1 /********************************************************************
3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2002 *
9 * by the XIPHOPHORUS Company http://www.xiph.org/ *
11 ********************************************************************
13 function: basic codebook pack/unpack/code/decode operations
14 last mod: $Id: codebook.c,v 1.38 2002/01/22 02:16:40 xiphmont Exp $
16 ********************************************************************/
22 #include "vorbis/codec.h"
28 /* packs the given codebook into the bitstream **************************/
30 int vorbis_staticbook_pack(const static_codebook *c,oggpack_buffer *opb){
34 /* first the basic parameters */
35 oggpack_write(opb,0x564342,24);
36 oggpack_write(opb,c->dim,16);
37 oggpack_write(opb,c->entries,24);
39 /* pack the codewords. There are two packings; length ordered and
40 length random. Decide between the two now. */
42 for(i=1;i<c->entries;i++)
43 if(c->lengthlist[i-1]==0 || c->lengthlist[i]<c->lengthlist[i-1])break;
44 if(i==c->entries)ordered=1;
47 /* length ordered. We only need to say how many codewords of
48 each length. The actual codewords are generated
52 oggpack_write(opb,1,1); /* ordered */
53 oggpack_write(opb,c->lengthlist[0]-1,5); /* 1 to 32 */
55 for(i=1;i<c->entries;i++){
56 long this=c->lengthlist[i];
57 long last=c->lengthlist[i-1];
59 for(j=last;j<this;j++){
60 oggpack_write(opb,i-count,_ilog(c->entries-count));
65 oggpack_write(opb,i-count,_ilog(c->entries-count));
68 /* length random. Again, we don't code the codeword itself, just
69 the length. This time, though, we have to encode each length */
70 oggpack_write(opb,0,1); /* unordered */
72 /* algortihmic mapping has use for 'unused entries', which we tag
73 here. The algorithmic mapping happens as usual, but the unused
74 entry has no codeword. */
75 for(i=0;i<c->entries;i++)
76 if(c->lengthlist[i]==0)break;
79 oggpack_write(opb,0,1); /* no unused entries */
80 for(i=0;i<c->entries;i++)
81 oggpack_write(opb,c->lengthlist[i]-1,5);
83 oggpack_write(opb,1,1); /* we have unused entries; thus we tag */
84 for(i=0;i<c->entries;i++){
85 if(c->lengthlist[i]==0){
86 oggpack_write(opb,0,1);
88 oggpack_write(opb,1,1);
89 oggpack_write(opb,c->lengthlist[i]-1,5);
95 /* is the entry number the desired return value, or do we have a
96 mapping? If we have a mapping, what type? */
97 oggpack_write(opb,c->maptype,4);
103 /* implicitly populated value mapping */
104 /* explicitly populated value mapping */
107 /* no quantlist? error */
111 /* values that define the dequantization */
112 oggpack_write(opb,c->q_min,32);
113 oggpack_write(opb,c->q_delta,32);
114 oggpack_write(opb,c->q_quant-1,4);
115 oggpack_write(opb,c->q_sequencep,1);
121 /* a single column of (c->entries/c->dim) quantized values for
122 building a full value list algorithmically (square lattice) */
123 quantvals=_book_maptype1_quantvals(c);
126 /* every value (c->entries*c->dim total) specified explicitly */
127 quantvals=c->entries*c->dim;
129 default: /* NOT_REACHABLE */
133 /* quantized values */
134 for(i=0;i<quantvals;i++)
135 oggpack_write(opb,labs(c->quantlist[i]),c->q_quant);
140 /* error case; we don't have any other map types now */
147 /* unpacks a codebook from the packet buffer into the codebook struct,
148 readies the codebook auxiliary structures for decode *************/
149 int vorbis_staticbook_unpack(oggpack_buffer *opb,static_codebook *s){
151 memset(s,0,sizeof(*s));
154 /* make sure alignment is correct */
155 if(oggpack_read(opb,24)!=0x564342)goto _eofout;
157 /* first the basic parameters */
158 s->dim=oggpack_read(opb,16);
159 s->entries=oggpack_read(opb,24);
160 if(s->entries==-1)goto _eofout;
162 /* codeword ordering.... length ordered or unordered? */
163 switch((int)oggpack_read(opb,1)){
166 s->lengthlist=_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
168 /* allocated but unused entries? */
169 if(oggpack_read(opb,1)){
170 /* yes, unused entries */
172 for(i=0;i<s->entries;i++){
173 if(oggpack_read(opb,1)){
174 long num=oggpack_read(opb,5);
175 if(num==-1)goto _eofout;
176 s->lengthlist[i]=num+1;
181 /* all entries used; no tagging */
182 for(i=0;i<s->entries;i++){
183 long num=oggpack_read(opb,5);
184 if(num==-1)goto _eofout;
185 s->lengthlist[i]=num+1;
193 long length=oggpack_read(opb,5)+1;
194 s->lengthlist=_ogg_malloc(sizeof(*s->lengthlist)*s->entries);
196 for(i=0;i<s->entries;){
197 long num=oggpack_read(opb,_ilog(s->entries-i));
198 if(num==-1)goto _eofout;
199 for(j=0;j<num && i<s->entries;j++,i++)
200 s->lengthlist[i]=length;
210 /* Do we have a mapping to unpack? */
211 switch((s->maptype=oggpack_read(opb,4))){
216 /* implicitly populated value mapping */
217 /* explicitly populated value mapping */
219 s->q_min=oggpack_read(opb,32);
220 s->q_delta=oggpack_read(opb,32);
221 s->q_quant=oggpack_read(opb,4)+1;
222 s->q_sequencep=oggpack_read(opb,1);
228 quantvals=_book_maptype1_quantvals(s);
231 quantvals=s->entries*s->dim;
235 /* quantized values */
236 s->quantlist=_ogg_malloc(sizeof(*s->quantlist)*quantvals);
237 for(i=0;i<quantvals;i++)
238 s->quantlist[i]=oggpack_read(opb,s->q_quant);
240 if(quantvals&&s->quantlist[quantvals-1]==-1)goto _eofout;
252 vorbis_staticbook_clear(s);
256 /* returns the number of bits ************************************************/
257 int vorbis_book_encode(codebook *book, int a, oggpack_buffer *b){
258 oggpack_write(b,book->codelist[a],book->c->lengthlist[a]);
259 return(book->c->lengthlist[a]);
262 /* One the encode side, our vector writers are each designed for a
263 specific purpose, and the encoder is not flexible without modification:
265 The LSP vector coder uses a single stage nearest-match with no
266 interleave, so no step and no error return. This is specced by floor0
269 Residue0 encoding interleaves, uses multiple stages, and each stage
270 peels of a specific amount of resolution from a lattice (thus we want
271 to match by threshold, not nearest match). Residue doesn't *have* to
272 be encoded that way, but to change it, one will need to add more
273 infrastructure on the encode side (decode side is specced and simpler) */
275 /* floor0 LSP (single stage, non interleaved, nearest match) */
276 /* returns entry number and *modifies a* to the quantization value *****/
277 int vorbis_book_errorv(codebook *book,float *a){
279 int best=_best(book,a,1);
281 a[k]=(book->valuelist+best*dim)[k];
285 /* returns the number of bits and *modifies a* to the quantization value *****/
286 int vorbis_book_encodev(codebook *book,int best,float *a,oggpack_buffer *b){
289 a[k]=(book->valuelist+best*dim)[k];
290 return(vorbis_book_encode(book,best,b));
293 /* res0 (multistage, interleave, lattice) */
294 /* returns the number of bits and *modifies a* to the remainder value ********/
295 int vorbis_book_encodevs(codebook *book,float *a,oggpack_buffer *b,
296 int step,int addmul){
298 int best=vorbis_book_besterror(book,a,step,addmul);
299 return(vorbis_book_encode(book,best,b));
302 /* the 'eliminate the decode tree' optimization actually requires the
303 codewords to be MSb first, not LSb. This is an annoying inelegancy
304 (and one of the first places where carefully thought out design
305 turned out to be wrong; Vorbis II and future Ogg codecs should go
306 to an MSb bitpacker), but not actually the huge hit it appears to
307 be. The first-stage decode table catches most words so that
308 bitreverse is not in the main execution path. */
310 static ogg_uint32_t bitreverse(ogg_uint32_t x){
311 x= ((x>>16)&0x0000ffff) | ((x<<16)&0xffff0000);
312 x= ((x>> 8)&0x00ff00ff) | ((x<< 8)&0xff00ff00);
313 x= ((x>> 4)&0x0f0f0f0f) | ((x<< 4)&0xf0f0f0f0);
314 x= ((x>> 2)&0x33333333) | ((x<< 2)&0xcccccccc);
315 return((x>> 1)&0x55555555) | ((x<< 1)&0xaaaaaaaa);
318 STIN long decode_packed_entry_number(codebook *book, oggpack_buffer *b){
319 int read=book->dec_maxlength;
321 long lok = oggpack_look(b,book->dec_firsttablen);
324 long entry = book->dec_firsttable[lok];
325 if(entry&0x80000000UL){
326 lo=(entry>>15)&0x7fff;
327 hi=book->used_entries-(entry&0x7fff);
329 oggpack_adv(b, book->dec_codelengths[entry-1]);
334 hi=book->used_entries;
337 lok = oggpack_look(b, read);
339 while(lok<0 && read>1)
340 lok = oggpack_look(b, --read);
343 /* bisect search for the codeword in the ordered list */
345 ogg_uint32_t testword=bitreverse((ogg_uint32_t)lok);
349 long test=book->codelist[lo+p]>testword;
354 if(book->dec_codelengths[lo]<=read){
355 oggpack_adv(b, book->dec_codelengths[lo]);
360 oggpack_adv(b, read);
364 /* Decode side is specced and easier, because we don't need to find
365 matches using different criteria; we simply read and map. There are
366 two things we need to do 'depending':
368 We may need to support interleave. We don't really, but it's
369 convenient to do it here rather than rebuild the vector later.
371 Cascades may be additive or multiplicitive; this is not inherent in
372 the codebook, but set in the code using the codebook. Like
373 interleaving, it's easiest to do it here.
374 addmul==0 -> declarative (set the value)
375 addmul==1 -> additive
376 addmul==2 -> multiplicitive */
378 /* returns the [original, not compacted] entry number or -1 on eof *********/
379 long vorbis_book_decode(codebook *book, oggpack_buffer *b){
380 long packed_entry=decode_packed_entry_number(book,b);
382 return(book->dec_index[packed_entry]);
384 /* if there's no dec_index, the codebook unpacking isn't collapsed */
385 return(packed_entry);
388 /* returns 0 on OK or -1 on eof *************************************/
389 long vorbis_book_decodevs_add(codebook *book,float *a,oggpack_buffer *b,int n){
390 int step=n/book->dim;
391 long *entry = alloca(sizeof(*entry)*step);
392 float **t = alloca(sizeof(*t)*step);
395 for (i = 0; i < step; i++) {
396 entry[i]=decode_packed_entry_number(book,b);
397 if(entry[i]==-1)return(-1);
398 t[i] = book->valuelist+entry[i]*book->dim;
400 for(i=0,o=0;i<book->dim;i++,o+=step)
406 long vorbis_book_decodev_add(codebook *book,float *a,oggpack_buffer *b,int n){
412 entry = decode_packed_entry_number(book,b);
413 if(entry==-1)return(-1);
414 t = book->valuelist+entry*book->dim;
415 for (j=0;j<book->dim;)
420 entry = decode_packed_entry_number(book,b);
421 if(entry==-1)return(-1);
422 t = book->valuelist+entry*book->dim;
424 switch((int)book->dim){
449 long vorbis_book_decodev_set(codebook *book,float *a,oggpack_buffer *b,int n){
454 entry = decode_packed_entry_number(book,b);
455 if(entry==-1)return(-1);
456 t = book->valuelist+entry*book->dim;
457 for (j=0;j<book->dim;)
463 long vorbis_book_decodevv_add(codebook *book,float **a,long offset,int ch,
464 oggpack_buffer *b,int n){
468 for(i=offset/ch;i<(offset+n)/ch;){
469 entry = decode_packed_entry_number(book,b);
470 if(entry==-1)return(-1);
472 const float *t = book->valuelist+entry*book->dim;
473 for (j=0;j<book->dim;j++){
486 /* Simple enough; pack a few candidate codebooks, unpack them. Code a
487 number of vectors through (keeping track of the quantized values),
488 and decode using the unpacked book. quantized version of in should
493 #include "vorbis/book/lsp20_0.vqh"
494 #include "vorbis/book/res0a_13.vqh"
497 float test1[TESTSIZE]={
549 float test3[TESTSIZE]={
550 0,1,-2,3,4,-5,6,7,8,9,
551 8,-2,7,-1,4,6,8,3,1,-9,
552 10,11,12,13,14,15,26,17,18,19,
553 30,-25,-30,-1,-5,-32,4,3,-2,0};
555 static_codebook *testlist[]={&_vq_book_lsp20_0,
556 &_vq_book_res0a_13,NULL};
557 float *testvec[]={test1,test3};
560 oggpack_buffer write;
563 oggpack_writeinit(&write);
565 fprintf(stderr,"Testing codebook abstraction...:\n");
567 while(testlist[ptr]){
570 float *qv=alloca(sizeof(*qv)*TESTSIZE);
571 float *iv=alloca(sizeof(*iv)*TESTSIZE);
572 memcpy(qv,testvec[ptr],sizeof(*qv)*TESTSIZE);
573 memset(iv,0,sizeof(*iv)*TESTSIZE);
575 fprintf(stderr,"\tpacking/coding %ld... ",ptr);
577 /* pack the codebook, write the testvector */
578 oggpack_reset(&write);
579 vorbis_book_init_encode(&c,testlist[ptr]); /* get it into memory
581 vorbis_staticbook_pack(testlist[ptr],&write);
582 fprintf(stderr,"Codebook size %ld bytes... ",oggpack_bytes(&write));
583 for(i=0;i<TESTSIZE;i+=c.dim){
584 int best=_best(&c,qv+i,1);
585 vorbis_book_encodev(&c,best,qv+i,&write);
587 vorbis_book_clear(&c);
589 fprintf(stderr,"OK.\n");
590 fprintf(stderr,"\tunpacking/decoding %ld... ",ptr);
592 /* transfer the write data to a read buffer and unpack/read */
593 oggpack_readinit(&read,oggpack_get_buffer(&write),oggpack_bytes(&write));
594 if(vorbis_staticbook_unpack(&read,&s)){
595 fprintf(stderr,"Error unpacking codebook.\n");
598 if(vorbis_book_init_decode(&c,&s)){
599 fprintf(stderr,"Error initializing codebook.\n");
603 for(i=0;i<TESTSIZE;i+=c.dim)
604 if(vorbis_book_decodev_set(&c,iv+i,&read,c.dim)==-1){
605 fprintf(stderr,"Error reading codebook test data (EOP).\n");
608 for(i=0;i<TESTSIZE;i++)
609 if(fabs(qv[i]-iv[i])>.000001){
610 fprintf(stderr,"read (%g) != written (%g) at position (%ld)\n",
615 fprintf(stderr,"OK\n");
619 /* The above is the trivial stuff; now try unquantizing a log scale codebook */