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 1994-2009 *
9 * by the Xiph.Org Foundation http://www.xiph.org/ *
11 ********************************************************************
13 function: basic codebook pack/unpack/code/decode operations
14 last mod: $Id: codebook.c 16227 2009-07-08 06:58:46Z xiphmont $
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 if(_ilog(s
->dim
)+_ilog(s
->entries
)>24)goto _eofout
;
164 /* codeword ordering.... length ordered or unordered? */
165 switch((int)oggpack_read(opb
,1)){
168 s
->lengthlist
=_ogg_malloc(sizeof(*s
->lengthlist
)*s
->entries
);
170 /* allocated but unused entries? */
171 if(oggpack_read(opb
,1)){
172 /* yes, unused entries */
174 for(i
=0;i
<s
->entries
;i
++){
175 if(oggpack_read(opb
,1)){
176 long num
=oggpack_read(opb
,5);
177 if(num
==-1)goto _eofout
;
178 s
->lengthlist
[i
]=num
+1;
183 /* all entries used; no tagging */
184 for(i
=0;i
<s
->entries
;i
++){
185 long num
=oggpack_read(opb
,5);
186 if(num
==-1)goto _eofout
;
187 s
->lengthlist
[i
]=num
+1;
195 long length
=oggpack_read(opb
,5)+1;
196 s
->lengthlist
=_ogg_malloc(sizeof(*s
->lengthlist
)*s
->entries
);
198 for(i
=0;i
<s
->entries
;){
199 long num
=oggpack_read(opb
,_ilog(s
->entries
-i
));
200 if(num
==-1)goto _eofout
;
201 for(j
=0;j
<num
&& i
<s
->entries
;j
++,i
++)
202 s
->lengthlist
[i
]=length
;
212 /* Do we have a mapping to unpack? */
213 switch((s
->maptype
=oggpack_read(opb
,4))){
218 /* implicitly populated value mapping */
219 /* explicitly populated value mapping */
221 s
->q_min
=oggpack_read(opb
,32);
222 s
->q_delta
=oggpack_read(opb
,32);
223 s
->q_quant
=oggpack_read(opb
,4)+1;
224 s
->q_sequencep
=oggpack_read(opb
,1);
225 if(s
->q_sequencep
==-1)goto _eofout
;
231 quantvals
=(s
->dim
==0?0:_book_maptype1_quantvals(s
));
234 quantvals
=s
->entries
*s
->dim
;
238 /* quantized values */
239 s
->quantlist
=_ogg_malloc(sizeof(*s
->quantlist
)*quantvals
);
240 for(i
=0;i
<quantvals
;i
++)
241 s
->quantlist
[i
]=oggpack_read(opb
,s
->q_quant
);
243 if(quantvals
&&s
->quantlist
[quantvals
-1]==-1)goto _eofout
;
255 vorbis_staticbook_clear(s
);
259 /* returns the number of bits ************************************************/
260 int vorbis_book_encode(codebook
*book
, int a
, oggpack_buffer
*b
){
261 if(a
<0 || a
>=book
->c
->entries
)return(0);
262 oggpack_write(b
,book
->codelist
[a
],book
->c
->lengthlist
[a
]);
263 return(book
->c
->lengthlist
[a
]);
266 /* One the encode side, our vector writers are each designed for a
267 specific purpose, and the encoder is not flexible without modification:
269 The LSP vector coder uses a single stage nearest-match with no
270 interleave, so no step and no error return. This is specced by floor0
273 Residue0 encoding interleaves, uses multiple stages, and each stage
274 peels of a specific amount of resolution from a lattice (thus we want
275 to match by threshold, not nearest match). Residue doesn't *have* to
276 be encoded that way, but to change it, one will need to add more
277 infrastructure on the encode side (decode side is specced and simpler) */
279 /* floor0 LSP (single stage, non interleaved, nearest match) */
280 /* returns entry number and *modifies a* to the quantization value *****/
281 int vorbis_book_errorv(codebook
*book
,float *a
){
283 int best
=_best(book
,a
,1);
285 a
[k
]=(book
->valuelist
+best
*dim
)[k
];
289 /* returns the number of bits and *modifies a* to the quantization value *****/
290 int vorbis_book_encodev(codebook
*book
,int best
,float *a
,oggpack_buffer
*b
){
293 a
[k
]=(book
->valuelist
+best
*dim
)[k
];
294 return(vorbis_book_encode(book
,best
,b
));
297 /* the 'eliminate the decode tree' optimization actually requires the
298 codewords to be MSb first, not LSb. This is an annoying inelegancy
299 (and one of the first places where carefully thought out design
300 turned out to be wrong; Vorbis II and future Ogg codecs should go
301 to an MSb bitpacker), but not actually the huge hit it appears to
302 be. The first-stage decode table catches most words so that
303 bitreverse is not in the main execution path. */
305 static ogg_uint32_t
bitreverse(ogg_uint32_t x
){
306 x
= ((x
>>16)&0x0000ffff) | ((x
<<16)&0xffff0000);
307 x
= ((x
>> 8)&0x00ff00ff) | ((x
<< 8)&0xff00ff00);
308 x
= ((x
>> 4)&0x0f0f0f0f) | ((x
<< 4)&0xf0f0f0f0);
309 x
= ((x
>> 2)&0x33333333) | ((x
<< 2)&0xcccccccc);
310 return((x
>> 1)&0x55555555) | ((x
<< 1)&0xaaaaaaaa);
313 STIN
long decode_packed_entry_number(codebook
*book
, oggpack_buffer
*b
){
314 int read
=book
->dec_maxlength
;
316 long lok
= oggpack_look(b
,book
->dec_firsttablen
);
319 long entry
= book
->dec_firsttable
[lok
];
320 if(entry
&0x80000000UL
){
321 lo
=(entry
>>15)&0x7fff;
322 hi
=book
->used_entries
-(entry
&0x7fff);
324 oggpack_adv(b
, book
->dec_codelengths
[entry
-1]);
329 hi
=book
->used_entries
;
332 lok
= oggpack_look(b
, read
);
334 while(lok
<0 && read
>1)
335 lok
= oggpack_look(b
, --read
);
338 /* bisect search for the codeword in the ordered list */
340 ogg_uint32_t testword
=bitreverse((ogg_uint32_t
)lok
);
344 long test
=book
->codelist
[lo
+p
]>testword
;
349 if(book
->dec_codelengths
[lo
]<=read
){
350 oggpack_adv(b
, book
->dec_codelengths
[lo
]);
355 oggpack_adv(b
, read
);
360 /* Decode side is specced and easier, because we don't need to find
361 matches using different criteria; we simply read and map. There are
362 two things we need to do 'depending':
364 We may need to support interleave. We don't really, but it's
365 convenient to do it here rather than rebuild the vector later.
367 Cascades may be additive or multiplicitive; this is not inherent in
368 the codebook, but set in the code using the codebook. Like
369 interleaving, it's easiest to do it here.
370 addmul==0 -> declarative (set the value)
371 addmul==1 -> additive
372 addmul==2 -> multiplicitive */
374 /* returns the [original, not compacted] entry number or -1 on eof *********/
375 long vorbis_book_decode(codebook
*book
, oggpack_buffer
*b
){
376 if(book
->used_entries
>0){
377 long packed_entry
=decode_packed_entry_number(book
,b
);
379 return(book
->dec_index
[packed_entry
]);
382 /* if there's no dec_index, the codebook unpacking isn't collapsed */
386 /* returns 0 on OK or -1 on eof *************************************/
387 long vorbis_book_decodevs_add(codebook
*book
,float *a
,oggpack_buffer
*b
,int n
){
388 if(book
->used_entries
>0){
389 int step
=n
/book
->dim
;
390 long *entry
= alloca(sizeof(*entry
)*step
);
391 float **t
= alloca(sizeof(*t
)*step
);
394 for (i
= 0; i
< step
; i
++) {
395 entry
[i
]=decode_packed_entry_number(book
,b
);
396 if(entry
[i
]==-1)return(-1);
397 t
[i
] = book
->valuelist
+entry
[i
]*book
->dim
;
399 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
){
407 if(book
->used_entries
>0){
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
){
451 long vorbis_book_decodev_set(codebook
*book
,float *a
,oggpack_buffer
*b
,int n
){
452 if(book
->used_entries
>0){
457 entry
= decode_packed_entry_number(book
,b
);
458 if(entry
==-1)return(-1);
459 t
= book
->valuelist
+entry
*book
->dim
;
460 for (j
=0;j
<book
->dim
;)
467 for (j
=0;j
<book
->dim
;)
474 long vorbis_book_decodevv_add(codebook
*book
,float **a
,long offset
,int ch
,
475 oggpack_buffer
*b
,int n
){
479 if(book
->used_entries
>0){
480 for(i
=offset
/ch
;i
<(offset
+n
)/ch
;){
481 entry
= decode_packed_entry_number(book
,b
);
482 if(entry
==-1)return(-1);
484 const float *t
= book
->valuelist
+entry
*book
->dim
;
485 for (j
=0;j
<book
->dim
;j
++){
499 /* Simple enough; pack a few candidate codebooks, unpack them. Code a
500 number of vectors through (keeping track of the quantized values),
501 and decode using the unpacked book. quantized version of in should
506 #include "vorbis/book/lsp20_0.vqh"
507 #include "vorbis/book/res0a_13.vqh"
510 float test1
[TESTSIZE
]={
562 float test3
[TESTSIZE
]={
563 0,1,-2,3,4,-5,6,7,8,9,
564 8,-2,7,-1,4,6,8,3,1,-9,
565 10,11,12,13,14,15,26,17,18,19,
566 30,-25,-30,-1,-5,-32,4,3,-2,0};
568 static_codebook
*testlist
[]={&_vq_book_lsp20_0
,
569 &_vq_book_res0a_13
,NULL
};
570 float *testvec
[]={test1
,test3
};
573 oggpack_buffer write
;
576 oggpack_writeinit(&write
);
578 fprintf(stderr
,"Testing codebook abstraction...:\n");
580 while(testlist
[ptr
]){
583 float *qv
=alloca(sizeof(*qv
)*TESTSIZE
);
584 float *iv
=alloca(sizeof(*iv
)*TESTSIZE
);
585 memcpy(qv
,testvec
[ptr
],sizeof(*qv
)*TESTSIZE
);
586 memset(iv
,0,sizeof(*iv
)*TESTSIZE
);
588 fprintf(stderr
,"\tpacking/coding %ld... ",ptr
);
590 /* pack the codebook, write the testvector */
591 oggpack_reset(&write
);
592 vorbis_book_init_encode(&c
,testlist
[ptr
]); /* get it into memory
594 vorbis_staticbook_pack(testlist
[ptr
],&write
);
595 fprintf(stderr
,"Codebook size %ld bytes... ",oggpack_bytes(&write
));
596 for(i
=0;i
<TESTSIZE
;i
+=c
.dim
){
597 int best
=_best(&c
,qv
+i
,1);
598 vorbis_book_encodev(&c
,best
,qv
+i
,&write
);
600 vorbis_book_clear(&c
);
602 fprintf(stderr
,"OK.\n");
603 fprintf(stderr
,"\tunpacking/decoding %ld... ",ptr
);
605 /* transfer the write data to a read buffer and unpack/read */
606 oggpack_readinit(&read
,oggpack_get_buffer(&write
),oggpack_bytes(&write
));
607 if(vorbis_staticbook_unpack(&read
,&s
)){
608 fprintf(stderr
,"Error unpacking codebook.\n");
611 if(vorbis_book_init_decode(&c
,&s
)){
612 fprintf(stderr
,"Error initializing codebook.\n");
616 for(i
=0;i
<TESTSIZE
;i
+=c
.dim
)
617 if(vorbis_book_decodev_set(&c
,iv
+i
,&read
,c
.dim
)==-1){
618 fprintf(stderr
,"Error reading codebook test data (EOP).\n");
621 for(i
=0;i
<TESTSIZE
;i
++)
622 if(fabs(qv
[i
]-iv
[i
])>.000001){
623 fprintf(stderr
,"read (%g) != written (%g) at position (%ld)\n",
628 fprintf(stderr
,"OK\n");
632 /* The above is the trivial stuff; now try unquantizing a log scale codebook */