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      1 
      2 /* -----------------------------------------------------------------------------------------------------------
      3 Software License for The Fraunhofer FDK AAC Codec Library for Android
      4 
      5  Copyright  1995 - 2015 Fraunhofer-Gesellschaft zur Frderung der angewandten Forschung e.V.
      6   All rights reserved.
      7 
      8  1.    INTRODUCTION
      9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
     10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
     11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
     12 
     13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
     14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
     15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
     16 of the MPEG specifications.
     17 
     18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
     19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
     20 individually for the purpose of encoding or decoding bit streams in products that are compliant with
     21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
     22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
     23 software may already be covered under those patent licenses when it is used for those licensed purposes only.
     24 
     25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
     26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
     27 applications information and documentation.
     28 
     29 2.    COPYRIGHT LICENSE
     30 
     31 Redistribution and use in source and binary forms, with or without modification, are permitted without
     32 payment of copyright license fees provided that you satisfy the following conditions:
     33 
     34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
     35 your modifications thereto in source code form.
     36 
     37 You must retain the complete text of this software license in the documentation and/or other materials
     38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
     39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
     40 modifications thereto to recipients of copies in binary form.
     41 
     42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
     43 prior written permission.
     44 
     45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
     46 software or your modifications thereto.
     47 
     48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
     49 and the date of any change. For modified versions of the FDK AAC Codec, the term
     50 "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
     51 "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
     52 
     53 3.    NO PATENT LICENSE
     54 
     55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
     56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
     57 respect to this software.
     58 
     59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
     60 by appropriate patent licenses.
     61 
     62 4.    DISCLAIMER
     63 
     64 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
     65 "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
     66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
     67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
     68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
     69 or business interruption, however caused and on any theory of liability, whether in contract, strict
     70 liability, or tort (including negligence), arising in any way out of the use of this software, even if
     71 advised of the possibility of such damage.
     72 
     73 5.    CONTACT INFORMATION
     74 
     75 Fraunhofer Institute for Integrated Circuits IIS
     76 Attention: Audio and Multimedia Departments - FDK AAC LL
     77 Am Wolfsmantel 33
     78 91058 Erlangen, Germany
     79 
     80 www.iis.fraunhofer.de/amm
     81 amm-info (at) iis.fraunhofer.de
     82 ----------------------------------------------------------------------------------------------------------- */
     83 
     84 #include "nf_est.h"
     85 
     86 #include "sbr_misc.h"
     87 
     88 #include "genericStds.h"
     89 
     90 /* smoothFilter[4]  = {0.05857864376269f, 0.2f, 0.34142135623731f, 0.4f}; */
     91 static const FIXP_DBL smoothFilter[4]  = { 0x077f813d, 0x19999995, 0x2bb3b1f5, 0x33333335 };
     92 
     93 /* static const INT smoothFilterLength = 4; */
     94 
     95 static const FIXP_DBL QuantOffset = (INT)0xfc000000;  /* ld64(0.25) */
     96 
     97 #ifndef min
     98 #define min(a,b) ( a < b ? a:b)
     99 #endif
    100 
    101 #ifndef max
    102 #define max(a,b) ( a > b ? a:b)
    103 #endif
    104 
    105 #define NOISE_FLOOR_OFFSET_SCALING  (4)
    106 
    107 
    108 
    109 /**************************************************************************/
    110 /*!
    111   \brief     The function applies smoothing to the noise levels.
    112 
    113 
    114 
    115   \return    none
    116 
    117 */
    118 /**************************************************************************/
    119 static void
    120 smoothingOfNoiseLevels(FIXP_DBL *NoiseLevels,        /*!< pointer to noise-floor levels.*/
    121                        INT nEnvelopes,               /*!< Number of noise floor envelopes.*/
    122                        INT noNoiseBands,             /*!< Number of noise bands for every noise floor envelope. */
    123                        FIXP_DBL prevNoiseLevels[NF_SMOOTHING_LENGTH][MAX_NUM_NOISE_VALUES],/*!< Previous noise floor envelopes. */
    124                        const FIXP_DBL *smoothFilter, /*!< filter used for smoothing the noise floor levels. */
    125                        INT transientFlag)            /*!< flag indicating if a transient is present*/
    126 
    127 {
    128   INT i,band,env;
    129   FIXP_DBL accu;
    130 
    131   for(env = 0; env < nEnvelopes; env++){
    132     if(transientFlag){
    133       for (i = 0; i < NF_SMOOTHING_LENGTH; i++){
    134         FDKmemcpy(prevNoiseLevels[i],NoiseLevels+env*noNoiseBands,noNoiseBands*sizeof(FIXP_DBL));
    135       }
    136     }
    137     else {
    138       for (i = 1; i < NF_SMOOTHING_LENGTH; i++){
    139         FDKmemcpy(prevNoiseLevels[i - 1],prevNoiseLevels[i],noNoiseBands*sizeof(FIXP_DBL));
    140       }
    141       FDKmemcpy(prevNoiseLevels[NF_SMOOTHING_LENGTH - 1],NoiseLevels+env*noNoiseBands,noNoiseBands*sizeof(FIXP_DBL));
    142     }
    143 
    144     for (band = 0; band < noNoiseBands; band++){
    145       accu = FL2FXCONST_DBL(0.0f);
    146       for (i = 0; i < NF_SMOOTHING_LENGTH; i++){
    147         accu += fMultDiv2(smoothFilter[i], prevNoiseLevels[i][band]);
    148       }
    149       FDK_ASSERT( (band + env*noNoiseBands) < MAX_NUM_NOISE_VALUES);
    150       NoiseLevels[band+ env*noNoiseBands] = accu<<1;
    151     }
    152   }
    153 }
    154 
    155 /**************************************************************************/
    156 /*!
    157   \brief     Does the noise floor level estiamtion.
    158 
    159   The noiseLevel samples are scaled by the factor 0.25
    160 
    161   \return    none
    162 
    163 */
    164 /**************************************************************************/
    165 static void
    166 qmfBasedNoiseFloorDetection(FIXP_DBL *noiseLevel,              /*!< Pointer to vector to store the noise levels in.*/
    167                             FIXP_DBL ** quotaMatrixOrig,       /*!< Matrix holding the quota values of the original. */
    168                             SCHAR *indexVector,                /*!< Index vector to obtain the patched data. */
    169                             INT startIndex,                    /*!< Start index. */
    170                             INT stopIndex,                     /*!< Stop index. */
    171                             INT startChannel,                  /*!< Start channel of the current noise floor band.*/
    172                             INT stopChannel,                   /*!< Stop channel of the current noise floor band. */
    173                             FIXP_DBL ana_max_level,            /*!< Maximum level of the adaptive noise.*/
    174                             FIXP_DBL noiseFloorOffset,         /*!< Noise floor offset. */
    175                             INT missingHarmonicFlag,           /*!< Flag indicating if a strong tonal component is missing.*/
    176                             FIXP_DBL weightFac,                /*!< Weightening factor for the difference between orig and sbr. */
    177                             INVF_MODE diffThres,               /*!< Threshold value to control the inverse filtering decision.*/
    178                             INVF_MODE inverseFilteringLevel)   /*!< Inverse filtering level of the current band.*/
    179 {
    180   INT scale, l, k;
    181   FIXP_DBL meanOrig=FL2FXCONST_DBL(0.0f), meanSbr=FL2FXCONST_DBL(0.0f), diff;
    182   FIXP_DBL invIndex = GetInvInt(stopIndex-startIndex);
    183   FIXP_DBL invChannel = GetInvInt(stopChannel-startChannel);
    184   FIXP_DBL accu;
    185 
    186    /*
    187    Calculate the mean value, over the current time segment, for the original, the HFR
    188    and the difference, over all channels in the current frequency range.
    189    */
    190 
    191   if(missingHarmonicFlag == 1){
    192     for(l = startChannel; l < stopChannel;l++){
    193       /* tonalityOrig */
    194       accu = FL2FXCONST_DBL(0.0f);
    195       for(k = startIndex ; k < stopIndex; k++){
    196         accu += fMultDiv2(quotaMatrixOrig[k][l], invIndex);
    197       }
    198       meanOrig = fixMax(meanOrig,(accu<<1));
    199 
    200       /* tonalitySbr */
    201       accu = FL2FXCONST_DBL(0.0f);
    202       for(k = startIndex ; k < stopIndex; k++){
    203         accu += fMultDiv2(quotaMatrixOrig[k][indexVector[l]], invIndex);
    204       }
    205       meanSbr  = fixMax(meanSbr,(accu<<1));
    206 
    207     }
    208   }
    209   else{
    210     for(l = startChannel; l < stopChannel;l++){
    211       /* tonalityOrig */
    212       accu = FL2FXCONST_DBL(0.0f);
    213       for(k = startIndex ; k < stopIndex; k++){
    214         accu += fMultDiv2(quotaMatrixOrig[k][l], invIndex);
    215       }
    216       meanOrig += fMult((accu<<1), invChannel);
    217 
    218       /* tonalitySbr */
    219       accu = FL2FXCONST_DBL(0.0f);
    220       for(k = startIndex ; k < stopIndex; k++){
    221         accu += fMultDiv2(quotaMatrixOrig[k][indexVector[l]], invIndex);
    222       }
    223       meanSbr  += fMult((accu<<1), invChannel);
    224     }
    225   }
    226 
    227   /* Small fix to avoid noise during silent passages.*/
    228   if( meanOrig <= FL2FXCONST_DBL(0.000976562f*RELAXATION_FLOAT) &&
    229       meanSbr <= FL2FXCONST_DBL(0.000976562f*RELAXATION_FLOAT) )
    230   {
    231     meanOrig = FL2FXCONST_DBL(101.5936673f*RELAXATION_FLOAT);
    232     meanSbr  = FL2FXCONST_DBL(101.5936673f*RELAXATION_FLOAT);
    233   }
    234 
    235   meanOrig = fixMax(meanOrig,RELAXATION);
    236   meanSbr  = fixMax(meanSbr,RELAXATION);
    237 
    238   if (missingHarmonicFlag == 1 ||
    239       inverseFilteringLevel == INVF_MID_LEVEL ||
    240       inverseFilteringLevel == INVF_LOW_LEVEL ||
    241       inverseFilteringLevel == INVF_OFF ||
    242       inverseFilteringLevel <= diffThres)
    243   {
    244     diff = RELAXATION;
    245   }
    246   else {
    247     accu = fDivNorm(meanSbr, meanOrig, &scale);
    248 
    249     diff = fixMax( RELAXATION,
    250                    fMult(RELAXATION_FRACT,fMult(weightFac,accu)) >>( RELAXATION_SHIFT-scale ) ) ;
    251   }
    252 
    253   /*
    254    * noise Level is now a positive value, i.e.
    255    * the more harmonic the signal is the higher noise level,
    256    * this makes no sense so we change the sign.
    257    *********************************************************/
    258   accu = fDivNorm(diff, meanOrig, &scale);
    259   scale -= 2;
    260 
    261   if ( (scale>0) && (accu > ((FIXP_DBL)MAXVAL_DBL)>>scale) ) {
    262     *noiseLevel = (FIXP_DBL)MAXVAL_DBL;
    263   }
    264   else {
    265     *noiseLevel = scaleValue(accu, scale);
    266   }
    267 
    268   /*
    269    * Add a noise floor offset to compensate for bias in the detector
    270    *****************************************************************/
    271   if(!missingHarmonicFlag) {
    272     *noiseLevel = fixMin(fMult(*noiseLevel, noiseFloorOffset), (FIXP_DBL)MAXVAL_DBL>>NOISE_FLOOR_OFFSET_SCALING) << NOISE_FLOOR_OFFSET_SCALING;
    273   }
    274 
    275   /*
    276    * check to see that we don't exceed the maximum allowed level
    277    **************************************************************/
    278   *noiseLevel = fixMin(*noiseLevel, ana_max_level);     /* ana_max_level is scaled with factor 0.25 */
    279 }
    280 
    281 /**************************************************************************/
    282 /*!
    283   \brief     Does the noise floor level estiamtion.
    284   The function calls the Noisefloor estimation function
    285   for the time segments decided based upon the transient
    286   information. The block is always divided into one or two segments.
    287 
    288 
    289   \return    none
    290 
    291 */
    292 /**************************************************************************/
    293 void
    294 FDKsbrEnc_sbrNoiseFloorEstimateQmf(HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */
    295                          const SBR_FRAME_INFO *frame_info,   /*!< Time frequency grid of the current frame. */
    296                          FIXP_DBL *noiseLevels,              /*!< Pointer to vector to store the noise levels in.*/
    297                          FIXP_DBL **quotaMatrixOrig,         /*!< Matrix holding the quota values of the original. */
    298                          SCHAR    *indexVector,              /*!< Index vector to obtain the patched data. */
    299                          INT missingHarmonicsFlag,           /*!< Flag indicating if a strong tonal component will be missing. */
    300                          INT startIndex,                     /*!< Start index. */
    301                          UINT numberOfEstimatesPerFrame,     /*!< The number of tonality estimates per frame. */
    302                          int transientFrame,                 /*!< A flag indicating if a transient is present. */
    303                          INVF_MODE* pInvFiltLevels,          /*!< Pointer to the vector holding the inverse filtering levels. */
    304                          UINT sbrSyntaxFlags
    305                          )
    306 
    307 {
    308 
    309   INT nNoiseEnvelopes, startPos[2], stopPos[2], env, band;
    310 
    311   INT noNoiseBands      = h_sbrNoiseFloorEstimate->noNoiseBands;
    312   INT *freqBandTable    = h_sbrNoiseFloorEstimate->freqBandTableQmf;
    313 
    314   nNoiseEnvelopes = frame_info->nNoiseEnvelopes;
    315 
    316   if (sbrSyntaxFlags & SBR_SYNTAX_LOW_DELAY) {
    317     nNoiseEnvelopes = 1;
    318     startPos[0] = startIndex;
    319     stopPos[0]  = startIndex + min(numberOfEstimatesPerFrame,2);
    320   } else
    321   if(nNoiseEnvelopes == 1){
    322     startPos[0] = startIndex;
    323     stopPos[0]  = startIndex + 2;
    324   }
    325   else{
    326     startPos[0] = startIndex;
    327     stopPos[0]  = startIndex + 1;
    328     startPos[1] = startIndex + 1;
    329     stopPos[1]  = startIndex + 2;
    330   }
    331 
    332   /*
    333    * Estimate the noise floor.
    334    **************************************/
    335   for(env = 0; env < nNoiseEnvelopes; env++){
    336     for(band = 0; band < noNoiseBands; band++){
    337       FDK_ASSERT( (band + env*noNoiseBands) < MAX_NUM_NOISE_VALUES);
    338       qmfBasedNoiseFloorDetection(&noiseLevels[band + env*noNoiseBands],
    339                                   quotaMatrixOrig,
    340                                   indexVector,
    341                                   startPos[env],
    342                                   stopPos[env],
    343                                   freqBandTable[band],
    344                                   freqBandTable[band+1],
    345                                   h_sbrNoiseFloorEstimate->ana_max_level,
    346                                   h_sbrNoiseFloorEstimate->noiseFloorOffset[band],
    347                                   missingHarmonicsFlag,
    348                                   h_sbrNoiseFloorEstimate->weightFac,
    349                                   h_sbrNoiseFloorEstimate->diffThres,
    350                                   pInvFiltLevels[band]);
    351     }
    352   }
    353 
    354 
    355   /*
    356    * Smoothing of the values.
    357    **************************/
    358   smoothingOfNoiseLevels(noiseLevels,
    359                          nNoiseEnvelopes,
    360                          h_sbrNoiseFloorEstimate->noNoiseBands,
    361                          h_sbrNoiseFloorEstimate->prevNoiseLevels,
    362                          h_sbrNoiseFloorEstimate->smoothFilter,
    363                          transientFrame);
    364 
    365 
    366   /* quantisation*/
    367   for(env = 0; env < nNoiseEnvelopes; env++){
    368     for(band = 0; band < noNoiseBands; band++){
    369       FDK_ASSERT( (band + env*noNoiseBands) < MAX_NUM_NOISE_VALUES);
    370       noiseLevels[band + env*noNoiseBands] =
    371          (FIXP_DBL)NOISE_FLOOR_OFFSET_64 - (FIXP_DBL)CalcLdData(noiseLevels[band + env*noNoiseBands]+(FIXP_DBL)1) + QuantOffset;
    372     }
    373   }
    374 }
    375 
    376 /**************************************************************************/
    377 /*!
    378   \brief
    379 
    380 
    381   \return    errorCode, noError if successful
    382 
    383 */
    384 /**************************************************************************/
    385 static INT
    386 downSampleLoRes(INT *v_result,              /*!<    */
    387                 INT num_result,             /*!<    */
    388                 const UCHAR *freqBandTableRef,/*!<    */
    389                 INT num_Ref)                /*!<    */
    390 {
    391   INT step;
    392   INT i,j;
    393   INT org_length,result_length;
    394   INT v_index[MAX_FREQ_COEFFS/2];
    395 
    396   /* init */
    397   org_length=num_Ref;
    398   result_length=num_result;
    399 
    400   v_index[0]=0;	/* Always use left border */
    401   i=0;
    402   while(org_length > 0)	/* Create downsample vector */
    403     {
    404       i++;
    405       step=org_length/result_length; /* floor; */
    406       org_length=org_length - step;
    407       result_length--;
    408       v_index[i]=v_index[i-1]+step;
    409     }
    410 
    411   if(i != num_result )	/* Should never happen */
    412     return (1);/* error downsampling */
    413 
    414   for(j=0;j<=i;j++)	/* Use downsample vector to index LoResolution vector. */
    415     {
    416       v_result[j]=freqBandTableRef[v_index[j]];
    417     }
    418 
    419   return (0);
    420 }
    421 
    422 /**************************************************************************/
    423 /*!
    424   \brief    Initialize an instance of the noise floor level estimation module.
    425 
    426 
    427   \return    errorCode, noError if successful
    428 
    429 */
    430 /**************************************************************************/
    431 INT
    432 FDKsbrEnc_InitSbrNoiseFloorEstimate (HANDLE_SBR_NOISE_FLOOR_ESTIMATE  h_sbrNoiseFloorEstimate,   /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */
    433                              INT ana_max_level,                       /*!< Maximum level of the adaptive noise. */
    434                              const UCHAR *freqBandTable,      /*!< Frequany band table. */
    435                              INT nSfb,                                /*!< Number of frequency bands. */
    436                              INT noiseBands,                          /*!< Number of noise bands per octave. */
    437                              INT noiseFloorOffset,                    /*!< Noise floor offset. */
    438                              INT timeSlots,                           /*!< Number of time slots in a frame. */
    439                              UINT useSpeechConfig             /*!< Flag: adapt tuning parameters according to speech */
    440                             )
    441 {
    442   INT i, qexp, qtmp;
    443   FIXP_DBL tmp, exp;
    444 
    445   FDKmemclear(h_sbrNoiseFloorEstimate,sizeof(SBR_NOISE_FLOOR_ESTIMATE));
    446 
    447   h_sbrNoiseFloorEstimate->smoothFilter = smoothFilter;
    448   if (useSpeechConfig) {
    449     h_sbrNoiseFloorEstimate->weightFac = (FIXP_DBL)MAXVAL_DBL;
    450     h_sbrNoiseFloorEstimate->diffThres = INVF_LOW_LEVEL;
    451   }
    452   else {
    453     h_sbrNoiseFloorEstimate->weightFac = FL2FXCONST_DBL(0.25f);
    454     h_sbrNoiseFloorEstimate->diffThres = INVF_MID_LEVEL;
    455   }
    456 
    457   h_sbrNoiseFloorEstimate->timeSlots     = timeSlots;
    458   h_sbrNoiseFloorEstimate->noiseBands    = noiseBands;
    459 
    460   /* h_sbrNoiseFloorEstimate->ana_max_level is scaled by 0.25  */
    461   switch(ana_max_level)
    462   {
    463   case 6:
    464       h_sbrNoiseFloorEstimate->ana_max_level = (FIXP_DBL)MAXVAL_DBL;
    465       break;
    466   case 3:
    467       h_sbrNoiseFloorEstimate->ana_max_level = FL2FXCONST_DBL(0.5);
    468       break;
    469   case -3:
    470       h_sbrNoiseFloorEstimate->ana_max_level = FL2FXCONST_DBL(0.125);
    471       break;
    472   default:
    473       /* Should not enter here */
    474       h_sbrNoiseFloorEstimate->ana_max_level = (FIXP_DBL)MAXVAL_DBL;
    475       break;
    476   }
    477 
    478   /*
    479     calculate number of noise bands and allocate
    480   */
    481   if(FDKsbrEnc_resetSbrNoiseFloorEstimate(h_sbrNoiseFloorEstimate,freqBandTable,nSfb))
    482     return(1);
    483 
    484   if(noiseFloorOffset == 0) {
    485     tmp = ((FIXP_DBL)MAXVAL_DBL)>>NOISE_FLOOR_OFFSET_SCALING;
    486   }
    487   else {
    488     /* noiseFloorOffset has to be smaller than 12, because
    489        the result of the calculation below must be smaller than 1:
    490        (2^(noiseFloorOffset/3))*2^4<1                                        */
    491     FDK_ASSERT(noiseFloorOffset<12);
    492 
    493     /* Assumes the noise floor offset in tuning table are in q31    */
    494     /* Change the qformat here when non-zero values would be filled */
    495     exp = fDivNorm((FIXP_DBL)noiseFloorOffset, 3, &qexp);
    496     tmp = fPow(2, DFRACT_BITS-1, exp, qexp, &qtmp);
    497     tmp = scaleValue(tmp, qtmp-NOISE_FLOOR_OFFSET_SCALING);
    498   }
    499 
    500   for(i=0;i<h_sbrNoiseFloorEstimate->noNoiseBands;i++) {
    501     h_sbrNoiseFloorEstimate->noiseFloorOffset[i] = tmp;
    502   }
    503 
    504   return (0);
    505 }
    506 
    507 /**************************************************************************/
    508 /*!
    509   \brief     Resets the current instance of the noise floor estiamtion
    510           module.
    511 
    512 
    513   \return    errorCode, noError if successful
    514 
    515 */
    516 /**************************************************************************/
    517 INT
    518 FDKsbrEnc_resetSbrNoiseFloorEstimate (HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate, /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */
    519                             const UCHAR *freqBandTable,             /*!< Frequany band table. */
    520                             INT nSfb)                             /*!< Number of bands in the frequency band table. */
    521 {
    522     INT k2,kx;
    523 
    524     /*
    525     * Calculate number of noise bands
    526     ***********************************/
    527     k2=freqBandTable[nSfb];
    528     kx=freqBandTable[0];
    529     if(h_sbrNoiseFloorEstimate->noiseBands == 0){
    530         h_sbrNoiseFloorEstimate->noNoiseBands = 1;
    531     }
    532     else{
    533         /*
    534         * Calculate number of noise bands 1,2 or 3 bands/octave
    535         ********************************************************/
    536         FIXP_DBL tmp, ratio, lg2;
    537         INT ratio_e, qlg2, nNoiseBands;
    538 
    539         ratio = fDivNorm(k2, kx, &ratio_e);
    540         lg2 = fLog2(ratio, ratio_e, &qlg2);
    541         tmp = fMult((FIXP_DBL)(h_sbrNoiseFloorEstimate->noiseBands<<24), lg2);
    542         tmp = scaleValue(tmp, qlg2-23);
    543 
    544         nNoiseBands = (INT)((tmp + (FIXP_DBL)1) >> 1);
    545 
    546 
    547         if (nNoiseBands > MAX_NUM_NOISE_COEFFS ) {
    548           nNoiseBands = MAX_NUM_NOISE_COEFFS;
    549         }
    550 
    551         if( nNoiseBands == 0 ) {
    552           nNoiseBands = 1;
    553         }
    554 
    555         h_sbrNoiseFloorEstimate->noNoiseBands = nNoiseBands;
    556 
    557     }
    558 
    559 
    560     return(downSampleLoRes(h_sbrNoiseFloorEstimate->freqBandTableQmf,
    561         h_sbrNoiseFloorEstimate->noNoiseBands,
    562         freqBandTable,nSfb));
    563 }
    564 
    565 /**************************************************************************/
    566 /*!
    567   \brief     Deletes the current instancce of the noise floor level
    568   estimation module.
    569 
    570 
    571   \return    none
    572 
    573 */
    574 /**************************************************************************/
    575 void
    576 FDKsbrEnc_deleteSbrNoiseFloorEstimate (HANDLE_SBR_NOISE_FLOOR_ESTIMATE h_sbrNoiseFloorEstimate)  /*!< Handle to SBR_NOISE_FLOOR_ESTIMATE struct */
    577 {
    578 
    579   if (h_sbrNoiseFloorEstimate) {
    580     /*
    581       nothing to do
    582     */
    583   }
    584 }
    585