comparison src/libvorbis-1.3.3/lib/sharedbook.c @ 1:05aa0afa9217

Bring in flac, ogg, vorbis

+/********************************************************************
+ *                                                                  *
+ * 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 1994-2009             *
+ * by the Xiph.Org Foundation http://www.xiph.org/                  *
+ *                                                                  *
+ ********************************************************************
+
+ function: basic shared codebook operations
+ last mod: $Id: sharedbook.c 17030 2010-03-25 06:52:55Z xiphmont $
+
+ ********************************************************************/
+
+#include <stdlib.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 _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. */
+
+/* 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;
+  return(ldexp(mant,exp-(VQ_FMAN-1)-VQ_FEXP_BIAS));
+}
+
+/* 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_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++;
+  }
+
+  /* sanity check the huffman tree; an underpopulated tree must be
+     rejected. The only exception is the one-node pseudo-nil tree,
+     which appears to be underpopulated because the tree doesn't
+     really exist; there's only one possible 'codeword' or zero bits,
+     but the above tree-gen code doesn't mark that. */
+  if(sparsecount != 1){
+    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);
+}
+
+/* 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){
+  long vals=floor(pow((float)b->entries,1.f/b->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^b->bim <= b->entries */
+  /* treat the above as an initial guess */
+  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++;
+      }
+    }
+  }
+}
+
+/* unpack the quantized list of values for encode/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 */
+float *_book_unquantize(const static_codebook *b,int n,int *sparsemap){
+  long j,k,count=0;
+  if(b->maptype==1 || b->maptype==2){
+    int quantvals;
+    float mindel=_float32_unpack(b->q_min);
+    float delta=_float32_unpack(b->q_delta);
+    float *r=_ogg_calloc(n*b->dim,sizeof(*r));
+
+    /* 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){
+          float last=0.f;
+          int indexdiv=1;
+          for(k=0;k<b->dim;k++){
+            int index= (j/indexdiv)%quantvals;
+            float val=b->quantlist[index];
+            val=fabs(val)*delta+mindel+last;
+            if(b->q_sequencep)last=val;
+            if(sparsemap)
+              r[sparsemap[count]*b->dim+k]=val;
+            else
+              r[count*b->dim+k]=val;
+            indexdiv*=quantvals;
+          }
+          count++;
+        }
+
+      }
+      break;
+    case 2:
+      for(j=0;j<b->entries;j++){
+        if((sparsemap && b->lengthlist[j]) || !sparsemap){
+          float last=0.f;
+
+          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;
+            if(sparsemap)
+              r[sparsemap[count]*b->dim+k]=val;
+            else
+              r[count*b->dim+k]=val;
+          }
+          count++;
+        }
+      }
+      break;
+    }
+
+    return(r);
+  }
+  return(NULL);
+}
+
+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);
+
+  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));
+}
+
+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->valuelist=_book_unquantize(s,s->entries,NULL);
+  c->quantvals=_book_maptype1_quantvals(s);
+  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 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=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=alloca(n*sizeof(*sortindex));
+    c->codelist=_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->dec_index=_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=_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_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);
+}
+
+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 long full_quantlist1[]={0,1,2,3,    4,5,6,7, 8,3,6,1};
+static long partial_quantlist1[]={0,7,2};
+
+/* no mapping */
+static_codebook test1={
+  4,16,
+  NULL,
+  0,
+  0,0,0,0,
+  NULL,
+  0
+};
+static float *test1_result=NULL;
+
+/* linear, full mapping, nonsequential */
+static_codebook test2={
+  4,3,
+  NULL,
+  2,
+  -533200896,1611661312,4,0,
+  full_quantlist1,
+  0
+};
+static float test2_result[]={-3,-2,-1,0, 1,2,3,4, 5,0,3,-2};
+
+/* linear, full mapping, sequential */
+static_codebook test3={
+  4,3,
+  NULL,
+  2,
+  -533200896,1611661312,4,1,
+  full_quantlist1,
+  0
+};
+static float test3_result[]={-3,-5,-6,-6, 1,3,6,10, 5,5,8,6};
+
+/* linear, algorithmic mapping, nonsequential */
+static_codebook test4={
+  3,27,
+  NULL,
+  1,
+  -533200896,1611661312,4,0,
+  partial_quantlist1,
+  0
+};
+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 */
+static_codebook test5={
+  3,27,
+  NULL,
+  1,
+  -533200896,1611661312,4,1,
+  partial_quantlist1,
+  0
+};
+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(static_codebook *b,float *comp){
+  float *out=_book_unquantize(b,b->entries,NULL);
+  int i;
+
+  if(comp){
+    if(!out){
+      fprintf(stderr,"_book_unquantize incorrectly returned NULL\n");
+      exit(1);
+    }
+
+    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);
+      }
+
+  }else{
+    if(out){
+      fprintf(stderr,"_book_unquantize returned a value array: \n"
+              " correct result should have been NULL\n");
+      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