diff options
Diffstat (limited to 'media/libtremor/lib/tremor_sharedbook.c')
-rw-r--r-- | media/libtremor/lib/tremor_sharedbook.c | 447 |
1 files changed, 447 insertions, 0 deletions
diff --git a/media/libtremor/lib/tremor_sharedbook.c b/media/libtremor/lib/tremor_sharedbook.c new file mode 100644 index 000000000..188485e3f --- /dev/null +++ b/media/libtremor/lib/tremor_sharedbook.c @@ -0,0 +1,447 @@ +/******************************************************************** + * * + * 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/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++; + } + + /* 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){ + /* 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_destroy(static_codebook *b){ + if(b->quantlist)_ogg_free(b->quantlist); + if(b->lengthlist)_ogg_free(b->lengthlist); + memset(b,0,sizeof(*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); +} + |