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

 *                                                                  *

 * 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 1994-2015             *

 * by the Xiph.Org Foundation https://xiph.org/                     *

 *                                                                  *

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

 function: floor backend 1 implementation

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

#include <stdlib.h>

#include <string.h>

#include <math.h>

#include <ogg/ogg.h>

#include "vorbis/codec.h"

#include "codec_internal.h"

#include "registry.h"

#include "codebook.h"

#include "misc.h"

#include "scales.h"

#include <stdio.h>

#define floor1_rangedB 140 /* floor 1 fixed at -140dB to 0dB range */

typedef struct lsfit_acc{

  int x0;

  int x1;

  int xa;

  int ya;

  int x2a;

  int y2a;

  int xya;

  int an;

  int xb;

  int yb;

  int x2b;

  int y2b;

  int xyb;

  int bn;

} lsfit_acc;

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

static void floor1_free_info(vorbis_info_floor *i){

  vorbis_info_floor1 *info=(vorbis_info_floor1 *)i;

  if(info){

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

    _ogg_free(info);

  }

}

static void floor1_free_look(vorbis_look_floor *i){

  vorbis_look_floor1 *look=(vorbis_look_floor1 *)i;

  if(look){

    /*fprintf(stderr,"floor 1 bit usage %f:%f (%f total)\n",

            (float)look->phrasebits/look->frames,

            (float)look->postbits/look->frames,

            (float)(look->postbits+look->phrasebits)/look->frames);*/

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

    _ogg_free(look);

  }

}

static void floor1_pack (vorbis_info_floor *i,oggpack_buffer *opb){

  vorbis_info_floor1 *info=(vorbis_info_floor1 *)i;

  int j,k;

  int count=0;

  int rangebits;

  int maxposit=info->postlist[1];

  int maxclass=-1;

  /* save out partitions */

  oggpack_write(opb,info->partitions,5); /* only 0 to 31 legal */

  for(j=0;j<info->partitions;j++){

    oggpack_write(opb,info->partitionclass[j],4); /* only 0 to 15 legal */

    if(maxclass<info->partitionclass[j])maxclass=info->partitionclass[j];

  }

  /* save out partition classes */

  for(j=0;j<maxclass+1;j++){

    oggpack_write(opb,info->class_dim[j]-1,3); /* 1 to 8 */

    oggpack_write(opb,info->class_subs[j],2); /* 0 to 3 */

    if(info->class_subs[j])oggpack_write(opb,info->class_book[j],8);

    for(k=0;k<(1<<info->class_subs[j]);k++)

      oggpack_write(opb,info->class_subbook[j][k]+1,8);

  }

  /* save out the post list */

  oggpack_write(opb,info->mult-1,2);     /* only 1,2,3,4 legal now */

  /* maxposit cannot legally be less than 1; this is encode-side, we

     can assume our setup is OK */

  oggpack_write(opb,ov_ilog(maxposit-1),4);

  rangebits=ov_ilog(maxposit-1);

  for(j=0,k=0;j<info->partitions;j++){

    count+=info->class_dim[info->partitionclass[j]];

    for(;k<count;k++)

      oggpack_write(opb,info->postlist[k+2],rangebits);

  }

}

static int icomp(const void *a,const void *b){

  return(**(int **)a-**(int **)b);

}

static vorbis_info_floor *floor1_unpack (vorbis_info *vi,oggpack_buffer *opb){

  codec_setup_info     *ci=vi->codec_setup;

  int j,k,count=0,maxclass=-1,rangebits;

  vorbis_info_floor1 *info=_ogg_calloc(1,sizeof(*info));

  /* read partitions */

  info->partitions=oggpack_read(opb,5); /* only 0 to 31 legal */

  for(j=0;j<info->partitions;j++){

    info->partitionclass[j]=oggpack_read(opb,4); /* only 0 to 15 legal */

    if(info->partitionclass[j]<0)goto err_out;

    if(maxclass<info->partitionclass[j])maxclass=info->partitionclass[j];

  }

  /* read partition classes */

  for(j=0;j<maxclass+1;j++){

    info->class_dim[j]=oggpack_read(opb,3)+1; /* 1 to 8 */

    info->class_subs[j]=oggpack_read(opb,2); /* 0,1,2,3 bits */

    if(info->class_subs[j]<0)

      goto err_out;

    if(info->class_subs[j])info->class_book[j]=oggpack_read(opb,8);

    if(info->class_book[j]<0 || info->class_book[j]>=ci->books)

      goto err_out;

    for(k=0;k<(1<<info->class_subs[j]);k++){

      info->class_subbook[j][k]=oggpack_read(opb,8)-1;

      if(info->class_subbook[j][k]<-1 || info->class_subbook[j][k]>=ci->books)

        goto err_out;

    }

  }

  /* read the post list */

  info->mult=oggpack_read(opb,2)+1;     /* only 1,2,3,4 legal now */

  rangebits=oggpack_read(opb,4);

  if(rangebits<0)goto err_out;

  for(j=0,k=0;j<info->partitions;j++){

    count+=info->class_dim[info->partitionclass[j]];

    if(count>VIF_POSIT) goto err_out;

    for(;k<count;k++){

      int t=info->postlist[k+2]=oggpack_read(opb,rangebits);

      if(t<0 || t>=(1<<rangebits))

        goto err_out;

    }

  }

  info->postlist[0]=0;

  info->postlist[1]=1<<rangebits;

  /* don't allow repeated values in post list as they'd result in

     zero-length segments */

  {

    int *sortpointer[VIF_POSIT+2];

    for(j=0;j<count+2;j++)sortpointer[j]=info->postlist+j;

    qsort(sortpointer,count+2,sizeof(*sortpointer),icomp);

    for(j=1;j<count+2;j++)

      if(*sortpointer[j-1]==*sortpointer[j])goto err_out;

  }

  return(info);

 err_out:

  floor1_free_info(info);

  return(NULL);

}

static vorbis_look_floor *floor1_look(vorbis_dsp_state *vd,

                                      vorbis_info_floor *in){

  int *sortpointer[VIF_POSIT+2];

  vorbis_info_floor1 *info=(vorbis_info_floor1 *)in;

  vorbis_look_floor1 *look=_ogg_calloc(1,sizeof(*look));

  int i,j,n=0;

  (void)vd;

  look->vi=info;

  look->n=info->postlist[1];

  /* we drop each position value in-between already decoded values,

     and use linear interpolation to predict each new value past the

     edges.  The positions are read in the order of the position

     list... we precompute the bounding positions in the lookup.  Of

     course, the neighbors can change (if a position is declined), but

     this is an initial mapping */

  for(i=0;i<info->partitions;i++)n+=info->class_dim[info->partitionclass[i]];

  n+=2;

  look->posts=n;

  /* also store a sorted position index */

  for(i=0;i<n;i++)sortpointer[i]=info->postlist+i;

  qsort(sortpointer,n,sizeof(*sortpointer),icomp);

  /* points from sort order back to range number */

  for(i=0;i<n;i++)look->forward_index[i]=sortpointer[i]-info->postlist;

  /* points from range order to sorted position */

  for(i=0;i<n;i++)look->reverse_index[look->forward_index[i]]=i;

  /* we actually need the post values too */

  for(i=0;i<n;i++)look->sorted_index[i]=info->postlist[look->forward_index[i]];

  /* quantize values to multiplier spec */

  switch(info->mult){

  case 1: /* 1024 -> 256 */

    look->quant_q=256;

    break;

  case 2: /* 1024 -> 128 */

    look->quant_q=128;

    break;

  case 3: /* 1024 -> 86 */

    look->quant_q=86;

    break;

  case 4: /* 1024 -> 64 */

    look->quant_q=64;

    break;

  }

  /* discover our neighbors for decode where we don't use fit flags

     (that would push the neighbors outward) */

  for(i=0;i<n-2;i++){

    int lo=0;

    int hi=1;

    int lx=0;

    int hx=look->n;

    int currentx=info->postlist[i+2];

    for(j=0;j<i+2;j++){

      int x=info->postlist[j];

      if(x>lx && x<currentx){

        lo=j;

        lx=x;

      }

      if(x<hx && x>currentx){

        hi=j;

        hx=x;

      }

    }

    look->loneighbor[i]=lo;

    look->hineighbor[i]=hi;

  }

  return(look);

}

static int render_point(int x0,int x1,int y0,int y1,int x){

  y0&=0x7fff; /* mask off flag */

  y1&=0x7fff;

  {

    int dy=y1-y0;

    int adx=x1-x0;

    int ady=abs(dy);

    int err=ady*(x-x0);

    int off=err/adx;

    if(dy<0)return(y0-off);

    return(y0+off);

  }

}

static int vorbis_dBquant(const float *x){

  int i= *x*7.3142857f+1023.5f;

  if(i>1023)return(1023);

  if(i<0)return(0);

  return i;

}

static const 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,

};

static void render_line(int n, int x0,int x1,int y0,int y1,float *d){

  int dy=y1-y0;

  int adx=x1-x0;

  int ady=abs(dy);

  int base=dy/adx;

  int sy=(dy<0?base-1:base+1);

  int x=x0;

  int y=y0;

  int err=0;

  ady-=abs(base*adx);

  if(n>x1)n=x1;

  if(x<n)

    d[x]*=FLOOR1_fromdB_LOOKUP[y];

  while(++x<n){

    err=err+ady;

    if(err>=adx){

      err-=adx;

      y+=sy;

    }else{

      y+=base;

    }

    d[x]*=FLOOR1_fromdB_LOOKUP[y];

  }

}

static void render_line0(int n, int x0,int x1,int y0,int y1,int *d){

  int dy=y1-y0;

  int adx=x1-x0;

  int ady=abs(dy);

  int base=dy/adx;

  int sy=(dy<0?base-1:base+1);

  int x=x0;

  int y=y0;

  int err=0;

  ady-=abs(base*adx);

  if(n>x1)n=x1;

  if(x<n)

    d[x]=y;

  while(++x<n){

    err=err+ady;

    if(err>=adx){

      err-=adx;

      y+=sy;

    }else{

      y+=base;

    }

    d[x]=y;

  }

}

/* the floor has already been filtered to only include relevant sections */

static int accumulate_fit(const float *flr,const float *mdct,

                          int x0, int x1,lsfit_acc *a,

                          int n,vorbis_info_floor1 *info){

  long i;

  int xa=0,ya=0,x2a=0,y2a=0,xya=0,na=0, xb=0,yb=0,x2b=0,y2b=0,xyb=0,nb=0;

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

  a->x0=x0;

  a->x1=x1;

  if(x1>=n)x1=n-1;

  for(i=x0;i<=x1;i++){

    int quantized=vorbis_dBquant(flr+i);

    if(quantized){

      if(mdct[i]+info->twofitatten>=flr[i]){

        xa  += i;

        ya  += quantized;

        x2a += i*i;

        y2a += quantized*quantized;

        xya += i*quantized;

        na++;

      }else{

        xb  += i;

        yb  += quantized;

        x2b += i*i;

        y2b += quantized*quantized;

        xyb += i*quantized;

        nb++;

      }

    }

  }

  a->xa=xa;

  a->ya=ya;

  a->x2a=x2a;

  a->y2a=y2a;

  a->xya=xya;

  a->an=na;

  a->xb=xb;

  a->yb=yb;

  a->x2b=x2b;

  a->y2b=y2b;

  a->xyb=xyb;

  a->bn=nb;

  return(na);

}

static int fit_line(lsfit_acc *a,int fits,int *y0,int *y1,

                    vorbis_info_floor1 *info){

  double xb=0,yb=0,x2b=0,y2b=0,xyb=0,bn=0;

  int i;

  int x0=a[0].x0;

  int x1=a[fits-1].x1;

  for(i=0;i<fits;i++){

    double weight = (a[i].bn+a[i].an)*info->twofitweight/(a[i].an+1)+1.;

    xb+=a[i].xb + a[i].xa * weight;

    yb+=a[i].yb + a[i].ya * weight;

    x2b+=a[i].x2b + a[i].x2a * weight;

    y2b+=a[i].y2b + a[i].y2a * weight;

    xyb+=a[i].xyb + a[i].xya * weight;

    bn+=a[i].bn + a[i].an * weight;

  }

  if(*y0>=0){

    xb+=   x0;

    yb+=  *y0;

    x2b+=  x0 *  x0;

    y2b+= *y0 * *y0;

    xyb+= *y0 *  x0;

    bn++;

  }

  if(*y1>=0){

    xb+=   x1;

    yb+=  *y1;

    x2b+=  x1 *  x1;

    y2b+= *y1 * *y1;

    xyb+= *y1 *  x1;

    bn++;

  }

  {

    double denom=(bn*x2b-xb*xb);

    if(denom>0.){

      double a=(yb*x2b-xyb*xb)/denom;

      double b=(bn*xyb-xb*yb)/denom;

      *y0=rint(a+b*x0);

      *y1=rint(a+b*x1);

      /* limit to our range! */

      if(*y0>1023)*y0=1023;

      if(*y1>1023)*y1=1023;

      if(*y0<0)*y0=0;

      if(*y1<0)*y1=0;

      return 0;

    }else{

      *y0=0;

      *y1=0;

      return 1;

    }

  }

}

static int inspect_error(int x0,int x1,int y0,int y1,const float *mask,

                         const float *mdct,

                         vorbis_info_floor1 *info){

  int dy=y1-y0;

  int adx=x1-x0;

  int ady=abs(dy);

  int base=dy/adx;

  int sy=(dy<0?base-1:base+1);

  int x=x0;

  int y=y0;

  int err=0;

  int val=vorbis_dBquant(mask+x);

  int mse=0;

  int n=0;

  ady-=abs(base*adx);

  mse=(y-val);

  mse*=mse;

  n++;

  if(mdct[x]+info->twofitatten>=mask[x]){

    if(y+info->maxover<val)return(1);

    if(y-info->maxunder>val)return(1);

  }

  while(++x<x1){

    err=err+ady;

    if(err>=adx){

      err-=adx;

      y+=sy;

    }else{

      y+=base;

    }

    val=vorbis_dBquant(mask+x);

    mse+=((y-val)*(y-val));

    n++;

    if(mdct[x]+info->twofitatten>=mask[x]){

      if(val){

        if(y+info->maxover<val)return(1);

        if(y-info->maxunder>val)return(1);

      }

    }

  }

  if(info->maxover*info->maxover/n>info->maxerr)return(0);

  if(info->maxunder*info->maxunder/n>info->maxerr)return(0);

  if(mse/n>info->maxerr)return(1);

  return(0);

}

static int post_Y(int *A,int *B,int pos){

  if(A[pos]<0)

    return B[pos];

  if(B[pos]<0)

    return A[pos];

  return (A[pos]+B[pos])>>1;

}

int *floor1_fit(vorbis_block *vb,vorbis_look_floor1 *look,

                          const float *logmdct,   /* in */

                          const float *logmask){

  long i,j;

  vorbis_info_floor1 *info=look->vi;

  long n=look->n;

  long posts=look->posts;

  long nonzero=0;

  lsfit_acc fits[VIF_POSIT+1];

  int fit_valueA[VIF_POSIT+2]; /* index by range list position */

  int fit_valueB[VIF_POSIT+2]; /* index by range list position */

  int loneighbor[VIF_POSIT+2]; /* sorted index of range list position (+2) */

  int hineighbor[VIF_POSIT+2];

  int *output=NULL;

  int memo[VIF_POSIT+2];

  for(i=0;i<posts;i++)fit_valueA[i]=-200; /* mark all unused */

  for(i=0;i<posts;i++)fit_valueB[i]=-200; /* mark all unused */

  for(i=0;i<posts;i++)loneighbor[i]=0; /* 0 for the implicit 0 post */

  for(i=0;i<posts;i++)hineighbor[i]=1; /* 1 for the implicit post at n */

  for(i=0;i<posts;i++)memo[i]=-1;      /* no neighbor yet */

  /* quantize the relevant floor points and collect them into line fit

     structures (one per minimal division) at the same time */

  if(posts==0){

    nonzero+=accumulate_fit(logmask,logmdct,0,n,fits,n,info);

  }else{

    for(i=0;i<posts-1;i++)

      nonzero+=accumulate_fit(logmask,logmdct,look->sorted_index[i],

                              look->sorted_index[i+1],fits+i,

                              n,info);

  }

  if(nonzero){

    /* start by fitting the implicit base case.... */

    int y0=-200;

    int y1=-200;

    fit_line(fits,posts-1,&y0,&y1,info);

    fit_valueA[0]=y0;

    fit_valueB[0]=y0;

    fit_valueB[1]=y1;

    fit_valueA[1]=y1;

    /* Non degenerate case */

    /* start progressive splitting.  This is a greedy, non-optimal

       algorithm, but simple and close enough to the best

       answer. */

    for(i=2;i<posts;i++){

      int sortpos=look->reverse_index[i];

      int ln=loneighbor[sortpos];

      int hn=hineighbor[sortpos];

      /* eliminate repeat searches of a particular range with a memo */

      if(memo[ln]!=hn){

        /* haven't performed this error search yet */

        int lsortpos=look->reverse_index[ln];

        int hsortpos=look->reverse_index[hn];

        memo[ln]=hn;

        {

          /* A note: we want to bound/minimize *local*, not global, error */

          int lx=info->postlist[ln];

          int hx=info->postlist[hn];

          int ly=post_Y(fit_valueA,fit_valueB,ln);

          int hy=post_Y(fit_valueA,fit_valueB,hn);

          if(ly==-1 || hy==-1){

            exit(1);

          }

          if(inspect_error(lx,hx,ly,hy,logmask,logmdct,info)){

            /* outside error bounds/begin search area.  Split it. */

            int ly0=-200;

            int ly1=-200;

            int hy0=-200;

            int hy1=-200;

            int ret0=fit_line(fits+lsortpos,sortpos-lsortpos,&ly0,&ly1,info);

            int ret1=fit_line(fits+sortpos,hsortpos-sortpos,&hy0,&hy1,info);

            if(ret0){

              ly0=ly;

              ly1=hy0;

            }

            if(ret1){

              hy0=ly1;

              hy1=hy;

            }

            if(ret0 && ret1){

              fit_valueA[i]=-200;

              fit_valueB[i]=-200;

            }else{

              /* store new edge values */

              fit_valueB[ln]=ly0;

              if(ln==0)fit_valueA[ln]=ly0;

              fit_valueA[i]=ly1;

              fit_valueB[i]=hy0;

              fit_valueA[hn]=hy1;

              if(hn==1)fit_valueB[hn]=hy1;

              if(ly1>=0 || hy0>=0){

                /* store new neighbor values */

                for(j=sortpos-1;j>=0;j--)

                  if(hineighbor[j]==hn)

                    hineighbor[j]=i;

                  else

                    break;

                for(j=sortpos+1;j<posts;j++)

                  if(loneighbor[j]==ln)

                    loneighbor[j]=i;

                  else

                    break;

              }

            }

          }else{

            fit_valueA[i]=-200;

            fit_valueB[i]=-200;

          }

        }

      }

    }

    output=_vorbis_block_alloc(vb,sizeof(*output)*posts);

    output[0]=post_Y(fit_valueA,fit_valueB,0);

    output[1]=post_Y(fit_valueA,fit_valueB,1);

    /* fill in posts marked as not using a fit; we will zero

       back out to 'unused' when encoding them so long as curve

       interpolation doesn't force them into use */

    for(i=2;i<posts;i++){

      int ln=look->loneighbor[i-2];

      int hn=look->hineighbor[i-2];

      int x0=info->postlist[ln];

      int x1=info->postlist[hn];

      int y0=output[ln];

      int y1=output[hn];

      int predicted=render_point(x0,x1,y0,y1,info->postlist[i]);

      int vx=post_Y(fit_valueA,fit_valueB,i);

      if(vx>=0 && predicted!=vx){

        output[i]=vx;

      }else{

        output[i]= predicted|0x8000;

      }

    }

  }

  return(output);

}

int *floor1_interpolate_fit(vorbis_block *vb,vorbis_look_floor1 *look,

                          int *A,int *B,

                          int del){

  long i;

  long posts=look->posts;

  int *output=NULL;

  if(A && B){

    output=_vorbis_block_alloc(vb,sizeof(*output)*posts);

    /* overly simpleminded--- look again post 1.2 */

    for(i=0;i<posts;i++){

      output[i]=((65536-del)*(A[i]&0x7fff)+del*(B[i]&0x7fff)+32768)>>16;

      if(A[i]&0x8000 && B[i]&0x8000)output[i]|=0x8000;

    }

  }

  return(output);

}

int floor1_encode(oggpack_buffer *opb,vorbis_block *vb,

                  vorbis_look_floor1 *look,

                  int *post,int *ilogmask){

  long i,j;

  vorbis_info_floor1 *info=look->vi;

  long posts=look->posts;

  codec_setup_info *ci=vb->vd->vi->codec_setup;

  int out[VIF_POSIT+2];

  static_codebook **sbooks=ci->book_param;

  codebook *books=ci->fullbooks;

  /* quantize values to multiplier spec */

  if(post){

    for(i=0;i<posts;i++){

      int val=post[i]&0x7fff;

      switch(info->mult){

      case 1: /* 1024 -> 256 */

        val>>=2;

        break;

      case 2: /* 1024 -> 128 */

        val>>=3;

        break;

      case 3: /* 1024 -> 86 */

        val/=12;

        break;

      case 4: /* 1024 -> 64 */

        val>>=4;

        break;

      }

      post[i]=val | (post[i]&0x8000);

    }

    out[0]=post[0];

    out[1]=post[1];

    /* find prediction values for each post and subtract them */

    for(i=2;i<posts;i++){

      int ln=look->loneighbor[i-2];

      int hn=look->hineighbor[i-2];

      int x0=info->postlist[ln];

      int x1=info->postlist[hn];

      int y0=post[ln];

      int y1=post[hn];

      int predicted=render_point(x0,x1,y0,y1,info->postlist[i]);

      if((post[i]&0x8000) || (predicted==post[i])){

        post[i]=predicted|0x8000; /* in case there was roundoff jitter

                                     in interpolation */

        out[i]=0;

      }else{

        int headroom=(look->quant_q-predicted<predicted?

                      look->quant_q-predicted:predicted);

        int val=post[i]-predicted;

        /* at this point the 'deviation' value is in the range +/- max

           range, but the real, unique range can always be mapped to

           only [0-maxrange).  So we want to wrap the deviation into

           this limited range, but do it in the way that least screws

           an essentially gaussian probability distribution. */

        if(val<0)

          if(val<-headroom)

            val=headroom-val-1;

          else

            val=-1-(val<<1);

        else

          if(val>=headroom)

            val= val+headroom;

          else

            val<<=1;

        out[i]=val;

        post[ln]&=0x7fff;

        post[hn]&=0x7fff;

      }

    }

    /* we have everything we need. pack it out */

    /* mark nontrivial floor */

    oggpack_write(opb,1,1);

    /* beginning/end post */

    look->frames++;

    look->postbits+=ov_ilog(look->quant_q-1)*2;

    oggpack_write(opb,out[0],ov_ilog(look->quant_q-1));

    oggpack_write(opb,out[1],ov_ilog(look->quant_q-1));

    /* partition by partition */

    for(i=0,j=2;i<info->partitions;i++){

      int class=info->partitionclass[i];

      int cdim=info->class_dim[class];

      int csubbits=info->class_subs[class];

      int csub=1<<csubbits;

      int bookas[8]={0,0,0,0,0,0,0,0};

      int cval=0;

      int cshift=0;

      int k,l;

      /* generate the partition's first stage cascade value */

      if(csubbits){

        int maxval[8]={0,0,0,0,0,0,0,0}; /* gcc's static analysis

                                            issues a warning without

                                            initialization */

        for(k=0;k<csub;k++){

          int booknum=info->class_subbook[class][k];

          if(booknum<0){

            maxval[k]=1;

          }else{

            maxval[k]=sbooks[info->class_subbook[class][k]]->entries;

          }

        }

        for(k=0;k<cdim;k++){

          for(l=0;l<csub;l++){

            int val=out[j+k];

            if(val<maxval[l]){

              bookas[k]=l;

              break;

            }

          }

          cval|= bookas[k]<<cshift;

          cshift+=csubbits;