diff -r e353ca78d28b -r f7e49eff3708 misc/libtremor/codebook.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/misc/libtremor/codebook.c	Sun Apr 24 22:57:57 2011 +0200
@@ -0,0 +1,371 @@
+/********************************************************************
+ *                                                                  *
+ * 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 codebook pack/unpack/code/decode operations
+
+ ********************************************************************/
+
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include "ogg.h"
+#include "ivorbiscodec.h"
+#include "codebook.h"
+#include "misc.h"
+
+/* unpacks a codebook from the packet buffer into the codebook struct,
+   readies the codebook auxiliary structures for decode *************/
+int vorbis_staticbook_unpack(oggpack_buffer *opb,static_codebook *s){
+  long i,j;
+  memset(s,0,sizeof(*s));
+
+  /* make sure alignment is correct */
+  if(oggpack_read(opb,24)!=0x564342)goto _eofout;
+
+  /* first the basic parameters */
+  s->dim=oggpack_read(opb,16);
+  s->entries=oggpack_read(opb,24);
+  if(s->entries==-1)goto _eofout;
+
+  /* codeword ordering.... length ordered or unordered? */
+  switch((int)oggpack_read(opb,1)){
+  case 0:
+    /* unordered */
+    s->lengthlist=(long *)_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
+
+    /* allocated but unused entries? */
+    if(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(num==-1)goto _eofout;
+	  s->lengthlist[i]=num+1;
+	}else
+	  s->lengthlist[i]=0;
+      }
+    }else{
+      /* all entries used; no tagging */
+      for(i=0;i<s->entries;i++){
+	long num=oggpack_read(opb,5);
+	if(num==-1)goto _eofout;
+	s->lengthlist[i]=num+1;
+      }
+    }
+    
+    break;
+  case 1:
+    /* ordered */
+    {
+      long length=oggpack_read(opb,5)+1;
+      s->lengthlist=(long *)_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
+
+      for(i=0;i<s->entries;){
+	long num=oggpack_read(opb,_ilog(s->entries-i));
+	if(num==-1)goto _eofout;
+	for(j=0;j<num && i<s->entries;j++,i++)
+	  s->lengthlist[i]=length;
+	length++;
+      }
+    }
+    break;
+  default:
+    /* EOF */
+    return(-1);
+  }
+  
+  /* Do we have a mapping to unpack? */
+  switch((s->maptype=oggpack_read(opb,4))){
+  case 0:
+    /* no mapping */
+    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);
+
+    {
+      int quantvals=0;
+      switch(s->maptype){
+      case 1:
+	quantvals=_book_maptype1_quantvals(s);
+	break;
+      case 2:
+	quantvals=s->entries*s->dim;
+	break;
+      }
+      
+      /* quantized values */
+      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(quantvals&&s->quantlist[quantvals-1]==-1)goto _eofout;
+    }
+    break;
+  default:
+    goto _errout;
+  }
+
+  /* all set */
+  return(0);
+  
+ _errout:
+ _eofout:
+  vorbis_staticbook_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){
+  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);
+
+  while(lok<0 && read>1)
+    lok = oggpack_look(b, --read);
+
+  if(lok<0){
+    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);
+
+    while(hi-lo>1){
+      long p=(hi-lo)>>1;
+      long test=book->codelist[lo+p]>testword;    
+      lo+=p&(test-1);
+      hi-=p&(-test);
+    }
+
+    if(book->dec_codelengths[lo]<=read){
+      oggpack_adv(b, book->dec_codelengths[lo]);
+      return(lo);
+    }
+  }
+  
+  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.
+
+   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 */
+
+/* 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]);
+  }
+
+  /* if there's no dec_index, the codebook unpacking isn't collapsed */
+  return(-1);
+}
+
+/* returns 0 on OK or -1 on eof *************************************/
+long vorbis_book_decodevs_add(codebook *book,ogg_int32_t *a,
+			      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);
+    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;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;j<step;j++)
+	  a[o+j]+=t[j][i]<<-shift;
+    }
+  }
+  return(0);
+}
+
+long vorbis_book_decodev_add(codebook *book,ogg_int32_t *a,
+			     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;
+    
+    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;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;j<book->dim;)
+	  a[i++]+=t[j++]<<-shift;
+      }
+    }
+  }
+  return(0);
+}
+
+long vorbis_book_decodev_set(codebook *book,ogg_int32_t *a,
+			     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;
+    
+    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;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;j<book->dim;){
+	  a[i++]=t[j++]<<-shift;
+	}
+      }
+    }
+  }else{
+
+    int i,j;
+    for(i=0;i<n;){
+      for (j=0;j<book->dim;){
+	a[i++]=0;
+      }
+    }
+  }
+  return(0);
+}
+
+long vorbis_book_decodevv_add(codebook *book,ogg_int32_t **a,\
+			      long offset,int ch,
+			      oggpack_buffer *b,int n,int point){
+  if(book->used_entries>0){
+    long i,j,entry;
+    int chptr=0;
+    int shift=point-book->binarypoint;
+    
+    if(shift>=0){
+      
+      for(i=offset;i<offset+n;){
+	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;j<book->dim;j++){
+	    a[chptr++][i]+=t[j]>>shift;
+	    if(chptr==ch){
+	      chptr=0;
+	      i++;
+	    }
+	  }
+	}
+      }
+    }else{
+      
+      for(i=offset;i<offset+n;){
+	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;j<book->dim;j++){
+	    a[chptr++][i]+=t[j]<<-shift;
+	    if(chptr==ch){
+	      chptr=0;
+	      i++;
+	    }
+	  }
+	}
+      }
+    }
+  }
+  return(0);
+}