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 1994-2001 *
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 1.25 2001/06/04 05:50:10 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(static_codebook));
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(oggpack_read(opb,1)){
166 s->lengthlist=_ogg_malloc(sizeof(long)*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(long)*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;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(long)*quantvals);
237 for(i=0;i<quantvals;i++)
238 s->quantlist[i]=oggpack_read(opb,s->q_quant);
240 if(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 /* Decode side is specced and easier, because we don't need to find
303 matches using different criteria; we simply read and map. There are
304 two things we need to do 'depending':
306 We may need to support interleave. We don't really, but it's
307 convenient to do it here rather than rebuild the vector later.
309 Cascades may be additive or multiplicitive; this is not inherent in
310 the codebook, but set in the code using the codebook. Like
311 interleaving, it's easiest to do it here.
312 addmul==0 -> declarative (set the value)
313 addmul==1 -> additive
314 addmul==2 -> multiplicitive */
316 /* returns the entry number or -1 on eof *************************************/
317 long vorbis_book_decode(codebook *book, oggpack_buffer *b){
319 decode_aux *t=book->decode_tree;
320 int lok = oggpack_look(b, t->tabn);
324 oggpack_adv(b, t->tabl[lok]);
330 switch(oggpack_read1(b)){
344 /* returns 0 on OK or -1 on eof *************************************/
345 long vorbis_book_decodevs(codebook *book,float *a,oggpack_buffer *b,
347 int step=n/book->dim;
348 long *entry = alloca(sizeof(long)*step);
349 float **t = alloca(sizeof(float *)*step);
352 for (i = 0; i < step; i++) {
353 entry[i]=vorbis_book_decode(book,b);
354 if(entry[i]==-1)return(-1);
355 t[i] = book->valuelist+entry[i]*book->dim;
359 for(i=0,o=0;i<book->dim;i++,o+=step)
364 for(i=0,o=0;i<book->dim;i++,o+=step)
369 for(i=0,o=0;i<book->dim;i++,o+=step)
377 long vorbis_book_decodev(codebook *book,float *a,oggpack_buffer *b,
385 entry = vorbis_book_decode(book,b);
386 if(entry==-1)return(-1);
387 t = book->valuelist+entry*book->dim;
388 for (j=0;j<book->dim;)
394 entry = vorbis_book_decode(book,b);
395 if(entry==-1)return(-1);
396 t = book->valuelist+entry*book->dim;
397 for (j=0;j<book->dim;)
403 entry = vorbis_book_decode(book,b);
404 if(entry==-1)return(-1);
405 t = book->valuelist+entry*book->dim;
406 for (j=0;j<book->dim;)
416 /* Simple enough; pack a few candidate codebooks, unpack them. Code a
417 number of vectors through (keeping track of the quantized values),
418 and decode using the unpacked book. quantized version of in should
423 #include "vorbis/book/lsp20_0.vqh"
424 #include "vorbis/book/res0a_13.vqh"
427 float test1[TESTSIZE]={
479 float test3[TESTSIZE]={
480 0,1,-2,3,4,-5,6,7,8,9,
481 8,-2,7,-1,4,6,8,3,1,-9,
482 10,11,12,13,14,15,26,17,18,19,
483 30,-25,-30,-1,-5,-32,4,3,-2,0};
485 static_codebook *testlist[]={&_vq_book_lsp20_0,
486 &_vq_book_res0a_13,NULL};
487 float *testvec[]={test1,test3};
490 oggpack_buffer write;
493 oggpack_writeinit(&write);
495 fprintf(stderr,"Testing codebook abstraction...:\n");
497 while(testlist[ptr]){
500 float *qv=alloca(sizeof(float)*TESTSIZE);
501 float *iv=alloca(sizeof(float)*TESTSIZE);
502 memcpy(qv,testvec[ptr],sizeof(float)*TESTSIZE);
503 memset(iv,0,sizeof(float)*TESTSIZE);
505 fprintf(stderr,"\tpacking/coding %ld... ",ptr);
507 /* pack the codebook, write the testvector */
508 oggpack_reset(&write);
509 vorbis_book_init_encode(&c,testlist[ptr]); /* get it into memory
511 vorbis_staticbook_pack(testlist[ptr],&write);
512 fprintf(stderr,"Codebook size %ld bytes... ",oggpack_bytes(&write));
513 for(i=0;i<TESTSIZE;i+=c.dim){
514 int best=_best(&c,qv+i,1);
515 vorbis_book_encodev(&c,best,qv+i,&write);
517 vorbis_book_clear(&c);
519 fprintf(stderr,"OK.\n");
520 fprintf(stderr,"\tunpacking/decoding %ld... ",ptr);
522 /* transfer the write data to a read buffer and unpack/read */
523 oggpack_readinit(&read,oggpack_get_buffer(&write),oggpack_bytes(&write));
524 if(vorbis_staticbook_unpack(&read,&s)){
525 fprintf(stderr,"Error unpacking codebook.\n");
528 if(vorbis_book_init_decode(&c,&s)){
529 fprintf(stderr,"Error initializing codebook.\n");
533 for(i=0;i<TESTSIZE;i+=c.dim)
534 if(vorbis_book_decodevs(&c,iv+i,&read,1,-1)==-1){
535 fprintf(stderr,"Error reading codebook test data (EOP).\n");
538 for(i=0;i<TESTSIZE;i++)
539 if(fabs(qv[i]-iv[i])>.000001){
540 fprintf(stderr,"read (%g) != written (%g) at position (%ld)\n",
545 fprintf(stderr,"OK\n");
549 /* The above is the trivial stuff; now try unquantizing a log scale codebook */