diff options
author | Dave Burke <daveburke@google.com> | 2012-04-17 09:51:45 -0700 |
---|---|---|
committer | Dave Burke <daveburke@google.com> | 2012-04-17 23:04:43 -0700 |
commit | 9bf37cc9712506b2483650c82d3c41152337ef7e (patch) | |
tree | 77db44e2bae06e3d144b255628be2b7a55c581d3 /libSBRenc/src/nf_est.cpp | |
parent | a37315fe10ee143d6d0b28c19d41a476a23e63ea (diff) | |
download | fdk-aac-9bf37cc9712506b2483650c82d3c41152337ef7e.tar.gz fdk-aac-9bf37cc9712506b2483650c82d3c41152337ef7e.tar.bz2 fdk-aac-9bf37cc9712506b2483650c82d3c41152337ef7e.zip |
Fraunhofer AAC codec.
License boilerplate update to follow.
Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5
Diffstat (limited to 'libSBRenc/src/nf_est.cpp')
-rw-r--r-- | libSBRenc/src/nf_est.cpp | 518 |
1 files changed, 518 insertions, 0 deletions
diff --git a/libSBRenc/src/nf_est.cpp b/libSBRenc/src/nf_est.cpp new file mode 100644 index 0000000..168698d --- /dev/null +++ b/libSBRenc/src/nf_est.cpp @@ -0,0 +1,518 @@ +/**************************************************************************** + + (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 "nf_est.h" + +#include "sbr_misc.h" + +#include "genericStds.h" + +/* smoothFilter[4] = {0.05857864376269f, 0.2f, 0.34142135623731f, 0.4f}; */ +static const FIXP_DBL smoothFilter[4] = { 0x077f813d, 0x19999995, 0x2bb3b1f5, 0x33333335 }; + +/* static const INT smoothFilterLength = 4; */ + +static const FIXP_DBL QuantOffset = (INT)0xfc000000; /* ld64(0.25) */ + +#ifndef min +#define min(a,b) ( a < b ? a:b) +#endif + +#ifndef max +#define max(a,b) ( a > b ? a:b) +#endif + +#define NOISE_FLOOR_OFFSET_SCALING (3) + + + +/**************************************************************************/ +/*! + \brief The function applies smoothing to the noise levels. + + + + \return none + +*/ +/**************************************************************************/ +static void +smoothingOfNoiseLevels(FIXP_DBL *NoiseLevels, /*!< pointer to noise-floor levels.*/ + INT nEnvelopes, /*!< Number of noise floor envelopes.*/ + INT noNoiseBands, /*!< Number of noise bands for every noise floor envelope. */ + FIXP_DBL prevNoiseLevels[NF_SMOOTHING_LENGTH][MAX_NUM_NOISE_VALUES],/*!< Previous noise floor envelopes. */ + const FIXP_DBL *smoothFilter, /*!< filter used for smoothing the noise floor levels. */ + INT transientFlag) /*!< flag indicating if a transient is present*/ + +{ + INT i,band,env; + FIXP_DBL accu; + + for(env = 0; env < nEnvelopes; env++){ + if(transientFlag){ + for (i = 0; i < NF_SMOOTHING_LENGTH; i++){ + FDKmemcpy(prevNoiseLevels[i],NoiseLevels+env*noNoiseBands,noNoiseBands*sizeof(FIXP_DBL)); + } + } + else { + for (i = 1; i < NF_SMOOTHING_LENGTH; i++){ + FDKmemcpy(prevNoiseLevels[i - 1],prevNoiseLevels[i],noNoiseBands*sizeof(FIXP_DBL)); + } + FDKmemcpy(prevNoiseLevels[NF_SMOOTHING_LENGTH - 1],NoiseLevels+env*noNoiseBands,noNoiseBands*sizeof(FIXP_DBL)); + } + + for (band = 0; band < noNoiseBands; band++){ + accu = FL2FXCONST_DBL(0.0f); + for (i = 0; i < NF_SMOOTHING_LENGTH; i++){ + accu += fMultDiv2(smoothFilter[i], prevNoiseLevels[i][band]); + } + FDK_ASSERT( (band + env*noNoiseBands) < MAX_NUM_NOISE_VALUES); + NoiseLevels[band+ env*noNoiseBands] = accu<<1; + } + } +} + +/**************************************************************************/ +/*! + \brief Does the noise floor level estiamtion. + + The noiseLevel samples are scaled by the factor 0.25 + + \return none + +*/ +/**************************************************************************/ +static void +qmfBasedNoiseFloorDetection(FIXP_DBL *noiseLevel, /*!< Pointer to vector to store the noise levels in.*/ + FIXP_DBL ** quotaMatrixOrig, /*!< Matrix holding the quota values of the original. */ + SCHAR *indexVector, /*!< Index vector to obtain the patched data. */ + INT startIndex, /*!< Start index. */ + INT stopIndex, /*!< Stop index. */ + INT startChannel, /*!< Start channel of the current noise floor band.*/ + INT stopChannel, /*!< Stop channel of the current noise floor band. */ + FIXP_DBL ana_max_level, /*!< Maximum level of the adaptive noise.*/ + FIXP_DBL noiseFloorOffset, /*!< Noise floor offset. */ + INT missingHarmonicFlag, /*!< Flag indicating if a strong tonal component is missing.*/ + FIXP_DBL weightFac, /*!< Weightening factor for the difference between orig and sbr. */ + INVF_MODE diffThres, /*!< Threshold value to control the inverse filtering decision.*/ + INVF_MODE inverseFilteringLevel) /*!< Inverse filtering level of the current band.*/ +{ + INT scale, l, k; + FIXP_DBL meanOrig=FL2FXCONST_DBL(0.0f), meanSbr=FL2FXCONST_DBL(0.0f), diff; + FIXP_DBL invIndex = GetInvInt(stopIndex-startIndex); + FIXP_DBL invChannel = GetInvInt(stopChannel-startChannel); + FIXP_DBL accu; + + /* + Calculate the mean value, over the current time segment, for the original, the HFR + and the difference, over all channels in the current frequency range. + */ + + if(missingHarmonicFlag == 1){ + for(l = startChannel; l < stopChannel;l++){ + /* tonalityOrig */ + accu = FL2FXCONST_DBL(0.0f); + for(k = startIndex ; k < stopIndex; k++){ + accu += fMultDiv2(quotaMatrixOrig[k][l], invIndex); + } + meanOrig = fixMax(meanOrig,(accu<<1)); + + /* tonalitySbr */ + accu = FL2FXCONST_DBL(0.0f); + for(k = startIndex ; k < stopIndex; k++){ + accu += fMultDiv2(quotaMatrixOrig[k][indexVector[l]], invIndex); + } + meanSbr = fixMax(meanSbr,(accu<<1)); + + } + } + else{ + for(l = startChannel; l < stopChannel;l++){ + /* tonalityOrig */ + accu = FL2FXCONST_DBL(0.0f); + for(k = startIndex ; k < stopIndex; k++){ + accu += fMultDiv2(quotaMatrixOrig[k][l], invIndex); + } + meanOrig += fMult((accu<<1), invChannel); + + /* tonalitySbr */ + accu = FL2FXCONST_DBL(0.0f); + for(k = startIndex ; k < stopIndex; k++){ + accu += fMultDiv2(quotaMatrixOrig[k][indexVector[l]], invIndex); + } + meanSbr += fMult((accu<<1), invChannel); + } + } + + /* Small fix to avoid noise during silent passages.*/ + if( meanOrig <= FL2FXCONST_DBL(0.000976562f*RELAXATION_FLOAT) && + meanSbr <= FL2FXCONST_DBL(0.000976562f*RELAXATION_FLOAT) ) + { + meanOrig = FL2FXCONST_DBL(101.5936673f*RELAXATION_FLOAT); + meanSbr = FL2FXCONST_DBL(101.5936673f*RELAXATION_FLOAT); + } + + meanOrig = fixMax(meanOrig,RELAXATION); + meanSbr = fixMax(meanSbr,RELAXATION); + + if (missingHarmonicFlag == 1 || + inverseFilteringLevel == INVF_MID_LEVEL || + inverseFilteringLevel == INVF_LOW_LEVEL || + inverseFilteringLevel == INVF_OFF || + inverseFilteringLevel <= diffThres) + { + diff = RELAXATION; + } + else { + accu = fDivNorm(meanSbr, meanOrig, &scale); + + diff = fixMax( RELAXATION, + fMult(RELAXATION_FRACT,fMult(weightFac,accu)) >>( RELAXATION_SHIFT-scale ) ) ; + } + + /* + * noise Level is now a positive value, i.e. + * the more harmonic the signal is the higher noise level, + * this makes no sense so we change the sign. + *********************************************************/ + accu = fDivNorm(diff, meanOrig, &scale); + scale -= 2; + + if ( (scale>0) && (accu > ((FIXP_DBL)MAXVAL_DBL)>>scale) ) { + *noiseLevel = (FIXP_DBL)MAXVAL_DBL; + } + else { + *noiseLevel = scaleValue(accu, scale); + } + + /* + * Add a noise floor offset to compensate for bias in the detector + *****************************************************************/ + if(!missingHarmonicFlag) + *noiseLevel = fMult(*noiseLevel, noiseFloorOffset)<<(NOISE_FLOOR_OFFSET_SCALING); + + /* + * check to see that we don't exceed the maximum allowed level + **************************************************************/ + *noiseLevel = fixMin(*noiseLevel, ana_max_level); /* ana_max_level is scaled with factor 0.25 */ +} + +/**************************************************************************/ +/*! + \brief Does the noise floor level estiamtion. + The function calls the Noisefloor estimation function + for the time segments decided based upon the transient + information. The block is always divided into one or two segments. + + + \return none + +*/ +/**************************************************************************/ +void +FDKsbrEnc_sbrNoiseFloorEstimateQmf(HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */ + const SBR_FRAME_INFO *frame_info, /*!< Time frequency grid of the current frame. */ + FIXP_DBL *noiseLevels, /*!< Pointer to vector to store the noise levels in.*/ + FIXP_DBL **quotaMatrixOrig, /*!< Matrix holding the quota values of the original. */ + SCHAR *indexVector, /*!< Index vector to obtain the patched data. */ + INT missingHarmonicsFlag, /*!< Flag indicating if a strong tonal component will be missing. */ + INT startIndex, /*!< Start index. */ + int numberOfEstimatesPerFrame, /*!< The number of tonality estimates per frame. */ + int transientFrame, /*!< A flag indicating if a transient is present. */ + INVF_MODE* pInvFiltLevels, /*!< Pointer to the vector holding the inverse filtering levels. */ + UINT sbrSyntaxFlags + ) + +{ + + INT nNoiseEnvelopes, startPos[2], stopPos[2], env, band; + + INT noNoiseBands = h_sbrNoiseFloorEstimate->noNoiseBands; + INT *freqBandTable = h_sbrNoiseFloorEstimate->freqBandTableQmf; + + nNoiseEnvelopes = frame_info->nNoiseEnvelopes; + + if (sbrSyntaxFlags & SBR_SYNTAX_LOW_DELAY) { + nNoiseEnvelopes = 1; + startPos[0] = startIndex; + stopPos[0] = startIndex + min(numberOfEstimatesPerFrame,2); + } else + if(nNoiseEnvelopes == 1){ + startPos[0] = startIndex; + stopPos[0] = startIndex + 2; + } + else{ + startPos[0] = startIndex; + stopPos[0] = startIndex + 1; + startPos[1] = startIndex + 1; + stopPos[1] = startIndex + 2; + } + + /* + * Estimate the noise floor. + **************************************/ + for(env = 0; env < nNoiseEnvelopes; env++){ + for(band = 0; band < noNoiseBands; band++){ + FDK_ASSERT( (band + env*noNoiseBands) < MAX_NUM_NOISE_VALUES); + qmfBasedNoiseFloorDetection(&noiseLevels[band + env*noNoiseBands], + quotaMatrixOrig, + indexVector, + startPos[env], + stopPos[env], + freqBandTable[band], + freqBandTable[band+1], + h_sbrNoiseFloorEstimate->ana_max_level, + h_sbrNoiseFloorEstimate->noiseFloorOffset[band], + missingHarmonicsFlag, + h_sbrNoiseFloorEstimate->weightFac, + h_sbrNoiseFloorEstimate->diffThres, + pInvFiltLevels[band]); + } + } + + + /* + * Smoothing of the values. + **************************/ + smoothingOfNoiseLevels(noiseLevels, + nNoiseEnvelopes, + h_sbrNoiseFloorEstimate->noNoiseBands, + h_sbrNoiseFloorEstimate->prevNoiseLevels, + h_sbrNoiseFloorEstimate->smoothFilter, + transientFrame); + + + /* quantisation*/ + for(env = 0; env < nNoiseEnvelopes; env++){ + for(band = 0; band < noNoiseBands; band++){ + FDK_ASSERT( (band + env*noNoiseBands) < MAX_NUM_NOISE_VALUES); + noiseLevels[band + env*noNoiseBands] = + (FIXP_DBL)NOISE_FLOOR_OFFSET_64 - (FIXP_DBL)CalcLdData(noiseLevels[band + env*noNoiseBands]+(FIXP_DBL)1) + QuantOffset; + } + } +} + +/**************************************************************************/ +/*! + \brief + + + \return errorCode, noError if successful + +*/ +/**************************************************************************/ +static INT +downSampleLoRes(INT *v_result, /*!< */ + INT num_result, /*!< */ + const UCHAR *freqBandTableRef,/*!< */ + INT num_Ref) /*!< */ +{ + INT step; + INT i,j; + INT org_length,result_length; + INT v_index[MAX_FREQ_COEFFS/2]; + + /* init */ + org_length=num_Ref; + result_length=num_result; + + v_index[0]=0; /* Always use left border */ + i=0; + while(org_length > 0) /* Create downsample vector */ + { + i++; + step=org_length/result_length; /* floor; */ + org_length=org_length - step; + result_length--; + v_index[i]=v_index[i-1]+step; + } + + if(i != num_result ) /* Should never happen */ + return (1);/* error downsampling */ + + for(j=0;j<=i;j++) /* Use downsample vector to index LoResolution vector. */ + { + v_result[j]=freqBandTableRef[v_index[j]]; + } + + return (0); +} + +/**************************************************************************/ +/*! + \brief Initialize an instance of the noise floor level estimation module. + + + \return errorCode, noError if successful + +*/ +/**************************************************************************/ +INT +FDKsbrEnc_InitSbrNoiseFloorEstimate (HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */ + INT ana_max_level, /*!< Maximum level of the adaptive noise. */ + const UCHAR *freqBandTable, /*!< Frequany band table. */ + INT nSfb, /*!< Number of frequency bands. */ + INT noiseBands, /*!< Number of noise bands per octave. */ + INT noiseFloorOffset, /*!< Noise floor offset. */ + INT timeSlots, /*!< Number of time slots in a frame. */ + UINT useSpeechConfig /*!< Flag: adapt tuning parameters according to speech */ + ) +{ + INT i, qexp, qtmp; + FIXP_DBL tmp, exp; + + FDKmemclear(h_sbrNoiseFloorEstimate,sizeof(SBR_NOISE_FLOOR_ESTIMATE)); + + h_sbrNoiseFloorEstimate->smoothFilter = smoothFilter; + if (useSpeechConfig) { + h_sbrNoiseFloorEstimate->weightFac = (FIXP_DBL)MAXVAL_DBL; + h_sbrNoiseFloorEstimate->diffThres = INVF_LOW_LEVEL; + } + else { + h_sbrNoiseFloorEstimate->weightFac = FL2FXCONST_DBL(0.25f); + h_sbrNoiseFloorEstimate->diffThres = INVF_MID_LEVEL; + } + + h_sbrNoiseFloorEstimate->timeSlots = timeSlots; + h_sbrNoiseFloorEstimate->noiseBands = noiseBands; + + /* h_sbrNoiseFloorEstimate->ana_max_level is scaled by 0.25 */ + switch(ana_max_level) + { + case 6: + h_sbrNoiseFloorEstimate->ana_max_level = (FIXP_DBL)MAXVAL_DBL; + break; + case 3: + h_sbrNoiseFloorEstimate->ana_max_level = FL2FXCONST_DBL(0.5); + break; + case -3: + h_sbrNoiseFloorEstimate->ana_max_level = FL2FXCONST_DBL(0.125); + break; + default: + /* Should not enter here */ + h_sbrNoiseFloorEstimate->ana_max_level = (FIXP_DBL)MAXVAL_DBL; + break; + } + + /* + calculate number of noise bands and allocate + */ + if(FDKsbrEnc_resetSbrNoiseFloorEstimate(h_sbrNoiseFloorEstimate,freqBandTable,nSfb)) + return(1); + + if(noiseFloorOffset == 0) { + tmp = ((FIXP_DBL)MAXVAL_DBL)>>NOISE_FLOOR_OFFSET_SCALING; + } + else { + FDK_ASSERT(noiseFloorOffset<=8); /* because of NOISE_FLOOR_OFFSET_SCALING */ + + /* Assumes the noise floor offset in tuning table are in q31 */ + /* Currently the table contains only 0 for noise floor offset */ + /* Change the qformat here when non-zero values would be filled */ + exp = fDivNorm((FIXP_DBL)noiseFloorOffset, 3, &qexp); + tmp = fPow(2, DFRACT_BITS-1, exp, qexp, &qtmp); + tmp = scaleValue(tmp, qtmp-NOISE_FLOOR_OFFSET_SCALING); + } + + for(i=0;i<h_sbrNoiseFloorEstimate->noNoiseBands;i++) { + h_sbrNoiseFloorEstimate->noiseFloorOffset[i] = tmp; + } + + return (0); +} + +/**************************************************************************/ +/*! + \brief Resets the current instance of the noise floor estiamtion + module. + + + \return errorCode, noError if successful + +*/ +/**************************************************************************/ +INT +FDKsbrEnc_resetSbrNoiseFloorEstimate (HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */ + const UCHAR *freqBandTable, /*!< Frequany band table. */ + INT nSfb) /*!< Number of bands in the frequency band table. */ +{ + INT k2,kx; + + /* + * Calculate number of noise bands + ***********************************/ + k2=freqBandTable[nSfb]; + kx=freqBandTable[0]; + if(h_sbrNoiseFloorEstimate->noiseBands == 0){ + h_sbrNoiseFloorEstimate->noNoiseBands = 1; + } + else{ + /* + * Calculate number of noise bands 1,2 or 3 bands/octave + ********************************************************/ + FIXP_DBL tmp, ratio, lg2; + INT ratio_e, qlg2; + + ratio = fDivNorm(k2, kx, &ratio_e); + lg2 = fLog2(ratio, ratio_e, &qlg2); + tmp = fMult((FIXP_DBL)(h_sbrNoiseFloorEstimate->noiseBands<<24), lg2); + tmp = scaleValue(tmp, qlg2-23); + + h_sbrNoiseFloorEstimate->noNoiseBands = (INT)((tmp + (FIXP_DBL)1) >> 1); + + if (h_sbrNoiseFloorEstimate->noNoiseBands > MAX_NUM_NOISE_COEFFS) + h_sbrNoiseFloorEstimate->noNoiseBands = MAX_NUM_NOISE_COEFFS; + + if( h_sbrNoiseFloorEstimate->noNoiseBands==0) + h_sbrNoiseFloorEstimate->noNoiseBands=1; + } + + + return(downSampleLoRes(h_sbrNoiseFloorEstimate->freqBandTableQmf, + h_sbrNoiseFloorEstimate->noNoiseBands, + freqBandTable,nSfb)); +} + +/**************************************************************************/ +/*! + \brief Deletes the current instancce of the noise floor level + estimation module. + + + \return none + +*/ +/**************************************************************************/ +void +FDKsbrEnc_deleteSbrNoiseFloorEstimate (HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate) /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */ +{ + + if (h_sbrNoiseFloorEstimate) { + /* + nothing to do + */ + } +} |