + + mHybridReal[2] = pfft[FFT_IDX_R(6)] << sc; + mHybridImag[2] = pfft[FFT_IDX_I(6)] << sc; + mHybridReal[3] = pfft[FFT_IDX_R(1)] << sc; + mHybridImag[3] = pfft[FFT_IDX_I(1)] << sc; + + mHybridReal[4] = pfft[FFT_IDX_R(2)] << sc; + mHybridReal[4] += pfft[FFT_IDX_R(5)] << sc; + mHybridImag[4] = pfft[FFT_IDX_I(2)] << sc; + mHybridImag[4] += pfft[FFT_IDX_I(5)] << sc; + + mHybridReal[5] = pfft[FFT_IDX_R(3)] << sc; + mHybridReal[5] += pfft[FFT_IDX_R(4)] << sc; + mHybridImag[5] = pfft[FFT_IDX_I(3)] << sc; + mHybridImag[5] += pfft[FFT_IDX_I(4)] << sc; + } + else { + for(k=0; k<8;k++ ) { + mHybridReal[k] = pfft[FFT_IDX_R(k)] << sc; + mHybridImag[k] = pfft[FFT_IDX_I(k)] << sc; + } + } +} + +static INT kChannelFiltering( + const FIXP_DBL *const pQmfReal, + const FIXP_DBL *const pQmfImag, + const INT *const pReadIdx, + FIXP_DBL *const mHybridReal, + FIXP_DBL *const mHybridImag, + const SCHAR hybridConfig + ) +{ + INT err = 0; + + switch (hybridConfig) { + case 2: + case -2: + dualChannelFiltering(pQmfReal, pQmfImag, pReadIdx, mHybridReal, mHybridImag, (hybridConfig<0) ? 1 : 0 ); + break; + case 4: + case -4: + fourChannelFiltering(pQmfReal, pQmfImag, pReadIdx, mHybridReal, mHybridImag, (hybridConfig<0) ? 1 : 0 ); + break; + case 8: + case -8: + eightChannelFiltering(pQmfReal, pQmfImag, pReadIdx, mHybridReal, mHybridImag, (hybridConfig<0) ? 1 : 0 ); + break; + default: + err = -1; + } + + return err; +} + + + |