Merge branch 'main' into seek-support

1 files changed, 664 insertions, 258 deletions

diff --git a/lib/tremor/codebook.c b/lib/tremor/codebook.c
index 1e1ae8a9..85a46eb2 100644
--- a/lib/tremor/codebook.c
+++ b/lib/tremor/codebook.c
@@ -1,12 +1,12 @@
 /********************************************************************
  *                                                                  *
- * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
+ * THIS FILE IS PART OF THE TremorOggVorbis '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    *
+ * THE TremorOggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
  *                                                                  *
  ********************************************************************
@@ -18,77 +18,385 @@
 #include <stdlib.h>
 #include <string.h>
 #include <math.h>
-#include <ogg/ogg.h>
+#include "tremor_ogg.h"
 #include "ivorbiscodec.h"
 #include "codebook.h"
 #include "misc.h"
+#include "os.h"
 
-/* unpacks a codebook from the packet buffer into the codebook struct,
-   readies the codebook auxiliary structures for decode *************/
-static_codebook *vorbis_staticbook_unpack(oggpack_buffer *opb){
-  long i,j;
-  static_codebook *s=_ogg_calloc(1,sizeof(*s));
+
+/**** pack/unpack helpers ******************************************/
+int _ilog(unsigned int v){
+  int ret=0;
+  while(v){
+    ret++;
+    v>>=1;
+  }
+  return(ret);
+}
+
+static tremor_ogg_uint32_t decpack(long entry,long used_entry,long quantvals,
+			    codebook *b,tremor_oggpack_buffer *opb,int maptype){
+  tremor_ogg_uint32_t ret=0;
+  int j;
+  
+  switch(b->dec_type){
+
+  case 0:
+    return (tremor_ogg_uint32_t)entry;
+
+  case 1:
+    if(maptype==1){
+      /* vals are already read into temporary column vector here */
+      for(j=0;j<b->dim;j++){
+	tremor_ogg_uint32_t off=entry%quantvals;
+	entry/=quantvals;
+	ret|=((tremor_ogg_uint16_t *)(b->q_val))[off]<<(b->q_bits*j);
+      }
+    }else{
+      for(j=0;j<b->dim;j++)
+	ret|=tremor_oggpack_read(opb,b->q_bits)<<(b->q_bits*j);
+    }
+    return ret;
+    
+  case 2:
+    for(j=0;j<b->dim;j++){
+      tremor_ogg_uint32_t off=entry%quantvals;
+      entry/=quantvals;
+      ret|=off<<(b->q_pack*j);
+    }
+    return ret;
+
+  case 3:
+    return (tremor_ogg_uint32_t)used_entry;
+
+  }
+  return 0; /* silence compiler */
+}
+
+/* 32 bit float (not IEEE; nonnormalized mantissa +
+   biased exponent) : neeeeeee eeemmmmm mmmmmmmm mmmmmmmm 
+   Why not IEEE?  It's just not that important here. */
+
+static tremor_ogg_int32_t _float32_unpack(long val,int *point){
+  long   mant=val&0x1fffff;
+  int    sign=val&0x80000000;
+  
+  *point=((val&0x7fe00000L)>>21)-788;
+
+  if(mant){
+    while(!(mant&0x40000000)){
+      mant<<=1;
+      *point-=1;
+    }
+    if(sign)mant= -mant;
+  }else{
+    *point=-9999;
+  }
+  return mant;
+}
+
+/* choose the smallest supported node size that fits our decode table.
+   Legal bytewidths are 1/1 1/2 2/2 2/4 4/4 */
+static int _determine_node_bytes(long used, int leafwidth){
+
+  /* special case small books to size 4 to avoid multiple special
+     cases in repack */
+  if(used<2)
+    return 4;
+
+  if(leafwidth==3)leafwidth=4;
+  if(_ilog(3*used-6)+1 <= leafwidth*4) 
+    return leafwidth/2?leafwidth/2:1;
+  return leafwidth;
+}
+
+/* convenience/clarity; leaves are specified as multiple of node word
+   size (1 or 2) */
+static int _determine_leaf_words(int nodeb, int leafwidth){
+  if(leafwidth>nodeb)return 2;
+  return 1;
+}
+
+/* given a list of word lengths, number of used entries, and byte
+   width of a leaf, generate the decode table */
+static int _make_words(char *l,long n,tremor_ogg_uint32_t *r,long quantvals,
+		       codebook *b, tremor_oggpack_buffer *opb,int maptype){
+  long i,j,count=0;
+  long top=0;
+  tremor_ogg_uint32_t marker[33];
+
+  if(n<2){
+    r[0]=0x80000000;
+  }else{
+    memset(marker,0,sizeof(marker));
+    
+    for(i=0;i<n;i++){
+      long length=l[i];
+      if(length){
+	tremor_ogg_uint32_t entry=marker[length];
+	long chase=0;
+	if(count && !entry)return -1; /* overpopulated tree! */
+	
+	/* chase the tree as far as it's already populated, fill in past */
+	for(j=0;j<length-1;j++){
+	  int bit=(entry>>(length-j-1))&1;
+	  if(chase>=top){ 
+	    top++;
+	    r[chase*2]=top;
+	    r[chase*2+1]=0;
+	  }else
+	    if(!r[chase*2+bit])
+	      r[chase*2+bit]=top;
+	  chase=r[chase*2+bit];
+	}
+	{	
+	  int bit=(entry>>(length-j-1))&1;
+	  if(chase>=top){ 
+	    top++;
+	    r[chase*2+1]=0;
+	  }
+	  r[chase*2+bit]= decpack(i,count++,quantvals,b,opb,maptype) | 
+	    0x80000000;
+	}
+
+	/* 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){
+	    marker[j]=marker[j-1]<<1;
+	    break;
+	  }
+	  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;
+      }
+    }
+  }
+  
+  return 0;
+}
+
+static int _make_decode_table(codebook *s,char *lengthlist,long quantvals,
+			      tremor_oggpack_buffer *opb,int maptype){
+  int i;
+  tremor_ogg_uint32_t *work;
+
+  if(s->dec_nodeb==4){
+    s->dec_table=_tremor_ogg_malloc((s->used_entries*2+1)*sizeof(*work));
+    /* +1 (rather than -2) is to accommodate 0 and 1 sized books,
+       which are specialcased to nodeb==4 */
+    if(_make_words(lengthlist,s->entries,
+		   s->dec_table,quantvals,s,opb,maptype))return 1;
+    
+    return 0;
+  }
+
+  work=alloca((s->used_entries*2-2)*sizeof(*work));
+  if(_make_words(lengthlist,s->entries,work,quantvals,s,opb,maptype))return 1;
+  s->dec_table=_tremor_ogg_malloc((s->used_entries*(s->dec_leafw+1)-2)*
+			   s->dec_nodeb);
+  
+  if(s->dec_leafw==1){
+    switch(s->dec_nodeb){
+    case 1:
+      for(i=0;i<s->used_entries*2-2;i++)
+	  ((unsigned char *)s->dec_table)[i]=
+	    ((work[i] & 0x80000000UL) >> 24) | work[i];
+      break;
+    case 2:
+      for(i=0;i<s->used_entries*2-2;i++)
+	  ((tremor_ogg_uint16_t *)s->dec_table)[i]=
+	    ((work[i] & 0x80000000UL) >> 16) | work[i];
+      break; 
+    }
+
+  }else{
+    /* more complex; we have to do a two-pass repack that updates the
+       node indexing. */
+    long top=s->used_entries*3-2;
+    if(s->dec_nodeb==1){
+      unsigned char *out=(unsigned char *)s->dec_table;
+
+      for(i=s->used_entries*2-4;i>=0;i-=2){
+	if(work[i]&0x80000000UL){
+	  if(work[i+1]&0x80000000UL){
+	    top-=4;
+	    out[top]=(work[i]>>8 & 0x7f)|0x80;
+	    out[top+1]=(work[i+1]>>8 & 0x7f)|0x80;
+	    out[top+2]=work[i] & 0xff;
+	    out[top+3]=work[i+1] & 0xff;
+	  }else{
+	    top-=3;
+	    out[top]=(work[i]>>8 & 0x7f)|0x80;
+	    out[top+1]=work[work[i+1]*2];
+	    out[top+2]=work[i] & 0xff;
+	  }
+	}else{
+	  if(work[i+1]&0x80000000UL){
+	    top-=3;
+	    out[top]=work[work[i]*2];
+	    out[top+1]=(work[i+1]>>8 & 0x7f)|0x80;
+	    out[top+2]=work[i+1] & 0xff;
+	  }else{
+	    top-=2;
+	    out[top]=work[work[i]*2];
+	    out[top+1]=work[work[i+1]*2];
+	  }
+	}
+	work[i]=top;
+      }
+    }else{
+      tremor_ogg_uint16_t *out=(tremor_ogg_uint16_t *)s->dec_table;
+      for(i=s->used_entries*2-4;i>=0;i-=2){
+	if(work[i]&0x80000000UL){
+	  if(work[i+1]&0x80000000UL){
+	    top-=4;
+	    out[top]=(work[i]>>16 & 0x7fff)|0x8000;
+	    out[top+1]=(work[i+1]>>16 & 0x7fff)|0x8000;
+	    out[top+2]=work[i] & 0xffff;
+	    out[top+3]=work[i+1] & 0xffff;
+	  }else{
+	    top-=3;
+	    out[top]=(work[i]>>16 & 0x7fff)|0x8000;
+	    out[top+1]=work[work[i+1]*2];
+	    out[top+2]=work[i] & 0xffff;
+	  }
+	}else{
+	  if(work[i+1]&0x80000000UL){
+	    top-=3;
+	    out[top]=work[work[i]*2];
+	    out[top+1]=(work[i+1]>>16 & 0x7fff)|0x8000;
+	    out[top+2]=work[i+1] & 0xffff;
+	  }else{
+	    top-=2;
+	    out[top]=work[work[i]*2];
+	    out[top+1]=work[work[i+1]*2];
+	  }
+	}
+	work[i]=top;
+      }
+    }
+  }
+	
+  return 0;
+}
+
+/* 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 */
+/* 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(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++;
+      }
+    }
+  }
+}
+
+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->q_val)_tremor_ogg_free(b->q_val);
+  if(b->dec_table)_tremor_ogg_free(b->dec_table);
+
+  memset(b,0,sizeof(*b));
+}
+
+int vorbis_book_unpack(tremor_oggpack_buffer *opb,codebook *s){
+  char         *lengthlist=NULL;
+  int           quantvals=0;
+  long          i,j;
+  int           maptype;
+
+  memset(s,0,sizeof(*s));
 
   /* make sure alignment is correct */
-  if(oggpack_read(opb,24)!=0x564342)goto _eofout;
+  if(tremor_oggpack_read(opb,24)!=0x564342)goto _eofout;
 
   /* first the basic parameters */
-  s->dim=oggpack_read(opb,16);
-  s->entries=oggpack_read(opb,24);
+  s->dim=tremor_oggpack_read(opb,16);
+  s->entries=tremor_oggpack_read(opb,24);
   if(s->entries==-1)goto _eofout;
 
-  if(_ilog(s->dim)+_ilog(s->entries)>24)goto _eofout;
-
   /* codeword ordering.... length ordered or unordered? */
-  switch((int)oggpack_read(opb,1)){
-  case 0:{
-    long unused;
-    /* allocated but unused entries? */
-    unused=oggpack_read(opb,1);
-    if((s->entries*(unused?1:5)+7)>>3>opb->storage-oggpack_bytes(opb))
-      goto _eofout;
+  switch((int)tremor_oggpack_read(opb,1)){
+  case 0:
     /* unordered */
-    s->lengthlist=(long *)_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
+    lengthlist=(char *)alloca(sizeof(*lengthlist)*s->entries);
 
     /* allocated but unused entries? */
-    if(unused){
+    if(tremor_oggpack_read(opb,1)){
       /* yes, unused entries */
 
       for(i=0;i<s->entries;i++){
-	if(oggpack_read(opb,1)){
-	  long num=oggpack_read(opb,5);
+	if(tremor_oggpack_read(opb,1)){
+	  long num=tremor_oggpack_read(opb,5);
 	  if(num==-1)goto _eofout;
-	  s->lengthlist[i]=num+1;
+	  lengthlist[i]=num+1;
+	  s->used_entries++;
+	  if(num+1>s->dec_maxlength)s->dec_maxlength=num+1;
 	}else
-	  s->lengthlist[i]=0;
+	  lengthlist[i]=0;
       }
     }else{
       /* all entries used; no tagging */
+      s->used_entries=s->entries;
       for(i=0;i<s->entries;i++){
-	long num=oggpack_read(opb,5);
+	long num=tremor_oggpack_read(opb,5);
 	if(num==-1)goto _eofout;
-	s->lengthlist[i]=num+1;
+	lengthlist[i]=num+1;
+	if(num+1>s->dec_maxlength)s->dec_maxlength=num+1;
       }
     }
     
     break;
-  }
   case 1:
     /* ordered */
     {
-      long length=oggpack_read(opb,5)+1;
-      if(length==0)goto _eofout;
-      s->lengthlist=(long *)_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
+      long length=tremor_oggpack_read(opb,5)+1;
 
+      s->used_entries=s->entries;
+      lengthlist=(char *)alloca(sizeof(*lengthlist)*s->entries);
+      
       for(i=0;i<s->entries;){
-	long num=oggpack_read(opb,_ilog(s->entries-i));
+	long num=tremor_oggpack_read(opb,_ilog(s->entries-i));
 	if(num==-1)goto _eofout;
-	if(length>32 || num>s->entries-i ||
-	   (num>0 && (num-1)>>(length>>1)>>((length+1)>>1))>0){
-	  goto _errout;
-	}
-	for(j=0;j<num;j++,i++)
-	  s->lengthlist[i]=length;
+	for(j=0;j<num && i<s->entries;j++,i++)
+	  lengthlist[i]=length;
+	s->dec_maxlength=length;
 	length++;
       }
     }
@@ -97,295 +405,393 @@ static_codebook *vorbis_staticbook_unpack(oggpack_buffer *opb){
     /* EOF */
     goto _eofout;
   }
-  
+
+
   /* Do we have a mapping to unpack? */
-  switch((s->maptype=oggpack_read(opb,4))){
+  
+  if((maptype=tremor_oggpack_read(opb,4))>0){
+    s->q_min=_float32_unpack(tremor_oggpack_read(opb,32),&s->q_minp);
+    s->q_del=_float32_unpack(tremor_oggpack_read(opb,32),&s->q_delp);
+    s->q_bits=tremor_oggpack_read(opb,4)+1;
+    s->q_seq=tremor_oggpack_read(opb,1);
+
+    s->q_del>>=s->q_bits;
+    s->q_delp+=s->q_bits;
+  }
+
+  switch(maptype){
   case 0:
-    /* no mapping */
+
+    /* no mapping; decode type 0 */
+
+    /* how many bytes for the indexing? */
+    /* this is the correct boundary here; we lose one bit to
+       node/leaf mark */
+    s->dec_nodeb=_determine_node_bytes(s->used_entries,_ilog(s->entries)/8+1); 
+    s->dec_leafw=_determine_leaf_words(s->dec_nodeb,_ilog(s->entries)/8+1); 
+    s->dec_type=0;
+
+    if(_make_decode_table(s,lengthlist,quantvals,opb,maptype)) goto _errout;
     break;
-  case 1: case 2:
-    /* implicitly populated value mapping */
-    /* explicitly populated value mapping */
 
-    s->q_min=oggpack_read(opb,32);
-    s->q_delta=oggpack_read(opb,32);
-    s->q_quant=oggpack_read(opb,4)+1;
-    s->q_sequencep=oggpack_read(opb,1);
-    if(s->q_sequencep==-1)goto _eofout;
+  case 1:
 
+    /* mapping type 1; implicit values by lattice  position */
+    quantvals=_book_maptype1_quantvals(s);
+    
+    /* dec_type choices here are 1,2; 3 doesn't make sense */
     {
-      int quantvals=0;
-      switch(s->maptype){
-      case 1:
-	quantvals=(s->dim==0?0:_book_maptype1_quantvals(s));
-	break;
-      case 2:
-	quantvals=s->entries*s->dim;
-	break;
-      }
+      /* packed values */
+      long total1=(s->q_bits*s->dim+8)/8; /* remember flag bit */
+      /* vector of column offsets; remember flag bit */
+      long total2=(_ilog(quantvals-1)*s->dim+8)/8+(s->q_bits+7)/8;
+
       
-      /* quantized values */
-      if((quantvals*s->q_quant+7)>>3>opb->storage-oggpack_bytes(opb))
-        goto _eofout;
-      s->quantlist=(long *)_ogg_malloc(sizeof(*s->quantlist)*quantvals);
-      for(i=0;i<quantvals;i++)
-	s->quantlist[i]=oggpack_read(opb,s->q_quant);
+      if(total1<=4 && total1<=total2){
+	/* use dec_type 1: vector of packed values */
+
+	/* need quantized values before  */
+	s->q_val=alloca(sizeof(tremor_ogg_uint16_t)*quantvals);
+	for(i=0;i<quantvals;i++)
+	  ((tremor_ogg_uint16_t *)s->q_val)[i]=tremor_oggpack_read(opb,s->q_bits);
+	
+	if(tremor_oggpack_eop(opb)){
+	  s->q_val=0; /* cleanup must not free alloca memory */
+	  goto _eofout;
+	}
+
+	s->dec_type=1;
+	s->dec_nodeb=_determine_node_bytes(s->used_entries,
+					   (s->q_bits*s->dim+8)/8); 
+	s->dec_leafw=_determine_leaf_words(s->dec_nodeb,
+					   (s->q_bits*s->dim+8)/8); 
+	if(_make_decode_table(s,lengthlist,quantvals,opb,maptype)){
+	  s->q_val=0; /* cleanup must not free alloca memory */
+	  goto _errout;
+	}
+	
+	s->q_val=0; /* about to go out of scope; _make_decode_table
+                       was using it */
+	
+      }else{
+	/* use dec_type 2: packed vector of column offsets */
+
+	/* need quantized values before */
+	if(s->q_bits<=8){
+	  s->q_val=_tremor_ogg_malloc(quantvals);
+	  for(i=0;i<quantvals;i++)
+	    ((unsigned char *)s->q_val)[i]=tremor_oggpack_read(opb,s->q_bits);
+	}else{
+	  s->q_val=_tremor_ogg_malloc(quantvals*2);
+	  for(i=0;i<quantvals;i++)
+	    ((tremor_ogg_uint16_t *)s->q_val)[i]=tremor_oggpack_read(opb,s->q_bits);
+	}
+
+	if(tremor_oggpack_eop(opb))goto _eofout;
+
+	s->q_pack=_ilog(quantvals-1); 
+	s->dec_type=2;
+	s->dec_nodeb=_determine_node_bytes(s->used_entries,
+					   (_ilog(quantvals-1)*s->dim+8)/8); 
+	s->dec_leafw=_determine_leaf_words(s->dec_nodeb,
+					   (_ilog(quantvals-1)*s->dim+8)/8); 
+	if(_make_decode_table(s,lengthlist,quantvals,opb,maptype))goto _errout;
+
+      }
+    }
+    break;
+  case 2:
+
+    /* mapping type 2; explicit array of values */
+    quantvals=s->entries*s->dim;
+    /* dec_type choices here are 1,3; 2 is not possible */
+
+    if( (s->q_bits*s->dim+8)/8 <=4){ /* remember flag bit */
+      /* use dec_type 1: vector of packed values */
+
+      s->dec_type=1;
+      s->dec_nodeb=_determine_node_bytes(s->used_entries,(s->q_bits*s->dim+8)/8); 
+      s->dec_leafw=_determine_leaf_words(s->dec_nodeb,(s->q_bits*s->dim+8)/8); 
+      if(_make_decode_table(s,lengthlist,quantvals,opb,maptype))goto _errout;
       
-      if(quantvals&&s->quantlist[quantvals-1]==-1)goto _eofout;
+    }else{
+      /* use dec_type 3: scalar offset into packed value array */
+
+      s->dec_type=3;
+      s->dec_nodeb=_determine_node_bytes(s->used_entries,_ilog(s->used_entries-1)/8+1); 
+      s->dec_leafw=_determine_leaf_words(s->dec_nodeb,_ilog(s->used_entries-1)/8+1); 
+      if(_make_decode_table(s,lengthlist,quantvals,opb,maptype))goto _errout;
+
+      /* get the vals & pack them */
+      s->q_pack=(s->q_bits+7)/8*s->dim;
+      s->q_val=_tremor_ogg_malloc(s->q_pack*s->used_entries);
+
+      if(s->q_bits<=8){
+	for(i=0;i<s->used_entries*s->dim;i++)
+	  ((unsigned char *)(s->q_val))[i]=tremor_oggpack_read(opb,s->q_bits);
+      }else{
+	for(i=0;i<s->used_entries*s->dim;i++)
+	  ((tremor_ogg_uint16_t *)(s->q_val))[i]=tremor_oggpack_read(opb,s->q_bits);
+      }
     }
     break;
   default:
     goto _errout;
   }
 
-  /* all set */
-  return(s);
-  
+  if(tremor_oggpack_eop(opb))goto _eofout;
+
+  return 0;
  _errout:
  _eofout:
-  vorbis_staticbook_destroy(s);
-  return(NULL); 
+  vorbis_book_clear(s);
+  return -1;
 }
 
-/* the 'eliminate the decode tree' optimization actually requires the
-   codewords to be MSb first, not LSb.  This is an annoying inelegancy
-   (and one of the first places where carefully thought out design
-   turned out to be wrong; Vorbis II and future Ogg codecs should go
-   to an MSb bitpacker), but not actually the huge hit it appears to
-   be.  The first-stage decode table catches most words so that
-   bitreverse is not in the main execution path. */
-
-static ogg_uint32_t bitreverse(ogg_uint32_t x){
-  x=    ((x>>16)&0x0000ffff) | ((x<<16)&0xffff0000);
-  x=    ((x>> 8)&0x00ff00ff) | ((x<< 8)&0xff00ff00);
-  x=    ((x>> 4)&0x0f0f0f0f) | ((x<< 4)&0xf0f0f0f0);
-  x=    ((x>> 2)&0x33333333) | ((x<< 2)&0xcccccccc);
-  return((x>> 1)&0x55555555) | ((x<< 1)&0xaaaaaaaa);
-}
-
-STIN long decode_packed_entry_number(codebook *book, 
-					      oggpack_buffer *b){
+static inline tremor_ogg_uint32_t decode_packed_entry_number(codebook *book, 
+						      tremor_oggpack_buffer *b){
+  tremor_ogg_uint32_t chase=0;
   int  read=book->dec_maxlength;
-  long lo,hi;
-  long lok = oggpack_look(b,book->dec_firsttablen);
- 
-  if (lok >= 0) {
-    long entry = book->dec_firsttable[lok];
-    if(entry&0x80000000UL){
-      lo=(entry>>15)&0x7fff;
-      hi=book->used_entries-(entry&0x7fff);
-    }else{
-      oggpack_adv(b, book->dec_codelengths[entry-1]);
-      return(entry-1);
-    }
-  }else{
-    lo=0;
-    hi=book->used_entries;
-  }
-
-  lok = oggpack_look(b, read);
-
+  long lok = tremor_oggpack_look(b,read),i;
+  
   while(lok<0 && read>1)
-    lok = oggpack_look(b, --read);
+    lok = tremor_oggpack_look(b, --read);
 
   if(lok<0){
-    oggpack_adv(b,1); /* force eop */
+    tremor_oggpack_adv(b,1); /* force eop */
     return -1;
   }
 
-  /* bisect search for the codeword in the ordered list */
-  {
-    ogg_uint32_t testword=bitreverse((ogg_uint32_t)lok);
+  /* chase the tree with the bits we got */
+  if(book->dec_nodeb==1){
+    if(book->dec_leafw==1){
+
+      /* 8/8 */
+      unsigned char *t=(unsigned char *)book->dec_table;
+      for(i=0;i<read;i++){
+	chase=t[chase*2+((lok>>i)&1)];
+	if(chase&0x80UL)break;
+      }
+      chase&=0x7fUL;
 
-    while(hi-lo>1){
-      long p=(hi-lo)>>1;
-      long test=book->codelist[lo+p]>testword;    
-      lo+=p&(test-1);
-      hi-=p&(-test);
+    }else{
+
+      /* 8/16 */
+      unsigned char *t=(unsigned char *)book->dec_table;
+      for(i=0;i<read;i++){
+	int bit=(lok>>i)&1;
+	int next=t[chase+bit];
+	if(next&0x80){
+	  chase= (next<<8) | t[chase+bit+1+(!bit || t[chase]&0x80)];
+	  break;
+	}
+	chase=next;
+      }
+      chase&=0x7fffUL;
     }
 
-    if(book->dec_codelengths[lo]<=read){
-      oggpack_adv(b, book->dec_codelengths[lo]);
-      return(lo);
+  }else{
+    if(book->dec_nodeb==2){
+      if(book->dec_leafw==1){
+	
+	/* 16/16 */
+	for(i=0;i<read;i++){
+	  chase=((tremor_ogg_uint16_t *)(book->dec_table))[chase*2+((lok>>i)&1)];
+	  if(chase&0x8000UL)break;
+	}
+	chase&=0x7fffUL;
+	
+      }else{
+	
+	/* 16/32 */
+	tremor_ogg_uint16_t *t=(tremor_ogg_uint16_t *)book->dec_table;
+	for(i=0;i<read;i++){
+	  int bit=(lok>>i)&1;
+	  int next=t[chase+bit];
+	  if(next&0x8000){
+	    chase= (next<<16) | t[chase+bit+1+(!bit || t[chase]&0x8000)];
+	    break;
+	  }
+	  chase=next;
+	}
+	chase&=0x7fffffffUL;
+      }
+      
+    }else{
+      
+      for(i=0;i<read;i++){
+	chase=((tremor_ogg_uint32_t *)(book->dec_table))[chase*2+((lok>>i)&1)];
+	if(chase&0x80000000UL)break;
+      }
+      chase&=0x7fffffffUL;
+      
     }
   }
   
-  oggpack_adv(b, read+1);
+  if(i<read){
+    tremor_oggpack_adv(b,i+1);
+    return chase;
+  }
+  tremor_oggpack_adv(b,read+1);
   return(-1);
 }
 
-/* Decode side is specced and easier, because we don't need to find
-   matches using different criteria; we simply read and map.  There are
-   two things we need to do 'depending':
-   
-   We may need to support interleave.  We don't really, but it's
-   convenient to do it here rather than rebuild the vector later.
+/* returns the [original, not compacted] entry number or -1 on eof *********/
+long vorbis_book_decode(codebook *book, tremor_oggpack_buffer *b){
+  if(book->dec_type)return -1;
+ return decode_packed_entry_number(book,b);
+}
+
+int decode_map(codebook *s, tremor_oggpack_buffer *b, tremor_ogg_int32_t *v, int point){
+  tremor_ogg_uint32_t entry = decode_packed_entry_number(s,b);
+  int i;
+  if(tremor_oggpack_eop(b))return(-1);
+
+  /* according to decode type */
+  switch(s->dec_type){
+  case 1:{
+    /* packed vector of values */
+    int mask=(1<<s->q_bits)-1;
+    for(i=0;i<s->dim;i++){
+      v[i]=entry&mask;
+      entry>>=s->q_bits;
+    }
+    break;
+  }
+  case 2:{
+    /* packed vector of column offsets */
+    int mask=(1<<s->q_pack)-1;
+    for(i=0;i<s->dim;i++){
+      if(s->q_bits<=8)
+	v[i]=((unsigned char *)(s->q_val))[entry&mask];
+      else
+	v[i]=((tremor_ogg_uint16_t *)(s->q_val))[entry&mask];
+      entry>>=s->q_pack;
+    }
+    break;
+  }
+  case 3:{
+    /* offset into array */
+    void *ptr=s->q_val+entry*s->q_pack;
 
-   Cascades may be additive or multiplicitive; this is not inherent in
-   the codebook, but set in the code using the codebook.  Like
-   interleaving, it's easiest to do it here.  
-   addmul==0 -> declarative (set the value)
-   addmul==1 -> additive
-   addmul==2 -> multiplicitive */
+    if(s->q_bits<=8){
+      for(i=0;i<s->dim;i++)
+	v[i]=((unsigned char *)ptr)[i];
+    }else{
+      for(i=0;i<s->dim;i++)
+	v[i]=((tremor_ogg_uint16_t *)ptr)[i];
+    }
+    break;
+  }
+  default:
+    return -1;
+  }
 
-/* returns the [original, not compacted] entry number or -1 on eof *********/
-long vorbis_book_decode(codebook *book, oggpack_buffer *b){
-  if(book->used_entries>0){
-    long packed_entry=decode_packed_entry_number(book,b);
-    if(packed_entry>=0)
-      return(book->dec_index[packed_entry]);
+  /* we have the unpacked multiplicands; compute final vals */
+  {
+    int shiftM=point-s->q_delp;
+    tremor_ogg_int32_t add=point-s->q_minp;
+    if(add>0)
+      add= s->q_min >> add;
+    else
+      add= s->q_min << -add;
+
+    if(shiftM>0)
+      for(i=0;i<s->dim;i++)
+	v[i]= add + ((v[i] * s->q_del) >> shiftM);
+    else
+      for(i=0;i<s->dim;i++)
+	v[i]= add + ((v[i] * s->q_del) << -shiftM);
+
+    if(s->q_seq)
+      for(i=1;i<s->dim;i++)
+	v[i]+=v[i-1];
   }
 
-  /* if there's no dec_index, the codebook unpacking isn't collapsed */
-  return(-1);
+  return 0;
 }
 
 /* returns 0 on OK or -1 on eof *************************************/
-/* decode vector / dim granularity gaurding is done in the upper layer */
-long vorbis_book_decodevs_add(codebook *book,ogg_int32_t *a,
-			      oggpack_buffer *b,int n,int point){
-  if(book->used_entries>0){  
+/* decode vector / dim granularity guarding is done in the upper layer */
+long vorbis_book_decodevs_add(codebook *book,tremor_ogg_int32_t *a,
+			      tremor_oggpack_buffer *b,int n,int point){
+  if(book->used_entries>0){
     int step=n/book->dim;
-    long *entry = (long *)alloca(sizeof(*entry)*step);
-    ogg_int32_t **t = (ogg_int32_t **)alloca(sizeof(*t)*step);
+    tremor_ogg_int32_t *v = (tremor_ogg_int32_t *)alloca(sizeof(*v)*book->dim);
     int i,j,o;
-    int shift=point-book->binarypoint;
     
-    if(shift>=0){
-      for (i = 0; i < step; i++) {
-	entry[i]=decode_packed_entry_number(book,b);
-	if(entry[i]==-1)return(-1);
-	t[i] = book->valuelist+entry[i]*book->dim;
-      }
-      for(i=0,o=0;i<book->dim;i++,o+=step)
-	for (j=0;o+j<n && j<step;j++)
-	  a[o+j]+=t[j][i]>>shift;
-    }else{
-      for (i = 0; i < step; i++) {
-	entry[i]=decode_packed_entry_number(book,b);
-	if(entry[i]==-1)return(-1);
-	t[i] = book->valuelist+entry[i]*book->dim;
-      }
-      for(i=0,o=0;i<book->dim;i++,o+=step)
-	for (j=0;o+j<n && j<step;j++)
-	  a[o+j]+=t[j][i]<<-shift;
+    for (j=0;j<step;j++){
+      if(decode_map(book,b,v,point))return -1;
+      for(i=0,o=j;i<book->dim;i++,o+=step)
+	a[o]+=v[i];
     }
   }
-  return(0);
+  return 0;
 }
 
-/* decode vector / dim granularity gaurding is done in the upper layer */
-long vorbis_book_decodev_add(codebook *book,ogg_int32_t *a,
-			     oggpack_buffer *b,int n,int point){
+/* decode vector / dim granularity guarding is done in the upper layer */
+long vorbis_book_decodev_add(codebook *book,tremor_ogg_int32_t *a,
+			     tremor_oggpack_buffer *b,int n,int point){
   if(book->used_entries>0){
-    int i,j,entry;
-    ogg_int32_t *t;
-    int shift=point-book->binarypoint;
+    tremor_ogg_int32_t *v = (tremor_ogg_int32_t *)alloca(sizeof(*v)*book->dim);
+    int i,j;
     
-    if(shift>=0){
-      for(i=0;i<n;){
-	entry = decode_packed_entry_number(book,b);
-	if(entry==-1)return(-1);
-	t     = book->valuelist+entry*book->dim;
-	for (j=0;i<n && j<book->dim;)
-	  a[i++]+=t[j++]>>shift;
-      }
-    }else{
-      for(i=0;i<n;){
-	entry = decode_packed_entry_number(book,b);
-	if(entry==-1)return(-1);
-	t     = book->valuelist+entry*book->dim;
-	for (j=0;i<n && j<book->dim;)
-	  a[i++]+=t[j++]<<-shift;
-      }
+    for(i=0;i<n;){
+      if(decode_map(book,b,v,point))return -1;
+      for (j=0;i<n && j<book->dim;j++)
+	a[i++]+=v[j];
     }
   }
-  return(0);
+  return 0;
 }
 
 /* unlike the others, we guard against n not being an integer number
-   of <dim> internally rather than in the upper layer (called only by
-   floor0) */
-long vorbis_book_decodev_set(codebook *book,ogg_int32_t *a,
-			     oggpack_buffer *b,int n,int point){
+ * of <dim> internally rather than in the upper layer (called only by
+ * floor0) */
+long vorbis_book_decodev_set(codebook *book,tremor_ogg_int32_t *a,
+			     tremor_oggpack_buffer *b,int n,int point){
   if(book->used_entries>0){
-    int i,j,entry;
-    ogg_int32_t *t;
-    int shift=point-book->binarypoint;
+    tremor_ogg_int32_t *v = (tremor_ogg_int32_t *)alloca(sizeof(*v)*book->dim);
+    int i,j;
     
-    if(shift>=0){
-      
-      for(i=0;i<n;){
-	entry = decode_packed_entry_number(book,b);
-	if(entry==-1)return(-1);
-	t     = book->valuelist+entry*book->dim;
-	for (j=0;i<n && j<book->dim;){
-	  a[i++]=t[j++]>>shift;
-	}
-      }
-    }else{
-      
-      for(i=0;i<n;){
-	entry = decode_packed_entry_number(book,b);
-	if(entry==-1)return(-1);
-	t     = book->valuelist+entry*book->dim;
-	for (j=0;i<n && j<book->dim;){
-	  a[i++]=t[j++]<<-shift;
-	}
-      }
+    for(i=0;i<n;){
+      if(decode_map(book,b,v,point))return -1;
+      for (j=0;i<n && j<book->dim;j++)
+	a[i++]=v[j];
     }
   }else{
-
-    int i,j;
+    int i;
+    
     for(i=0;i<n;){
       a[i++]=0;
     }
   }
-  return(0);
+
+  return 0;
 }
 
-/* decode vector / dim granularity gaurding is done in the upper layer */
-long vorbis_book_decodevv_add(codebook *book,ogg_int32_t **a,\
+/* decode vector / dim granularity guarding is done in the upper layer */
+long vorbis_book_decodevv_add(codebook *book,tremor_ogg_int32_t **a,
 			      long offset,int ch,
-			      oggpack_buffer *b,int n,int point){
+			      tremor_oggpack_buffer *b,int n,int point){
   if(book->used_entries>0){
-    long i,j,entry;
+    
+    tremor_ogg_int32_t *v = (tremor_ogg_int32_t *)alloca(sizeof(*v)*book->dim);
+    long i,j;
     int chptr=0;
-    int shift=point-book->binarypoint;
-    int m=offset+n;
-    if(shift>=0){
-      
-      for(i=offset;i<m;){
-	entry = decode_packed_entry_number(book,b);
-	if(entry==-1)return(-1);
-	{
-	  const ogg_int32_t *t = book->valuelist+entry*book->dim;
-	  for (j=0;i<m && j<book->dim;j++){
-	    a[chptr++][i]+=t[j]>>shift;
-	    if(chptr==ch){
-	      chptr=0;
-	      i++;
-	    }
-	  }
-	}
-      }
-    }else{
-      
-      for(i=offset;i<m;){
-	entry = decode_packed_entry_number(book,b);
-	if(entry==-1)return(-1);
-	{
-	  const ogg_int32_t *t = book->valuelist+entry*book->dim;
-	  for (j=0;i<m && j<book->dim;j++){
-	    a[chptr++][i]+=t[j]<<-shift;
-	    if(chptr==ch){
-	      chptr=0;
-	      i++;
-	    }
-	  }
+    long m=offset+n;
+    
+    for(i=offset;i<m;){
+      if(decode_map(book,b,v,point))return -1;
+      for (j=0;i<m && j<book->dim;j++){
+	a[chptr++][i]+=v[j];
+	if(chptr==ch){
+	  chptr=0;
+	  i++;
 	}
       }
     }
   }
-  return(0);
+
+  return 0;
 }