/**************************************************************************** (C) Copyright Fraunhofer IIS (2005) 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. 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. $Id$ *******************************************************************************/ #include "psdec_hybrid.h" #include "fft.h" #include "sbr_ram.h" #include "FDK_tools_rom.h" #include "sbr_rom.h" /******************************************************************************* Functionname: InitHybridFilterBank ******************************************************************************* Description: Init one instance of HANDLE_HYBRID stuct Arguments: Return: none *******************************************************************************/ SBR_ERROR InitHybridFilterBank ( HANDLE_HYBRID hs, /*!< Handle to HYBRID struct. */ SCHAR frameSize, /*!< Framesize (in Qmf súbband samples). */ SCHAR noBands, /*!< Number of Qmf bands for hybrid filtering. */ const UCHAR *pResolution ) /*!< Resolution in Qmf bands (length noBands). */ { SCHAR i; UCHAR maxNoChannels = 0; for (i = 0; i < noBands; i++) { hs->pResolution[i] = pResolution[i]; if(pResolution[i] > maxNoChannels) maxNoChannels = pResolution[i]; } hs->nQmfBands = noBands; hs->frameSize = frameSize; hs->qmfBufferMove = HYBRID_FILTER_LENGTH - 1; hs->sf_mQmfBuffer = 0; return SBRDEC_OK; } /******************************************************************************* Functionname: dualChannelFiltering ******************************************************************************* Description: fast 2-channel real-valued filtering with 6-tap delay. Arguments: Return: none *******************************************************************************/ /*! 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 slotBasedDualChannelFiltering( const FIXP_DBL *pQmfReal, const FIXP_DBL *pQmfImag, FIXP_DBL *mHybridReal, FIXP_DBL *mHybridImag) { FIXP_DBL t1, t3, t5, t6; /* symmetric filter coefficients */ /* you don't have to shift the result after fMult because of p2_13_20 <= 0.5 */ t1 = fMultDiv2(p2_13_20[1] , ( (pQmfReal[1] >> 1) + (pQmfReal[11] >> 1))); t3 = fMultDiv2(p2_13_20[3] , ( (pQmfReal[3] >> 1) + (pQmfReal[ 9] >> 1))); t5 = fMultDiv2(p2_13_20[5] , ( (pQmfReal[5] >> 1) + (pQmfReal[ 7] >> 1))); t6 = fMultDiv2(p2_13_20[6] , (pQmfReal[6] >> 1) ); mHybridReal[0] = (t1 + t3 + t5 + t6) << 2; mHybridReal[1] = (- t1 - t3 - t5 + t6) << 2; t1 = fMultDiv2(p2_13_20[1] , ( (pQmfImag[1] >> 1) + (pQmfImag[11] >> 1))); t3 = fMultDiv2(p2_13_20[3] , ( (pQmfImag[3] >> 1) + (pQmfImag[ 9] >> 1))); t5 = fMultDiv2(p2_13_20[5] , ( (pQmfImag[5] >> 1) + (pQmfImag[ 7] >> 1))); t6 = fMultDiv2(p2_13_20[6] , pQmfImag[6] >> 1 ); mHybridImag[0] = (t1 + t3 + t5 + t6) << 2; mHybridImag[1] = (- t1 - t3 - t5 + t6) << 2; } /******************************************************************************* Functionname: eightChannelFiltering ******************************************************************************* Description: fast 8-channel complex-valued filtering with 6-tap delay. Arguments: Return: none *******************************************************************************/ /*! 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) | |*/ /* defining rotation factors for *ChannelFiltering */ #define cos0Pi FL2FXCONST_DBL( 1.f) #define sin0Pi FL2FXCONST_DBL( 0.f) #define cos1Pi FL2FXCONST_DBL(-1.f) #define sin1Pi FL2FXCONST_DBL( 0.f) #define cos1Pi_2 FL2FXCONST_DBL( 0.f) #define sin1Pi_2 FL2FXCONST_DBL( 1.f) #define cos1Pi_3 FL2FXCONST_DBL( 0.5f) #define sin1Pi_3 FL2FXCONST_DBL( 0.86602540378444f) #define cos0Pi_4 cos0Pi #define cos1Pi_4 FL2FXCONST_DBL(0.70710678118655f) #define cos2Pi_4 cos1Pi_2 #define cos3Pi_4 (-cos1Pi_4) #define cos4Pi_4 (-cos0Pi_4) #define cos5Pi_4 cos3Pi_4 #define cos6Pi_4 cos2Pi_4 #define sin0Pi_4 sin0Pi #define sin1Pi_4 FL2FXCONST_DBL(0.70710678118655f) #define sin2Pi_4 sin1Pi_2 #define sin3Pi_4 sin1Pi_4 #define sin4Pi_4 sin0Pi_4 #define sin5Pi_4 (-sin3Pi_4) #define sin6Pi_4 (-sin2Pi_4) #define cos0Pi_8 cos0Pi #define cos1Pi_8 FL2FXCONST_DBL(0.92387953251129f) #define cos2Pi_8 cos1Pi_4 #define cos3Pi_8 FL2FXCONST_DBL(0.38268343236509f) #define cos4Pi_8 cos2Pi_4 #define cos5Pi_8 (-cos3Pi_8) #define cos6Pi_8 (-cos2Pi_8) #define sin0Pi_8 sin0Pi #define sin1Pi_8 cos3Pi_8 #define sin2Pi_8 sin1Pi_4 #define sin3Pi_8 cos1Pi_8 #define sin4Pi_8 sin2Pi_4 #define sin5Pi_8 sin3Pi_8 #define sin6Pi_8 sin1Pi_4 #if defined(ARCH_PREFER_MULT_32x16) #define FIXP_HYB FIXP_SGL #define FIXP_CAST FX_DBL2FX_SGL #else #define FIXP_HYB FIXP_DBL #define FIXP_CAST #endif static const FIXP_HYB cr[13] = { FIXP_CAST(cos6Pi_8), FIXP_CAST(cos5Pi_8), FIXP_CAST(cos4Pi_8), FIXP_CAST(cos3Pi_8), FIXP_CAST(cos2Pi_8), FIXP_CAST(cos1Pi_8), FIXP_CAST(cos0Pi_8), FIXP_CAST(cos1Pi_8), FIXP_CAST(cos2Pi_8), FIXP_CAST(cos3Pi_8), FIXP_CAST(cos4Pi_8), FIXP_CAST(cos5Pi_8), FIXP_CAST(cos6Pi_8) }; static const FIXP_HYB ci[13] = { FIXP_CAST( sin6Pi_8), FIXP_CAST( sin5Pi_8), FIXP_CAST( sin4Pi_8), FIXP_CAST( sin3Pi_8), FIXP_CAST( sin2Pi_8), FIXP_CAST( sin1Pi_8), FIXP_CAST( sin0Pi_8) , FIXP_CAST(-sin1Pi_8), FIXP_CAST(-sin2Pi_8), FIXP_CAST(-sin3Pi_8), FIXP_CAST(-sin4Pi_8), FIXP_CAST(-sin5Pi_8), FIXP_CAST(-sin6Pi_8) }; static void slotBasedEightChannelFiltering( const FIXP_DBL *pQmfReal, const FIXP_DBL *pQmfImag, FIXP_DBL *mHybridReal, FIXP_DBL *mHybridImag) { int bin; FIXP_DBL _fft[128 + ALIGNMENT_DEFAULT - 1]; FIXP_DBL *fft = (FIXP_DBL *)ALIGN_PTR(_fft); #if defined(ARCH_PREFER_MULT_32x16) const FIXP_SGL *p = p8_13_20; /* BASELINE_PS */ #else const FIXP_DBL *p = p8_13_20; /* BASELINE_PS */ #endif /* pre twiddeling */ /* x*(a*b + c*d) = fMultDiv2(x, fMultAddDiv2(fMultDiv2(a, b), c, d)) */ /* x*(a*b - c*d) = fMultDiv2(x, fMultSubDiv2(fMultDiv2(a, b), c, d)) */ FIXP_DBL accu1, accu2, accu3, accu4; #define TWIDDLE_1(n_0,n_1,n_2) \ cplxMultDiv2(&accu1, &accu2, pQmfReal[n_0], pQmfImag[n_0], cr[n_0], ci[n_0]); \ accu1 = fMultDiv2(p[n_0], accu1); \ accu2 = fMultDiv2(p[n_0], accu2); \ cplxMultDiv2(&accu3, &accu4, pQmfReal[n_1], pQmfImag[n_1], cr[n_1], ci[n_1]); \ accu3 = fMultDiv2(p[n_1], accu3); \ accu4 = fMultDiv2(p[n_1], accu4); \ fft[FIXP_FFT_IDX_R(n_2)] = accu1 + accu3; \ fft[FIXP_FFT_IDX_I(n_2)] = accu2 + accu4; #define TWIDDLE_0(n_0,n_1) \ cplxMultDiv2(&accu1, &accu2, pQmfReal[n_0], pQmfImag[n_0], cr[n_0], ci[n_0]); \ fft[FIXP_FFT_IDX_R(n_1)] = fMultDiv2(p[n_0], accu1); \ fft[FIXP_FFT_IDX_I(n_1)] = fMultDiv2(p[n_0], accu2); TWIDDLE_0( 6, 0) TWIDDLE_0( 7, 1) TWIDDLE_1( 0, 8, 2) TWIDDLE_1( 1, 9, 3) TWIDDLE_1( 2,10, 4) TWIDDLE_1( 3,11, 5) TWIDDLE_1( 4,12, 6) TWIDDLE_0( 5, 7) fft_8 (fft); /* resort fft data into output array*/ for(bin=0; bin<8;bin++ ) { mHybridReal[bin] = fft[FIXP_FFT_IDX_R(bin)] << 4; mHybridImag[bin] = fft[FIXP_FFT_IDX_I(bin)] << 4; } } /******************************************************************************* Functionname: fillHybridDelayLine ******************************************************************************* Description: The delay line of the hybrid filter is filled and copied from left to right. Return: none *******************************************************************************/ void fillHybridDelayLine( FIXP_DBL **fixpQmfReal, /*!< Qmf real Values */ FIXP_DBL **fixpQmfImag, /*!< Qmf imag Values */ FIXP_DBL fixpHybridLeftR[12], /*!< Hybrid real Values left channel */ FIXP_DBL fixpHybridLeftI[12], /*!< Hybrid imag Values left channel */ FIXP_DBL fixpHybridRightR[12], /*!< Hybrid real Values right channel */ FIXP_DBL fixpHybridRightI[12], /*!< Hybrid imag Values right channel */ HANDLE_HYBRID hHybrid ) { int i; for (i = 0; i < HYBRID_FILTER_DELAY; i++) { slotBasedHybridAnalysis ( fixpQmfReal[i], fixpQmfReal[i], fixpHybridLeftR, fixpHybridLeftI, hHybrid ); } FDKmemcpy(fixpHybridRightR, fixpHybridLeftR, sizeof(FIXP_DBL)*NO_SUB_QMF_CHANNELS); FDKmemcpy(fixpHybridRightI, fixpHybridLeftI, sizeof(FIXP_DBL)*NO_SUB_QMF_CHANNELS); } /******************************************************************************* Functionname: slotBasedHybridAnalysis ******************************************************************************* Description: The lower QMF subbands are further split to provide better frequency resolution for PS processing. Return: none *******************************************************************************/ void slotBasedHybridAnalysis ( FIXP_DBL *fixpQmfReal, /*!< Qmf real Values */ FIXP_DBL *fixpQmfImag, /*!< Qmf imag Values */ FIXP_DBL fixpHybridReal[12], /*!< Hybrid real Values */ FIXP_DBL fixpHybridImag[12], /*!< Hybrid imag Values */ HANDLE_HYBRID hHybrid) { int k, band; HYBRID_RES hybridRes; int chOffset = 0; C_ALLOC_SCRATCH_START(pTempRealSlot, FIXP_DBL, 4*HYBRID_FILTER_LENGTH); FIXP_DBL *pTempImagSlot = pTempRealSlot + HYBRID_FILTER_LENGTH; FIXP_DBL *pWorkRealSlot = pTempImagSlot + HYBRID_FILTER_LENGTH; FIXP_DBL *pWorkImagSlot = pWorkRealSlot + HYBRID_FILTER_LENGTH; /*! Hybrid filtering is applied to the first hHybrid->nQmfBands QMF bands (3 when 10 or 20 stereo bands are used, 5 when 34 stereo bands are used). For the remaining QMF bands a delay would be necessary. But there is no need to implement a delay because there is a look-ahead of HYBRID_FILTER_DELAY = 6 QMF samples in the low-band buffer. */ for(band = 0; band < hHybrid->nQmfBands; band++) { /* get hybrid resolution per qmf band */ /* in case of baseline ps 10/20 band stereo mode : */ /* */ /* qmfBand[0] : 8 ( HYBRID_8_CPLX ) */ /* qmfBand[1] : 2 ( HYBRID_2_REAL ) */ /* qmfBand[2] : 2 ( HYBRID_2_REAL ) */ /* */ /* (split the 3 lower qmf band to 12 hybrid bands) */ hybridRes = (HYBRID_RES)hHybrid->pResolution[band]; FDKmemcpy(pWorkRealSlot, hHybrid->mQmfBufferRealSlot[band], hHybrid->qmfBufferMove * sizeof(FIXP_DBL)); FDKmemcpy(pWorkImagSlot, hHybrid->mQmfBufferImagSlot[band], hHybrid->qmfBufferMove * sizeof(FIXP_DBL)); pWorkRealSlot[hHybrid->qmfBufferMove] = fixpQmfReal[band]; pWorkImagSlot[hHybrid->qmfBufferMove] = fixpQmfImag[band]; FDKmemcpy(hHybrid->mQmfBufferRealSlot[band], pWorkRealSlot + 1, hHybrid->qmfBufferMove * sizeof(FIXP_DBL)); FDKmemcpy(hHybrid->mQmfBufferImagSlot[band], pWorkImagSlot + 1, hHybrid->qmfBufferMove * sizeof(FIXP_DBL)); if (fixpQmfReal) { /* actual filtering only if output signal requested */ switch( hybridRes ) { /* HYBRID_2_REAL & HYBRID_8_CPLX are only needful for baseline ps */ case HYBRID_2_REAL: slotBasedDualChannelFiltering( pWorkRealSlot, pWorkImagSlot, pTempRealSlot, pTempImagSlot); break; case HYBRID_8_CPLX: slotBasedEightChannelFiltering( pWorkRealSlot, pWorkImagSlot, pTempRealSlot, pTempImagSlot); break; default: FDK_ASSERT(0); } for(k = 0; k < (SCHAR)hybridRes; k++) { fixpHybridReal [chOffset + k] = pTempRealSlot[k]; fixpHybridImag [chOffset + k] = pTempImagSlot[k]; } chOffset += hybridRes; } /* if (mHybridReal) */ } /* group hybrid channels 3+4 -> 3 and 2+5 -> 2 */ fixpHybridReal[3] += fixpHybridReal[4]; fixpHybridImag[3] += fixpHybridImag[4]; fixpHybridReal[4] = (FIXP_DBL)0; fixpHybridImag[4] = (FIXP_DBL)0; fixpHybridReal[2] += fixpHybridReal[5]; fixpHybridImag[2] += fixpHybridImag[5]; fixpHybridReal[5] = (FIXP_DBL)0; fixpHybridImag[5] = (FIXP_DBL)0; /* free memory on scratch */ C_ALLOC_SCRATCH_END(pTempRealSlot, FIXP_DBL, 4*HYBRID_FILTER_LENGTH); } /******************************************************************************* Functionname: slotBasedHybridSynthesis ******************************************************************************* Description: The coefficients offering higher resolution for the lower QMF channel are simply added prior to the synthesis with the 54 subbands QMF. Arguments: Return: none *******************************************************************************/ /*!
l,r0(n) ---\ l,r1(n) ---- + --\ l,r2(n) ---/ \ + --> F0(w) l,r3(n) ---\ / l,r4(n) ---- + --/ l,r5(n) ---/ l,r6(n) ---\ + ---------> F1(w) l,r7(n) ---/ l,r8(n) ---\ + ---------> F2(w) l,r9(n) ---/Hybrid QMF synthesis filterbank for the 10 and 20 stereo-bands configurations. The coefficients offering higher resolution for the lower QMF channel are simply added prior to the synthesis with the 54 subbands QMF. [see ISO/IEC 14496-3:2001/FDAM 2:2004(E) - Page 52] */ void slotBasedHybridSynthesis ( FIXP_DBL *fixpHybridReal, /*!< Hybrid real Values */ FIXP_DBL *fixpHybridImag, /*!< Hybrid imag Values */ FIXP_DBL *fixpQmfReal, /*!< Qmf real Values */ FIXP_DBL *fixpQmfImag, /*!< Qmf imag Values */ HANDLE_HYBRID hHybrid ) /*!< Handle to HYBRID struct. */ { int k, band; HYBRID_RES hybridRes; int chOffset = 0; for(band = 0; band < hHybrid->nQmfBands; band++) { FIXP_DBL qmfReal = FL2FXCONST_DBL(0.f); FIXP_DBL qmfImag = FL2FXCONST_DBL(0.f); hybridRes = (HYBRID_RES)hHybrid->pResolution[band]; for(k = 0; k < (SCHAR)hybridRes; k++) { qmfReal += fixpHybridReal[chOffset + k]; qmfImag += fixpHybridImag[chOffset + k]; } fixpQmfReal[band] = qmfReal; fixpQmfImag[band] = qmfImag; chOffset += hybridRes; } }