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+/*************************** 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;
+}
+
+
+