--- /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);
+}