--- /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);
+}
+