psy.c

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/********************************************************************
 *                                                                  *
 * 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 17569 2010-10-26 17:09:47Z xiphmont $

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

#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<EHMER_MAX;i++)if(c2[i]<c[i])c[i]=c2[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<EHMER_MAX;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<P_BANDS;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<EHMER_MAX;j++){
      float min=999.;
      for(k=0;k<4;k++)
        if(j+k+ath_offset<MAX_ATH){
          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<P_LEVELS;j++){
      for(k=0;k<EHMER_MAX;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<P_LEVELS;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<P_LEVELS;j++){
      min_curve(athc[j],athc[j-1]);
      min_curve(workc[i][j],athc[j]);
    }
  }

  for(i=0;i<P_BANDS;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<P_LEVELS;m++){
      ret[i][m]=_ogg_malloc(sizeof(***ret)*(EHMER_MAX+2));

      for(j=0;j<n;j++)brute_buffer[j]=999.;

      /* 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<EHMER_MAX;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<l)l=lo_bin;
          if(hi_bin<0)hi_bin=0;
          if(hi_bin>n)hi_bin=n;

          for(;l<hi_bin && l<n;l++)
            if(brute_buffer[l]>workc[k][m][j])
              brute_buffer[l]=workc[k][m][j];
        }

        for(;l<n;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<P_BANDS){
        int l=0;
        k=i+1;
        for(j=0;j<EHMER_MAX;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<l)l=lo_bin;
          if(hi_bin<0)hi_bin=0;
          if(hi_bin>n)hi_bin=n;

          for(;l<hi_bin && l<n;l++)
            if(brute_buffer[l]>workc[k][m][j])
              brute_buffer[l]=workc[k][m][j];
        }

        for(;l<n;l++)
          if(brute_buffer[l]>workc[k][m][EHMER_MAX-1])
            brute_buffer[l]=workc[k][m][EHMER_MAX-1];

      }


      for(j=0;j<EHMER_MAX;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<EHMER_OFFSET;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<MAX_ATH-1;i++){
    int endpos=rint(fromOC((i+1)*.125-2.)*2*n/rate);
    float base=ATH[i];
    if(j<endpos){
      float delta=(ATH[i+1]-base)/(endpos-j);
      for(;j<endpos && j<n;j++){
        p->ath[j]=base+100.;
        base+=delta;
      }
    }
  }

  for(;j<n;j++){
    p->ath[j]=p->ath[j-1];
  }

  for(i=0;i<n;i++){
    float bark=toBARK(rate/(2*n)*i);

    for(;lo+vi->noisewindowlomin<i &&
          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<n;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_NOISECURVES;i++)
    p->noiseoffset[i]=_ogg_malloc(n*sizeof(**p->noiseoffset));

  for(i=0;i<n;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_NOISECURVES;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<P_BANDS;i++){
        for(j=0;j<P_LEVELS;j++){
          _ogg_free(p->tonecurves[i][j]);
        }
        _ogg_free(p->tonecurves[i]);
      }
      _ogg_free(p->tonecurves);
    }
    if(p->noiseoffset){
      for(i=0;i<P_NOISECURVES;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<post1;i++){
    if(seedptr>0){
      float lin=amp+curve[i];
      if(seed[seedptr]<lin)seed[seedptr]=lin;
    }
    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<n;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<n;i++){
    if(stack<2){
      posstack[stack]=i;
      ampstack[stack++]=seeds[i];
    }else{
      while(1){
        if(seeds[i]<ampstack[stack-1]){
          posstack[stack]=i;
          ampstack[stack++]=seeds[i];
          break;
        }else{
          if(i<posstack[stack-1]+linesper){
            if(stack>1 && ampstack[stack-1]<=ampstack[stack-2] &&
               i<posstack[stack-2]+linesper){
              /* 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<stack;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<endpos;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) || minV==NEGINF)
        minV=seed[pos];
    }

    end=pos+p->firstoc;
    for(;linpos<p->n && p->octave[linpos]<=end;linpos++)
      if(flr[linpos]<minV)flr[linpos]=minV;
  }

  {
    float minV=seed[p->total_octave_lines-1];
    for(;linpos<p->n;linpos++)
      if(flr[linpos]<minV)flr[linpos]=minV;
  }

}

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<n;i++)work[i]=logmdct[i]-logmask[i];

  bark_noise_hybridmp(n,p->bark,work,logmask,0.,
                      p->vi->noisewindowfixed);

  for(i=0;i<n;i++)work[i]=logmdct[i]-work[i];

#if 0
  {
    static int seq=0;

    float work2[n];
    for(i=0;i<n;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<n;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<n;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<n;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 */
    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,
  0.0011863665F, 0.0012634633F, 0.0013455702F, 0.0014330129F,
  0.0015261382F, 0.0016253153F, 0.0017309374F, 0.0018434235F,
  0.0019632195F, 0.0020908006F, 0.0022266726F, 0.0023713743F,
  0.0025254795F, 0.0026895994F, 0.0028643847F, 0.0030505286F,
  0.0032487691F, 0.0034598925F, 0.0036847358F, 0.0039241906F,
  0.0041792066F, 0.0044507950F, 0.0047400328F, 0.0050480668F,
  0.0053761186F, 0.0057254891F, 0.0060975636F, 0.0064938176F,
  0.0069158225F, 0.0073652516F, 0.0078438871F, 0.0083536271F,
  0.0088964928F, 0.009474637F, 0.010090352F, 0.010746080F,
  0.011444421F, 0.012188144F, 0.012980198F, 0.013823725F,
  0.014722068F, 0.015678791F, 0.016697687F, 0.017782797F,
  0.018938423F, 0.020169149F, 0.021479854F, 0.022875735F,
  0.024362330F, 0.025945531F, 0.027631618F, 0.029427276F,
  0.031339626F, 0.033376252F, 0.035545228F, 0.037855157F,
  0.040315199F, 0.042935108F, 0.045725273F, 0.048696758F,
  0.051861348F, 0.055231591F, 0.058820850F, 0.062643361F,
  0.066714279F, 0.071049749F, 0.075666962F, 0.080584227F,
  0.085821044F, 0.091398179F, 0.097337747F, 0.10366330F,
  0.11039993F, 0.11757434F, 0.12521498F, 0.13335215F,
  0.14201813F, 0.15124727F, 0.16107617F, 0.17154380F,
  0.18269168F, 0.19456402F, 0.20720788F, 0.22067342F,
  0.23501402F, 0.25028656F, 0.26655159F, 0.28387361F,
  0.30232132F, 0.32196786F, 0.34289114F, 0.36517414F,
  0.38890521F, 0.41417847F, 0.44109412F, 0.46975890F,
  0.50028648F, 0.53279791F, 0.56742212F, 0.60429640F,
  0.64356699F, 0.68538959F, 0.72993007F, 0.77736504F,
  0.82788260F, 0.88168307F, 0.9389798F, 1.F,
};

/* this is for per-channel noise normalization */
static int apsort(const void *a, const void *b){
  float f1=**(float**)a;
  float f2=**(float**)b;
  return (f1<f2)-(f1>f2);
}

static void flag_lossless(int limit, float prepoint, float postpoint, float *mdct,
                         float *floor, int *flag, int i, int jn){
  int j;
  for(j=0;j<jn;j++){
    float point = j>=limit-i ? postpoint : prepoint;
    float r = fabs(mdct[j])/floor[j];
    if(r<point)
      flag[j]=0;
    else
      flag[j]=1;
  }
}

/* Overload/Side effect: On input, the *q vector holds either the
   quantized energy (for elements with the flag set) or the absolute
   values of the *r vector (for elements with flag unset).  On output,
   *q holds the quantized energy for all elements */
static float noise_normalize(vorbis_look_psy *p, int limit, float *r, float *q, float *f, int *flags, float acc, int i, int n, int *out){

  vorbis_info_psy *vi=p->vi;
  float **sort = alloca(n*sizeof(*sort));
  int j,count=0;
  int start = (vi->normal_p ? vi->normal_start-i : n);
  if(start>n)start=n;

  /* force classic behavior where only energy in the current band is considered */
  acc=0.f;

  /* still responsible for populating *out where noise norm not in
     effect.  There's no need to [re]populate *q in these areas */
  for(j=0;j<start;j++){
    if(!flags || !flags[j]){ /* lossless coupling already quantized.
                                Don't touch; requantizing based on
                                energy would be incorrect. */
      float ve = q[j]/f[j];
      if(r[j]<0)
        out[j] = -rint(sqrt(ve));
      else
        out[j] = rint(sqrt(ve));
    }
  }

  /* sort magnitudes for noise norm portion of partition */
  for(;j<n;j++){
    if(!flags || !flags[j]){ /* can't noise norm elements that have
                                already been loslessly coupled; we can
                                only account for their energy error */
      float ve = q[j]/f[j];
      /* Despite all the new, more capable coupling code, for now we
         implement noise norm as it has been up to this point. Only
         consider promotions to unit magnitude from 0.  In addition
         the only energy error counted is quantizations to zero. */
      /* also-- the original point code only applied noise norm at > pointlimit */
      if(ve<.25f && (!flags || j>=limit-i)){
        acc += ve;
        sort[count++]=q+j; /* q is fabs(r) for unflagged element */
      }else{
        /* For now: no acc adjustment for nonzero quantization.  populate *out and q as this value is final. */
        if(r[j]<0)
          out[j] = -rint(sqrt(ve));
        else
          out[j] = rint(sqrt(ve));
        q[j] = out[j]*out[j]*f[j];
      }
    }/* else{
        again, no energy adjustment for error in nonzero quant-- for now
        }*/
  }

  if(count){
    /* noise norm to do */
    qsort(sort,count,sizeof(*sort),apsort);
    for(j=0;j<count;j++){
      int k=sort[j]-q;
      if(acc>=vi->normal_thresh){
        out[k]=unitnorm(r[k]);
        acc-=1.f;
        q[k]=f[k];
      }else{
        out[k]=0;
        q[k]=0.f;
      }
    }
  }

  return acc;
}

/* Noise normalization, quantization and coupling are not wholly
   seperable processes in depth>1 coupling. */
void _vp_couple_quantize_normalize(int blobno,
                                   vorbis_info_psy_global *g,
                                   vorbis_look_psy *p,
                                   vorbis_info_mapping0 *vi,
                                   float **mdct,
                                   int   **iwork,
                                   int    *nonzero,
                                   int     sliding_lowpass,
                                   int     ch){

  int i;
  int n = p->n;
  int partition=(p->vi->normal_p ? p->vi->normal_partition : 16);
  int limit = g->coupling_pointlimit[p->vi->blockflag][blobno];
  float prepoint=stereo_threshholds[g->coupling_prepointamp[blobno]];
  float postpoint=stereo_threshholds[g->coupling_postpointamp[blobno]];
  float de=0.1*p->m_val; /* a blend of the AoTuV M2 and M3 code here and below */

  /* mdct is our raw mdct output, floor not removed. */
  /* inout passes in the ifloor, passes back quantized result */

  /* unquantized energy (negative indicates amplitude has negative sign) */
  float **raw = alloca(ch*sizeof(*raw));

  /* dual pupose; quantized energy (if flag set), othersize fabs(raw) */
  float **quant = alloca(ch*sizeof(*quant));

  /* floor energy */
  float **floor = alloca(ch*sizeof(*floor));

  /* flags indicating raw/quantized status of elements in raw vector */
  int   **flag  = alloca(ch*sizeof(*flag));

  /* non-zero flag working vector */
  int    *nz    = alloca(ch*sizeof(*nz));

  /* energy surplus/defecit tracking */
  float  *acc   = alloca((ch+vi->coupling_steps)*sizeof(*acc));

  /* The threshold of a stereo is changed with the size of n */
  if(n > 1000)
    postpoint=stereo_threshholds_limited[g->coupling_postpointamp[blobno]];

  raw[0]   = alloca(ch*partition*sizeof(**raw));
  quant[0] = alloca(ch*partition*sizeof(**quant));
  floor[0] = alloca(ch*partition*sizeof(**floor));
  flag[0]  = alloca(ch*partition*sizeof(**flag));

  for(i=1;i<ch;i++){
    raw[i]   = &raw[0][partition*i];
    quant[i] = &quant[0][partition*i];
    floor[i] = &floor[0][partition*i];
    flag[i]  = &flag[0][partition*i];
  }
  for(i=0;i<ch+vi->coupling_steps;i++)
    acc[i]=0.f;

  for(i=0;i<n;i+=partition){
    int k,j,jn = partition > n-i ? n-i : partition;
    int step,track = 0;

    memcpy(nz,nonzero,sizeof(*nz)*ch);

    /* prefill */
    memset(flag[0],0,ch*partition*sizeof(**flag));
    for(k=0;k<ch;k++){
      int *iout = &iwork[k][i];
      if(nz[k]){

        for(j=0;j<jn;j++)
          floor[k][j] = FLOOR1_fromdB_LOOKUP[iout[j]];

        flag_lossless(limit,prepoint,postpoint,&mdct[k][i],floor[k],flag[k],i,jn);

        for(j=0;j<jn;j++){
          quant[k][j] = raw[k][j] = mdct[k][i+j]*mdct[k][i+j];
          if(mdct[k][i+j]<0.f) raw[k][j]*=-1.f;
          floor[k][j]*=floor[k][j];
        }

        acc[track]=noise_normalize(p,limit,raw[k],quant[k],floor[k],NULL,acc[track],i,jn,iout);

      }else{
        for(j=0;j<jn;j++){
          floor[k][j] = 1e-10f;
          raw[k][j] = 0.f;
          quant[k][j] = 0.f;
          flag[k][j] = 0;
          iout[j]=0;
        }
        acc[track]=0.f;
      }
      track++;
    }

    /* coupling */
    for(step=0;step<vi->coupling_steps;step++){
      int Mi = vi->coupling_mag[step];
      int Ai = vi->coupling_ang[step];
      int *iM = &iwork[Mi][i];
      int *iA = &iwork[Ai][i];
      float *reM = raw[Mi];
      float *reA = raw[Ai];
      float *qeM = quant[Mi];
      float *qeA = quant[Ai];
      float *floorM = floor[Mi];
      float *floorA = floor[Ai];
      int *fM = flag[Mi];
      int *fA = flag[Ai];

      if(nz[Mi] || nz[Ai]){
        nz[Mi] = nz[Ai] = 1;

        for(j=0;j<jn;j++){

          if(j<sliding_lowpass-i){
            if(fM[j] || fA[j]){
              /* lossless coupling */

              reM[j] = fabs(reM[j])+fabs(reA[j]);
              qeM[j] = qeM[j]+qeA[j];
              fM[j]=fA[j]=1;

              /* couple iM/iA */
              {
                int A = iM[j];
                int B = iA[j];

                if(abs(A)>abs(B)){
                  iA[j]=(A>0?A-B:B-A);
                }else{
                  iA[j]=(B>0?A-B:B-A);
                  iM[j]=B;
                }

                /* collapse two equivalent tuples to one */
                if(iA[j]>=abs(iM[j])*2){
                  iA[j]= -iA[j];
                  iM[j]= -iM[j];
                }

              }

            }else{
              /* lossy (point) coupling */
              if(j<limit-i){
                /* dipole */
                reM[j] += reA[j];
                qeM[j] = fabs(reM[j]);
              }else{
                /* AoTuV */
                /*float derate = (1.0 - de*((float)(j-limit+i) / (float)(n-limit)));
                /* elliptical 
                if(reM[j]+reA[j]<0){
                  reM[j] = - (qeM[j] = (fabs(reM[j])+fabs(reA[j]))*derate*derate);
                }else{
                  reM[j] =   (qeM[j] = (fabs(reM[j])+fabs(reA[j]))*derate*derate);
                  }*/

                /* elliptical */
                if(reM[j]+reA[j]<0){
                  reM[j] = - (qeM[j] = fabs(reM[j])+fabs(reA[j]));
                }else{
                  reM[j] =   (qeM[j] = fabs(reM[j])+fabs(reA[j]));
                }


              }
              reA[j]=qeA[j]=0.f;
              fA[j]=1;
              iA[j]=0;
            }
          }
          floorM[j]=floorA[j]=floorM[j]+floorA[j];
        }
        /* normalize the resulting mag vector */
        acc[track]=noise_normalize(p,limit,raw[Mi],quant[Mi],floor[Mi],flag[Mi],acc[track],i,jn,iM);
        track++;
      }
    }
  }

  for(i=0;i<vi->coupling_steps;i++){
    /* make sure coupling a zero and a nonzero channel results in two
       nonzero channels. */
    if(nonzero[vi->coupling_mag[i]] ||
       nonzero[vi->coupling_ang[i]]){
      nonzero[vi->coupling_mag[i]]=1;
      nonzero[vi->coupling_ang[i]]=1;
    }
  }
}