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 1.37 2002/01/21 20:51:28 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);
319 static long decode_packed_entry_number(codebook *book, oggpack_buffer *b){
320 int read=book->dec_maxlength;
322 long lok = oggpack_look(b, book->dec_firsttablen);
325 long entry = book->dec_firsttable[lok];
326 if(entry&0x80000000UL){
327 lo=(entry>>15)&0x7fff;
328 hi=book->used_entries-(entry&0x7fff);
330 oggpack_adv(b, book->dec_codelengths[entry-1]);
335 hi=book->used_entries;
338 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[p]<=testword)-1;
355 if(book->dec_codelengths[p]<=read){
356 oggpack_adv(b, book->dec_codelengths[p]);
361 oggpack_adv(b, read);
365 /* Decode side is specced and easier, because we don't need to find
366 matches using different criteria; we simply read and map. There are
367 two things we need to do 'depending':
369 We may need to support interleave. We don't really, but it's
370 convenient to do it here rather than rebuild the vector later.
372 Cascades may be additive or multiplicitive; this is not inherent in
373 the codebook, but set in the code using the codebook. Like
374 interleaving, it's easiest to do it here.
375 addmul==0 -> declarative (set the value)
376 addmul==1 -> additive
377 addmul==2 -> multiplicitive */
379 /* returns the [original, not compacted] entry number or -1 on eof *********/
380 long vorbis_book_decode(codebook *book, oggpack_buffer *b){
381 long packed_entry=decode_packed_entry_number(book,b);
383 return(book->dec_index[packed_entry]);
385 /* if there's no dec_index, the codebook unpacking isn't collapsed */
386 return(packed_entry);
389 /* returns 0 on OK or -1 on eof *************************************/
390 long vorbis_book_decodevs_add(codebook *book,float *a,oggpack_buffer *b,int n){
391 int step=n/book->dim;
392 long *entry = alloca(sizeof(*entry)*step);
393 float **t = alloca(sizeof(*t)*step);
396 for (i = 0; i < step; i++) {
397 entry[i]=decode_packed_entry_number(book,b);
398 if(entry[i]==-1)return(-1);
399 t[i] = book->valuelist+entry[i]*book->dim;
401 for(i=0,o=0;i<book->dim;i++,o+=step)
407 long vorbis_book_decodev_add(codebook *book,float *a,oggpack_buffer *b,int n){
413 entry = decode_packed_entry_number(book,b);
414 if(entry==-1)return(-1);
415 t = book->valuelist+entry*book->dim;
416 for (j=0;j<book->dim;)
421 entry = decode_packed_entry_number(book,b);
422 if(entry==-1)return(-1);
423 t = book->valuelist+entry*book->dim;
425 switch((int)book->dim){
450 long vorbis_book_decodev_set(codebook *book,float *a,oggpack_buffer *b,int n){
455 entry = decode_packed_entry_number(book,b);
456 if(entry==-1)return(-1);
457 t = book->valuelist+entry*book->dim;
458 for (j=0;j<book->dim;)
464 long vorbis_book_decodevv_add(codebook *book,float **a,long offset,int ch,
465 oggpack_buffer *b,int n){
469 for(i=offset/ch;i<(offset+n)/ch;){
470 entry = decode_packed_entry_number(book,b);
471 if(entry==-1)return(-1);
473 const float *t = book->valuelist+entry*book->dim;
474 for (j=0;j<book->dim;j++){
487 /* Simple enough; pack a few candidate codebooks, unpack them. Code a
488 number of vectors through (keeping track of the quantized values),
489 and decode using the unpacked book. quantized version of in should
494 #include "vorbis/book/lsp20_0.vqh"
495 #include "vorbis/book/res0a_13.vqh"
498 float test1[TESTSIZE]={
550 float test3[TESTSIZE]={
551 0,1,-2,3,4,-5,6,7,8,9,
552 8,-2,7,-1,4,6,8,3,1,-9,
553 10,11,12,13,14,15,26,17,18,19,
554 30,-25,-30,-1,-5,-32,4,3,-2,0};
556 static_codebook *testlist[]={&_vq_book_lsp20_0,
557 &_vq_book_res0a_13,NULL};
558 float *testvec[]={test1,test3};
561 oggpack_buffer write;
564 oggpack_writeinit(&write);
566 fprintf(stderr,"Testing codebook abstraction...:\n");
568 while(testlist[ptr]){
571 float *qv=alloca(sizeof(*qv)*TESTSIZE);
572 float *iv=alloca(sizeof(*iv)*TESTSIZE);
573 memcpy(qv,testvec[ptr],sizeof(*qv)*TESTSIZE);
574 memset(iv,0,sizeof(*iv)*TESTSIZE);
576 fprintf(stderr,"\tpacking/coding %ld... ",ptr);
578 /* pack the codebook, write the testvector */
579 oggpack_reset(&write);
580 vorbis_book_init_encode(&c,testlist[ptr]); /* get it into memory
582 vorbis_staticbook_pack(testlist[ptr],&write);
583 fprintf(stderr,"Codebook size %ld bytes... ",oggpack_bytes(&write));
584 for(i=0;i<TESTSIZE;i+=c.dim){
585 int best=_best(&c,qv+i,1);
586 vorbis_book_encodev(&c,best,qv+i,&write);
588 vorbis_book_clear(&c);
590 fprintf(stderr,"OK.\n");
591 fprintf(stderr,"\tunpacking/decoding %ld... ",ptr);
593 /* transfer the write data to a read buffer and unpack/read */
594 oggpack_readinit(&read,oggpack_get_buffer(&write),oggpack_bytes(&write));
595 if(vorbis_staticbook_unpack(&read,&s)){
596 fprintf(stderr,"Error unpacking codebook.\n");
599 if(vorbis_book_init_decode(&c,&s)){
600 fprintf(stderr,"Error initializing codebook.\n");
604 for(i=0;i<TESTSIZE;i+=c.dim)
605 if(vorbis_book_decodev_set(&c,iv+i,&read,c.dim)==-1){
606 fprintf(stderr,"Error reading codebook test data (EOP).\n");
609 for(i=0;i<TESTSIZE;i++)
610 if(fabs(qv[i]-iv[i])>.000001){
611 fprintf(stderr,"read (%g) != written (%g) at position (%ld)\n",
616 fprintf(stderr,"OK\n");
620 /* The above is the trivial stuff; now try unquantizing a log scale codebook */