| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. |
| All rights reserved. |
| |
| 1. INTRODUCTION |
| The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements |
| the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. |
| This FDK AAC Codec software is intended to be used on a wide variety of Android devices. |
| |
| AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual |
| audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by |
| independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part |
| of the MPEG specifications. |
| |
| Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) |
| may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners |
| individually for the purpose of encoding or decoding bit streams in products that are compliant with |
| the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license |
| these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec |
| software may already be covered under those patent licenses when it is used for those licensed purposes only. |
| |
| Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, |
| are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional |
| applications information and documentation. |
| |
| 2. COPYRIGHT LICENSE |
| |
| Redistribution and use in source and binary forms, with or without modification, are permitted without |
| payment of copyright license fees provided that you satisfy the following conditions: |
| |
| You must retain the complete text of this software license in redistributions of the FDK AAC Codec or |
| your modifications thereto in source code form. |
| |
| You must retain the complete text of this software license in the documentation and/or other materials |
| provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. |
| You must make available free of charge copies of the complete source code of the FDK AAC Codec and your |
| modifications thereto to recipients of copies in binary form. |
| |
| The name of Fraunhofer may not be used to endorse or promote products derived from this library without |
| prior written permission. |
| |
| You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec |
| software or your modifications thereto. |
| |
| Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software |
| and the date of any change. For modified versions of the FDK AAC Codec, the term |
| "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term |
| "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." |
| |
| 3. NO PATENT LICENSE |
| |
| NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, |
| ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with |
| respect to this software. |
| |
| You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized |
| by appropriate patent licenses. |
| |
| 4. DISCLAIMER |
| |
| This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors |
| "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties |
| of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR |
| CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, |
| including but not limited to procurement of substitute goods or services; loss of use, data, or profits, |
| or business interruption, however caused and on any theory of liability, whether in contract, strict |
| liability, or tort (including negligence), arising in any way out of the use of this software, even if |
| advised of the possibility of such damage. |
| |
| 5. CONTACT INFORMATION |
| |
| Fraunhofer Institute for Integrated Circuits IIS |
| Attention: Audio and Multimedia Departments - FDK AAC LL |
| Am Wolfsmantel 33 |
| 91058 Erlangen, Germany |
| |
| www.iis.fraunhofer.de/amm |
| amm-info@iis.fraunhofer.de |
| ----------------------------------------------------------------------------------------------------------- */ |
| |
| #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<nSfb; j++) { |
| #define NRG_SCALE 3 |
| /* init with some energy to prevent division by zero |
| and to prevent splitting for very low levels */ |
| accu1 = ((FL2FXCONST_DBL((1.0e6*NORM_QMF_ENERGY*8.0/32))) << fixMin(scaleEnergies[0],25))>>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<border; i++) { |
| accu1 += (Energies[i][j]>>NRG_SCALE); |
| } |
| |
| /* Sum up energies in second half */ |
| for (i=border; i<stop; i++) { |
| accu2 += (Energies[i][j]>>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<YBufferWriteOffset; ts++) { |
| for (k = 0; k < freqBandTable[0]; k++) { |
| accu1 += Energies[ts][k] >> 6; |
| } |
| } |
| for (; ts<tran_offdiv2+(slots>>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<sbrSlots; slotOut++) { |
| slotIn = 2*slotOut; |
| |
| for (j=0; j<nSfb; j++) { |
| accu = FL2FXCONST_DBL(0.0f); |
| |
| li = freqBandTable[j]; |
| ui = freqBandTable[j + 1]; |
| |
| for (k=li; k<ui; k++) { |
| for (i=0; i<timeStep; i++) { |
| accu += (Energies[(slotIn+i)>>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<sbrSlots; slotOut++) { |
| for (j=0; j<nSfb; j++) { |
| accu += (EnergiesM[slotOut][j] >> 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<noRows; i++) |
| { |
| int startEnergy = (tran_off>>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<YBufferWriteOffset; j++) |
| accu0 += fMult(Energies[j][i], i_noCols); |
| for (; j<endEnergy; j++) |
| accu1 += fMult(Energies[j][i], i_noCols); |
| |
| mean_val = (accu0 >> 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<YBufferWriteOffset; j++) { |
| temp = ((FIXP_DBL)mean_val - ((FIXP_DBL)Energies[j][i] >> scaleFactor0))<<shift; |
| temp = fPow2(temp); |
| temp = fMult(temp, i_noCols1); |
| accu += temp; |
| } |
| for (; j<endEnergy; j++) { |
| temp = ((FIXP_DBL)mean_val - ((FIXP_DBL)Energies[j][i] >> scaleFactor1))<<shift; |
| temp = fPow2(temp); |
| temp = fMult(temp, i_noCols1); |
| accu += temp; |
| } |
| |
| std_val = sqrtFixp(accu)>>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))-1)>>YBufferSzShift; /* YBufferSzShift shifts because of half energy values. */ |
| |
| /* Compute differential values with two different weightings in every subband */ |
| for (i=start_band; i<stop_band; i++) |
| { |
| FIXP_DBL thres = thresholds[i]; |
| |
| if((LONG)thresholds[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<YBufferWriteOffset; j++) { |
| FIXP_DBL tmp = Energies[j][i]; |
| EnergiesTemp[(j<<1)+1] = EnergiesTemp[j<<1] = tmp>>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<YBufferWriteOffset; j++) { |
| FIXP_DBL tmp = Energies[j][i]; |
| EnergiesTemp[j] = tmp>>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; i<qmfStartSample + no_cols; 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) { |
| transient_info[0] = (i - qmfStartSample)>>timeStepShift; |
| transient_info[1] = 1; |
| break; |
| } |
| } |
| |
| if ( h_sbrTran->frameShift != 0) { |
| /* transient prediction for LDSBR */ |
| /* Check for transients in first <frameShift> qmf-slots of second frame */ |
| for (i=qmfStartSample+no_cols; i<qmfStartSample + no_cols+h_sbrTran->frameShift; 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); |
| } |
| |
