/**************************************************************************** (C) Copyright Fraunhofer IIS (2004) 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 "tran_det.h" #include "fram_gen.h" #include "sbr_ram.h" #include "sbr_misc.h" #include "genericStds.h" #define NORM_QMF_ENERGY 5.684341886080801486968994140625e-14 /* 2^-44 */ /* static FIXP_DBL ABS_THRES = fixMax( FL2FXCONST_DBL(1.28e5 * NORM_QMF_ENERGY), (FIXP_DBL)1) Minimum threshold for detecting changes */ #define ABS_THRES ((FIXP_DBL)16) /******************************************************************************* Functionname: spectralChange ******************************************************************************* \brief Calculates a measure for the spectral change within the frame The function says how good it would be to split the frame at the given border position into 2 envelopes. The return value delta_sum is scaled with the factor 1/64 \return calculated value *******************************************************************************/ static FIXP_DBL spectralChange(FIXP_DBL Energies[NUMBER_TIME_SLOTS_2304][MAX_FREQ_COEFFS], INT *scaleEnergies, FIXP_DBL EnergyTotal, INT nSfb, INT start, INT border, INT stop) { INT i,j; INT len1,len2; FIXP_DBL delta,tmp0,tmp1,tmp2; FIXP_DBL accu1,accu2,delta_sum,result; FDK_ASSERT(scaleEnergies[0] >= 0); /* equal for aac (would be not equal for mp3) */ len1 = border-start; len2 = stop-border; /* prefer borders near the middle of the frame */ FIXP_DBL pos_weight; pos_weight = FL2FXCONST_DBL(0.5f) - (len1*GetInvInt(len1+len2)); pos_weight = /*FL2FXCONST_DBL(1.0)*/ (FIXP_DBL)MAXVAL_DBL - (fMult(pos_weight, pos_weight)<<2); delta_sum = FL2FXCONST_DBL(0.0f); /* Sum up energies of all QMF-timeslots for both halfs */ for (j=0; j>NRG_SCALE; /* complex init for compare with original version */ accu2 = ((FL2FXCONST_DBL((1.0e6*NORM_QMF_ENERGY*8.0/32))) << fixMin(scaleEnergies[0],25))>>NRG_SCALE; /* can be simplified in dsp implementation */ /* Sum up energies in first half */ for (i=start; i>NRG_SCALE); } /* Sum up energies in second half */ for (i=border; i>NRG_SCALE); } /* Energy change in current band */ tmp0 = CalcLdData(accu2); tmp1 = CalcLdData(accu1); tmp2 = (tmp0 - tmp1 + CalcLdData(len1)-CalcLdData(len2)); delta = fixp_abs(fMult(tmp2, FL2FXCONST_DBL(0.6931471806f))); /* Weighting with amplitude ratio of this band */ result = (EnergyTotal == FL2FXCONST_DBL(0.0f)) ? FL2FXCONST_DBL(0.f) : FDKsbrEnc_LSI_divide_scale_fract( (accu1+accu2), (EnergyTotal>>NRG_SCALE)+(FIXP_DBL)1, (FIXP_DBL)MAXVAL_DBL >> fixMin(scaleEnergies[0],(DFRACT_BITS-1)) ); delta_sum += (FIXP_DBL)(fMult(sqrtFixp(result), delta)); } return fMult(delta_sum, pos_weight); } /******************************************************************************* Functionname: addLowbandEnergies ******************************************************************************* \brief Calculates total lowband energy The return value nrgTotal is scaled by the factor (1/32.0) \return total energy in the lowband *******************************************************************************/ static FIXP_DBL addLowbandEnergies(FIXP_DBL **Energies, int *scaleEnergies, int YBufferWriteOffset, int nrgSzShift, int tran_off, UCHAR *freqBandTable, int slots) { FIXP_DBL nrgTotal; FIXP_DBL accu1 = FL2FXCONST_DBL(0.0f); FIXP_DBL accu2 = FL2FXCONST_DBL(0.0f); int tran_offdiv2 = tran_off>>nrgSzShift; int ts,k; /* Sum up lowband energy from one frame at offset tran_off */ for (ts=tran_offdiv2; ts> 6; } } for (; ts>nrgSzShift); ts++) { for (k = 0; k < freqBandTable[0]; k++) { accu2 += Energies[ts][k] >> 6; } } nrgTotal = ( (accu1 >> fixMin(scaleEnergies[0],(DFRACT_BITS-1))) + (accu2 >> fixMin(scaleEnergies[1],(DFRACT_BITS-1))) ) << (2); return(nrgTotal); } /******************************************************************************* Functionname: addHighbandEnergies ******************************************************************************* \brief Add highband energies Highband energies are mapped to an array with smaller dimension: Its time resolution is only 1 SBR-timeslot and its frequency resolution is 1 SBR-band. Therefore the data to be fed into the spectralChange function is reduced. The values EnergiesM are scaled by the factor (1/32.0) and scaleEnergies[0] The return value nrgTotal is scaled by the factor (1/32.0) \return total energy in the highband *******************************************************************************/ static FIXP_DBL addHighbandEnergies(FIXP_DBL **RESTRICT Energies, /*!< input */ INT *scaleEnergies, FIXP_DBL EnergiesM[NUMBER_TIME_SLOTS_2304][MAX_FREQ_COEFFS], /*!< Combined output */ UCHAR *RESTRICT freqBandTable, INT nSfb, INT sbrSlots, INT timeStep) { INT i,j,k,slotIn,slotOut,scale; INT li,ui; FIXP_DBL nrgTotal; FIXP_DBL accu = FL2FXCONST_DBL(0.0f); /* Combine QMF-timeslots to SBR-timeslots, combine QMF-bands to SBR-bands, combine Left and Right channel */ for (slotOut=0; slotOut>1][k] >> 5); } } EnergiesM[slotOut][j] = accu; } } scale = fixMin(8,scaleEnergies[0]); /* scale energies down before add up */ if ((scaleEnergies[0]-1) > (DFRACT_BITS-1) ) nrgTotal = FL2FXCONST_DBL(0.0f); else { /* Now add all energies */ accu = FL2FXCONST_DBL(0.0f); for (slotOut=0; slotOut> scale); } } nrgTotal = accu >> (scaleEnergies[0]-scale); } return(nrgTotal); } /******************************************************************************* Functionname: FDKsbrEnc_frameSplitter ******************************************************************************* \brief Decides if a FIXFIX-frame shall be splitted into 2 envelopes If no transient has been detected before, the frame can still be splitted into 2 envelopes. *******************************************************************************/ void FDKsbrEnc_frameSplitter(FIXP_DBL **Energies, INT *scaleEnergies, HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector, UCHAR *freqBandTable, UCHAR *tran_vector, int YBufferWriteOffset, int YBufferSzShift, int nSfb, int timeStep, int no_cols) { if (tran_vector[1]==0) /* no transient was detected */ { FIXP_DBL delta; FIXP_DBL EnergiesM[NUMBER_TIME_SLOTS_2304][MAX_FREQ_COEFFS]; FIXP_DBL EnergyTotal,newLowbandEnergy,newHighbandEnergy; INT border; INT sbrSlots = fMultI(GetInvInt(timeStep),no_cols); FDK_ASSERT( sbrSlots * timeStep == no_cols ); /* Get Lowband-energy over a range of 2 frames (Look half a frame back and ahead). */ newLowbandEnergy = addLowbandEnergies(Energies, scaleEnergies, YBufferWriteOffset, YBufferSzShift, h_sbrTransientDetector->tran_off, freqBandTable, no_cols); newHighbandEnergy = addHighbandEnergies(Energies, scaleEnergies, EnergiesM, freqBandTable, nSfb, sbrSlots, timeStep); if ( h_sbrTransientDetector->frameShift != 0 ) { if (tran_vector[1]==0) tran_vector[0] = 0; } else { /* prevLowBandEnergy: Corresponds to 1 frame, starting with half a frame look-behind newLowbandEnergy: Corresponds to 1 frame, starting in the middle of the current frame */ EnergyTotal = (newLowbandEnergy + h_sbrTransientDetector->prevLowBandEnergy) >> 1; EnergyTotal += newHighbandEnergy; /* The below border should specify the same position as the middle border of a FIXFIX-frame with 2 envelopes. */ border = (sbrSlots+1) >> 1; delta = spectralChange(EnergiesM, scaleEnergies, EnergyTotal, nSfb, 0, border, sbrSlots); if (delta > (h_sbrTransientDetector->split_thr >> LD_DATA_SHIFT)) /* delta scaled by 1/64 */ tran_vector[0] = 1; /* Set flag for splitting */ else tran_vector[0] = 0; } /* Update prevLowBandEnergy */ h_sbrTransientDetector->prevLowBandEnergy = newLowbandEnergy; h_sbrTransientDetector->prevHighBandEnergy = newHighbandEnergy; } } /* * Calculate transient energy threshold for each QMF band */ static void calculateThresholds(FIXP_DBL **RESTRICT Energies, INT *RESTRICT scaleEnergies, FIXP_DBL *RESTRICT thresholds, int YBufferWriteOffset, int YBufferSzShift, int noCols, int noRows, int tran_off) { FIXP_DBL mean_val,std_val,temp; FIXP_DBL i_noCols; FIXP_DBL i_noCols1; FIXP_DBL accu,accu0,accu1; int scaleFactor0,scaleFactor1,commonScale; int i,j; i_noCols = GetInvInt(noCols + tran_off ) << YBufferSzShift; i_noCols1 = GetInvInt(noCols + tran_off - 1) << YBufferSzShift; /* calc minimum scale of energies of previous and current frame */ commonScale = fixMin(scaleEnergies[0],scaleEnergies[1]); /* calc scalefactors to adapt energies to common scale */ scaleFactor0 = fixMin((scaleEnergies[0]-commonScale), (DFRACT_BITS-1)); scaleFactor1 = fixMin((scaleEnergies[1]-commonScale), (DFRACT_BITS-1)); FDK_ASSERT((scaleFactor0 >= 0) && (scaleFactor1 >= 0)); /* calculate standard deviation in every subband */ for (i=0; i>YBufferSzShift); int endEnergy = ((noCols>>YBufferSzShift)+tran_off); int shift; /* calculate mean value over decimated energy values (downsampled by 2). */ accu0 = accu1 = FL2FXCONST_DBL(0.0f); for (j=startEnergy; j> scaleFactor0) + (accu1 >> scaleFactor1); /* average */ shift = fixMax(0,CountLeadingBits(mean_val)-6); /* -6 to keep room for accumulating upto N = 24 values */ /* calculate standard deviation */ accu = FL2FXCONST_DBL(0.0f); /* summe { ((mean_val-nrg)^2) * i_noCols1 } */ for (j=startEnergy; j> scaleFactor0))<> scaleFactor1))<>shift; /* standard deviation */ /* Take new threshold as average of calculated standard deviation ratio and old threshold if greater than absolute threshold */ temp = ( commonScale<=(DFRACT_BITS-1) ) ? fMult(FL2FXCONST_DBL(0.66f), thresholds[i]) + (fMult(FL2FXCONST_DBL(0.34f), std_val) >> commonScale) : (FIXP_DBL) 0; thresholds[i] = fixMax(ABS_THRES,temp); FDK_ASSERT(commonScale >= 0); } } /* * Calculate transient levels for each QMF time slot. */ static void extractTransientCandidates(FIXP_DBL **RESTRICT Energies, INT *RESTRICT scaleEnergies, FIXP_DBL *RESTRICT thresholds, FIXP_DBL *RESTRICT transients, int YBufferWriteOffset, int YBufferSzShift, int noCols, int start_band, int stop_band, int tran_off, int addPrevSamples) { FIXP_DBL i_thres; C_ALLOC_SCRATCH_START(EnergiesTemp, FIXP_DBL, 2*QMF_MAX_TIME_SLOTS); FIXP_DBL *RESTRICT pEnergiesTemp = EnergiesTemp; int tmpScaleEnergies0, tmpScaleEnergies1; int endCond; int startEnerg,endEnerg; int i,j,jIndex,jpBM; tmpScaleEnergies0 = scaleEnergies[0]; tmpScaleEnergies1 = scaleEnergies[1]; /* Scale value for first energies, upto YBufferWriteOffset */ tmpScaleEnergies0 = fixMin(tmpScaleEnergies0, MAX_SHIFT_DBL); /* Scale value for first energies, from YBufferWriteOffset upwards */ tmpScaleEnergies1 = fixMin(tmpScaleEnergies1, MAX_SHIFT_DBL); FDK_ASSERT((tmpScaleEnergies0 >= 0) && (tmpScaleEnergies1 >= 0)); /* Keep addPrevSamples extra previous transient candidates. */ FDKmemmove(transients, transients + noCols - addPrevSamples, (tran_off+addPrevSamples) * sizeof (FIXP_DBL)); FDKmemclear(transients + tran_off + addPrevSamples, noCols * sizeof (FIXP_DBL)); endCond = noCols; /* Amount of new transient values to be calculated. */ startEnerg = (tran_off-3)>>YBufferSzShift; /* >>YBufferSzShift because of amount of energy values. -3 because of neighbors being watched. */ endEnerg = ((noCols+ (YBufferWriteOffset<>YBufferSzShift; /* YBufferSzShift shifts because of half energy values. */ /* Compute differential values with two different weightings in every subband */ for (i=start_band; i=256) i_thres = (LONG)( (LONG)MAXVAL_DBL / ((((LONG)thresholds[i]))+1) )<<(32-24); else i_thres = (LONG)MAXVAL_DBL; /* Copy one timeslot and de-scale and de-squish */ if (YBufferSzShift == 1) { for(j=startEnerg; j>tmpScaleEnergies0; } for(; j<=endEnerg; j++) { FIXP_DBL tmp = Energies[j][i]; EnergiesTemp[(j<<1)+1] = EnergiesTemp[j<<1] = tmp>>tmpScaleEnergies1; } } else { for(j=startEnerg; j>tmpScaleEnergies0; } for(; j<=endEnerg; j++) { FIXP_DBL tmp = Energies[j][i]; EnergiesTemp[j] = tmp>>tmpScaleEnergies1; } } /* Detect peaks in energy values. */ jIndex = tran_off; jpBM = jIndex+addPrevSamples; for (j=endCond; j--; jIndex++, jpBM++) { FIXP_DBL delta, tran; int d; delta = (FIXP_DBL)0; tran = (FIXP_DBL)0; for (d=1; d<4; d++) { delta += pEnergiesTemp[jIndex+d]; /* R */ delta -= pEnergiesTemp[jIndex-d]; /* L */ delta -= thres; if ( delta > (FIXP_DBL)0 ) { tran += fMult(i_thres, delta); } } transients[jpBM] += tran; } } C_ALLOC_SCRATCH_END(EnergiesTemp, FIXP_DBL, 2*QMF_MAX_TIME_SLOTS); } void FDKsbrEnc_transientDetect(HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTran, FIXP_DBL **Energies, INT *scaleEnergies, UCHAR *transient_info, int YBufferWriteOffset, int YBufferSzShift, int timeStep, int frameMiddleBorder) { int no_cols = h_sbrTran->no_cols; int qmfStartSample; int addPrevSamples; int timeStepShift=0; int i, cond; /* Where to start looking for transients in the transient candidate buffer */ qmfStartSample = timeStep * frameMiddleBorder; /* We need to look one value backwards in the transients, so we might need one more previous value. */ addPrevSamples = (qmfStartSample > 0) ? 0: 1; switch (timeStep) { case 1: timeStepShift = 0; break; case 2: timeStepShift = 1; break; case 4: timeStepShift = 2; break; } calculateThresholds(Energies, scaleEnergies, h_sbrTran->thresholds, YBufferWriteOffset, YBufferSzShift, h_sbrTran->no_cols, h_sbrTran->no_rows, h_sbrTran->tran_off); extractTransientCandidates(Energies, scaleEnergies, h_sbrTran->thresholds, h_sbrTran->transients, YBufferWriteOffset, YBufferSzShift, h_sbrTran->no_cols, 0, h_sbrTran->no_rows, h_sbrTran->tran_off, addPrevSamples ); transient_info[0] = 0; transient_info[1] = 0; transient_info[2] = 0; /* Offset by the amount of additional previous transient candidates being kept. */ qmfStartSample += addPrevSamples; /* Check for transients in second granule (pick the last value of subsequent values) */ for (i=qmfStartSample; itransients[i] < fMult(FL2FXCONST_DBL(0.9f), h_sbrTran->transients[i - 1]) ) && (h_sbrTran->transients[i - 1] > h_sbrTran->tran_thr); if (cond) { transient_info[0] = (i - qmfStartSample)>>timeStepShift; /* FDKprintf("\nSBR Transient at timeSlot %d\n", transient_info[0]); */ transient_info[1] = 1; break; } } if ( h_sbrTran->frameShift != 0) { /* transient prediction for LDSBR */ /* Check for transients in first qmf-slots of second frame */ for (i=qmfStartSample+no_cols; iframeShift; i++) { cond = (h_sbrTran->transients[i] < fMult(FL2FXCONST_DBL(0.9f), h_sbrTran->transients[i - 1]) ) && (h_sbrTran->transients[i - 1] > h_sbrTran->tran_thr); if (cond) { int pos = (int) ( (i - qmfStartSample-no_cols) >> timeStepShift ); if ((pos < 3) && (transient_info[1]==0)) { transient_info[2] = 1; } break; } } } } int FDKsbrEnc_InitSbrTransientDetector(HANDLE_SBR_TRANSIENT_DETECTOR h_sbrTransientDetector, INT frameSize, INT sampleFreq, sbrConfigurationPtr params, int tran_fc, int no_cols, int no_rows, int YBufferWriteOffset, int YBufferSzShift, int frameShift, int tran_off) { INT totalBitrate = params->codecSettings.standardBitrate * params->codecSettings.nChannels; INT codecBitrate = params->codecSettings.bitRate; FIXP_DBL bitrateFactor_fix, framedur_fix; INT scale_0, scale_1; FDKmemclear(h_sbrTransientDetector,sizeof(SBR_TRANSIENT_DETECTOR)); h_sbrTransientDetector->frameShift = frameShift; h_sbrTransientDetector->tran_off = tran_off; if(codecBitrate) { bitrateFactor_fix = fDivNorm((FIXP_DBL)totalBitrate, (FIXP_DBL)(codecBitrate<<2),&scale_0); } else { bitrateFactor_fix = FL2FXCONST_DBL(1.0/4.0); scale_0 = 0; } framedur_fix = fDivNorm(frameSize, sampleFreq); /* The longer the frames, the more often should the FIXFIX- case transmit 2 envelopes instead of 1. Frame durations below 10 ms produce the highest threshold so that practically always only 1 env is transmitted. */ FIXP_DBL tmp = framedur_fix - FL2FXCONST_DBL(0.010); tmp = fixMax(tmp, FL2FXCONST_DBL(0.0001)); tmp = fDivNorm(FL2FXCONST_DBL(0.000075), fPow2(tmp), &scale_1); scale_1 = -(scale_1 + scale_0 + 2); FDK_ASSERT(no_cols <= QMF_MAX_TIME_SLOTS); FDK_ASSERT(no_rows <= QMF_CHANNELS); h_sbrTransientDetector->no_cols = no_cols; h_sbrTransientDetector->tran_thr = (FIXP_DBL)((params->tran_thr << (32-24-1)) / no_rows); h_sbrTransientDetector->tran_fc = tran_fc; if (scale_1>=0) { h_sbrTransientDetector->split_thr = fMult(tmp, bitrateFactor_fix) >> scale_1; } else { h_sbrTransientDetector->split_thr = fMult(tmp, bitrateFactor_fix) << (-scale_1); } h_sbrTransientDetector->no_rows = no_rows; h_sbrTransientDetector->mode = params->tran_det_mode; h_sbrTransientDetector->prevLowBandEnergy = FL2FXCONST_DBL(0.0f); return (0); }