1/************************************************************************
2 * Copyright (C) 2002-2009, Xiph.org Foundation
3 * Copyright (C) 2010, Robin Watts for Pinknoise Productions Ltd
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 *     * Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 *     * Redistributions in binary form must reproduce the above
13 * copyright notice, this list of conditions and the following disclaimer
14 * in the documentation and/or other materials provided with the
15 * distribution.
16 *     * Neither the names of the Xiph.org Foundation nor Pinknoise
17 * Productions Ltd nor the names of its contributors may be used to
18 * endorse or promote products derived from this software without
19 * specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32 ************************************************************************
33
34 function: basic codebook pack/unpack/code/decode operations
35
36 ************************************************************************/
37
38#include <stdlib.h>
39#include <string.h>
40#include <math.h>
41#include <limits.h>
42#include "ogg.h"
43#include "ivorbiscodec.h"
44#include "codebook.h"
45#include "misc.h"
46#include "os.h"
47
48
49/**** pack/unpack helpers ******************************************/
50int _ilog(unsigned int v){
51  int ret=0;
52  while(v){
53    ret++;
54    v>>=1;
55  }
56  return(ret);
57}
58
59static ogg_uint32_t decpack(long entry,long used_entry,long quantvals,
60			    codebook *b,oggpack_buffer *opb,int maptype){
61  ogg_uint32_t ret=0;
62  int j;
63
64  switch(b->dec_type){
65
66  case 0:
67    return (ogg_uint32_t)entry;
68
69  case 1:
70    if(maptype==1){
71      /* vals are already read into temporary column vector here */
72      for(j=0;j<b->dim;j++){
73	ogg_uint32_t off=entry%quantvals;
74	entry/=quantvals;
75	ret|=((ogg_uint16_t *)(b->q_val))[off]<<(b->q_bits*j);
76      }
77    }else{
78      for(j=0;j<b->dim;j++)
79	ret|=oggpack_read(opb,b->q_bits)<<(b->q_bits*j);
80    }
81    return ret;
82
83  case 2:
84    for(j=0;j<b->dim;j++){
85      ogg_uint32_t off=entry%quantvals;
86      entry/=quantvals;
87      ret|=off<<(b->q_pack*j);
88    }
89    return ret;
90
91  case 3:
92    return (ogg_uint32_t)used_entry;
93
94  }
95  return 0; /* silence compiler */
96}
97
98/* 32 bit float (not IEEE; nonnormalized mantissa +
99   biased exponent) : neeeeeee eeemmmmm mmmmmmmm mmmmmmmm
100   Why not IEEE?  It's just not that important here. */
101
102static ogg_int32_t _float32_unpack(long val,int *point){
103  long   mant=val&0x1fffff;
104  int    sign=val&0x80000000;
105
106  *point=((val&0x7fe00000L)>>21)-788;
107
108  if(mant){
109    while(!(mant&0x40000000)){
110      mant<<=1;
111      *point-=1;
112    }
113    if(sign)mant= -mant;
114  }else{
115    *point=-9999;
116  }
117  return mant;
118}
119
120/* choose the smallest supported node size that fits our decode table.
121   Legal bytewidths are 1/1 1/2 2/2 2/4 4/4 */
122static int _determine_node_bytes(long used, int leafwidth){
123
124  /* special case small books to size 4 to avoid multiple special
125     cases in repack */
126  if(used<2)
127    return 4;
128
129  if(leafwidth==3)leafwidth=4;
130  if(_ilog(3*used-6)+1 <= leafwidth*4)
131    return leafwidth/2?leafwidth/2:1;
132  return leafwidth;
133}
134
135/* convenience/clarity; leaves are specified as multiple of node word
136   size (1 or 2) */
137static int _determine_leaf_words(int nodeb, int leafwidth){
138  if(leafwidth>nodeb)return 2;
139  return 1;
140}
141
142/* given a list of word lengths, number of used entries, and byte
143   width of a leaf, generate the decode table */
144static int _make_words(char *l,long n,ogg_uint32_t *r,long quantvals,
145		       codebook *b, oggpack_buffer *opb,int maptype){
146  long i,j,count=0;
147  long top=0;
148  ogg_uint32_t marker[33];
149
150  if (n<1)
151    return 1;
152
153  if(n<2){
154    r[0]=0x80000000;
155  }else{
156    memset(marker,0,sizeof(marker));
157
158    for(i=0;i<n;i++){
159      long length=l[i];
160      if(length){
161	ogg_uint32_t entry=marker[length];
162	long chase=0;
163	if(count && !entry)return -1; /* overpopulated tree! */
164
165	/* chase the tree as far as it's already populated, fill in past */
166	for(j=0;j<length-1;j++){
167	  int bit=(entry>>(length-j-1))&1;
168	  if(chase>=top){
169	    if (chase < 0 || chase >= n) return 1;
170	    top++;
171	    r[chase*2]=top;
172	    r[chase*2+1]=0;
173	  }else
174	    if (chase < 0 || chase >= n || chase*2+bit > n*2+1) return 1;
175	    if(!r[chase*2+bit])
176	      r[chase*2+bit]=top;
177	  chase=r[chase*2+bit];
178	  if (chase < 0 || chase >= n) return 1;
179	}
180	{
181	  int bit=(entry>>(length-j-1))&1;
182	  if(chase>=top){
183	    top++;
184	    r[chase*2+1]=0;
185	  }
186	  r[chase*2+bit]= decpack(i,count++,quantvals,b,opb,maptype) |
187	    0x80000000;
188	}
189
190	/* Look to see if the next shorter marker points to the node
191	   above. if so, update it and repeat.  */
192	for(j=length;j>0;j--){
193	  if(marker[j]&1){
194	    marker[j]=marker[j-1]<<1;
195	    break;
196	  }
197	  marker[j]++;
198	}
199
200	/* prune the tree; the implicit invariant says all the longer
201	   markers were dangling from our just-taken node.  Dangle them
202	   from our *new* node. */
203	for(j=length+1;j<33;j++)
204	  if((marker[j]>>1) == entry){
205	    entry=marker[j];
206	    marker[j]=marker[j-1]<<1;
207	  }else
208	    break;
209      }
210    }
211  }
212
213  // following sanity check copied from libvorbis
214  /* sanity check the huffman tree; an underpopulated tree must be
215     rejected. The only exception is the one-node pseudo-nil tree,
216     which appears to be underpopulated because the tree doesn't
217     really exist; there's only one possible 'codeword' or zero bits,
218     but the above tree-gen code doesn't mark that. */
219  if(b->used_entries != 1){
220    for(i=1;i<33;i++)
221      if(marker[i] & (0xffffffffUL>>(32-i))){
222          return 1;
223      }
224  }
225
226
227  return 0;
228}
229
230static int _make_decode_table(codebook *s,char *lengthlist,long quantvals,
231			      oggpack_buffer *opb,int maptype){
232  int i;
233  ogg_uint32_t *work;
234
235  if (!lengthlist) return 1;
236  if(s->dec_nodeb==4){
237    /* Over-allocate by using s->entries instead of used_entries.
238     * This means that we can use s->entries to enforce size in
239     * _make_words without messing up length list looping.
240     * This probably wastes a bit of space, but it shouldn't
241     * impact behavior or size too much.
242     */
243    s->dec_table=_ogg_malloc((s->entries*2+1)*sizeof(*work));
244    if (!s->dec_table) return 1;
245    /* +1 (rather than -2) is to accommodate 0 and 1 sized books,
246       which are specialcased to nodeb==4 */
247    if(_make_words(lengthlist,s->entries,
248		   s->dec_table,quantvals,s,opb,maptype))return 1;
249
250    return 0;
251  }
252
253  if (s->used_entries > INT_MAX/2 ||
254      s->used_entries*2 > INT_MAX/((long) sizeof(*work)) - 1) return 1;
255  /* Overallocate as above */
256  work=calloc((s->entries*2+1),sizeof(*work));
257  if (!work) return 1;
258  if(_make_words(lengthlist,s->entries,work,quantvals,s,opb,maptype)) goto error_out;
259  if (s->used_entries > INT_MAX/(s->dec_leafw+1)) goto error_out;
260  if (s->dec_nodeb && s->used_entries * (s->dec_leafw+1) > INT_MAX/s->dec_nodeb) goto error_out;
261  s->dec_table=_ogg_malloc((s->used_entries*(s->dec_leafw+1)-2)*
262			   s->dec_nodeb);
263  if (!s->dec_table) goto error_out;
264
265  if(s->dec_leafw==1){
266    switch(s->dec_nodeb){
267    case 1:
268      for(i=0;i<s->used_entries*2-2;i++)
269	  ((unsigned char *)s->dec_table)[i]=(unsigned char)
270	    (((work[i] & 0x80000000UL) >> 24) | work[i]);
271      break;
272    case 2:
273      for(i=0;i<s->used_entries*2-2;i++)
274	  ((ogg_uint16_t *)s->dec_table)[i]=(ogg_uint16_t)
275	    (((work[i] & 0x80000000UL) >> 16) | work[i]);
276      break;
277    }
278
279  }else{
280    /* more complex; we have to do a two-pass repack that updates the
281       node indexing. */
282    long top=s->used_entries*3-2;
283    if(s->dec_nodeb==1){
284      unsigned char *out=(unsigned char *)s->dec_table;
285
286      for(i=s->used_entries*2-4;i>=0;i-=2){
287	if(work[i]&0x80000000UL){
288	  if(work[i+1]&0x80000000UL){
289	    top-=4;
290	    out[top]=(work[i]>>8 & 0x7f)|0x80;
291	    out[top+1]=(work[i+1]>>8 & 0x7f)|0x80;
292	    out[top+2]=work[i] & 0xff;
293	    out[top+3]=work[i+1] & 0xff;
294	  }else{
295	    top-=3;
296	    out[top]=(work[i]>>8 & 0x7f)|0x80;
297	    out[top+1]=work[work[i+1]*2];
298	    out[top+2]=work[i] & 0xff;
299	  }
300	}else{
301	  if(work[i+1]&0x80000000UL){
302	    top-=3;
303	    out[top]=work[work[i]*2];
304	    out[top+1]=(work[i+1]>>8 & 0x7f)|0x80;
305	    out[top+2]=work[i+1] & 0xff;
306	  }else{
307	    top-=2;
308	    out[top]=work[work[i]*2];
309	    out[top+1]=work[work[i+1]*2];
310	  }
311	}
312	work[i]=top;
313      }
314    }else{
315      ogg_uint16_t *out=(ogg_uint16_t *)s->dec_table;
316      for(i=s->used_entries*2-4;i>=0;i-=2){
317	if(work[i]&0x80000000UL){
318	  if(work[i+1]&0x80000000UL){
319	    top-=4;
320	    out[top]=(work[i]>>16 & 0x7fff)|0x8000;
321	    out[top+1]=(work[i+1]>>16 & 0x7fff)|0x8000;
322	    out[top+2]=work[i] & 0xffff;
323	    out[top+3]=work[i+1] & 0xffff;
324	  }else{
325	    top-=3;
326	    out[top]=(work[i]>>16 & 0x7fff)|0x8000;
327	    out[top+1]=work[work[i+1]*2];
328	    out[top+2]=work[i] & 0xffff;
329	  }
330	}else{
331	  if(work[i+1]&0x80000000UL){
332	    top-=3;
333	    out[top]=work[work[i]*2];
334	    out[top+1]=(work[i+1]>>16 & 0x7fff)|0x8000;
335	    out[top+2]=work[i+1] & 0xffff;
336	  }else{
337	    top-=2;
338	    out[top]=work[work[i]*2];
339	    out[top+1]=work[work[i+1]*2];
340	  }
341	}
342	work[i]=top;
343      }
344    }
345  }
346
347  free(work);
348  return 0;
349error_out:
350  free(work);
351  return 1;
352}
353
354/* most of the time, entries%dimensions == 0, but we need to be
355   well defined.  We define that the possible vales at each
356   scalar is values == entries/dim.  If entries%dim != 0, we'll
357   have 'too few' values (values*dim<entries), which means that
358   we'll have 'left over' entries; left over entries use zeroed
359   values (and are wasted).  So don't generate codebooks like
360   that */
361/* there might be a straightforward one-line way to do the below
362   that's portable and totally safe against roundoff, but I haven't
363   thought of it.  Therefore, we opt on the side of caution */
364long _book_maptype1_quantvals(codebook *b){
365  /* get us a starting hint, we'll polish it below */
366  int bits=_ilog(b->entries);
367  int vals=b->entries>>((bits-1)*(b->dim-1)/b->dim);
368
369  while(1){
370    long acc=1;
371    long acc1=1;
372    int i;
373    for(i=0;i<b->dim;i++){
374      acc*=vals;
375      acc1*=vals+1;
376    }
377    if(acc<=b->entries && acc1>b->entries){
378      return(vals);
379    }else{
380      if(acc>b->entries){
381        vals--;
382      }else{
383        vals++;
384      }
385    }
386  }
387}
388
389void vorbis_book_clear(codebook *b){
390  /* static book is not cleared; we're likely called on the lookup and
391     the static codebook belongs to the info struct */
392  if(b->q_val)_ogg_free(b->q_val);
393  if(b->dec_table)_ogg_free(b->dec_table);
394  if(b->dec_buf)_ogg_free(b->dec_buf);
395
396  memset(b,0,sizeof(*b));
397}
398
399int vorbis_book_unpack(oggpack_buffer *opb,codebook *s){
400  char         *lengthlist=NULL;
401  int           quantvals=0;
402  long          i,j;
403  int           maptype;
404
405  memset(s,0,sizeof(*s));
406
407  /* make sure alignment is correct */
408  if(oggpack_read(opb,24)!=0x564342)goto _eofout;
409
410  /* first the basic parameters */
411  s->dim=oggpack_read(opb,16);
412  s->dec_buf=_ogg_malloc(sizeof(ogg_int32_t)*s->dim);
413  if (s->dec_buf == NULL)
414      goto _errout;
415  s->entries=oggpack_read(opb,24);
416  if(s->entries<=0)goto _eofout;
417  if(s->dim<=0)goto _eofout;
418  if(_ilog(s->dim)+_ilog(s->entries)>24)goto _eofout;
419  if (s->dim > INT_MAX/s->entries) goto _eofout;
420
421  /* codeword ordering.... length ordered or unordered? */
422  switch((int)oggpack_read(opb,1)){
423  case 0:
424    /* unordered */
425    lengthlist=(char *)calloc(s->entries, sizeof(*lengthlist));
426    if(!lengthlist) goto _eofout;
427
428    /* allocated but unused entries? */
429    if(oggpack_read(opb,1)){
430      /* yes, unused entries */
431
432      for(i=0;i<s->entries;i++){
433	if(oggpack_read(opb,1)){
434	  long num=oggpack_read(opb,5);
435	  if(num==-1)goto _eofout;
436	  lengthlist[i]=(char)(num+1);
437	  s->used_entries++;
438	  if(num+1>s->dec_maxlength)s->dec_maxlength=num+1;
439	}else
440	  lengthlist[i]=0;
441      }
442    }else{
443      /* all entries used; no tagging */
444      s->used_entries=s->entries;
445      for(i=0;i<s->entries;i++){
446	long num=oggpack_read(opb,5);
447	if(num==-1)goto _eofout;
448	lengthlist[i]=(char)(num+1);
449	if(num+1>s->dec_maxlength)s->dec_maxlength=num+1;
450      }
451    }
452
453    break;
454  case 1:
455    /* ordered */
456    {
457      long length=oggpack_read(opb,5)+1;
458
459      s->used_entries=s->entries;
460      lengthlist=(char *)calloc(s->entries, sizeof(*lengthlist));
461      if (!lengthlist) goto _eofout;
462
463      for(i=0;i<s->entries;){
464	long num=oggpack_read(opb,_ilog(s->entries-i));
465	if(num<0)goto _eofout;
466	for(j=0;j<num && i<s->entries;j++,i++)
467	  lengthlist[i]=(char)length;
468	s->dec_maxlength=length;
469	length++;
470      }
471    }
472    break;
473  default:
474    /* EOF */
475    goto _eofout;
476  }
477
478
479  /* Do we have a mapping to unpack? */
480
481  if((maptype=oggpack_read(opb,4))>0){
482    s->q_min=_float32_unpack(oggpack_read(opb,32),&s->q_minp);
483    s->q_del=_float32_unpack(oggpack_read(opb,32),&s->q_delp);
484    s->q_bits=oggpack_read(opb,4)+1;
485    s->q_seq=oggpack_read(opb,1);
486
487    s->q_del>>=s->q_bits;
488    s->q_delp+=s->q_bits;
489  }
490
491  switch(maptype){
492  case 0:
493
494    /* no mapping; decode type 0 */
495
496    /* how many bytes for the indexing? */
497    /* this is the correct boundary here; we lose one bit to
498       node/leaf mark */
499    s->dec_nodeb=_determine_node_bytes(s->used_entries,_ilog(s->entries)/8+1);
500    s->dec_leafw=_determine_leaf_words(s->dec_nodeb,_ilog(s->entries)/8+1);
501    s->dec_type=0;
502
503    if(_make_decode_table(s,lengthlist,quantvals,opb,maptype)) goto _errout;
504    break;
505
506  case 1:
507
508    /* mapping type 1; implicit values by lattice  position */
509    quantvals=_book_maptype1_quantvals(s);
510
511    /* dec_type choices here are 1,2; 3 doesn't make sense */
512    {
513      /* packed values */
514      long total1=(s->q_bits*s->dim+8)/8; /* remember flag bit */
515      if (s->dim > (INT_MAX-8)/s->q_bits) goto _eofout;
516      /* vector of column offsets; remember flag bit */
517      long total2=(_ilog(quantvals-1)*s->dim+8)/8+(s->q_bits+7)/8;
518
519
520      if(total1<=4 && total1<=total2){
521	/* use dec_type 1: vector of packed values */
522
523	/* need quantized values before  */
524	s->q_val=calloc(sizeof(ogg_uint16_t), quantvals);
525	if (!s->q_val) goto _eofout;
526	for(i=0;i<quantvals;i++)
527	  ((ogg_uint16_t *)s->q_val)[i]=(ogg_uint16_t)oggpack_read(opb,s->q_bits);
528
529	if(oggpack_eop(opb)){
530	  goto _eofout;
531	}
532
533	s->dec_type=1;
534	s->dec_nodeb=_determine_node_bytes(s->used_entries,
535					   (s->q_bits*s->dim+8)/8);
536	s->dec_leafw=_determine_leaf_words(s->dec_nodeb,
537					   (s->q_bits*s->dim+8)/8);
538	if(_make_decode_table(s,lengthlist,quantvals,opb,maptype)){
539	  goto _errout;
540	}
541
542	free(s->q_val);
543	s->q_val=0;
544
545      }else{
546	/* use dec_type 2: packed vector of column offsets */
547
548	/* need quantized values before */
549	if(s->q_bits<=8){
550	  s->q_val=_ogg_malloc(quantvals);
551	  if (!s->q_val) goto _eofout;
552	  for(i=0;i<quantvals;i++)
553	    ((unsigned char *)s->q_val)[i]=(unsigned char)oggpack_read(opb,s->q_bits);
554	}else{
555	  s->q_val=_ogg_malloc(quantvals*2);
556	  if (!s->q_val) goto _eofout;
557	  for(i=0;i<quantvals;i++)
558	    ((ogg_uint16_t *)s->q_val)[i]=(ogg_uint16_t)oggpack_read(opb,s->q_bits);
559	}
560
561	if(oggpack_eop(opb))goto _eofout;
562
563	s->q_pack=_ilog(quantvals-1);
564	s->dec_type=2;
565	s->dec_nodeb=_determine_node_bytes(s->used_entries,
566					   (_ilog(quantvals-1)*s->dim+8)/8);
567	s->dec_leafw=_determine_leaf_words(s->dec_nodeb,
568					   (_ilog(quantvals-1)*s->dim+8)/8);
569	if(_make_decode_table(s,lengthlist,quantvals,opb,maptype))goto _errout;
570
571      }
572    }
573    break;
574  case 2:
575
576    /* mapping type 2; explicit array of values */
577    quantvals=s->entries*s->dim;
578    /* dec_type choices here are 1,3; 2 is not possible */
579
580    if( (s->q_bits*s->dim+8)/8 <=4){ /* remember flag bit */
581      /* use dec_type 1: vector of packed values */
582
583      s->dec_type=1;
584      s->dec_nodeb=_determine_node_bytes(s->used_entries,(s->q_bits*s->dim+8)/8);
585      s->dec_leafw=_determine_leaf_words(s->dec_nodeb,(s->q_bits*s->dim+8)/8);
586      if(_make_decode_table(s,lengthlist,quantvals,opb,maptype))goto _errout;
587
588    }else{
589      /* use dec_type 3: scalar offset into packed value array */
590
591      s->dec_type=3;
592      s->dec_nodeb=_determine_node_bytes(s->used_entries,_ilog(s->used_entries-1)/8+1);
593      s->dec_leafw=_determine_leaf_words(s->dec_nodeb,_ilog(s->used_entries-1)/8+1);
594      if(_make_decode_table(s,lengthlist,quantvals,opb,maptype))goto _errout;
595
596      /* get the vals & pack them */
597      s->q_pack=(s->q_bits+7)/8*s->dim;
598      s->q_val=_ogg_malloc(s->q_pack*s->used_entries);
599
600      if(s->q_bits<=8){
601	for(i=0;i<s->used_entries*s->dim;i++)
602	  ((unsigned char *)(s->q_val))[i]=(unsigned char)oggpack_read(opb,s->q_bits);
603      }else{
604	for(i=0;i<s->used_entries*s->dim;i++)
605	  ((ogg_uint16_t *)(s->q_val))[i]=(ogg_uint16_t)oggpack_read(opb,s->q_bits);
606      }
607    }
608    break;
609  default:
610    goto _errout;
611  }
612
613  if (s->dec_nodeb==1)
614    if (s->dec_leafw == 1)
615      s->dec_method = 0;
616    else
617      s->dec_method = 1;
618  else if (s->dec_nodeb==2)
619    if (s->dec_leafw == 1)
620      s->dec_method = 2;
621    else
622      s->dec_method = 3;
623  else
624    s->dec_method = 4;
625
626  if(oggpack_eop(opb))goto _eofout;
627
628  free(lengthlist);
629  return 0;
630 _errout:
631 _eofout:
632  vorbis_book_clear(s);
633  free(lengthlist);
634  free(s->q_val);
635  return -1;
636}
637
638#ifndef ONLY_C
639ogg_uint32_t decode_packed_entry_number(codebook *book,
640                                        oggpack_buffer *b);
641#else
642static inline ogg_uint32_t decode_packed_entry_number(codebook *book,
643						      oggpack_buffer *b){
644  ogg_uint32_t chase=0;
645  int  read=book->dec_maxlength;
646  long lok = oggpack_look(b,read),i;
647
648  while(lok<0 && read>1)
649    lok = oggpack_look(b, --read);
650
651  if(lok<0){
652    oggpack_adv(b,1); /* force eop */
653    return -1;
654  }
655
656  /* chase the tree with the bits we got */
657  switch (book->dec_method)
658  {
659    case 0:
660    {
661      /* book->dec_nodeb==1, book->dec_leafw==1 */
662      /* 8/8 - Used */
663      unsigned char *t=(unsigned char *)book->dec_table;
664
665      for(i=0;i<read;i++){
666	chase=t[chase*2+((lok>>i)&1)];
667	if(chase&0x80UL)break;
668      }
669      chase&=0x7fUL;
670      break;
671    }
672    case 1:
673    {
674      /* book->dec_nodeb==1, book->dec_leafw!=1 */
675      /* 8/16 - Used by infile2 */
676      unsigned char *t=(unsigned char *)book->dec_table;
677      for(i=0;i<read;i++){
678	int bit=(lok>>i)&1;
679	int next=t[chase+bit];
680	if(next&0x80){
681	  chase= (next<<8) | t[chase+bit+1+(!bit || t[chase]&0x80)];
682	  break;
683	}
684	chase=next;
685      }
686      //chase&=0x7fffUL;
687      chase&=~0x8000UL;
688      break;
689    }
690    case 2:
691    {
692      /* book->dec_nodeb==2, book->dec_leafw==1 */
693      /* 16/16 - Used */
694      for(i=0;i<read;i++){
695	chase=((ogg_uint16_t *)(book->dec_table))[chase*2+((lok>>i)&1)];
696	if(chase&0x8000UL)break;
697      }
698      //chase&=0x7fffUL;
699      chase&=~0x8000UL;
700      break;
701    }
702    case 3:
703    {
704      /* book->dec_nodeb==2, book->dec_leafw!=1 */
705      /* 16/32 - Used by infile2 */
706      ogg_uint16_t *t=(ogg_uint16_t *)book->dec_table;
707      for(i=0;i<read;i++){
708	int bit=(lok>>i)&1;
709	int next=t[chase+bit];
710	if(next&0x8000){
711	  chase= (next<<16) | t[chase+bit+1+(!bit || t[chase]&0x8000)];
712	  break;
713	}
714	chase=next;
715      }
716      //chase&=0x7fffffffUL;
717      chase&=~0x80000000UL;
718      break;
719    }
720    case 4:
721    {
722      //Output("32/32");
723      for(i=0;i<read;i++){
724	chase=((ogg_uint32_t *)(book->dec_table))[chase*2+((lok>>i)&1)];
725	if(chase&0x80000000UL)break;
726      }
727      //chase&=0x7fffffffUL;
728      chase&=~0x80000000UL;
729      break;
730    }
731  }
732
733  if(i<read){
734    oggpack_adv(b,i+1);
735    return chase;
736  }
737  oggpack_adv(b,read+1);
738  return(-1);
739}
740#endif
741
742/* returns the [original, not compacted] entry number or -1 on eof *********/
743long vorbis_book_decode(codebook *book, oggpack_buffer *b){
744  if(book->dec_type)return -1;
745 return decode_packed_entry_number(book,b);
746}
747
748#ifndef ONLY_C
749int decode_map(codebook *s, oggpack_buffer *b, ogg_int32_t *v, int point);
750#else
751static int decode_map(codebook *s, oggpack_buffer *b, ogg_int32_t *v, int point){
752  ogg_uint32_t entry = decode_packed_entry_number(s,b);
753  int i;
754  if(oggpack_eop(b))return(-1);
755
756  /* 1 used by test file 0 */
757
758  /* according to decode type */
759  switch(s->dec_type){
760  case 1:{
761    /* packed vector of values */
762    int mask=(1<<s->q_bits)-1;
763    for(i=0;i<s->dim;i++){
764      v[i]=entry&mask;
765      entry>>=s->q_bits;
766    }
767    break;
768  }
769  case 2:{
770    /* packed vector of column offsets */
771    int mask=(1<<s->q_pack)-1;
772    for(i=0;i<s->dim;i++){
773      if(s->q_bits<=8)
774	v[i]=((unsigned char *)(s->q_val))[entry&mask];
775      else
776	v[i]=((ogg_uint16_t *)(s->q_val))[entry&mask];
777      entry>>=s->q_pack;
778    }
779    break;
780  }
781  case 3:{
782    /* offset into array */
783    void *ptr=s->q_val+entry*s->q_pack;
784
785    if(s->q_bits<=8){
786      for(i=0;i<s->dim;i++)
787	v[i]=((unsigned char *)ptr)[i];
788    }else{
789      for(i=0;i<s->dim;i++)
790	v[i]=((ogg_uint16_t *)ptr)[i];
791    }
792    break;
793  }
794  default:
795    return -1;
796  }
797
798  /* we have the unpacked multiplicands; compute final vals */
799  {
800    int         shiftM = point-s->q_delp;
801    ogg_int32_t add    = point-s->q_minp;
802    int         mul    = s->q_del;
803
804    if(add>0)
805      add= s->q_min >> add;
806    else
807      add= s->q_min << -add;
808    if (shiftM<0)
809    {
810      mul <<= -shiftM;
811      shiftM = 0;
812    }
813    add <<= shiftM;
814
815    for(i=0;i<s->dim;i++)
816      v[i]= ((add + v[i] * mul) >> shiftM);
817
818    if(s->q_seq)
819      for(i=1;i<s->dim;i++)
820	v[i]+=v[i-1];
821  }
822
823  return 0;
824}
825#endif
826
827/* returns 0 on OK or -1 on eof *************************************/
828long vorbis_book_decodevs_add(codebook *book,ogg_int32_t *a,
829			      oggpack_buffer *b,int n,int point){
830  if(book->used_entries>0){
831    int step=n/book->dim;
832    ogg_int32_t *v = book->dec_buf;//(ogg_int32_t *)alloca(sizeof(*v)*book->dim);
833    int i,j,o;
834    if (!v) return -1;
835
836    for (j=0;j<step;j++){
837      if(decode_map(book,b,v,point))return -1;
838      for(i=0,o=j;i<book->dim;i++,o+=step)
839	a[o]+=v[i];
840    }
841  }
842  return 0;
843}
844
845long vorbis_book_decodev_add(codebook *book,ogg_int32_t *a,
846			     oggpack_buffer *b,int n,int point){
847  if(book->used_entries>0){
848    ogg_int32_t *v = book->dec_buf;//(ogg_int32_t *)alloca(sizeof(*v)*book->dim);
849    int i,j;
850
851    if (!v) return -1;
852    for(i=0;i<n;){
853      if(decode_map(book,b,v,point))return -1;
854      for (j=0;j<book->dim;j++)
855	a[i++]+=v[j];
856    }
857  }
858  return 0;
859}
860
861long vorbis_book_decodev_set(codebook *book,ogg_int32_t *a,
862			     oggpack_buffer *b,int n,int point){
863  if(book->used_entries>0){
864    ogg_int32_t *v = book->dec_buf;//(ogg_int32_t *)alloca(sizeof(*v)*book->dim);
865    int i,j;
866
867    if (!v) return -1;
868    for(i=0;i<n;){
869      if(decode_map(book,b,v,point))return -1;
870      for (j=0;j<book->dim;j++)
871	a[i++]=v[j];
872    }
873  }else{
874    int i,j;
875
876    for(i=0;i<n;){
877      for (j=0;j<book->dim;j++)
878	a[i++]=0;
879    }
880  }
881
882  return 0;
883}
884
885#ifndef ONLY_C
886long vorbis_book_decodevv_add(codebook *book,ogg_int32_t **a,
887			      long offset,int ch,
888			      oggpack_buffer *b,int n,int point);
889#else
890long vorbis_book_decodevv_add(codebook *book,ogg_int32_t **a,
891			      long offset,int ch,
892			      oggpack_buffer *b,int n,int point){
893  if(book->used_entries>0){
894
895    ogg_int32_t *v = book->dec_buf;//(ogg_int32_t *)alloca(sizeof(*v)*book->dim);
896    long i,j;
897    int chptr=0;
898
899    if (!v) return -1;
900    for(i=offset;i<offset+n;){
901      if(decode_map(book,b,v,point))return -1;
902      for (j=0;j<book->dim;j++){
903	a[chptr++][i]+=v[j];
904	if(chptr==ch){
905	  chptr=0;
906	  i++;
907	}
908      }
909    }
910  }
911
912  return 0;
913}
914#endif
915