| /* ----------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2018 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 |
| ----------------------------------------------------------------------------- */ |
| |
| /**************************** SBR encoder library ****************************** |
| |
| Author(s): Tobias Chalupka |
| |
| Description: SBR encoder transient detector |
| |
| *******************************************************************************/ |
| |
| #include "tran_det.h" |
| |
| #include "fram_gen.h" |
| #include "sbrenc_ram.h" |
| #include "sbr_misc.h" |
| |
| #include "genericStds.h" |
| |
| #define NORM_QMF_ENERGY 9.31322574615479E-10 /* 2^-30 */ |
| |
| /* 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 |
| *******************************************************************************/ |
| #define NRG_SHIFT 3 /* for energy summation */ |
| |
| 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 YBufferWriteOffset, INT stop, INT *result_e) { |
| INT i, j; |
| INT len1, len2; |
| SCHAR energies_e_diff[NUMBER_TIME_SLOTS_2304], energies_e, energyTotal_e = 19, |
| energies_e_add; |
| SCHAR prevEnergies_e_diff, newEnergies_e_diff; |
| FIXP_DBL tmp0, tmp1; |
| FIXP_DBL delta, delta_sum; |
| INT accu_e, tmp_e; |
| |
| delta_sum = FL2FXCONST_DBL(0.0f); |
| *result_e = 0; |
| |
| 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); |
| |
| /*** Calc scaling for energies ***/ |
| FDK_ASSERT(scaleEnergies[0] >= 0); |
| FDK_ASSERT(scaleEnergies[1] >= 0); |
| |
| energies_e = 19 - fMin(scaleEnergies[0], scaleEnergies[1]); |
| |
| /* limit shift for energy accumulation, energies_e can be -10 min. */ |
| if (energies_e < -10) { |
| energies_e_add = -10 - energies_e; |
| energies_e = -10; |
| } else if (energies_e > 17) { |
| energies_e_add = energies_e - 17; |
| energies_e = 17; |
| } else { |
| energies_e_add = 0; |
| } |
| |
| /* compensate scaling differences between scaleEnergies[0] and |
| * scaleEnergies[1] */ |
| prevEnergies_e_diff = scaleEnergies[0] - |
| fMin(scaleEnergies[0], scaleEnergies[1]) + |
| energies_e_add + NRG_SHIFT; |
| newEnergies_e_diff = scaleEnergies[1] - |
| fMin(scaleEnergies[0], scaleEnergies[1]) + |
| energies_e_add + NRG_SHIFT; |
| |
| prevEnergies_e_diff = fMin(prevEnergies_e_diff, DFRACT_BITS - 1); |
| newEnergies_e_diff = fMin(newEnergies_e_diff, DFRACT_BITS - 1); |
| |
| for (i = start; i < YBufferWriteOffset; i++) { |
| energies_e_diff[i] = prevEnergies_e_diff; |
| } |
| for (i = YBufferWriteOffset; i < stop; i++) { |
| energies_e_diff[i] = newEnergies_e_diff; |
| } |
| |
| /* Sum up energies of all QMF-timeslots for both halfs */ |
| FDK_ASSERT(len1 <= 8); /* otherwise an overflow is possible */ |
| FDK_ASSERT(len2 <= 8); /* otherwise an overflow is possible */ |
| |
| for (j = 0; j < nSfb; j++) { |
| FIXP_DBL accu1 = FL2FXCONST_DBL(0.f); |
| FIXP_DBL accu2 = FL2FXCONST_DBL(0.f); |
| accu_e = energies_e + 3; |
| |
| /* Sum up energies in first half */ |
| for (i = start; i < border; i++) { |
| accu1 += scaleValue(Energies[i][j], -energies_e_diff[i]); |
| } |
| |
| /* Sum up energies in second half */ |
| for (i = border; i < stop; i++) { |
| accu2 += scaleValue(Energies[i][j], -energies_e_diff[i]); |
| } |
| |
| /* Ensure certain energy to prevent division by zero and to prevent |
| * splitting for very low levels */ |
| accu1 = fMax(accu1, (FIXP_DBL)len1); |
| accu2 = fMax(accu2, (FIXP_DBL)len2); |
| |
| /* Energy change in current band */ |
| #define LN2 FL2FXCONST_DBL(0.6931471806f) /* ln(2) */ |
| tmp0 = fLog2(accu2, accu_e) - fLog2(accu1, accu_e); |
| tmp1 = fLog2((FIXP_DBL)len1, 31) - fLog2((FIXP_DBL)len2, 31); |
| delta = fMult(LN2, (tmp0 + tmp1)); |
| delta = (FIXP_DBL)fAbs(delta); |
| |
| /* Weighting with amplitude ratio of this band */ |
| accu_e++; /* scale at least one bit due to (accu1+accu2) */ |
| accu1 >>= 1; |
| accu2 >>= 1; |
| |
| if (accu_e & 1) { |
| accu_e++; /* for a defined square result exponent, the exponent has to be |
| even */ |
| accu1 >>= 1; |
| accu2 >>= 1; |
| } |
| |
| delta_sum += fMult(sqrtFixp(accu1 + accu2), delta); |
| *result_e = ((accu_e >> 1) + LD_DATA_SHIFT); |
| } |
| |
| if (energyTotal_e & 1) { |
| energyTotal_e += 1; /* for a defined square result exponent, the exponent |
| has to be even */ |
| EnergyTotal >>= 1; |
| } |
| |
| delta_sum = fMult(delta_sum, invSqrtNorm2(EnergyTotal, &tmp_e)); |
| *result_e = *result_e + (tmp_e - (energyTotal_e >> 1)); |
| |
| return fMult(delta_sum, pos_weight); |
| } |
| |
| /******************************************************************************* |
| Functionname: addLowbandEnergies |
| ******************************************************************************* |
| \brief Calculates total lowband energy |
| |
| The input values Energies[0] (low-band) are scaled by the factor |
| 2^(14-*scaleEnergies[0]) |
| The input values Energies[1] (high-band) are scaled by the factor |
| 2^(14-*scaleEnergies[1]) |
| |
| \return total energy in the lowband, scaled by the factor 2^19 |
| *******************************************************************************/ |
| static FIXP_DBL addLowbandEnergies(FIXP_DBL **Energies, int *scaleEnergies, |
| int YBufferWriteOffset, int nrgSzShift, |
| int tran_off, UCHAR *freqBandTable, |
| int slots) { |
| INT nrgTotal_e; |
| FIXP_DBL nrgTotal_m; |
| FIXP_DBL accu1 = FL2FXCONST_DBL(0.0f); |
| FIXP_DBL accu2 = FL2FXCONST_DBL(0.0f); |
| int tran_offdiv2 = tran_off >> nrgSzShift; |
| const int sc1 = |
| DFRACT_BITS - |
| fNormz((FIXP_DBL)fMax( |
| 1, (freqBandTable[0] * (YBufferWriteOffset - tran_offdiv2) - 1))); |
| const int sc2 = |
| DFRACT_BITS - |
| fNormz((FIXP_DBL)fMax( |
| 1, (freqBandTable[0] * |
| (tran_offdiv2 + (slots >> nrgSzShift) - YBufferWriteOffset) - |
| 1))); |
| int ts, k; |
| |
| /* Sum up lowband energy from one frame at offset tran_off */ |
| /* freqBandTable[LORES] has MAX_FREQ_COEFFS/2 +1 coeefs max. */ |
| for (ts = tran_offdiv2; ts < YBufferWriteOffset; ts++) { |
| for (k = 0; k < freqBandTable[0]; k++) { |
| accu1 += Energies[ts][k] >> sc1; |
| } |
| } |
| for (; ts < tran_offdiv2 + (slots >> nrgSzShift); ts++) { |
| for (k = 0; k < freqBandTable[0]; k++) { |
| accu2 += Energies[ts][k] >> sc2; |
| } |
| } |
| |
| nrgTotal_m = fAddNorm(accu1, (sc1 - 5) - scaleEnergies[0], accu2, |
| (sc2 - 5) - scaleEnergies[1], &nrgTotal_e); |
| nrgTotal_m = scaleValueSaturate(nrgTotal_m, nrgTotal_e); |
| |
| return (nrgTotal_m); |
| } |
| |
| /******************************************************************************* |
| 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 (2^19-scaleEnergies[0]) for |
| slots<YBufferWriteOffset and by the factor (2^19-scaleEnergies[1]) for |
| slots>=YBufferWriteOffset. |
| |
| \return total energy in the highband, scaled by factor 2^19 |
| *******************************************************************************/ |
| |
| static FIXP_DBL addHighbandEnergies( |
| FIXP_DBL **RESTRICT Energies, /*!< input */ |
| INT *scaleEnergies, INT YBufferWriteOffset, |
| 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[2]; |
| 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++) { |
| /* Note: Below slotIn = slotOut and not slotIn = timeStep*slotOut |
| because the Energies[] time resolution is always the SBR slot resolution |
| regardless of the timeStep. */ |
| slotIn = 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][k] >> 5; |
| } |
| } |
| EnergiesM[slotOut][j] = accu; |
| } |
| } |
| |
| /* scale energies down before add up */ |
| scale[0] = fixMin(8, scaleEnergies[0]); |
| scale[1] = fixMin(8, scaleEnergies[1]); |
| |
| if ((scaleEnergies[0] - scale[0]) > (DFRACT_BITS - 1) || |
| (scaleEnergies[1] - scale[1]) > (DFRACT_BITS - 1)) |
| nrgTotal = FL2FXCONST_DBL(0.0f); |
| else { |
| /* Now add all energies */ |
| accu = FL2FXCONST_DBL(0.0f); |
| |
| for (slotOut = 0; slotOut < YBufferWriteOffset; slotOut++) { |
| for (j = 0; j < nSfb; j++) { |
| accu += (EnergiesM[slotOut][j] >> scale[0]); |
| } |
| } |
| nrgTotal = accu >> (scaleEnergies[0] - scale[0]); |
| |
| for (slotOut = YBufferWriteOffset; slotOut < sbrSlots; slotOut++) { |
| for (j = 0; j < nSfb; j++) { |
| accu += (EnergiesM[slotOut][j] >> scale[0]); |
| } |
| } |
| nrgTotal = fAddSaturate(nrgTotal, accu >> (scaleEnergies[1] - scale[1])); |
| } |
| |
| 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, FIXP_DBL *tonality) { |
| if (tran_vector[1] == 0) /* no transient was detected */ |
| { |
| FIXP_DBL delta; |
| INT delta_e; |
| FIXP_DBL(*EnergiesM)[MAX_FREQ_COEFFS]; |
| FIXP_DBL EnergyTotal, newLowbandEnergy, newHighbandEnergy; |
| INT border; |
| INT sbrSlots = fMultI(GetInvInt(timeStep), no_cols); |
| C_ALLOC_SCRATCH_START(_EnergiesM, FIXP_DBL, |
| NUMBER_TIME_SLOTS_2304 * MAX_FREQ_COEFFS) |
| |
| FDK_ASSERT(sbrSlots * timeStep == no_cols); |
| |
| EnergiesM = (FIXP_DBL(*)[MAX_FREQ_COEFFS])_EnergiesM; |
| |
| /* |
| 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, YBufferWriteOffset, |
| EnergiesM, freqBandTable, nSfb, sbrSlots, timeStep); |
| |
| { |
| /* 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 >> 1) + |
| (h_sbrTransientDetector->prevLowBandEnergy >> |
| 1); /* mean of new and prev LB NRG */ |
| EnergyTotal = |
| fAddSaturate(EnergyTotal, newHighbandEnergy); /* Add HB NRG */ |
| /* The below border should specify the same position as the middle border |
| of a FIXFIX-frame with 2 envelopes. */ |
| border = (sbrSlots + 1) >> 1; |
| |
| if ((INT)EnergyTotal & 0xffffffe0 && |
| (scaleEnergies[0] < 32 || scaleEnergies[1] < 32)) /* i.e. > 31 */ { |
| delta = spectralChange(EnergiesM, scaleEnergies, EnergyTotal, nSfb, 0, |
| border, YBufferWriteOffset, sbrSlots, &delta_e); |
| } else { |
| delta = FL2FXCONST_DBL(0.0f); |
| delta_e = 0; |
| |
| /* set tonality to 0 when energy is very low, since the amplitude |
| resolution should then be low as well */ |
| *tonality = FL2FXCONST_DBL(0.0f); |
| } |
| |
| if (fIsLessThan(h_sbrTransientDetector->split_thr_m, |
| h_sbrTransientDetector->split_thr_e, delta, delta_e)) { |
| tran_vector[0] = 1; /* Set flag for splitting */ |
| } else { |
| tran_vector[0] = 0; |
| } |
| } |
| |
| /* Update prevLowBandEnergy */ |
| h_sbrTransientDetector->prevLowBandEnergy = newLowbandEnergy; |
| h_sbrTransientDetector->prevHighBandEnergy = newHighbandEnergy; |
| C_ALLOC_SCRATCH_END(_EnergiesM, FIXP_DBL, |
| NUMBER_TIME_SLOTS_2304 * MAX_FREQ_COEFFS) |
| } |
| } |
| |
| /* |
| * 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 = fMultAddDiv2(accu0, Energies[j][i], i_noCols); |
| for (; j < endEnergy; j++) |
| accu1 = fMultAddDiv2(accu1, Energies[j][i], i_noCols); |
| |
| mean_val = ((accu0 << 1) >> scaleFactor0) + |
| ((accu1 << 1) >> 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 = fPow2Div2(temp); |
| accu = fMultAddDiv2(accu, temp, i_noCols1); |
| } |
| for (; j < endEnergy; j++) { |
| temp = ((FIXP_DBL)mean_val - ((FIXP_DBL)Energies[j][i] >> scaleFactor1)) |
| << shift; |
| temp = fPow2Div2(temp); |
| accu = fMultAddDiv2(accu, temp, i_noCols1); |
| } |
| accu <<= 2; |
| 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 * 32) |
| 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 += EnergiesTemp[jIndex + d]; /* R */ |
| delta -= EnergiesTemp[jIndex - d]; /* L */ |
| delta -= thres; |
| |
| if (delta > (FIXP_DBL)0) { |
| tran = fMultAddDiv2(tran, i_thres, delta); |
| } |
| } |
| transients[jpBM] += (tran << 1); |
| } |
| } |
| C_ALLOC_SCRATCH_END(EnergiesTemp, FIXP_DBL, 2 * 32) |
| } |
| |
| 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, |
| UINT sbrSyntaxFlags, /* SBR syntax flags derived from AOT. */ |
| 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_m, framedur_fix; |
| INT bitrateFactor_e, tmp_e; |
| |
| FDKmemclear(h_sbrTransientDetector, sizeof(SBR_TRANSIENT_DETECTOR)); |
| |
| h_sbrTransientDetector->frameShift = frameShift; |
| h_sbrTransientDetector->tran_off = tran_off; |
| |
| if (codecBitrate) { |
| bitrateFactor_m = fDivNorm((FIXP_DBL)totalBitrate, |
| (FIXP_DBL)(codecBitrate << 2), &bitrateFactor_e); |
| bitrateFactor_e += 2; |
| } else { |
| bitrateFactor_m = FL2FXCONST_DBL(1.0 / 4.0); |
| bitrateFactor_e = 2; |
| } |
| |
| 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), &tmp_e); |
| |
| bitrateFactor_e = (tmp_e + bitrateFactor_e); |
| |
| if (sbrSyntaxFlags & SBR_SYNTAX_LOW_DELAY) { |
| bitrateFactor_e--; /* divide by 2 */ |
| } |
| |
| FDK_ASSERT(no_cols <= 32); |
| FDK_ASSERT(no_rows <= 64); |
| |
| 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; |
| h_sbrTransientDetector->split_thr_m = fMult(tmp, bitrateFactor_m); |
| h_sbrTransientDetector->split_thr_e = bitrateFactor_e; |
| h_sbrTransientDetector->no_rows = no_rows; |
| h_sbrTransientDetector->mode = params->tran_det_mode; |
| h_sbrTransientDetector->prevLowBandEnergy = FL2FXCONST_DBL(0.0f); |
| |
| return (0); |
| } |
| |
| #define ENERGY_SCALING_SIZE 32 |
| |
| INT FDKsbrEnc_InitSbrFastTransientDetector( |
| HANDLE_FAST_TRAN_DET h_sbrFastTransientDetector, |
| const INT time_slots_per_frame, const INT bandwidth_qmf_slot, |
| const INT no_qmf_channels, const INT sbr_qmf_1st_band) { |
| int i; |
| int buff_size; |
| FIXP_DBL myExp; |
| FIXP_DBL myExpSlot; |
| |
| h_sbrFastTransientDetector->lookahead = TRAN_DET_LOOKAHEAD; |
| h_sbrFastTransientDetector->nTimeSlots = time_slots_per_frame; |
| |
| buff_size = h_sbrFastTransientDetector->nTimeSlots + |
| h_sbrFastTransientDetector->lookahead; |
| |
| for (i = 0; i < buff_size; i++) { |
| h_sbrFastTransientDetector->delta_energy[i] = FL2FXCONST_DBL(0.0f); |
| h_sbrFastTransientDetector->energy_timeSlots[i] = FL2FXCONST_DBL(0.0f); |
| h_sbrFastTransientDetector->lowpass_energy[i] = FL2FXCONST_DBL(0.0f); |
| h_sbrFastTransientDetector->transientCandidates[i] = 0; |
| } |
| |
| FDK_ASSERT(bandwidth_qmf_slot > 0.f); |
| h_sbrFastTransientDetector->stopBand = |
| fMin(TRAN_DET_STOP_FREQ / bandwidth_qmf_slot, no_qmf_channels); |
| h_sbrFastTransientDetector->startBand = |
| fMin(sbr_qmf_1st_band, |
| h_sbrFastTransientDetector->stopBand - TRAN_DET_MIN_QMFBANDS); |
| |
| FDK_ASSERT(h_sbrFastTransientDetector->startBand < no_qmf_channels); |
| FDK_ASSERT(h_sbrFastTransientDetector->startBand < |
| h_sbrFastTransientDetector->stopBand); |
| FDK_ASSERT(h_sbrFastTransientDetector->startBand > 1); |
| FDK_ASSERT(h_sbrFastTransientDetector->stopBand > 1); |
| |
| /* the energy weighting and adding up has a headroom of 6 Bits, |
| so up to 64 bands can be added without potential overflow. */ |
| FDK_ASSERT(h_sbrFastTransientDetector->stopBand - |
| h_sbrFastTransientDetector->startBand <= |
| 64); |
| |
| /* QMF_HP_dB_SLOPE_FIX says that we want a 20 dB per 16 kHz HP filter. |
| The following lines map this to the QMF bandwidth. */ |
| #define EXP_E 7 /* 64 (=64) multiplications max, max. allowed sum is 0.5 */ |
| myExp = fMultNorm(QMF_HP_dBd_SLOPE_FIX, 0, (FIXP_DBL)bandwidth_qmf_slot, |
| DFRACT_BITS - 1, EXP_E); |
| myExpSlot = myExp; |
| |
| for (i = 0; i < 64; i++) { |
| /* Calculate dBf over all qmf bands: |
| dBf = (10^(0.002266f/10*bw(slot)))^(band) = |
| = 2^(log2(10)*0.002266f/10*bw(slot)*band) = |
| = 2^(0.00075275f*bw(slot)*band) */ |
| |
| FIXP_DBL dBf_m; /* dBf mantissa */ |
| INT dBf_e; /* dBf exponent */ |
| INT tmp; |
| |
| INT dBf_int; /* dBf integer part */ |
| FIXP_DBL dBf_fract; /* dBf fractional part */ |
| |
| /* myExp*(i+1) = myExp_int - myExp_fract |
| myExp*(i+1) is split up here for better accuracy of CalcInvLdData(), |
| for its result can be split up into an integer and a fractional part */ |
| |
| /* Round up to next integer */ |
| FIXP_DBL myExp_int = |
| (myExpSlot & (FIXP_DBL)0xfe000000) + (FIXP_DBL)0x02000000; |
| |
| /* This is the fractional part that needs to be substracted */ |
| FIXP_DBL myExp_fract = myExp_int - myExpSlot; |
| |
| /* Calc integer part */ |
| dBf_int = CalcInvLdData(myExp_int); |
| /* The result needs to be re-scaled. The ld(myExp_int) had been scaled by |
| EXP_E, the CalcInvLdData expects the operand to be scaled by |
| LD_DATA_SHIFT. Therefore, the correctly scaled result is |
| dBf_int^(2^(EXP_E-LD_DATA_SHIFT)), which is dBf_int^2 */ |
| |
| if (dBf_int <= |
| 46340) { /* compare with maximum allowed value for signed integer |
| multiplication, 46340 = |
| (INT)floor(sqrt((double)(((UINT)1<<(DFRACT_BITS-1))-1))) */ |
| dBf_int *= dBf_int; |
| |
| /* Calc fractional part */ |
| dBf_fract = CalcInvLdData(-myExp_fract); |
| /* The result needs to be re-scaled. The ld(myExp_fract) had been scaled |
| by EXP_E, the CalcInvLdData expects the operand to be scaled by |
| LD_DATA_SHIFT. Therefore, the correctly scaled result is |
| dBf_fract^(2^(EXP_E-LD_DATA_SHIFT)), which is dBf_fract^2 */ |
| dBf_fract = fMultNorm(dBf_fract, dBf_fract, &tmp); |
| |
| /* Get worst case scaling of multiplication result */ |
| dBf_e = (DFRACT_BITS - 1 - tmp) - CountLeadingBits(dBf_int); |
| |
| /* Now multiply integer with fractional part of the result, thus resulting |
| in the overall accurate fractional result */ |
| dBf_m = fMultNorm(dBf_int, DFRACT_BITS - 1, dBf_fract, tmp, dBf_e); |
| |
| myExpSlot += myExp; |
| } else { |
| dBf_m = (FIXP_DBL)0; |
| dBf_e = 0; |
| } |
| |
| /* Keep the results */ |
| h_sbrFastTransientDetector->dBf_m[i] = dBf_m; |
| h_sbrFastTransientDetector->dBf_e[i] = dBf_e; |
| } |
| |
| /* Make sure that dBf is greater than 1.0 (because it should be a highpass) */ |
| /* ... */ |
| |
| return 0; |
| } |
| |
| void FDKsbrEnc_fastTransientDetect( |
| const HANDLE_FAST_TRAN_DET h_sbrFastTransientDetector, |
| const FIXP_DBL *const *Energies, const int *const scaleEnergies, |
| const INT YBufferWriteOffset, UCHAR *const tran_vector) { |
| int timeSlot, band; |
| |
| FIXP_DBL max_delta_energy; /* helper to store maximum energy ratio */ |
| int max_delta_energy_scale; /* helper to store scale of maximum energy ratio |
| */ |
| int ind_max = 0; /* helper to store index of maximum energy ratio */ |
| int isTransientInFrame = 0; |
| |
| const int nTimeSlots = h_sbrFastTransientDetector->nTimeSlots; |
| const int lookahead = h_sbrFastTransientDetector->lookahead; |
| const int startBand = h_sbrFastTransientDetector->startBand; |
| const int stopBand = h_sbrFastTransientDetector->stopBand; |
| |
| int *transientCandidates = h_sbrFastTransientDetector->transientCandidates; |
| |
| FIXP_DBL *energy_timeSlots = h_sbrFastTransientDetector->energy_timeSlots; |
| int *energy_timeSlots_scale = |
| h_sbrFastTransientDetector->energy_timeSlots_scale; |
| |
| FIXP_DBL *delta_energy = h_sbrFastTransientDetector->delta_energy; |
| int *delta_energy_scale = h_sbrFastTransientDetector->delta_energy_scale; |
| |
| const FIXP_DBL thr = TRAN_DET_THRSHLD; |
| const INT thr_scale = TRAN_DET_THRSHLD_SCALE; |
| |
| /*reset transient info*/ |
| tran_vector[2] = 0; |
| |
| /* reset transient candidates */ |
| FDKmemclear(transientCandidates + lookahead, nTimeSlots * sizeof(int)); |
| |
| for (timeSlot = lookahead; timeSlot < nTimeSlots + lookahead; timeSlot++) { |
| int i, norm; |
| FIXP_DBL tmpE = FL2FXCONST_DBL(0.0f); |
| int headroomEnSlot = DFRACT_BITS - 1; |
| |
| FIXP_DBL smallNRG = FL2FXCONST_DBL(1e-2f); |
| FIXP_DBL denominator; |
| INT denominator_scale; |
| |
| /* determine minimum headroom of energy values for this timeslot */ |
| for (band = startBand; band < stopBand; band++) { |
| int tmp_headroom = fNormz(Energies[timeSlot][band]) - 1; |
| if (tmp_headroom < headroomEnSlot) { |
| headroomEnSlot = tmp_headroom; |
| } |
| } |
| |
| for (i = 0, band = startBand; band < stopBand; band++, i++) { |
| /* energy is weighted by weightingfactor stored in dBf_m array */ |
| /* dBf_m index runs from 0 to stopBand-startband */ |
| /* energy shifted by calculated headroom for maximum precision */ |
| FIXP_DBL weightedEnergy = |
| fMult(Energies[timeSlot][band] << headroomEnSlot, |
| h_sbrFastTransientDetector->dBf_m[i]); |
| |
| /* energy is added up */ |
| /* shift by 6 to have a headroom for maximum 64 additions */ |
| /* shift by dBf_e to handle weighting factor dependent scale factors */ |
| tmpE += |
| weightedEnergy >> (6 + (10 - h_sbrFastTransientDetector->dBf_e[i])); |
| } |
| |
| /* store calculated energy for timeslot */ |
| energy_timeSlots[timeSlot] = tmpE; |
| |
| /* calculate overall scale factor for energy of this timeslot */ |
| /* = original scale factor of energies |
| * (-scaleEnergies[0]+2*QMF_SCALE_OFFSET or |
| * -scaleEnergies[1]+2*QMF_SCALE_OFFSET */ |
| /* depending on YBufferWriteOffset) */ |
| /* + weighting factor scale (10) */ |
| /* + adding up scale factor ( 6) */ |
| /* - headroom of energy value (headroomEnSlot) */ |
| if (timeSlot < YBufferWriteOffset) { |
| energy_timeSlots_scale[timeSlot] = |
| (-scaleEnergies[0] + 2 * QMF_SCALE_OFFSET) + (10 + 6) - |
| headroomEnSlot; |
| } else { |
| energy_timeSlots_scale[timeSlot] = |
| (-scaleEnergies[1] + 2 * QMF_SCALE_OFFSET) + (10 + 6) - |
| headroomEnSlot; |
| } |
| |
| /* Add a small energy to the denominator, thus making the transient |
| detection energy-dependent. Loud transients are being detected, |
| silent ones not. */ |
| |
| /* make sure that smallNRG does not overflow */ |
| if (-energy_timeSlots_scale[timeSlot - 1] + 1 > 5) { |
| denominator = smallNRG; |
| denominator_scale = 0; |
| } else { |
| /* Leave an additional headroom of 1 bit for this addition. */ |
| smallNRG = |
| scaleValue(smallNRG, -(energy_timeSlots_scale[timeSlot - 1] + 1)); |
| denominator = (energy_timeSlots[timeSlot - 1] >> 1) + smallNRG; |
| denominator_scale = energy_timeSlots_scale[timeSlot - 1] + 1; |
| } |
| |
| delta_energy[timeSlot] = |
| fDivNorm(energy_timeSlots[timeSlot], denominator, &norm); |
| delta_energy_scale[timeSlot] = |
| energy_timeSlots_scale[timeSlot] - denominator_scale + norm; |
| } |
| |
| /*get transient candidates*/ |
| /* For every timeslot, check if delta(E) exceeds the threshold. If it did, |
| it could potentially be marked as a transient candidate. However, the 2 |
| slots before the current one must not be transients with an energy higher |
| than 1.4*E(current). If both aren't transients or if the energy of the |
| current timesolot is more than 1.4 times higher than the energy in the |
| last or the one before the last slot, it is marked as a transient.*/ |
| |
| FDK_ASSERT(lookahead >= 2); |
| for (timeSlot = lookahead; timeSlot < nTimeSlots + lookahead; timeSlot++) { |
| FIXP_DBL energy_cur_slot_weighted = |
| fMult(energy_timeSlots[timeSlot], FL2FXCONST_DBL(1.0f / 1.4f)); |
| if (!fIsLessThan(delta_energy[timeSlot], delta_energy_scale[timeSlot], thr, |
| thr_scale) && |
| (((transientCandidates[timeSlot - 2] == 0) && |
| (transientCandidates[timeSlot - 1] == 0)) || |
| !fIsLessThan(energy_cur_slot_weighted, |
| energy_timeSlots_scale[timeSlot], |
| energy_timeSlots[timeSlot - 1], |
| energy_timeSlots_scale[timeSlot - 1]) || |
| !fIsLessThan(energy_cur_slot_weighted, |
| energy_timeSlots_scale[timeSlot], |
| energy_timeSlots[timeSlot - 2], |
| energy_timeSlots_scale[timeSlot - 2]))) { |
| /* in case of strong transients, subsequent |
| * qmf slots might be recognized as transients. */ |
| transientCandidates[timeSlot] = 1; |
| } |
| } |
| |
| /*get transient with max energy*/ |
| max_delta_energy = FL2FXCONST_DBL(0.0f); |
| max_delta_energy_scale = 0; |
| ind_max = 0; |
| isTransientInFrame = 0; |
| for (timeSlot = 0; timeSlot < nTimeSlots; timeSlot++) { |
| int scale = fMax(delta_energy_scale[timeSlot], max_delta_energy_scale); |
| if (transientCandidates[timeSlot] && |
| ((delta_energy[timeSlot] >> (scale - delta_energy_scale[timeSlot])) > |
| (max_delta_energy >> (scale - max_delta_energy_scale)))) { |
| max_delta_energy = delta_energy[timeSlot]; |
| max_delta_energy_scale = scale; |
| ind_max = timeSlot; |
| isTransientInFrame = 1; |
| } |
| } |
| |
| /*from all transient candidates take the one with the biggest energy*/ |
| if (isTransientInFrame) { |
| tran_vector[0] = ind_max; |
| tran_vector[1] = 1; |
| } else { |
| /*reset transient info*/ |
| tran_vector[0] = tran_vector[1] = 0; |
| } |
| |
| /*check for transients in lookahead*/ |
| for (timeSlot = nTimeSlots; timeSlot < nTimeSlots + lookahead; timeSlot++) { |
| if (transientCandidates[timeSlot]) { |
| tran_vector[2] = 1; |
| } |
| } |
| |
| /*update buffers*/ |
| for (timeSlot = 0; timeSlot < lookahead; timeSlot++) { |
| transientCandidates[timeSlot] = transientCandidates[nTimeSlots + timeSlot]; |
| |
| /* fixpoint stuff */ |
| energy_timeSlots[timeSlot] = energy_timeSlots[nTimeSlots + timeSlot]; |
| energy_timeSlots_scale[timeSlot] = |
| energy_timeSlots_scale[nTimeSlots + timeSlot]; |
| |
| delta_energy[timeSlot] = delta_energy[nTimeSlots + timeSlot]; |
| delta_energy_scale[timeSlot] = delta_energy_scale[nTimeSlots + timeSlot]; |
| } |
| } |
