/********************************************************************

 *                                                                  *

 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE.   *

 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *

 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *

 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *

 *                                                                  *

 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2010             *

 * by the Xiph.Org Foundation http://www.xiph.org/                  *

 *                                                                  *

 ********************************************************************

 function: psychoacoustics not including preecho

 last mod: $Id: psy.c 18077 2011-09-02 02:49:00Z giles $

 ********************************************************************/

#include <stdlib.h>

#include <math.h>

#include <string.h>

#include "vorbis/codec.h"

#include "codec_internal.h"

#include "masking.h"

#include "psy.h"

#include "os.h"

#include "lpc.h"

#include "smallft.h"

#include "scales.h"

#include "misc.h"

#define NEGINF -9999.f

static const double stereo_threshholds[]={0.0, .5, 1.0, 1.5, 2.5, 4.5, 8.5, 16.5, 9e10};

static const double stereo_threshholds_limited[]={0.0, .5, 1.0, 1.5, 2.0, 2.5, 4.5, 8.5, 9e10};

vorbis_look_psy_global *_vp_global_look(vorbis_info *vi){

  codec_setup_info *ci=vi->codec_setup;

  vorbis_info_psy_global *gi=&ci->psy_g_param;

  vorbis_look_psy_global *look=_ogg_calloc(1,sizeof(*look));

  look->channels=vi->channels;

  look->ampmax=-9999.;

  look->gi=gi;

  return(look);

}

void _vp_global_free(vorbis_look_psy_global *look){

  if(look){

    memset(look,0,sizeof(*look));

    _ogg_free(look);

  }

}

void _vi_gpsy_free(vorbis_info_psy_global *i){

  if(i){

    memset(i,0,sizeof(*i));

    _ogg_free(i);

  }

}

void _vi_psy_free(vorbis_info_psy *i){

  if(i){

    memset(i,0,sizeof(*i));

    _ogg_free(i);

  }

}

static void min_curve(float *c,

                       float *c2){

  int i;

  for(i=0;i

}

static void max_curve(float *c,

                       float *c2){

  int i;

  for(i=0;i<EHMER_MAX;i++)if(c2[i]>c[i])c[i]=c2[i];

}

static void attenuate_curve(float *c,float att){

  int i;

  for(i=0;i

    c[i]+=att;

}

static float ***setup_tone_curves(float curveatt_dB[P_BANDS],float binHz,int n,

                                  float center_boost, float center_decay_rate){

  int i,j,k,m;

  float ath[EHMER_MAX];

  float workc[P_BANDS][P_LEVELS][EHMER_MAX];

  float athc[P_LEVELS][EHMER_MAX];

  float *brute_buffer=alloca(n*sizeof(*brute_buffer));

  float ***ret=_ogg_malloc(sizeof(*ret)*P_BANDS);

  memset(workc,0,sizeof(workc));

  for(i=0;i

    /* we add back in the ATH to avoid low level curves falling off to

       -infinity and unnecessarily cutting off high level curves in the

       curve limiting (last step). */

    /* A half-band's settings must be valid over the whole band, and

       it's better to mask too little than too much */

    int ath_offset=i*4;

    for(j=0;j

      float min=999.;

      for(k=0;k<4;k++)

        if(j+k+ath_offset

          if(min>ATH[j+k+ath_offset])min=ATH[j+k+ath_offset];

        }else{

          if(min>ATH[MAX_ATH-1])min=ATH[MAX_ATH-1];

        }

      ath[j]=min;

    }

    /* copy curves into working space, replicate the 50dB curve to 30

       and 40, replicate the 100dB curve to 110 */

    for(j=0;j<6;j++)

      memcpy(workc[i][j+2],tonemasks[i][j],EHMER_MAX*sizeof(*tonemasks[i][j]));

    memcpy(workc[i][0],tonemasks[i][0],EHMER_MAX*sizeof(*tonemasks[i][0]));

    memcpy(workc[i][1],tonemasks[i][0],EHMER_MAX*sizeof(*tonemasks[i][0]));

    /* apply centered curve boost/decay */

    for(j=0;j

      for(k=0;k

        float adj=center_boost+abs(EHMER_OFFSET-k)*center_decay_rate;

        if(adj<0. && center_boost>0)adj=0.;

        if(adj>0. && center_boost<0)adj=0.;

        workc[i][j][k]+=adj;

      }

    }

    /* normalize curves so the driving amplitude is 0dB */

    /* make temp curves with the ATH overlayed */

    for(j=0;j

      attenuate_curve(workc[i][j],curveatt_dB[i]+100.-(j<2?2:j)*10.-P_LEVEL_0);

      memcpy(athc[j],ath,EHMER_MAX*sizeof(**athc));

      attenuate_curve(athc[j],+100.-j*10.f-P_LEVEL_0);

      max_curve(athc[j],workc[i][j]);

    }

    /* Now limit the louder curves.

       the idea is this: We don't know what the playback attenuation

       will be; 0dB SL moves every time the user twiddles the volume

       knob. So that means we have to use a single 'most pessimal' curve

       for all masking amplitudes, right?  Wrong.  The *loudest* sound

       can be in (we assume) a range of ...+100dB] SL.  However, sounds

       20dB down will be in a range ...+80], 40dB down is from ...+60],

       etc... */

    for(j=1;j

      min_curve(athc[j],athc[j-1]);

      min_curve(workc[i][j],athc[j]);

    }

  }

  for(i=0;i

    int hi_curve,lo_curve,bin;

    ret[i]=_ogg_malloc(sizeof(**ret)*P_LEVELS);

    /* low frequency curves are measured with greater resolution than

       the MDCT/FFT will actually give us; we want the curve applied

       to the tone data to be pessimistic and thus apply the minimum

       masking possible for a given bin.  That means that a single bin

       could span more than one octave and that the curve will be a

       composite of multiple octaves.  It also may mean that a single

       bin may span > an eighth of an octave and that the eighth

       octave values may also be composited. */

    /* which octave curves will we be compositing? */

    bin=floor(fromOC(i*.5)/binHz);

    lo_curve=  ceil(toOC(bin*binHz+1)*2);

    hi_curve=  floor(toOC((bin+1)*binHz)*2);

    if(lo_curve>i)lo_curve=i;

    if(lo_curve<0)lo_curve=0;

    if(hi_curve>=P_BANDS)hi_curve=P_BANDS-1;

    for(m=0;m

      ret[i][m]=_ogg_malloc(sizeof(***ret)*(EHMER_MAX+2));

      for(j=0;j

      /* render the curve into bins, then pull values back into curve.

         The point is that any inherent subsampling aliasing results in

         a safe minimum */

      for(k=lo_curve;k<=hi_curve;k++){

        int l=0;

        for(j=0;j

          int lo_bin= fromOC(j*.125+k*.5-2.0625)/binHz;

          int hi_bin= fromOC(j*.125+k*.5-1.9375)/binHz+1;

          if(lo_bin<0)lo_bin=0;

          if(lo_bin>n)lo_bin=n;

          if(lo_bin

          if(hi_bin<0)hi_bin=0;

          if(hi_bin>n)hi_bin=n;

          for(;l

            if(brute_buffer[l]>workc[k][m][j])

              brute_buffer[l]=workc[k][m][j];

        }

        for(;l

          if(brute_buffer[l]>workc[k][m][EHMER_MAX-1])

            brute_buffer[l]=workc[k][m][EHMER_MAX-1];

      }

      /* be equally paranoid about being valid up to next half ocatve */

      if(i+1

        int l=0;

        k=i+1;

        for(j=0;j

          int lo_bin= fromOC(j*.125+i*.5-2.0625)/binHz;

          int hi_bin= fromOC(j*.125+i*.5-1.9375)/binHz+1;

          if(lo_bin<0)lo_bin=0;

          if(lo_bin>n)lo_bin=n;

          if(lo_bin

          if(hi_bin<0)hi_bin=0;

          if(hi_bin>n)hi_bin=n;

          for(;l

            if(brute_buffer[l]>workc[k][m][j])

              brute_buffer[l]=workc[k][m][j];

        }

        for(;l

          if(brute_buffer[l]>workc[k][m][EHMER_MAX-1])

            brute_buffer[l]=workc[k][m][EHMER_MAX-1];

      }

      for(j=0;j

        int bin=fromOC(j*.125+i*.5-2.)/binHz;

        if(bin<0){

          ret[i][m][j+2]=-999.;

        }else{

          if(bin>=n){

            ret[i][m][j+2]=-999.;

          }else{

            ret[i][m][j+2]=brute_buffer[bin];

          }

        }

      }

      /* add fenceposts */

      for(j=0;j

        if(ret[i][m][j+2]>-200.f)break;

      ret[i][m][0]=j;

      for(j=EHMER_MAX-1;j>EHMER_OFFSET+1;j--)

        if(ret[i][m][j+2]>-200.f)

          break;

      ret[i][m][1]=j;

    }

  }

  return(ret);

}

void _vp_psy_init(vorbis_look_psy *p,vorbis_info_psy *vi,

                  vorbis_info_psy_global *gi,int n,long rate){

  long i,j,lo=-99,hi=1;

  long maxoc;

  memset(p,0,sizeof(*p));

  p->eighth_octave_lines=gi->eighth_octave_lines;

  p->shiftoc=rint(log(gi->eighth_octave_lines*8.f)/log(2.f))-1;

  p->firstoc=toOC(.25f*rate*.5/n)*(1<<(p->shiftoc+1))-gi->eighth_octave_lines;

  maxoc=toOC((n+.25f)*rate*.5/n)*(1<<(p->shiftoc+1))+.5f;

  p->total_octave_lines=maxoc-p->firstoc+1;

  p->ath=_ogg_malloc(n*sizeof(*p->ath));

  p->octave=_ogg_malloc(n*sizeof(*p->octave));

  p->bark=_ogg_malloc(n*sizeof(*p->bark));

  p->vi=vi;

  p->n=n;

  p->rate=rate;

  /* AoTuV HF weighting */

  p->m_val = 1.;

  if(rate < 26000) p->m_val = 0;

  else if(rate < 38000) p->m_val = .94;   /* 32kHz */

  else if(rate > 46000) p->m_val = 1.275; /* 48kHz */

  /* set up the lookups for a given blocksize and sample rate */

  for(i=0,j=0;i

    int endpos=rint(fromOC((i+1)*.125-2.)*2*n/rate);

    float base=ATH[i];

    if(j

      float delta=(ATH[i+1]-base)/(endpos-j);

      for(;j

        p->ath[j]=base+100.;

        base+=delta;

      }

    }

  }

  for(;j

    p->ath[j]=p->ath[j-1];

  }

  for(i=0;i

    float bark=toBARK(rate/(2*n)*i);

    for(;lo+vi->noisewindowlomin

          toBARK(rate/(2*n)*lo)<(bark-vi->noisewindowlo);lo++);

    for(;hi<=n && (hi<i+vi->noisewindowhimin ||

          toBARK(rate/(2*n)*hi)<(bark+vi->noisewindowhi));hi++);

    p->bark[i]=((lo-1)<<16)+(hi-1);

  }

  for(i=0;i

    p->octave[i]=toOC((i+.25f)*.5*rate/n)*(1<<(p->shiftoc+1))+.5f;

  p->tonecurves=setup_tone_curves(vi->toneatt,rate*.5/n,n,

                                  vi->tone_centerboost,vi->tone_decay);

  /* set up rolling noise median */

  p->noiseoffset=_ogg_malloc(P_NOISECURVES*sizeof(*p->noiseoffset));

  for(i=0;i

    p->noiseoffset[i]=_ogg_malloc(n*sizeof(**p->noiseoffset));

  for(i=0;i

    float halfoc=toOC((i+.5)*rate/(2.*n))*2.;

    int inthalfoc;

    float del;

    if(halfoc<0)halfoc=0;

    if(halfoc>=P_BANDS-1)halfoc=P_BANDS-1;

    inthalfoc=(int)halfoc;

    del=halfoc-inthalfoc;

    for(j=0;j

      p->noiseoffset[j][i]=

        p->vi->noiseoff[j][inthalfoc]*(1.-del) +

        p->vi->noiseoff[j][inthalfoc+1]*del;

  }

#if 0

  {

    static int ls=0;

    _analysis_output_always("noiseoff0",ls,p->noiseoffset[0],n,1,0,0);

    _analysis_output_always("noiseoff1",ls,p->noiseoffset[1],n,1,0,0);

    _analysis_output_always("noiseoff2",ls++,p->noiseoffset[2],n,1,0,0);

  }

#endif

}

void _vp_psy_clear(vorbis_look_psy *p){

  int i,j;

  if(p){

    if(p->ath)_ogg_free(p->ath);

    if(p->octave)_ogg_free(p->octave);

    if(p->bark)_ogg_free(p->bark);

    if(p->tonecurves){

      for(i=0;i

        for(j=0;j

          _ogg_free(p->tonecurves[i][j]);

        }

        _ogg_free(p->tonecurves[i]);

      }

      _ogg_free(p->tonecurves);

    }

    if(p->noiseoffset){

      for(i=0;i

        _ogg_free(p->noiseoffset[i]);

      }

      _ogg_free(p->noiseoffset);

    }

    memset(p,0,sizeof(*p));

  }

}

/* octave/(8*eighth_octave_lines) x scale and dB y scale */

static void seed_curve(float *seed,

                       const float **curves,

                       float amp,

                       int oc, int n,

                       int linesper,float dBoffset){

  int i,post1;

  int seedptr;

  const float *posts,*curve;

  int choice=(int)((amp+dBoffset-P_LEVEL_0)*.1f);

  choice=max(choice,0);

  choice=min(choice,P_LEVELS-1);

  posts=curves[choice];

  curve=posts+2;

  post1=(int)posts[1];

  seedptr=oc+(posts[0]-EHMER_OFFSET)*linesper-(linesper>>1);

  for(i=posts[0];i

    if(seedptr>0){

      float lin=amp+curve[i];

      if(seed[seedptr]

    }

    seedptr+=linesper;

    if(seedptr>=n)break;

  }

}

static void seed_loop(vorbis_look_psy *p,

                      const float ***curves,

                      const float *f,

                      const float *flr,

                      float *seed,

                      float specmax){

  vorbis_info_psy *vi=p->vi;

  long n=p->n,i;

  float dBoffset=vi->max_curve_dB-specmax;

  /* prime the working vector with peak values */

  for(i=0;i

    float max=f[i];

    long oc=p->octave[i];

    while(i+1<n && p->octave[i+1]==oc){

      i++;

      if(f[i]>max)max=f[i];

    }

    if(max+6.f>flr[i]){

      oc=oc>>p->shiftoc;

      if(oc>=P_BANDS)oc=P_BANDS-1;

      if(oc<0)oc=0;

      seed_curve(seed,

                 curves[oc],

                 max,

                 p->octave[i]-p->firstoc,

                 p->total_octave_lines,

                 p->eighth_octave_lines,

                 dBoffset);

    }

  }

}

static void seed_chase(float *seeds, int linesper, long n){

  long  *posstack=alloca(n*sizeof(*posstack));

  float *ampstack=alloca(n*sizeof(*ampstack));

  long   stack=0;

  long   pos=0;

  long   i;

  for(i=0;i

    if(stack<2){

      posstack[stack]=i;

      ampstack[stack++]=seeds[i];

    }else{

      while(1){

        if(seeds[i]

          posstack[stack]=i;

          ampstack[stack++]=seeds[i];

          break;

        }else{

          if(i

            if(stack>1 && ampstack[stack-1]<=ampstack[stack-2] &&

               i

              /* we completely overlap, making stack-1 irrelevant.  pop it */

              stack--;

              continue;

            }

          }

          posstack[stack]=i;

          ampstack[stack++]=seeds[i];

          break;

        }

      }

    }

  }

  /* the stack now contains only the positions that are relevant. Scan

     'em straight through */

  for(i=0;i

    long endpos;

    if(i<stack-1 && ampstack[i+1]>ampstack[i]){

      endpos=posstack[i+1];

    }else{

      endpos=posstack[i]+linesper+1; /* +1 is important, else bin 0 is

                                        discarded in short frames */

    }

    if(endpos>n)endpos=n;

    for(;pos

      seeds[pos]=ampstack[i];

  }

  /* there.  Linear time.  I now remember this was on a problem set I

     had in Grad Skool... I didn't solve it at the time ;-) */

}

/* bleaugh, this is more complicated than it needs to be */

#include<stdio.h>

static void max_seeds(vorbis_look_psy *p,

                      float *seed,

                      float *flr){

  long   n=p->total_octave_lines;

  int    linesper=p->eighth_octave_lines;

  long   linpos=0;

  long   pos;

  seed_chase(seed,linesper,n); /* for masking */

  pos=p->octave[0]-p->firstoc-(linesper>>1);

  while(linpos+1<p->n){

    float minV=seed[pos];

    long end=((p->octave[linpos]+p->octave[linpos+1])>>1)-p->firstoc;

    if(minV>p->vi->tone_abs_limit)minV=p->vi->tone_abs_limit;

    while(pos+1<=end){

      pos++;

      if((seed[pos]>NEGINF && seed[pos]

        minV=seed[pos];

    }

    end=pos+p->firstoc;

    for(;linpos<p->n && p->octave[linpos]<=end;linpos++)

      if(flr[linpos]

  }

  {

    float minV=seed[p->total_octave_lines-1];

    for(;linpos<p->n;linpos++)

      if(flr[linpos]

  }

}

static void bark_noise_hybridmp(int n,const long *b,

                                const float *f,

                                float *noise,

                                const float offset,

                                const int fixed){

  float *N=alloca(n*sizeof(*N));

  float *X=alloca(n*sizeof(*N));

  float *XX=alloca(n*sizeof(*N));

  float *Y=alloca(n*sizeof(*N));

  float *XY=alloca(n*sizeof(*N));

  float tN, tX, tXX, tY, tXY;

  int i;

  int lo, hi;

  float R=0.f;

  float A=0.f;

  float B=0.f;

  float D=1.f;

  float w, x, y;

  tN = tX = tXX = tY = tXY = 0.f;

  y = f[0] + offset;

  if (y < 1.f) y = 1.f;

  w = y * y * .5;

  tN += w;

  tX += w;

  tY += w * y;

  N[0] = tN;

  X[0] = tX;

  XX[0] = tXX;

  Y[0] = tY;

  XY[0] = tXY;

  for (i = 1, x = 1.f; i < n; i++, x += 1.f) {

    y = f[i] + offset;

    if (y < 1.f) y = 1.f;

    w = y * y;

    tN += w;

    tX += w * x;

    tXX += w * x * x;

    tY += w * y;

    tXY += w * x * y;

    N[i] = tN;

    X[i] = tX;

    XX[i] = tXX;

    Y[i] = tY;

    XY[i] = tXY;

  }

  for (i = 0, x = 0.f;; i++, x += 1.f) {

    lo = b[i] >> 16;

    if( lo>=0 ) break;

    hi = b[i] & 0xffff;

    tN = N[hi] + N[-lo];

    tX = X[hi] - X[-lo];

    tXX = XX[hi] + XX[-lo];

    tY = Y[hi] + Y[-lo];

    tXY = XY[hi] - XY[-lo];

    A = tY * tXX - tX * tXY;

    B = tN * tXY - tX * tY;

    D = tN * tXX - tX * tX;

    R = (A + x * B) / D;

    if (R < 0.f)

      R = 0.f;

    noise[i] = R - offset;

  }

  for ( ;; i++, x += 1.f) {

    lo = b[i] >> 16;

    hi = b[i] & 0xffff;

    if(hi>=n)break;

    tN = N[hi] - N[lo];

    tX = X[hi] - X[lo];

    tXX = XX[hi] - XX[lo];

    tY = Y[hi] - Y[lo];

    tXY = XY[hi] - XY[lo];

    A = tY * tXX - tX * tXY;

    B = tN * tXY - tX * tY;

    D = tN * tXX - tX * tX;

    R = (A + x * B) / D;

    if (R < 0.f) R = 0.f;

    noise[i] = R - offset;

  }

  for ( ; i < n; i++, x += 1.f) {

    R = (A + x * B) / D;

    if (R < 0.f) R = 0.f;

    noise[i] = R - offset;

  }

  if (fixed <= 0) return;

  for (i = 0, x = 0.f;; i++, x += 1.f) {

    hi = i + fixed / 2;

    lo = hi - fixed;

    if(lo>=0)break;

    tN = N[hi] + N[-lo];

    tX = X[hi] - X[-lo];

    tXX = XX[hi] + XX[-lo];

    tY = Y[hi] + Y[-lo];

    tXY = XY[hi] - XY[-lo];

    A = tY * tXX - tX * tXY;

    B = tN * tXY - tX * tY;

    D = tN * tXX - tX * tX;

    R = (A + x * B) / D;

    if (R - offset < noise[i]) noise[i] = R - offset;

  }

  for ( ;; i++, x += 1.f) {

    hi = i + fixed / 2;

    lo = hi - fixed;

    if(hi>=n)break;

    tN = N[hi] - N[lo];

    tX = X[hi] - X[lo];

    tXX = XX[hi] - XX[lo];

    tY = Y[hi] - Y[lo];

    tXY = XY[hi] - XY[lo];

    A = tY * tXX - tX * tXY;

    B = tN * tXY - tX * tY;

    D = tN * tXX - tX * tX;

    R = (A + x * B) / D;

    if (R - offset < noise[i]) noise[i] = R - offset;

  }

  for ( ; i < n; i++, x += 1.f) {

    R = (A + x * B) / D;

    if (R - offset < noise[i]) noise[i] = R - offset;

  }

}

void _vp_noisemask(vorbis_look_psy *p,

                   float *logmdct,

                   float *logmask){

  int i,n=p->n;

  float *work=alloca(n*sizeof(*work));

  bark_noise_hybridmp(n,p->bark,logmdct,logmask,

                      140.,-1);

  for(i=0;i

  bark_noise_hybridmp(n,p->bark,work,logmask,0.,

                      p->vi->noisewindowfixed);

  for(i=0;i

#if 0

  {

    static int seq=0;

    float work2[n];

    for(i=0;i

      work2[i]=logmask[i]+work[i];

    }

    if(seq&1)

      _analysis_output("median2R",seq/2,work,n,1,0,0);

    else

      _analysis_output("median2L",seq/2,work,n,1,0,0);

    if(seq&1)

      _analysis_output("envelope2R",seq/2,work2,n,1,0,0);

    else

      _analysis_output("envelope2L",seq/2,work2,n,1,0,0);

    seq++;

  }

#endif

  for(i=0;i

    int dB=logmask[i]+.5;

    if(dB>=NOISE_COMPAND_LEVELS)dB=NOISE_COMPAND_LEVELS-1;

    if(dB<0)dB=0;

    logmask[i]= work[i]+p->vi->noisecompand[dB];

  }

}

void _vp_tonemask(vorbis_look_psy *p,

                  float *logfft,

                  float *logmask,

                  float global_specmax,

                  float local_specmax){

  int i,n=p->n;

  float *seed=alloca(sizeof(*seed)*p->total_octave_lines);

  float att=local_specmax+p->vi->ath_adjatt;

  for(i=0;i<p->total_octave_lines;i++)seed[i]=NEGINF;

  /* set the ATH (floating below localmax, not global max by a

     specified att) */

  if(att<p->vi->ath_maxatt)att=p->vi->ath_maxatt;

  for(i=0;i

    logmask[i]=p->ath[i]+att;

  /* tone masking */

  seed_loop(p,(const float ***)p->tonecurves,logfft,logmask,seed,global_specmax);

  max_seeds(p,seed,logmask);

}

void _vp_offset_and_mix(vorbis_look_psy *p,

                        float *noise,

                        float *tone,

                        int offset_select,

                        float *logmask,

                        float *mdct,

                        float *logmdct){

  int i,n=p->n;

  float de, coeffi, cx;/* AoTuV */

  float toneatt=p->vi->tone_masteratt[offset_select];

  cx = p->m_val;

  for(i=0;i

    float val= noise[i]+p->noiseoffset[offset_select][i];

    if(val>p->vi->noisemaxsupp)val=p->vi->noisemaxsupp;

    logmask[i]=max(val,tone[i]+toneatt);

    /* AoTuV */

    /** @ M1 **

        The following codes improve a noise problem.

        A fundamental idea uses the value of masking and carries out

        the relative compensation of the MDCT.

        However, this code is not perfect and all noise problems cannot be solved.

        by Aoyumi @ 2004/04/18

    */

    if(offset_select == 1) {

      coeffi = -17.2;       /* coeffi is a -17.2dB threshold */

      val = val - logmdct[i];  /* val == mdct line value relative to floor in dB */

      if(val > coeffi){

        /* mdct value is > -17.2 dB below floor */

        de = 1.0-((val-coeffi)*0.005*cx);

        /* pro-rated attenuation:

           -0.00 dB boost if mdct value is -17.2dB (relative to floor)

           -0.77 dB boost if mdct value is 0dB (relative to floor)

           -1.64 dB boost if mdct value is +17.2dB (relative to floor)

           etc... */

        if(de < 0) de = 0.0001;

      }else

        /* mdct value is <= -17.2 dB below floor */

        de = 1.0-((val-coeffi)*0.0003*cx);

      /* pro-rated attenuation:

         +0.00 dB atten if mdct value is -17.2dB (relative to floor)

         +0.45 dB atten if mdct value is -34.4dB (relative to floor)

         etc... */

      mdct[i] *= de;

    }

  }

}

float _vp_ampmax_decay(float amp,vorbis_dsp_state *vd){

  vorbis_info *vi=vd->vi;

  codec_setup_info *ci=vi->codec_setup;

  vorbis_info_psy_global *gi=&ci->psy_g_param;

  int n=ci->blocksizes[vd->W]/2;

  float secs=(float)n/vi->rate;

  amp+=secs*gi->ampmax_att_per_sec;

  if(amp<-9999)amp=-9999;

  return(amp);

}

static float FLOOR1_fromdB_LOOKUP[256]={

  1.0649863e-07F, 1.1341951e-07F, 1.2079015e-07F, 1.2863978e-07F,

  1.3699951e-07F, 1.4590251e-07F, 1.5538408e-07F, 1.6548181e-07F,

  1.7623575e-07F, 1.8768855e-07F, 1.9988561e-07F, 2.128753e-07F,

  2.2670913e-07F, 2.4144197e-07F, 2.5713223e-07F, 2.7384213e-07F,

  2.9163793e-07F, 3.1059021e-07F, 3.3077411e-07F, 3.5226968e-07F,

  3.7516214e-07F, 3.9954229e-07F, 4.2550680e-07F, 4.5315863e-07F,

  4.8260743e-07F, 5.1396998e-07F, 5.4737065e-07F, 5.8294187e-07F,

  6.2082472e-07F, 6.6116941e-07F, 7.0413592e-07F, 7.4989464e-07F,

  7.9862701e-07F, 8.5052630e-07F, 9.0579828e-07F, 9.6466216e-07F,

  1.0273513e-06F, 1.0941144e-06F, 1.1652161e-06F, 1.2409384e-06F,

  1.3215816e-06F, 1.4074654e-06F, 1.4989305e-06F, 1.5963394e-06F,

  1.7000785e-06F, 1.8105592e-06F, 1.9282195e-06F, 2.0535261e-06F,

  2.1869758e-06F, 2.3290978e-06F, 2.4804557e-06F, 2.6416497e-06F,

  2.8133190e-06F, 2.9961443e-06F, 3.1908506e-06F, 3.3982101e-06F,

  3.6190449e-06F, 3.8542308e-06F, 4.1047004e-06F, 4.3714470e-06F,

  4.6555282e-06F, 4.9580707e-06F, 5.2802740e-06F, 5.6234160e-06F,

  5.9888572e-06F, 6.3780469e-06F, 6.7925283e-06F, 7.2339451e-06F,

  7.7040476e-06F, 8.2047000e-06F, 8.7378876e-06F, 9.3057248e-06F,

  9.9104632e-06F, 1.0554501e-05F, 1.1240392e-05F, 1.1970856e-05F,

  1.2748789e-05F, 1.3577278e-05F, 1.4459606e-05F, 1.5399272e-05F,

  1.6400004e-05F, 1.7465768e-05F, 1.8600792e-05F, 1.9809576e-05F,

  2.1096914e-05F, 2.2467911e-05F, 2.3928002e-05F, 2.5482978e-05F,

  2.7139006e-05F, 2.8902651e-05F, 3.0780908e-05F, 3.2781225e-05F,

  3.4911534e-05F, 3.7180282e-05F, 3.9596466e-05F, 4.2169667e-05F,

  4.4910090e-05F, 4.7828601e-05F, 5.0936773e-05F, 5.4246931e-05F,

  5.7772202e-05F, 6.1526565e-05F, 6.5524908e-05F, 6.9783085e-05F,

  7.4317983e-05F, 7.9147585e-05F, 8.4291040e-05F, 8.9768747e-05F,

  9.5602426e-05F, 0.00010181521F, 0.00010843174F, 0.00011547824F,

  0.00012298267F, 0.00013097477F, 0.00013948625F, 0.00014855085F,

  0.00015820453F, 0.00016848555F, 0.00017943469F, 0.00019109536F,

  0.00020351382F, 0.00021673929F, 0.00023082423F, 0.00024582449F,

  0.00026179955F, 0.00027881276F, 0.00029693158F, 0.00031622787F,

  0.00033677814F, 0.00035866388F, 0.00038197188F, 0.00040679456F,

  0.00043323036F, 0.00046138411F, 0.00049136745F, 0.00052329927F,

  0.00055730621F, 0.00059352311F, 0.00063209358F, 0.00067317058F,

  0.00071691700F, 0.00076350630F, 0.00081312324F, 0.00086596457F,

  0.00092223983F, 0.00098217216F, 0.0010459992F, 0.0011139742F,