/********************************************************************
* *
* 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 <limits.h>
#include "ogg.h"
#include "ivorbiscodec.h"
#include "codebook.h"
#include "misc.h"
#include "os.h"
/**** pack/unpack helpers ******************************************/
int _ilog(unsigned int v){
int ret=0;
while(v){
ret++;
v>>=1;
}
return(ret);
}
static ogg_uint32_t decpack(long entry,long used_entry,long quantvals,
codebook *b,oggpack_buffer *opb,int maptype){
ogg_uint32_t ret=0;
int j;
switch(b->dec_type){
case 0:
return (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++){
ogg_uint32_t off=entry%quantvals;
entry/=quantvals;
ret|=((ogg_uint16_t *)(b->q_val))[off]<<(b->q_bits*j);
}
}else{
for(j=0;j<b->dim;j++)
ret|=oggpack_read(opb,b->q_bits)<<(b->q_bits*j);
}
return ret;
case 2:
for(j=0;j<b->dim;j++){
ogg_uint32_t off=entry%quantvals;
entry/=quantvals;
ret|=off<<(b->q_pack*j);
}
return ret;
case 3:
return (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 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,ogg_uint32_t *r,long quantvals,
codebook *b, oggpack_buffer *opb,int maptype){
long i,j,count=0;
long top=0;
ogg_uint32_t marker[33];
if (n<1)
return 1;
if(n<2){
r[0]=0x80000000;
}else{
memset(marker,0,sizeof(marker));
for(i=0;i<n;i++){
long length=l[i];
if(length){
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){
if (chase < 0 || chase >= n) return 1;
top++;
r[chase*2]=top;
r[chase*2+1]=0;
}else
if (chase < 0 || chase >= n || chase*2+bit > n*2+1) return 1;
if(!r[chase*2+bit])
r[chase*2+bit]=top;
chase=r[chase*2+bit];
if (chase < 0 || chase >= n) return 1;
}
{
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,
oggpack_buffer *opb,int maptype){
int i;
ogg_uint32_t *work;
if (!lengthlist) return 1;
if(s->dec_nodeb==4){
/* Over-allocate by using s->entries instead of used_entries.
* This means that we can use s->entries to enforce size in
* _make_words without messing up length list looping.
* This probably wastes a bit of space, but it shouldn't
* impact behavior or size too much.
*/
s->dec_table=_ogg_malloc((s->entries*2+1)*sizeof(*work));
if (!s->dec_table) return 1;
/* +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;
}
if (s->used_entries > INT_MAX/2 ||
s->used_entries*2 > INT_MAX/((long) sizeof(*work)) - 1) return 1;
/* Overallocate as above */
work=alloca((s->entries*2+1)*sizeof(*work));
if (!work) return 1;
if(_make_words(lengthlist,s->entries,work,quantvals,s,opb,maptype))return 1;
if (s->used_entries > INT_MAX/(s->dec_leafw+1)) return 1;
if (s->dec_nodeb && s->used_entries * (s->dec_leafw+1) > INT_MAX/s->dec_nodeb) return 1;
s->dec_table=_ogg_malloc((s->used_entries*(s->dec_leafw+1)-2)*
s->dec_nodeb);
if (!s->dec_table) return 1;
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++)
((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{
ogg_uint16_t *out=(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)_ogg_free(b->q_val);
if(b->dec_table)_ogg_free(b->dec_table);
memset(b,0,sizeof(*b));
}
int vorbis_book_unpack(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;
/* first the basic parameters */
s->dim=oggpack_read(opb,16);
s->entries=oggpack_read(opb,24);
if(s->entries<=0)goto _eofout;
if(s->dim<=0)goto _eofout;
if(_ilog(s->dim)+_ilog(s->entries)>24)goto _eofout;
if (s->dim > INT_MAX/s->entries) goto _eofout;
/* codeword ordering.... length ordered or unordered? */
switch((int)oggpack_read(opb,1)){
case 0:
/* unordered */
lengthlist=(char *)alloca(sizeof(*lengthlist)*s->entries);
if(!lengthlist) goto _eofout;
/* 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;
lengthlist[i]=num+1;
s->used_entries++;
if(num+1>s->dec_maxlength)s->dec_maxlength=num+1;
}else
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);
if(num==-1)goto _eofout;
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;
s->used_entries=s->entries;
lengthlist=(char *)alloca(sizeof(*lengthlist)*s->entries);
if (!lengthlist) goto _eofout;
for(i=0;i<s->entries;){
long num=oggpack_read(opb,_ilog(s->entries-i));
if(num<0)goto _eofout;
for(j=0;j<num && i<s->entries;j++,i++)
lengthlist[i]=length;
s->dec_maxlength=length;
length++;
}
}
break;
default:
/* EOF */
goto _eofout;
}
/* Do we have a mapping to unpack? */
if((maptype=oggpack_read(opb,4))>0){
s->q_min=_float32_unpack(oggpack_read(opb,32),&s->q_minp);
s->q_del=_float32_unpack(oggpack_read(opb,32),&s->q_delp);
s->q_bits=oggpack_read(opb,4)+1;
s->q_seq=oggpack_read(opb,1);
s->q_del>>=s->q_bits;
s->q_delp+=s->q_bits;
}
switch(maptype){
case 0:
/* 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:
/* 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 */
{
/* packed values */
long total1=(s->q_bits*s->dim+8)/8; /* remember flag bit */
if (s->dim > (INT_MAX-8)/s->q_bits) goto _eofout;
/* vector of column offsets; remember flag bit */
long total2=(_ilog(quantvals-1)*s->dim+8)/8+(s->q_bits+7)/8;
if(total1<=4 && total1<=total2){
/* use dec_type 1: vector of packed values */
/* need quantized values before */
s->q_val=alloca(sizeof(ogg_uint16_t)*quantvals);
if (!s->q_val) goto _eofout;
for(i=0;i<quantvals;i++)
((ogg_uint16_t *)s->q_val)[i]=oggpack_read(opb,s->q_bits);
if(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=_ogg_malloc(quantvals);
if (!s->q_val) goto _eofout;
for(i=0;i<quantvals;i++)
((unsigned char *)s->q_val)[i]=oggpack_read(opb,s->q_bits);
}else{
s->q_val=_ogg_malloc(quantvals*2);
if (!s->q_val) goto _eofout;
for(i=0;i<quantvals;i++)
((ogg_uint16_t *)s->q_val)[i]=oggpack_read(opb,s->q_bits);
}
if(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;
}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=_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]=oggpack_read(opb,s->q_bits);
}else{
for(i=0;i<s->used_entries*s->dim;i++)
((ogg_uint16_t *)(s->q_val))[i]=oggpack_read(opb,s->q_bits);
}
}
break;
default:
goto _errout;
}
if(oggpack_eop(opb))goto _eofout;
return 0;
_errout:
_eofout:
vorbis_book_clear(s);
return -1;
}
static inline ogg_uint32_t decode_packed_entry_number(codebook *book,
oggpack_buffer *b){
ogg_uint32_t chase=0;
int read=book->dec_maxlength;
long lok = oggpack_look(b,read),i;
while(lok<0 && read>1)
lok = oggpack_look(b, --read);
if(lok<0){
oggpack_adv(b,1); /* force eop */
return -1;
}
/* 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;
}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;
}
}else{
if(book->dec_nodeb==2){
if(book->dec_leafw==1){
/* 16/16 */
for(i=0;i<read;i++){
chase=((ogg_uint16_t *)(book->dec_table))[chase*2+((lok>>i)&1)];
if(chase&0x8000UL)break;
}
chase&=0x7fffUL;
}else{
/* 16/32 */
ogg_uint16_t *t=(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=((ogg_uint32_t *)(book->dec_table))[chase*2+((lok>>i)&1)];
if(chase&0x80000000UL)break;
}
chase&=0x7fffffffUL;
}
}
if(i<read){
oggpack_adv(b,i+1);
return chase;
}
oggpack_adv(b,read+1);
return(-1);
}
/* returns the [original, not compacted] entry number or -1 on eof *********/
long vorbis_book_decode(codebook *book, oggpack_buffer *b){
if(book->dec_type)return -1;
return decode_packed_entry_number(book,b);
}
int decode_map(codebook *s, oggpack_buffer *b, ogg_int32_t *v, int point){
ogg_uint32_t entry = decode_packed_entry_number(s,b);
int i;
if(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]=((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;
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]=((ogg_uint16_t *)ptr)[i];
}
break;
}
default:
return -1;
}
/* we have the unpacked multiplicands; compute final vals */
{
int shiftM=point-s->q_delp;
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];
}
return 0;
}
/* 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;
ogg_int32_t *v = (ogg_int32_t *)alloca(sizeof(*v)*book->dim);
int i,j,o;
if (!v) return -1;
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;
}
long vorbis_book_decodev_add(codebook *book,ogg_int32_t *a,
oggpack_buffer *b,int n,int point){
if(book->used_entries>0){
ogg_int32_t *v = (ogg_int32_t *)alloca(sizeof(*v)*book->dim);
int i,j;
if (!v) return -1;
for(i=0;i<n;){
if(decode_map(book,b,v,point))return -1;
for (j=0;j<book->dim;j++)
a[i++]+=v[j];
}
}
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){
ogg_int32_t *v = (ogg_int32_t *)alloca(sizeof(*v)*book->dim);
int i,j;
if (!v) return -1;
for(i=0;i<n;){
if(decode_map(book,b,v,point))return -1;
for (j=0;j<book->dim;j++)
a[i++]=v[j];
}
}else{
int i,j;
for(i=0;i<n;){
for (j=0;j<book->dim;j++)
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){
ogg_int32_t *v = (ogg_int32_t *)alloca(sizeof(*v)*book->dim);
long i,j;
int chptr=0;
if (!v) return -1;
for(i=offset;i<offset+n;){
if(decode_map(book,b,v,point))return -1;
for (j=0;j<book->dim;j++){
a[chptr++][i]+=v[j];
if(chptr==ch){
chptr=0;
i++;
}
}
}
}
return 0;
}