diff -r 2bc61f8841a1 -r 519d5bc91dd3 misc/libtremor/tremor/sharedbook.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libtremor/tremor/sharedbook.c	Sun Oct 28 15:15:39 2012 +0100
@@ -0,0 +1,439 @@
+/********************************************************************
+ *                                                                  *
+ * THIS FILE IS PART OF THE OggVorbis 'TREMOR' 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 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
+ * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: basic shared codebook operations
+
+ ********************************************************************/
+
+#include <stdlib.h>
+#include <math.h>
+#include <string.h>
+#include "ogg.h"
+#include "misc.h"
+#include "ivorbiscodec.h"
+#include "codebook.h"
+
+/**** pack/unpack helpers ******************************************/
+int _ilog(unsigned int v){
+  int ret=0;
+  while(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. */
+
+static ogg_int32_t _float32_unpack(long val,int *point){
+  long   mant=val&0x1fffff;
+  int    sign=val&0x80000000;
+  long   exp =(val&0x7fe00000L)>>VQ_FMAN;
+
+  exp-=(VQ_FMAN-1)+VQ_FEXP_BIAS;
+
+  if(mant){
+    while(!(mant&0x40000000)){
+      mant<<=1;
+      exp-=1;
+    }
+
+    if(sign)mant= -mant;
+  }else{
+    sign=0;
+    exp=-9999;
+  }
+
+  *point=exp;
+  return mant;
+}
+
+/* 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(long *l,long n,long sparsecount){
+  long i,j,count=0;
+  ogg_uint32_t marker[33];
+  ogg_uint32_t *r=(ogg_uint32_t *)_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++;
+  }
+    
+  /* 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);
+}
+
+/* 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(const static_codebook *b){
+  /* get us a starting hint, we'll polish it below */
+  int bits=_ilog(b->entries);
+  int vals=b->entries>>((bits-1)*(b->dim-1)/b->dim);
+
+  while(1){
+    long acc=1;
+    long acc1=1;
+    int i;
+    for(i=0;i<b->dim;i++){
+      acc*=vals;
+      acc1*=vals+1;
+    }
+    if(acc<=b->entries && acc1>b->entries){
+      return(vals);
+    }else{
+      if(acc>b->entries){
+	vals--;
+      }else{
+	vals++;
+      }
+    }
+  }
+}
+
+/* different than what _book_unquantize does for mainline:
+   we repack the book in a fixed point format that shares the same
+   binary point.  Upon first use, we can shift point if needed */
+
+/* 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 */
+
+ogg_int32_t *_book_unquantize(const static_codebook *b,int n,int *sparsemap,
+			      int *maxpoint){
+  long j,k,count=0;
+  if(b->maptype==1 || b->maptype==2){
+    int quantvals;
+    int minpoint,delpoint;
+    ogg_int32_t mindel=_float32_unpack(b->q_min,&minpoint);
+    ogg_int32_t delta=_float32_unpack(b->q_delta,&delpoint);
+    ogg_int32_t *r=(ogg_int32_t *)_ogg_calloc(n*b->dim,sizeof(*r));
+    int *rp=(int *)_ogg_calloc(n*b->dim,sizeof(*rp));
+
+    *maxpoint=minpoint;
+
+    /* 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=_book_maptype1_quantvals(b);
+      for(j=0;j<b->entries;j++){
+	if((sparsemap && b->lengthlist[j]) || !sparsemap){
+	  ogg_int32_t last=0;
+	  int lastpoint=0;
+	  int indexdiv=1;
+	  for(k=0;k<b->dim;k++){
+	    int index= (j/indexdiv)%quantvals;
+	    int point=0;
+	    int val=VFLOAT_MULTI(delta,delpoint,
+				 abs(b->quantlist[index]),&point);
+
+	    val=VFLOAT_ADD(mindel,minpoint,val,point,&point);
+	    val=VFLOAT_ADD(last,lastpoint,val,point,&point);
+	    
+	    if(b->q_sequencep){
+	      last=val;	  
+	      lastpoint=point;
+	    }
+	    
+	    if(sparsemap){
+	      r[sparsemap[count]*b->dim+k]=val;
+	      rp[sparsemap[count]*b->dim+k]=point;
+	    }else{
+	      r[count*b->dim+k]=val;
+	      rp[count*b->dim+k]=point;
+	    }
+	    if(*maxpoint<point)*maxpoint=point;
+	    indexdiv*=quantvals;
+	  }
+	  count++;
+	}
+
+      }
+      break;
+    case 2:
+      for(j=0;j<b->entries;j++){
+	if((sparsemap && b->lengthlist[j]) || !sparsemap){
+	  ogg_int32_t last=0;
+	  int         lastpoint=0;
+
+	  for(k=0;k<b->dim;k++){
+	    int point=0;
+	    int val=VFLOAT_MULTI(delta,delpoint,
+				 abs(b->quantlist[j*b->dim+k]),&point);
+
+	    val=VFLOAT_ADD(mindel,minpoint,val,point,&point);
+	    val=VFLOAT_ADD(last,lastpoint,val,point,&point);
+	    
+	    if(b->q_sequencep){
+	      last=val;	  
+	      lastpoint=point;
+	    }
+
+	    if(sparsemap){
+	      r[sparsemap[count]*b->dim+k]=val;
+	      rp[sparsemap[count]*b->dim+k]=point;
+	    }else{
+	      r[count*b->dim+k]=val;
+	      rp[count*b->dim+k]=point;
+	    }
+	    if(*maxpoint<point)*maxpoint=point;
+	  }
+	  count++;
+	}
+      }
+      break;
+    }
+
+    for(j=0;j<n*b->dim;j++)
+      if(rp[j]<*maxpoint)
+	r[j]>>=*maxpoint-rp[j];
+	    
+    _ogg_free(rp);
+    return(r);
+  }
+  return(NULL);
+}
+
+void vorbis_staticbook_clear(static_codebook *b){
+  if(b->quantlist)_ogg_free(b->quantlist);
+  if(b->lengthlist)_ogg_free(b->lengthlist);
+  memset(b,0,sizeof(*b));
+
+}
+
+void vorbis_staticbook_destroy(static_codebook *b){
+  vorbis_staticbook_clear(b);
+  _ogg_free(b);
+}
+
+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);
+
+  if(b->dec_index)_ogg_free(b->dec_index);
+  if(b->dec_codelengths)_ogg_free(b->dec_codelengths);
+  if(b->dec_firsttable)_ogg_free(b->dec_firsttable);
+
+  memset(b,0,sizeof(*b));
+}
+
+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 sort32a(const void *a,const void *b){
+  return (**(ogg_uint32_t **)a>**(ogg_uint32_t **)b)-
+    (**(ogg_uint32_t **)a<**(ogg_uint32_t **)b);
+}
+
+/* decode codebook arrangement is more heavily optimized than encode */
+int vorbis_book_init_decode(codebook *c,const static_codebook *s){
+  int i,j,n=0,tabn;
+  int *sortindex;
+  memset(c,0,sizeof(*c));
+  
+  /* count actually used entries */
+  for(i=0;i<s->entries;i++)
+    if(s->lengthlist[i]>0)
+      n++;
+
+  c->entries=s->entries;
+  c->used_entries=n;
+  c->dim=s->dim;
+
+  if(n>0){
+    /* 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 */
+    ogg_uint32_t *codes=_make_words(s->lengthlist,s->entries,c->used_entries);
+    ogg_uint32_t **codep=(ogg_uint32_t **)alloca(sizeof(*codep)*n);
+    
+    if(codes==NULL)goto err_out;
+
+    for(i=0;i<n;i++){
+      codes[i]=bitreverse(codes[i]);
+      codep[i]=codes+i;
+    }
+
+    qsort(codep,n,sizeof(*codep),sort32a);
+
+    sortindex=(int *)alloca(n*sizeof(*sortindex));
+    c->codelist=(ogg_uint32_t *)_ogg_malloc(n*sizeof(*c->codelist));
+    /* the index is a reverse index */
+    for(i=0;i<n;i++){
+      int position=codep[i]-codes;
+      sortindex[position]=i;
+    }
+
+    for(i=0;i<n;i++)
+      c->codelist[sortindex[i]]=codes[i];
+    _ogg_free(codes);
+    
+    
+    
+    c->valuelist=_book_unquantize(s,n,sortindex,&c->binarypoint);
+    c->dec_index=(int *)_ogg_malloc(n*sizeof(*c->dec_index));
+    
+    for(n=0,i=0;i<s->entries;i++)
+      if(s->lengthlist[i]>0)
+	c->dec_index[sortindex[n++]]=i;
+    
+    c->dec_codelengths=(char *)_ogg_malloc(n*sizeof(*c->dec_codelengths));
+    for(n=0,i=0;i<s->entries;i++)
+      if(s->lengthlist[i]>0)
+	c->dec_codelengths[sortindex[n++]]=s->lengthlist[i];
+    
+    c->dec_firsttablen=_ilog(c->used_entries)-4; /* this is magic */
+    if(c->dec_firsttablen<5)c->dec_firsttablen=5;
+    if(c->dec_firsttablen>8)c->dec_firsttablen=8;
+    
+    tabn=1<<c->dec_firsttablen;
+    c->dec_firsttable=(ogg_uint32_t *)_ogg_calloc(tabn,sizeof(*c->dec_firsttable));
+    c->dec_maxlength=0;
+    
+    for(i=0;i<n;i++){
+      if(c->dec_maxlength<c->dec_codelengths[i])
+	c->dec_maxlength=c->dec_codelengths[i];
+      if(c->dec_codelengths[i]<=c->dec_firsttablen){
+	ogg_uint32_t orig=bitreverse(c->codelist[i]);
+	for(j=0;j<(1<<(c->dec_firsttablen-c->dec_codelengths[i]));j++)
+	  c->dec_firsttable[orig|(j<<c->dec_codelengths[i])]=i+1;
+      }
+    }
+    
+    /* 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->dec_firsttablen);
+      long lo=0,hi=0;
+      
+      for(i=0;i<tabn;i++){
+	ogg_uint32_t word=i<<(32-c->dec_firsttablen);
+	if(c->dec_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), encode as the difference from the extremes. */
+	  {
+	    unsigned long loval=lo;
+	    unsigned long hival=n-hi;
+	    
+	    if(loval>0x7fff)loval=0x7fff;
+	    if(hival>0x7fff)hival=0x7fff;
+	    c->dec_firsttable[bitreverse(word)]=
+	      0x80000000UL | (loval<<15) | hival;
+	  }
+	}
+      }
+    }
+  }
+
+  return(0);
+ err_out:
+  vorbis_book_clear(c);
+  return(-1);
+}
+