/********************************************************************
 *                                                                  *
 * 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: basic shared codebook operations

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

#include <stdlib.h>
#include <limits.h>
#include <math.h>
#include <string.h>
#include <ogg/ogg.h>
#include "os.h"
#include "misc.h"
#include "vorbis/codec.h"
#include "codebook.h"
#include "scales.h"

/**** pack/unpack helpers ******************************************/

int ov_ilog(ogg_uint32_t v){
  int ret;
  for(ret=0;v;ret++)v>>=1;
  return ret;
}

/* 32 bit float (not IEEE; nonnormalized mantissa +
   biased exponent) : neeeeeee eeemmmmm mmmmmmmm mmmmmmmm
   Why not IEEE?  It's just not that important here. */

#define VQ_FEXP 10
#define VQ_FMAN 21
#define VQ_FEXP_BIAS 768 /* bias toward values smaller than 1. */

/* doesn't currently guard under/overflow */
long _float32_pack(float val){
  int sign=0;
  long exp;
  long mant;
  if(val<0){
    sign=0x80000000;
    val= -val;
  }
  exp= floor(log(val)/log(2.f)+.001); /* +epsilon */
  mant=rint(ldexp(val,(VQ_FMAN-1)-exp));
  exp=(exp+VQ_FEXP_BIAS)<<VQ_FMAN;

  return(sign|exp|mant);
}

float _float32_unpack(long val){
  double mant=val&0x1fffff;
  int    sign=val&0x80000000;
  long   exp =(val&0x7fe00000L)>>VQ_FMAN;
  if(sign)mant= -mant;
  exp=exp-(VQ_FMAN-1)-VQ_FEXP_BIAS;
  /* clamp excessive exponent values */
  if (exp>63){
    exp=63;
  }
  if (exp<-63){
    exp=-63;
  }
  return(ldexp(mant,exp));
}

/* given a list of word lengths, generate a list of codewords.  Works
   for length ordered or unordered, always assigns the lowest valued
   codewords first.  Extended to handle unused entries (length 0) */
ogg_uint32_t *_make_words(char *l,long n,long sparsecount){
  long i,j,count=0;
  ogg_uint32_t marker[33];
  ogg_uint32_t *r=_ogg_malloc((sparsecount?sparsecount:n)*sizeof(*r));
  memset(marker,0,sizeof(marker));

  for(i=0;i<n;i++){
    long length=l[i];
    if(length>0){
      ogg_uint32_t entry=marker[length];

      /* when we claim a node for an entry, we also claim the nodes
         below it (pruning off the imagined tree that may have dangled
         from it) as well as blocking the use of any nodes directly
         above for leaves */

      /* update ourself */
      if(length<32 && (entry>>length)){
        /* error condition; the lengths must specify an overpopulated tree */
        _ogg_free(r);
        return(NULL);
      }
      r[count++]=entry;

      /* Look to see if the next shorter marker points to the node
         above. if so, update it and repeat.  */
      {
        for(j=length;j>0;j--){

          if(marker[j]&1){
            /* have to jump branches */
            if(j==1)
              marker[1]++;
            else
              marker[j]=marker[j-1]<<1;
            break; /* invariant says next upper marker would already
                      have been moved if it was on the same path */
          }
          marker[j]++;
        }
      }

      /* prune the tree; the implicit invariant says all the longer
         markers were dangling from our just-taken node.  Dangle them
         from our *new* node. */
      for(j=length+1;j<33;j++)
        if((marker[j]>>1) == entry){
          entry=marker[j];
          marker[j]=marker[j-1]<<1;
        }else
          break;
    }else
      if(sparsecount==0)count++;
  }

  /* any underpopulated tree must be rejected. */
  /* Single-entry codebooks are a retconned extension to the spec.
     They have a single codeword '0' of length 1 that results in an
     underpopulated tree.  Shield that case from the underformed tree check. */
  if(!(count==1 && marker[2]==2)){
    for(i=1;i<33;i++)
      if(marker[i] & (0xffffffffUL>>(32-i))){
        _ogg_free(r);
        return(NULL);
      }
  }

  /* bitreverse the words because our bitwise packer/unpacker is LSb
     endian */
  for(i=0,count=0;i<n;i++){
    ogg_uint32_t temp=0;
    for(j=0;j<l[i];j++){
      temp<<=1;
      temp|=(r[count]>>j)&1;
    }

    if(sparsecount){
      if(l[i])
        r[count++]=temp;
    }else
      r[count++]=temp;
  }

  return(r);
}

/* given a list of word lengths, generate a list of packed MSb codewords and
   entry numbers.  This is like the above, except that the codewords are MSb
   first and aligned to be 32-bits in size, and the lower 24 bits include the
   entry number the codeword corresponds to. */
static ogg_int64_t *dec_make_words(signed char *l,long n,long sparsecount){
  long i,j,count=0;
  ogg_uint32_t marker[33];
  ogg_int64_t *r=_ogg_malloc((sparsecount?sparsecount:n)*sizeof(*r));
  if(r==NULL)return(NULL);
  memset(marker,0,sizeof(marker));

  for(i=0;i<n;i++){
    long length=l[i];
    if(length>0){
      ogg_uint32_t entry=marker[length];

      /* when we claim a node for an entry, we also claim the nodes
         below it (pruning off the imagined tree that may have dangled
         from it) as well as blocking the use of any nodes directly
         above for leaves */

      /* update ourself */
      if(length<32 && (entry>>length)){
        /* error condition; the lengths must specify an overpopulated tree */
        _ogg_free(r);
        return(NULL);
      }
      r[count++]=(ogg_int64_t)entry<<(32-l[i]+24)|i;

      /* Look to see if the next shorter marker points to the node
         above. if so, update it and repeat.  */
      {
        for(j=length;j>0;j--){

          if(marker[j]&1){
            /* have to jump branches */
            if(j==1)
              marker[1]++;
            else
              marker[j]=marker[j-1]<<1;
            break; /* invariant says next upper marker would already
                      have been moved if it was on the same path */
          }
          marker[j]++;
        }
      }

      /* prune the tree; the implicit invariant says all the longer
         markers were dangling from our just-taken node.  Dangle them
         from our *new* node. */
      for(j=length+1;j<33;j++)
        if((marker[j]>>1) == entry){
          entry=marker[j];
          marker[j]=marker[j-1]<<1;
        }else
          break;
    }else
      if(sparsecount==0)count++;
  }

  /* any underpopulated tree must be rejected. */
  /* Single-entry codebooks are a retconned extension to the spec.
     They have a single codeword '0' of length 1 that results in an
     underpopulated tree.  Shield that case from the underformed tree check. */
  if(!(count==1 && marker[2]==2)){
    for(i=1;i<33;i++)
      if(marker[i] & (0xffffffffUL>>(32-i))){
        _ogg_free(r);
        return(NULL);
      }
  }

  return(r);
}

/* there might be a straightforward one-line way to do the below
   that's portable and totally safe against roundoff, but I haven't
   thought of it.  Therefore, we opt on the side of caution */
long _book_maptype1_quantvals(long dim, long entries){
  long vals;
  if(entries<1){
    return(0);
  }
  vals=floor(pow((float)entries,1.f/dim));

  /* the above *should* be reliable, but we'll not assume that FP is
     ever reliable when bitstream sync is at stake; verify via integer
     means that vals really is the greatest value of dim for which
     vals^dim <= entries */
  /* treat the above as an initial guess */
  if(vals<1){
    vals=1;
  }
  while(1){
    long acc=1;
    long acc1=1;
    int i;
    for(i=0;i<dim;i++){
      if(entries/vals<acc)break;
      acc*=vals;
      if(LONG_MAX/(vals+1)<acc1)acc1=LONG_MAX;
      else acc1*=vals+1;
    }
    if(i>=dim && acc<=entries && acc1>entries){
      return(vals);
    }else{
      if(i<dim || acc>entries){
        vals--;
      }else{
        vals++;
      }
    }
  }
}

/* unpack the quantized list of values for decode ***********/
/* we need to deal with two map types: in map type 1, the values are
   generated algorithmically (each column of the vector counts through
   the values in the quant vector). in map type 2, all the values came
   in in an explicit list.  Both value lists must be unpacked */
void _book_unquantize(float *r,const dec_codebook *b,ogg_int32_t n,
                      ogg_int64_t *sparsemap){
  ogg_int32_t i,j,k;
  if(b->maptype==1 || b->maptype==2){
    ogg_int32_t quantvals;
    float mindel=_float32_unpack(b->q_min);
    float delta=_float32_unpack(b->q_delta);

    /* maptype 1 and 2 both use a quantized value vector, but
       different sizes */
    switch(b->maptype){
    case 1:
      /* most of the time, entries%dimensions == 0, but we need to be
         well defined.  We define that the possible vales at each
         scalar is values == entries/dim.  If entries%dim != 0, we'll
         have 'too few' values (values*dim<entries), which means that
         we'll have 'left over' entries; left over entries use zeroed
         values (and are wasted).  So don't generate codebooks like
         that */
      quantvals=(ogg_int32_t)_book_maptype1_quantvals(b->dim, b->entries);
      for(i=0;i<n;i++){
        float last=0.f;
        int indexdiv=1;
        j=(long)(sparsemap?sparsemap[i]&0xffffff:i);
        for(k=0;k<b->dim;k++){
          ogg_int32_t index=(j/indexdiv)%quantvals;
          float val=b->quantlist[index];
          val=fabs(val)*delta+mindel+last;
          if(b->q_sequencep)last=val;
          r[i*b->dim+k]=val;
          indexdiv*=quantvals;
        }
      }
      break;
    case 2:
      for(i=0;i<n;i++){
        float last=0.f;
        j=(ogg_int32_t)(sparsemap?sparsemap[i]&0xffffff:i);
        for(k=0;k<b->dim;k++){
          float val=b->quantlist[j*b->dim+k];
          val=fabs(val)*delta+mindel+last;
          if(b->q_sequencep)last=val;
          r[i*b->dim+k]=val;
        }
      }
      break;
    }

  }
}

void vorbis_staticbook_destroy(static_codebook *b){
  if(b->allocedp){
    if(b->quantlist)_ogg_free(b->quantlist);
    if(b->lengthlist)_ogg_free(b->lengthlist);
    memset(b,0,sizeof(*b));
    _ogg_free(b);
  } /* otherwise, it is in static memory */
}

void vorbis_book_clear(codebook *b){
  /* static book is not cleared; we're likely called on the lookup and
     the static codebook belongs to the info struct */
  if(b->valuelist)_ogg_free(b->valuelist);
  if(b->codelist)_ogg_free(b->codelist);

  memset(b,0,sizeof(*b));
}

void vorbis_decbook_clear(dec_codebook *b){
  if(b->quantlist)_ogg_free(b->quantlist);
  if(b->firsttable)_ogg_free(b->firsttable);
  if(b->codelist)_ogg_free(b->codelist);
  if(b->codelengths)_ogg_free(b->codelengths);
  if(b->index)_ogg_free(b->index);
  if(b->valuelist)_ogg_free(b->valuelist);
  memset(b,0,sizeof(*b));
}

int vorbis_book_init_encode(codebook *c,const static_codebook *s){

  memset(c,0,sizeof(*c));
  c->c=s;
  c->entries=s->entries;
  c->used_entries=s->entries;
  c->dim=s->dim;
  c->codelist=_make_words(s->lengthlist,s->entries,0);
  c->quantvals=_book_maptype1_quantvals(s->dim, s->entries);
  c->minval=(int)rint(_float32_unpack(s->q_min));
  c->delta=(int)rint(_float32_unpack(s->q_delta));

  return(0);
}

static ogg_uint32_t bitreverse(ogg_uint32_t x){
  x=    ((x>>16)&0x0000ffffUL) | ((x<<16)&0xffff0000UL);
  x=    ((x>> 8)&0x00ff00ffUL) | ((x<< 8)&0xff00ff00UL);
  x=    ((x>> 4)&0x0f0f0f0fUL) | ((x<< 4)&0xf0f0f0f0UL);
  x=    ((x>> 2)&0x33333333UL) | ((x<< 2)&0xccccccccUL);
  return((x>> 1)&0x55555555UL) | ((x<< 1)&0xaaaaaaaaUL);
}

static int sort64a(const void *a,const void *b){
  return ( *(ogg_int64_t *)a>*(ogg_int64_t *)b)-
    ( *(ogg_int64_t *)a<*(ogg_int64_t *)b);
}

/* decode codebook arrangement is more heavily optimized than encode */
int vorbis_book_init_decode(dec_codebook *c){
  ogg_int32_t i,j,n;
  ogg_int64_t *codes=NULL;

  /* only initialize once */
  if(c->codelist)return(0);

  if(c->codelengths){
    /* unordered codebook */
    /* count actually used entries */
    n=0;
    for(i=0;i<c->entries;i++)
      if(c->codelengths[i]>0)
        n++;

    if(n>0){
      signed char *codelengths;
      /* two different remappings go on here.

      First, we collapse the likely sparse codebook down only to
      actually represented values/words.  This collapsing needs to be
      indexed as map-valueless books are used to encode original entry
      positions as integers.

      Second, we reorder all vectors, including the entry index above,
      by sorted bitreversed codeword to allow treeless decode. */

      /* perform sort */
      codes=dec_make_words(c->codelengths,c->entries,n);
      if(codes==NULL)goto err_out;

      qsort(codes,n,sizeof(*codes),sort64a);

      c->codelist=_ogg_malloc(n*sizeof(*c->codelist));
      if(c->codelist==NULL)goto err_out;

      for(i=0;i<n;i++){
        c->codelist[i]=(ogg_uint32_t)(codes[i]>>24);
      }

      if(c->maptype==1 || c->maptype==2){
        c->valuelist=_ogg_malloc(c->dim*n*sizeof(*c->valuelist));
        if(c->valuelist==NULL)goto err_out;
        _book_unquantize(c->valuelist,c,n,codes);
        _ogg_free(c->quantlist);
        c->quantlist=NULL;
      }
      c->index=_ogg_malloc(n*sizeof(*c->index));
      if(c->index==NULL)goto err_out;
      codelengths=_ogg_malloc(n*sizeof(*c->codelengths));
      if(codelengths==NULL)goto err_out;

      /* save the index of used entries, compact and reorder the codelengths,
         and find min/max length */
      c->minlength=32;
      c->maxlength=0;
      for(i=0;i<n;i++){
        j=(ogg_int32_t)(codes[i]&0xffffff);
        c->index[i]=j;
        codelengths[i]=c->codelengths[j];
        if(codelengths[i]<c->minlength)
          c->minlength=codelengths[i];
        if(codelengths[i]>c->maxlength)
          c->maxlength=codelengths[i];
      }
      _ogg_free(codes);
      codes=NULL;
      _ogg_free(c->codelengths);
      c->codelengths=codelengths;
    }
  }else{
    /* ordered codebook:
       we can avoid building an explicit list of codepoints, which can be a big
       advantage as we approach the limits of the spec with upwards of 16
       million codebook entries.  We follow the approach of Alistair Moffat and
       Andrew Turpin: On the Implementation of Minimum Redundancy Prefix Codes,
       IEEE Transactions on Communications, 45(10):1200--1207, October, 1997,
       except modified to have codewords in order of increasing length, instead
       of decreasing. */
    n=c->entries;
    if(n>0){
      ogg_uint32_t prev_entry;
      ogg_uint32_t code;
      int nlengths;
      int length;
      int l;
      nlengths=c->maxlength-c->minlength+1;
      c->codelist=_ogg_malloc(nlengths*sizeof(*c->codelist));
      if(c->codelist==NULL)goto err_out;
      /* for this case, codelist[l] contains the last codeword of the l'th
         length, left-aligned in a 32-bit word, with all remaining bits filled
         with trailing 1's.  This ensures that 32 bits taken from the stream
         will be <= codelist[l] if the codeword length is <= length l. */
      prev_entry=0;
      code=0;
      length=c->minlength;
      for(l=0;l<nlengths;l++,length++){
        ogg_uint32_t nentries;
        nentries=c->index[l]-prev_entry;
        /* guard against an over-populated tree.  We do not check the last
           length, because it should exactly use the remaining space, which
           causes code to wrap to 0 (something this check prevents for any
           earlier length).  We'll check it after the loop. */
        if(l+1<nlengths && nentries>((0xffffffffUL-code)>>(32-length)))
          goto err_out;
        code+=nentries<<(32-length);
        /* this requires that the first length have a non-zero number of
           entries, or c->codelist[0] will wrap to 0xffffffff, making the list
           non-monotonic. */
        c->codelist[l]=code-1;
        prev_entry=c->index[l];
      }
      /* for a complete tree, the last value will have all bits set, which
         guarantees we will not walk past the end of the array during decode */
      if(c->codelist[nlengths-1]!=0xffffffffUL){
        /* reject over/underpopulated trees, with the exception of a
           single-entry codebook. */
        if(n!=1 || c->maxlength!=1)goto err_out;
      }
      if(c->maptype==1 || c->maptype==2){
        c->valuelist=_ogg_malloc(c->dim*n*sizeof(*c->valuelist));
        if(c->valuelist==NULL)goto err_out;
        _book_unquantize(c->valuelist,c,n,NULL);
        _ogg_free(c->quantlist);
        c->quantlist=NULL;
      }
    }
  }
  /* build the fastpath lookup table */
  if(n>0){
    if(n==1 && c->maxlength==1){
      /* special case the 'single entry codebook' with a single bit
       fastpath table (that always returns entry 0 )in order to use
       unmodified decode paths. */
      c->firsttablen=1;
      c->firsttable=_ogg_calloc(2,sizeof(*c->firsttable));
      if(c->firsttable==NULL)goto err_out;
      c->firsttable[0]=c->firsttable[1]=1;

    }else{
      int used_bits;
      int tabn;
      used_bits=ov_ilog(n);
      c->firsttablen=(signed char)(used_bits-4); /* this is magic */
      if(c->firsttablen<5)c->firsttablen=5;
      /* if the codewords all have similar lengths, we might wind up with a
         table smaller than the shorter codes: increase the size or we could
         take the slow path in a large fraction of cases */
      if(c->firsttablen<c->minlength+1)
        c->firsttablen=c->minlength+1;
      /* also cap the table by the max length, or we are just wasting space */
      if(c->firsttablen>c->maxlength)
        c->firsttablen=c->maxlength;
      /* if we have an ordered book with a very large minimum length, an 8-bit
         table would be mostly wasted.  Instead, try to make one just large
         enough to get a good guess for the codeword length. */
      if(c->codelengths==NULL && c->minlength>8)
        c->firsttablen=c->maxlength-c->minlength+1;
      if(c->firsttablen>8)c->firsttablen=8;

      tabn=1<<c->firsttablen;
      c->firsttable=_ogg_calloc(tabn,sizeof(*c->firsttable));
      if(c->firsttable==NULL)goto err_out;

      if(c->codelengths!=NULL){
        /* unordered codebook:
           use the codewords for each entry to build the fastpath table */
        for(i=0;i<n;i++){
          if(c->codelengths[i]<=c->firsttablen){
            ogg_uint32_t orig=bitreverse(c->codelist[i]);
            for(j=0;j<(1<<(c->firsttablen-c->codelengths[i]));j++)
              /* pack the length into the table, too, to avoid an extra lookup.
                 This also guarantees the table value is non-zero, since the
                 length of any used entry is positive. */
              c->firsttable[orig|(j<<c->codelengths[i])]=
               i<<6|c->codelengths[i];
          }
        }

        /* now fill in 'unused' entries in the firsttable with hi/lo search
           hints for the non-direct-hits */
        {
          ogg_uint32_t mask=0xfffffffeUL<<(31-c->firsttablen);
          long lo=0,hi=0;
          int hint_shift;

          c->hi_max=n;
          hint_shift=used_bits>15?used_bits-15:0;
          c->hint_shift=(signed char)hint_shift;
          for(i=0;i<tabn;i++){
            ogg_uint32_t word=((ogg_uint32_t)i<<(32-c->firsttablen));
            if(c->firsttable[bitreverse(word)]==0){
              while((lo+1)<n && c->codelist[lo+1]<=word)lo++;
              while(    hi<n && word>=(c->codelist[hi]&mask))hi++;

              /* we only actually have 15 bits per hint to play with here.
                 In order to overflow gracefully (nothing breaks, efficiency
                 just drops), shift the values down when the range gets too
                 large.  We encode the hi value as a difference from the max so
                 truncation error moves it upwards without risk of stepping
                 past the end of the arrays. */
              {
                unsigned long loval=lo>>hint_shift;
                unsigned long hival=(n-hi)>>hint_shift;

                if(loval>0x7fff)loval=0x7fff;
                if(hival>0x7fff)hival=0x7fff;
                c->firsttable[bitreverse(word)]=
                  0x80000000UL | (loval<<15) | hival;
              }
            }
          }
        }
      }else{
        ogg_uint32_t code;
        int nlengths;
        int length;
        int l;
        /* ordered codebook:
           step through the code lengths to build the fastpath table */
        nlengths=c->maxlength-c->minlength+1;
        c->hi_max=nlengths-1;
        c->hint_shift=0;
        length=c->minlength;
        code=0;
        for(i=l=0;length<=c->firsttablen;l++,length++){
          for(;i<c->index[l];i++,code++){
            ogg_uint32_t orig=bitreverse(code<<(32-length));
            for(j=0;j<(1<<(c->firsttablen-length));j++){
              /* pack the length into the table to avoid an extra lookup */
              c->firsttable[(j<<length)|orig]=i<<6|length;
            }
          }
          code<<=1;
        }

        /* now fill in 'unused' entries in the firsttable with length search
           hints for the non-direct hits.  In this case, instead of storing the
           hi/lo entry codewords in the table, we store the (index of) the
           shortest and longest lengths of any codeword that starts with that
           prefix. */
        if(l<nlengths){
          int lo=l;
          do{
            ogg_uint32_t nleft;
            ogg_uint32_t slot_count;
            /* how many more codes are left of this length? */
            nleft=(c->codelist[l]>>(32-length))-code+1;
            slot_count=(ogg_uint32_t)1<<(length-c->firsttablen);
            if(nleft>=slot_count){
              ogg_uint32_t word=code>>(length-c->firsttablen);
              c->firsttable[bitreverse(word<<(32-c->firsttablen))]=
               0x80000000UL | ((ogg_uint32_t)lo<<15) | (nlengths-1-l);
              code+=slot_count;
              lo=l;
            }else{
              /* not enough: consider longer codes */
              l++;
              length++;
              code<<=1;
              if(nleft==0)lo=l;
            }
          }
          while(l<nlengths);
        }
      }
    }
  }

  return(0);
 err_out:
  if(codes)_ogg_free(codes);
  /* our caller will clean up the partially initialized book */
  return(-1);
}

long vorbis_book_codeword(codebook *book,int entry){
  if(book->c) /* only use with encode; decode optimizations are
                 allowed to break this */
    return book->codelist[entry];
  return -1;
}

long vorbis_book_codelen(codebook *book,int entry){
  if(book->c) /* only use with encode; decode optimizations are
                 allowed to break this */
    return book->c->lengthlist[entry];
  return -1;
}

#ifdef _V_SELFTEST

/* Unit tests of the dequantizer; this stuff will be OK
   cross-platform, I simply want to be sure that special mapping cases
   actually work properly; a bug could go unnoticed for a while */

#include <stdio.h>

/* cases:

   no mapping
   full, explicit mapping
   algorithmic mapping

   nonsequential
   sequential
*/

static ogg_uint16_t full_quantlist1[]={0,1,2,3,    4,5,6,7, 8,3,6,1};
static ogg_uint16_t partial_quantlist1[]={0,7,2};

/* no mapping */
dec_codebook test1={
  4,0,0,0,16,0,0,
  0,0,0,0,0,
  NULL,
  NULL,NULL,NULL,NULL,NULL
};
static float *test1_result=NULL;

/* linear, full mapping, nonsequential */
dec_codebook test2={
  4,0,0,0,3,0,0,
  2,4,0,3761766400U,1611661312,
  full_quantlist1,
  NULL,NULL,NULL,NULL,NULL
};
static float test2_result[]={-3,-2,-1,0, 1,2,3,4, 5,0,3,-2};

/* linear, full mapping, sequential */
dec_codebook test3={
  4,0,0,0,3,0,0,
  2,4,1,3761766400U,1611661312,
  full_quantlist1,
  NULL,NULL,NULL,NULL,NULL
};
static float test3_result[]={-3,-5,-6,-6, 1,3,6,10, 5,5,8,6};

/* linear, algorithmic mapping, nonsequential */
dec_codebook test4={
  3,0,0,0,27,0,0,
  1,4,0,3761766400U,1611661312,
  partial_quantlist1,
  NULL,NULL,NULL,NULL,NULL
};
static float test4_result[]={-3,-3,-3, 4,-3,-3, -1,-3,-3,
                              -3, 4,-3, 4, 4,-3, -1, 4,-3,
                              -3,-1,-3, 4,-1,-3, -1,-1,-3,
                              -3,-3, 4, 4,-3, 4, -1,-3, 4,
                              -3, 4, 4, 4, 4, 4, -1, 4, 4,
                              -3,-1, 4, 4,-1, 4, -1,-1, 4,
                              -3,-3,-1, 4,-3,-1, -1,-3,-1,
                              -3, 4,-1, 4, 4,-1, -1, 4,-1,
                              -3,-1,-1, 4,-1,-1, -1,-1,-1};

/* linear, algorithmic mapping, sequential */
dec_codebook test5={
  3,0,0,0,27,0,0,
  1,4,1,3761766400U,1611661312,
  partial_quantlist1,
  NULL,NULL,NULL,NULL,NULL,
};
static float test5_result[]={-3,-6,-9, 4, 1,-2, -1,-4,-7,
                              -3, 1,-2, 4, 8, 5, -1, 3, 0,
                              -3,-4,-7, 4, 3, 0, -1,-2,-5,
                              -3,-6,-2, 4, 1, 5, -1,-4, 0,
                              -3, 1, 5, 4, 8,12, -1, 3, 7,
                              -3,-4, 0, 4, 3, 7, -1,-2, 2,
                              -3,-6,-7, 4, 1, 0, -1,-4,-5,
                              -3, 1, 0, 4, 8, 7, -1, 3, 2,
                              -3,-4,-5, 4, 3, 2, -1,-2,-3};

void run_test(dec_codebook *b,float *comp){
  float out[3*27];
  int i;

  if(comp){
    _book_unquantize(out,b,b->entries,NULL);
    for(i=0;i<b->entries*b->dim;i++)
      if(fabs(out[i]-comp[i])>.0001){
        fprintf(stderr,"disagreement in unquantized and reference data:\n"
                "position %d, %g != %g\n",i,out[i],comp[i]);
        exit(1);
      }

  }
}

int main(){
  /* run the nine dequant tests, and compare to the hand-rolled results */
  fprintf(stderr,"Dequant test 1... ");
  run_test(&test1,test1_result);
  fprintf(stderr,"OK\nDequant test 2... ");
  run_test(&test2,test2_result);
  fprintf(stderr,"OK\nDequant test 3... ");
  run_test(&test3,test3_result);
  fprintf(stderr,"OK\nDequant test 4... ");
  run_test(&test4,test4_result);
  fprintf(stderr,"OK\nDequant test 5... ");
  run_test(&test5,test5_result);
  fprintf(stderr,"OK\n\n");

  return(0);
}

#endif