make some tables const
[ffmpeg.git] / libavcodec / vorbis.c
1 /**
2  * @file vorbis.c
3  * Vorbis I decoder
4  * @author Denes Balatoni  ( dbalatoni programozo hu )
5
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  *
20  */
21
22 #undef V_DEBUG
23 //#define V_DEBUG
24 //#define AV_DEBUG(...) av_log(NULL, AV_LOG_INFO, __VA_ARGS__)
25
26 #include <math.h>
27
28 #define ALT_BITSTREAM_READER_LE
29 #include "avcodec.h"
30 #include "bitstream.h"
31 #include "dsputil.h"
32
33 #include "vorbis.h"
34
35 #define V_NB_BITS 8
36 #define V_NB_BITS2 11
37 #define V_MAX_VLCS (1<<16)
38
39 #ifndef V_DEBUG
40 #define AV_DEBUG(...)
41 #endif
42
43 #undef NDEBUG
44 #include <assert.h>
45
46 /* Helper functions */
47
48 /**
49  *  reads 0-32 bits when using the ALT_BITSTREAM_READER_LE bitstream reader
50  */
51 static unsigned int get_bits_long_le(GetBitContext *s, int n){
52     if(n<=17) return get_bits(s, n);
53     else{
54         int ret= get_bits(s, 16);
55         return ret | (get_bits(s, n-16) << 16);
56     }
57 }
58
59 #define ilog(i) av_log2(2*(i))
60
61 #define BARK(x) \
62     (13.1f*atan(0.00074f*(x))+2.24f*atan(1.85e-8f*(x)*(x))+1e-4f*(x))
63
64 static unsigned int nth_root(unsigned int x, unsigned int n) {   // x^(1/n)
65     unsigned int ret=0, i, j;
66
67     do {
68         ++ret;
69         for(i=0,j=ret;i<n-1;i++) j*=ret;
70     } while (j<=x);
71
72     return (ret-1);
73 }
74
75 static float vorbisfloat2float(uint_fast32_t val) {
76     double mant=val&0x1fffff;
77     long exp=(val&0x7fe00000L)>>21;
78     if (val&0x80000000) mant=-mant;
79     return(ldexp(mant, exp-20-768));
80 }
81
82
83 // Generate vlc codes from vorbis huffman code lengths
84
85 static int vorbis_len2vlc(vorbis_context *vc, uint_fast8_t *bits, uint_fast32_t *codes, uint_fast32_t num) {
86     uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
87         0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
88
89     uint_fast8_t i,j;
90     uint_fast32_t code,p;
91
92 #ifdef V_DEBUG
93     GetBitContext gb;
94 #endif
95
96     for(p=0;(bits[p]==0) && (p<num);++p);
97     if (p==num) {
98 //        av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
99         return 0;
100     }
101
102     codes[p]=0;
103     for(i=0;i<bits[p];++i) {
104         exit_at_level[i+1]=1<<i;
105     }
106
107 #ifdef V_DEBUG
108     av_log(vc->avccontext, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]);
109     init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
110     for(i=0;i<bits[p];++i) {
111         av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
112     }
113     av_log(vc->avccontext, AV_LOG_INFO, "\n");
114 #endif
115
116     ++p;
117
118     for(;p<num;++p) {
119         if (bits[p]==0) continue;
120         // find corresponding exit(node which the tree can grow further from)
121         for(i=bits[p];i>0;--i) {
122             if (exit_at_level[i]) break;
123         }
124         if (!i) return 1; // overspecified tree
125         code=exit_at_level[i];
126         exit_at_level[i]=0;
127         // construct code (append 0s to end) and introduce new exits
128         for(j=i+1;j<=bits[p];++j) {
129             exit_at_level[j]=code+(1<<(j-1));
130         }
131         codes[p]=code;
132
133 #ifdef V_DEBUG
134         av_log(vc->avccontext, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
135         init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
136         for(i=0;i<bits[p];++i) {
137             av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
138         }
139         av_log(vc->avccontext, AV_LOG_INFO, "\n");
140 #endif
141
142     }
143
144     //FIXME no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
145
146     return 0;
147 }
148
149 // Free all allocated memory -----------------------------------------
150
151 static void vorbis_free(vorbis_context *vc) {
152     int_fast16_t i;
153
154     av_freep(&vc->channel_residues);
155     av_freep(&vc->channel_floors);
156     av_freep(&vc->saved);
157     av_freep(&vc->ret);
158     av_freep(&vc->buf);
159     av_freep(&vc->buf_tmp);
160
161     av_freep(&vc->residues);
162     av_freep(&vc->modes);
163
164     ff_mdct_end(&vc->mdct0);
165     ff_mdct_end(&vc->mdct1);
166
167     for(i=0;i<vc->codebook_count;++i) {
168         av_free(vc->codebooks[i].codevectors);
169         free_vlc(&vc->codebooks[i].vlc);
170     }
171     av_freep(&vc->codebooks);
172
173     for(i=0;i<vc->floor_count;++i) {
174         if(vc->floors[i].floor_type==0) {
175             av_free(vc->floors[i].data.t0.map[0]);
176             av_free(vc->floors[i].data.t0.map[1]);
177             av_free(vc->floors[i].data.t0.book_list);
178             av_free(vc->floors[i].data.t0.lsp);
179         }
180         else {
181             av_free(vc->floors[i].data.t1.x_list);
182             av_free(vc->floors[i].data.t1.x_list_order);
183             av_free(vc->floors[i].data.t1.low_neighbour);
184             av_free(vc->floors[i].data.t1.high_neighbour);
185         }
186     }
187     av_freep(&vc->floors);
188
189     for(i=0;i<vc->mapping_count;++i) {
190         av_free(vc->mappings[i].magnitude);
191         av_free(vc->mappings[i].angle);
192         av_free(vc->mappings[i].mux);
193     }
194     av_freep(&vc->mappings);
195 }
196
197 // Parse setup header -------------------------------------------------
198
199 // Process codebooks part
200
201 static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
202     uint_fast16_t cb;
203     uint_fast8_t *tmp_vlc_bits;
204     uint_fast32_t *tmp_vlc_codes;
205     GetBitContext *gb=&vc->gb;
206
207     vc->codebook_count=get_bits(gb,8)+1;
208
209     AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);
210
211     vc->codebooks=(vorbis_codebook *)av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
212     tmp_vlc_bits=(uint_fast8_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast8_t));
213     tmp_vlc_codes=(uint_fast32_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast32_t));
214
215     for(cb=0;cb<vc->codebook_count;++cb) {
216         vorbis_codebook *codebook_setup=&vc->codebooks[cb];
217         uint_fast8_t ordered;
218         uint_fast32_t t, used_entries=0;
219         uint_fast32_t entries;
220
221         AV_DEBUG(" %d. Codebook \n", cb);
222
223         if (get_bits(gb, 24)!=0x564342) {
224             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook setup data corrupt. \n", cb);
225             goto error;
226         }
227
228         codebook_setup->dimensions=get_bits(gb, 16);
229         if (codebook_setup->dimensions>16) {
230             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook's dimension is too large (%d). \n", cb, codebook_setup->dimensions);
231             goto error;
232         }
233         entries=get_bits(gb, 24);
234         if (entries>V_MAX_VLCS) {
235             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook has too many entries (%"PRIdFAST32"). \n", cb, entries);
236             goto error;
237         }
238
239         ordered=get_bits1(gb);
240
241         AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);
242
243         if (!ordered) {
244             uint_fast16_t ce;
245             uint_fast8_t flag;
246             uint_fast8_t sparse=get_bits1(gb);
247
248             AV_DEBUG(" not ordered \n");
249
250             if (sparse) {
251                 AV_DEBUG(" sparse \n");
252
253                 used_entries=0;
254                 for(ce=0;ce<entries;++ce) {
255                     flag=get_bits1(gb);
256                     if (flag) {
257                         tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
258                         ++used_entries;
259                     }
260                     else tmp_vlc_bits[ce]=0;
261                 }
262             } else {
263                 AV_DEBUG(" not sparse \n");
264
265                 used_entries=entries;
266                 for(ce=0;ce<entries;++ce) {
267                     tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
268                 }
269             }
270         } else {
271             uint_fast16_t current_entry=0;
272             uint_fast8_t current_length=get_bits(gb, 5)+1;
273
274             AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME
275
276             used_entries=entries;
277             for(;current_entry<used_entries;++current_length) {
278                 uint_fast16_t i, number;
279
280                 AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));
281
282                 number=get_bits(gb, ilog(entries - current_entry));
283
284                 AV_DEBUG(" number: %d \n", number);
285
286                 for(i=current_entry;i<number+current_entry;++i) {
287                     if (i<used_entries) tmp_vlc_bits[i]=current_length;
288                 }
289
290                 current_entry+=number;
291             }
292             if (current_entry>used_entries) {
293                 av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
294                 goto error;
295             }
296         }
297
298         codebook_setup->lookup_type=get_bits(gb, 4);
299
300         AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup" );
301
302 // If the codebook is used for (inverse) VQ, calculate codevectors.
303
304         if (codebook_setup->lookup_type==1) {
305             uint_fast16_t i, j, k;
306             uint_fast16_t codebook_lookup_values=nth_root(entries, codebook_setup->dimensions);
307             uint_fast16_t codebook_multiplicands[codebook_lookup_values];
308
309             float codebook_minimum_value=vorbisfloat2float(get_bits_long_le(gb, 32));
310             float codebook_delta_value=vorbisfloat2float(get_bits_long_le(gb, 32));
311             uint_fast8_t codebook_value_bits=get_bits(gb, 4)+1;
312             uint_fast8_t codebook_sequence_p=get_bits1(gb);
313
314             AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
315             AV_DEBUG("  delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);
316
317             for(i=0;i<codebook_lookup_values;++i) {
318                 codebook_multiplicands[i]=get_bits(gb, codebook_value_bits);
319
320                 AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
321                 AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
322             }
323
324 // Weed out unused vlcs and build codevector vector
325             codebook_setup->codevectors=(float *)av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float));
326             for(j=0, i=0;i<entries;++i) {
327                 uint_fast8_t dim=codebook_setup->dimensions;
328
329                 if (tmp_vlc_bits[i]) {
330                     float last=0.0;
331                     uint_fast32_t lookup_offset=i;
332
333 #ifdef V_DEBUG
334                     av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
335 #endif
336
337                     for(k=0;k<dim;++k) {
338                         uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
339                         codebook_setup->codevectors[j*dim+k]=codebook_multiplicands[multiplicand_offset]*codebook_delta_value+codebook_minimum_value+last;
340                         if (codebook_sequence_p) {
341                             last=codebook_setup->codevectors[j*dim+k];
342                         }
343                         lookup_offset/=codebook_lookup_values;
344                     }
345                     tmp_vlc_bits[j]=tmp_vlc_bits[i];
346
347 #ifdef V_DEBUG
348                     av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
349                     for(k=0;k<dim;++k) {
350                         av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j*dim+k]);
351                     }
352                     av_log(vc->avccontext, AV_LOG_INFO, "\n");
353 #endif
354
355                     ++j;
356                 }
357             }
358             if (j!=used_entries) {
359                 av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
360                 goto error;
361             }
362             entries=used_entries;
363         }
364         else if (codebook_setup->lookup_type>=2) {
365             av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
366             goto error;
367         }
368
369 // Initialize VLC table
370         if (vorbis_len2vlc(vc, tmp_vlc_bits, tmp_vlc_codes, entries)) {
371             av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
372             goto error;
373         }
374         codebook_setup->maxdepth=0;
375         for(t=0;t<entries;++t)
376             if (tmp_vlc_bits[t]>=codebook_setup->maxdepth) codebook_setup->maxdepth=tmp_vlc_bits[t];
377
378         if(codebook_setup->maxdepth > 3*V_NB_BITS) codebook_setup->nb_bits=V_NB_BITS2;
379         else                                       codebook_setup->nb_bits=V_NB_BITS;
380
381         codebook_setup->maxdepth=(codebook_setup->maxdepth+codebook_setup->nb_bits-1)/codebook_setup->nb_bits;
382
383         if (init_vlc(&codebook_setup->vlc, codebook_setup->nb_bits, entries, tmp_vlc_bits, sizeof(*tmp_vlc_bits), sizeof(*tmp_vlc_bits), tmp_vlc_codes, sizeof(*tmp_vlc_codes), sizeof(*tmp_vlc_codes), INIT_VLC_LE)) {
384             av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
385             goto error;
386         }
387     }
388
389     av_free(tmp_vlc_bits);
390     av_free(tmp_vlc_codes);
391     return 0;
392
393 // Error:
394 error:
395     av_free(tmp_vlc_bits);
396     av_free(tmp_vlc_codes);
397     return 1;
398 }
399
400 // Process time domain transforms part (unused in Vorbis I)
401
402 static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc) {
403     GetBitContext *gb=&vc->gb;
404     uint_fast8_t i;
405     uint_fast8_t vorbis_time_count=get_bits(gb, 6)+1;
406
407     for(i=0;i<vorbis_time_count;++i) {
408         uint_fast16_t vorbis_tdtransform=get_bits(gb, 16);
409
410         AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);
411
412         if (vorbis_tdtransform) {
413             av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
414             return 1;
415         }
416     }
417     return 0;
418 }
419
420 // Process floors part
421
422 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
423                                          vorbis_floor_data *vfu, float *vec);
424 static void create_map( vorbis_context * vc, uint_fast8_t floor_number );
425 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc,
426                                          vorbis_floor_data *vfu, float *vec);
427 static int vorbis_parse_setup_hdr_floors(vorbis_context *vc) {
428     GetBitContext *gb=&vc->gb;
429     uint_fast16_t i,j,k;
430
431     vc->floor_count=get_bits(gb, 6)+1;
432
433     vc->floors=(vorbis_floor *)av_mallocz(vc->floor_count * sizeof(vorbis_floor));
434
435     for (i=0;i<vc->floor_count;++i) {
436         vorbis_floor *floor_setup=&vc->floors[i];
437
438         floor_setup->floor_type=get_bits(gb, 16);
439
440         AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);
441
442         if (floor_setup->floor_type==1) {
443             uint_fast8_t maximum_class=0;
444             uint_fast8_t rangebits;
445             uint_fast16_t floor1_values=2;
446
447             floor_setup->decode=vorbis_floor1_decode;
448
449             floor_setup->data.t1.partitions=get_bits(gb, 5);
450
451             AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->data.t1.partitions);
452
453             for(j=0;j<floor_setup->data.t1.partitions;++j) {
454                 floor_setup->data.t1.partition_class[j]=get_bits(gb, 4);
455                 if (floor_setup->data.t1.partition_class[j]>maximum_class) maximum_class=floor_setup->data.t1.partition_class[j];
456
457                 AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->data.t1.partition_class[j]);
458
459             }
460
461             AV_DEBUG(" maximum class %d \n", maximum_class);
462
463             floor_setup->data.t1.maximum_class=maximum_class;
464
465             for(j=0;j<=maximum_class;++j) {
466                 floor_setup->data.t1.class_dimensions[j]=get_bits(gb, 3)+1;
467                 floor_setup->data.t1.class_subclasses[j]=get_bits(gb, 2);
468
469                 AV_DEBUG(" %d floor %d class dim: %d subclasses %d \n", i, j, floor_setup->data.t1.class_dimensions[j], floor_setup->data.t1.class_subclasses[j]);
470
471                 if (floor_setup->data.t1.class_subclasses[j]) {
472                     floor_setup->data.t1.class_masterbook[j]=get_bits(gb, 8);
473
474                     AV_DEBUG("   masterbook: %d \n", floor_setup->data.t1.class_masterbook[j]);
475                 }
476
477                 for(k=0;k<(1<<floor_setup->data.t1.class_subclasses[j]);++k) {
478                     floor_setup->data.t1.subclass_books[j][k]=(int16_t)get_bits(gb, 8)-1;
479
480                     AV_DEBUG("    book %d. : %d \n", k, floor_setup->data.t1.subclass_books[j][k]);
481                 }
482             }
483
484             floor_setup->data.t1.multiplier=get_bits(gb, 2)+1;
485             floor_setup->data.t1.x_list_dim=2;
486
487             for(j=0;j<floor_setup->data.t1.partitions;++j) {
488                 floor_setup->data.t1.x_list_dim+=floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];
489             }
490
491             floor_setup->data.t1.x_list=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
492             floor_setup->data.t1.x_list_order=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
493             floor_setup->data.t1.low_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
494             floor_setup->data.t1.high_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
495
496
497             rangebits=get_bits(gb, 4);
498             floor_setup->data.t1.x_list[0] = 0;
499             floor_setup->data.t1.x_list[1] = (1<<rangebits);
500
501             for(j=0;j<floor_setup->data.t1.partitions;++j) {
502                 for(k=0;k<floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];++k,++floor1_values) {
503                     floor_setup->data.t1.x_list[floor1_values]=get_bits(gb, rangebits);
504
505                     AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->data.t1.x_list[floor1_values]);
506                 }
507             }
508
509 // Precalculate order of x coordinates - needed for decode
510
511             for(k=0;k<floor_setup->data.t1.x_list_dim;++k) {
512                 floor_setup->data.t1.x_list_order[k]=k;
513             }
514
515             for(k=0;k<floor_setup->data.t1.x_list_dim-1;++k) {   // FIXME optimize sorting ?
516                 for(j=k+1;j<floor_setup->data.t1.x_list_dim;++j) {
517                     if(floor_setup->data.t1.x_list[floor_setup->data.t1.x_list_order[k]]>floor_setup->data.t1.x_list[floor_setup->data.t1.x_list_order[j]]) {
518                         uint_fast16_t tmp=floor_setup->data.t1.x_list_order[k];
519                         floor_setup->data.t1.x_list_order[k]=floor_setup->data.t1.x_list_order[j];
520                         floor_setup->data.t1.x_list_order[j]=tmp;
521                     }
522                 }
523             }
524
525 // Precalculate low and high neighbours
526
527             for(k=2;k<floor_setup->data.t1.x_list_dim;++k) {
528                 floor_setup->data.t1.low_neighbour[k]=0;
529                 floor_setup->data.t1.high_neighbour[k]=1;  // correct according to SPEC requirements
530
531                 for (j=0;j<k;++j) {
532                     if ((floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[k]) &&
533                       (floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[floor_setup->data.t1.low_neighbour[k]])) {
534                         floor_setup->data.t1.low_neighbour[k]=j;
535                     }
536                     if ((floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[k]) &&
537                       (floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[floor_setup->data.t1.high_neighbour[k]])) {
538                         floor_setup->data.t1.high_neighbour[k]=j;
539                     }
540                 }
541             }
542         }
543         else if(floor_setup->floor_type==0) {
544             uint_fast8_t max_codebook_dim=0;
545
546             floor_setup->decode=vorbis_floor0_decode;
547
548             floor_setup->data.t0.order=get_bits(gb, 8);
549             floor_setup->data.t0.rate=get_bits(gb, 16);
550             floor_setup->data.t0.bark_map_size=get_bits(gb, 16);
551             floor_setup->data.t0.amplitude_bits=get_bits(gb, 6);
552             /* zero would result in a div by zero later *
553              * 2^0 - 1 == 0                             */
554             if (floor_setup->data.t0.amplitude_bits == 0) {
555               av_log(vc->avccontext, AV_LOG_ERROR,
556                      "Floor 0 amplitude bits is 0.\n");
557               return 1;
558             }
559             floor_setup->data.t0.amplitude_offset=get_bits(gb, 8);
560             floor_setup->data.t0.num_books=get_bits(gb, 4)+1;
561
562             /* allocate mem for booklist */
563             floor_setup->data.t0.book_list=
564                 av_malloc(floor_setup->data.t0.num_books);
565             if(!floor_setup->data.t0.book_list) { return 1; }
566             /* read book indexes */
567             {
568                 int idx;
569                 uint_fast8_t book_idx;
570                 for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
571                     book_idx=get_bits(gb, 8);
572                     floor_setup->data.t0.book_list[idx]=book_idx;
573                     if (vc->codebooks[book_idx].dimensions > max_codebook_dim)
574                         max_codebook_dim=vc->codebooks[book_idx].dimensions;
575
576                     if (floor_setup->data.t0.book_list[idx]>vc->codebook_count)
577                         return 1;
578                 }
579             }
580
581             create_map( vc, i );
582
583             /* allocate mem for lsp coefficients */
584             {
585                 /* codebook dim is for padding if codebook dim doesn't *
586                  * divide order+1 then we need to read more data       */
587                 floor_setup->data.t0.lsp=
588                     av_malloc((floor_setup->data.t0.order+1 + max_codebook_dim)
589                               * sizeof(float));
590                 if(!floor_setup->data.t0.lsp) { return 1; }
591             }
592
593 #ifdef V_DEBUG /* debug output parsed headers */
594             AV_DEBUG("floor0 order: %u\n", floor_setup->data.t0.order);
595             AV_DEBUG("floor0 rate: %u\n", floor_setup->data.t0.rate);
596             AV_DEBUG("floor0 bark map size: %u\n",
597               floor_setup->data.t0.bark_map_size);
598             AV_DEBUG("floor0 amplitude bits: %u\n",
599               floor_setup->data.t0.amplitude_bits);
600             AV_DEBUG("floor0 amplitude offset: %u\n",
601               floor_setup->data.t0.amplitude_offset);
602             AV_DEBUG("floor0 number of books: %u\n",
603               floor_setup->data.t0.num_books);
604             AV_DEBUG("floor0 book list pointer: %p\n",
605               floor_setup->data.t0.book_list);
606             {
607               int idx;
608               for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
609                 AV_DEBUG( "  Book %d: %u\n",
610                   idx+1,
611                   floor_setup->data.t0.book_list[idx] );
612               }
613             }
614 #endif
615         }
616         else {
617             av_log(vc->avccontext, AV_LOG_ERROR, "Invalid floor type!\n");
618             return 1;
619         }
620     }
621     return 0;
622 }
623
624 // Process residues part
625
626 static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
627     GetBitContext *gb=&vc->gb;
628     uint_fast8_t i, j, k;
629
630     vc->residue_count=get_bits(gb, 6)+1;
631     vc->residues=(vorbis_residue *)av_mallocz(vc->residue_count * sizeof(vorbis_residue));
632
633     AV_DEBUG(" There are %d residues. \n", vc->residue_count);
634
635     for(i=0;i<vc->residue_count;++i) {
636         vorbis_residue *res_setup=&vc->residues[i];
637         uint_fast8_t cascade[64];
638         uint_fast8_t high_bits;
639         uint_fast8_t low_bits;
640
641         res_setup->type=get_bits(gb, 16);
642
643         AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);
644
645         res_setup->begin=get_bits(gb, 24);
646         res_setup->end=get_bits(gb, 24);
647         res_setup->partition_size=get_bits(gb, 24)+1;
648         res_setup->classifications=get_bits(gb, 6)+1;
649         res_setup->classbook=get_bits(gb, 8);
650
651         AV_DEBUG("    begin %d end %d part.size %d classif.s %d classbook %d \n", res_setup->begin, res_setup->end, res_setup->partition_size,
652           res_setup->classifications, res_setup->classbook);
653
654         for(j=0;j<res_setup->classifications;++j) {
655             high_bits=0;
656             low_bits=get_bits(gb, 3);
657             if (get_bits1(gb)) {
658                 high_bits=get_bits(gb, 5);
659             }
660             cascade[j]=(high_bits<<3)+low_bits;
661
662             AV_DEBUG("     %d class casscade depth: %d \n", j, ilog(cascade[j]));
663         }
664
665         res_setup->maxpass=0;
666         for(j=0;j<res_setup->classifications;++j) {
667             for(k=0;k<8;++k) {
668                 if (cascade[j]&(1<<k)) {
669                         res_setup->books[j][k]=get_bits(gb, 8);
670
671                     AV_DEBUG("     %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);
672
673                     if (k>res_setup->maxpass) {
674                         res_setup->maxpass=k;
675                     }
676                 } else {
677                     res_setup->books[j][k]=-1;
678                 }
679             }
680         }
681     }
682     return 0;
683 }
684
685 // Process mappings part
686
687 static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc) {
688     GetBitContext *gb=&vc->gb;
689     uint_fast8_t i, j;
690
691     vc->mapping_count=get_bits(gb, 6)+1;
692     vc->mappings=(vorbis_mapping *)av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));
693
694     AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);
695
696     for(i=0;i<vc->mapping_count;++i) {
697         vorbis_mapping *mapping_setup=&vc->mappings[i];
698
699         if (get_bits(gb, 16)) {
700             av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
701             return 1;
702         }
703         if (get_bits1(gb)) {
704             mapping_setup->submaps=get_bits(gb, 4)+1;
705         } else {
706             mapping_setup->submaps=1;
707         }
708
709         if (get_bits1(gb)) {
710             mapping_setup->coupling_steps=get_bits(gb, 8)+1;
711             mapping_setup->magnitude=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
712             mapping_setup->angle=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
713             for(j=0;j<mapping_setup->coupling_steps;++j) {
714                 mapping_setup->magnitude[j]=get_bits(gb, ilog(vc->audio_channels-1));
715                 mapping_setup->angle[j]=get_bits(gb, ilog(vc->audio_channels-1));
716                 // FIXME: sanity checks
717             }
718         } else {
719             mapping_setup->coupling_steps=0;
720         }
721
722         AV_DEBUG("   %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);
723
724         if(get_bits(gb, 2)) {
725             av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
726             return 1; // following spec.
727         }
728
729         if (mapping_setup->submaps>1) {
730             mapping_setup->mux=(uint_fast8_t *)av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
731             for(j=0;j<vc->audio_channels;++j) {
732                 mapping_setup->mux[j]=get_bits(gb, 4);
733             }
734         }
735
736         for(j=0;j<mapping_setup->submaps;++j) {
737             get_bits(gb, 8); // FIXME check?
738             mapping_setup->submap_floor[j]=get_bits(gb, 8);
739             mapping_setup->submap_residue[j]=get_bits(gb, 8);
740
741             AV_DEBUG("   %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
742         }
743     }
744     return 0;
745 }
746
747 // Process modes part
748
749 static void create_map( vorbis_context * vc, uint_fast8_t floor_number )
750 {
751     vorbis_floor * floors=vc->floors;
752     vorbis_floor0 * vf;
753     int idx;
754     int_fast8_t blockflag;
755     int_fast32_t * map;
756     int_fast32_t n; //TODO: could theoretically be smaller?
757
758     for (blockflag=0;blockflag<2;++blockflag)
759     {
760     n=(blockflag ? vc->blocksize_1 : vc->blocksize_0) / 2;
761     floors[floor_number].data.t0.map[blockflag]=
762         av_malloc((n+1) * sizeof(int_fast32_t)); // n+sentinel
763
764     map=floors[floor_number].data.t0.map[blockflag];
765     vf=&floors[floor_number].data.t0;
766
767     for (idx=0; idx<n;++idx) {
768         map[idx]=floor( BARK((vf->rate*idx)/(2.0f*n)) *
769                               ((vf->bark_map_size)/
770                                BARK(vf->rate/2.0f )) );
771         if (vf->bark_map_size-1 < map[idx]) {
772             map[idx]=vf->bark_map_size-1;
773         }
774     }
775     map[n]=-1;
776     vf->map_size[blockflag]=n;
777     }
778
779 #   ifdef V_DEBUG
780     for(idx=0;idx<=n;++idx) {
781         AV_DEBUG("floor0 map: map at pos %d is %d\n",
782                  idx, map[idx]);
783     }
784 #   endif
785 }
786
787 static int vorbis_parse_setup_hdr_modes(vorbis_context *vc) {
788     GetBitContext *gb=&vc->gb;
789     uint_fast8_t i;
790
791     vc->mode_count=get_bits(gb, 6)+1;
792     vc->modes=(vorbis_mode *)av_mallocz(vc->mode_count * sizeof(vorbis_mode));
793
794     AV_DEBUG(" There are %d modes.\n", vc->mode_count);
795
796     for(i=0;i<vc->mode_count;++i) {
797         vorbis_mode *mode_setup=&vc->modes[i];
798
799         mode_setup->blockflag=get_bits(gb, 1);
800         mode_setup->windowtype=get_bits(gb, 16); //FIXME check
801         mode_setup->transformtype=get_bits(gb, 16); //FIXME check
802         mode_setup->mapping=get_bits(gb, 8); //FIXME check
803
804         AV_DEBUG(" %d mode: blockflag %d, windowtype %d, transformtype %d, mapping %d \n", i, mode_setup->blockflag, mode_setup->windowtype, mode_setup->transformtype, mode_setup->mapping);
805     }
806     return 0;
807 }
808
809 // Process the whole setup header using the functions above
810
811 static int vorbis_parse_setup_hdr(vorbis_context *vc) {
812     GetBitContext *gb=&vc->gb;
813
814     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
815     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
816     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
817         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
818         return 1;
819     }
820
821     if (vorbis_parse_setup_hdr_codebooks(vc)) {
822         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
823         return 2;
824     }
825     if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
826         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
827         return 3;
828     }
829     if (vorbis_parse_setup_hdr_floors(vc)) {
830         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
831         return 4;
832     }
833     if (vorbis_parse_setup_hdr_residues(vc)) {
834         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
835         return 5;
836     }
837     if (vorbis_parse_setup_hdr_mappings(vc)) {
838         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
839         return 6;
840     }
841     if (vorbis_parse_setup_hdr_modes(vc)) {
842         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
843         return 7;
844     }
845     if (!get_bits1(gb)) {
846         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
847         return 8; // framing flag bit unset error
848     }
849
850     return 0;
851 }
852
853 // Process the identification header
854
855 static int vorbis_parse_id_hdr(vorbis_context *vc){
856     GetBitContext *gb=&vc->gb;
857     uint_fast8_t bl0, bl1;
858     const float *vwin[8]={ vwin64, vwin128, vwin256, vwin512, vwin1024, vwin2048, vwin4096, vwin8192 };
859
860     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
861     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
862     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
863         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
864         return 1;
865     }
866
867     vc->version=get_bits_long_le(gb, 32);    //FIXME check 0
868     vc->audio_channels=get_bits(gb, 8);   //FIXME check >0
869     vc->audio_samplerate=get_bits_long_le(gb, 32);   //FIXME check >0
870     vc->bitrate_maximum=get_bits_long_le(gb, 32);
871     vc->bitrate_nominal=get_bits_long_le(gb, 32);
872     vc->bitrate_minimum=get_bits_long_le(gb, 32);
873     bl0=get_bits(gb, 4);
874     bl1=get_bits(gb, 4);
875     vc->blocksize_0=(1<<bl0);
876     vc->blocksize_1=(1<<bl1);
877     if (bl0>13 || bl0<6 || bl1>13 || bl1<6 || bl1<bl0) {
878         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
879         return 3;
880     }
881     // output format int16
882     if (vc->blocksize_1/2 * vc->audio_channels * 2 >
883                                              AVCODEC_MAX_AUDIO_FRAME_SIZE) {
884         av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis channel count makes "
885                "output packets too large.\n");
886         return 4;
887     }
888     vc->swin=vwin[bl0-6];
889     vc->lwin=vwin[bl1-6];
890
891     if ((get_bits1(gb)) == 0) {
892         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
893         return 2;
894     }
895
896     vc->channel_residues=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
897     vc->channel_floors=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
898     vc->saved=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
899     vc->ret=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
900     vc->buf=(float *)av_malloc(vc->blocksize_1 * sizeof(float));
901     vc->buf_tmp=(float *)av_malloc(vc->blocksize_1 * sizeof(float));
902     vc->saved_start=0;
903
904     ff_mdct_init(&vc->mdct0, bl0, 1);
905     ff_mdct_init(&vc->mdct1, bl1, 1);
906
907     AV_DEBUG(" vorbis version %d \n audio_channels %d \n audio_samplerate %d \n bitrate_max %d \n bitrate_nom %d \n bitrate_min %d \n blk_0 %d blk_1 %d \n ",
908             vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize_0, vc->blocksize_1);
909
910 /*
911     BLK=vc->blocksize_0;
912     for(i=0;i<BLK/2;++i) {
913         vc->swin[i]=sin(0.5*3.14159265358*(sin(((float)i+0.5)/(float)BLK*3.14159265358))*(sin(((float)i+0.5)/(float)BLK*3.14159265358)));
914     }
915 */
916
917     return 0;
918 }
919
920 // Process the extradata using the functions above (identification header, setup header)
921
922 static int vorbis_decode_init(AVCodecContext *avccontext) {
923     vorbis_context *vc = avccontext->priv_data ;
924     uint8_t *headers = avccontext->extradata;
925     int headers_len=avccontext->extradata_size;
926     uint8_t *header_start[3];
927     int header_len[3];
928     GetBitContext *gb = &(vc->gb);
929     int i, j, hdr_type;
930
931     vc->avccontext = avccontext;
932
933     if (!headers_len) {
934         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
935         return -1;
936     }
937
938     if(headers[0] == 0 && headers[1] == 30) {
939         for(i = 0; i < 3; i++){
940             header_len[i] = *headers++ << 8;
941             header_len[i] += *headers++;
942             header_start[i] = headers;
943             headers += header_len[i];
944         }
945     } else if(headers[0] == 2) {
946         for(j=1,i=0;i<2;++i, ++j) {
947             header_len[i]=0;
948             while(j<headers_len && headers[j]==0xff) {
949                 header_len[i]+=0xff;
950                 ++j;
951             }
952             if (j>=headers_len) {
953                 av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
954                 return -1;
955             }
956             header_len[i]+=headers[j];
957         }
958         header_len[2]=headers_len-header_len[0]-header_len[1]-j;
959         headers+=j;
960         header_start[0] = headers;
961         header_start[1] = header_start[0] + header_len[0];
962         header_start[2] = header_start[1] + header_len[1];
963     } else {
964         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
965         return -1;
966     }
967
968     init_get_bits(gb, header_start[0], header_len[0]*8);
969     hdr_type=get_bits(gb, 8);
970     if (hdr_type!=1) {
971         av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
972         return -1;
973     }
974     if (vorbis_parse_id_hdr(vc)) {
975         av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
976         vorbis_free(vc);
977         return -1;
978     }
979
980     init_get_bits(gb, header_start[2], header_len[2]*8);
981     hdr_type=get_bits(gb, 8);
982     if (hdr_type!=5) {
983         av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
984         return -1;
985     }
986     if (vorbis_parse_setup_hdr(vc)) {
987         av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
988         vorbis_free(vc);
989         return -1;
990     }
991
992     avccontext->channels = vc->audio_channels;
993     avccontext->sample_rate = vc->audio_samplerate;
994
995     return 0 ;
996 }
997
998 // Decode audiopackets -------------------------------------------------
999
1000 // Read and decode floor
1001
1002 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
1003                                          vorbis_floor_data *vfu, float *vec) {
1004     vorbis_floor0 * vf=&vfu->t0;
1005     float * lsp=vf->lsp;
1006     uint_fast32_t amplitude;
1007     uint_fast32_t book_idx;
1008     uint_fast8_t blockflag=vc->modes[vc->mode_number].blockflag;
1009
1010     amplitude=get_bits(&vc->gb, vf->amplitude_bits);
1011     if (amplitude>0) {
1012         float last = 0;
1013         uint_fast16_t lsp_len = 0;
1014         uint_fast16_t idx;
1015         vorbis_codebook codebook;
1016
1017         book_idx=get_bits(&vc->gb, ilog(vf->num_books));
1018         if ( book_idx >= vf->num_books ) {
1019             av_log( vc->avccontext, AV_LOG_ERROR,
1020                     "floor0 dec: booknumber too high!\n" );
1021             //FIXME: look above
1022         }
1023         AV_DEBUG( "floor0 dec: booknumber: %u\n", book_idx );
1024         codebook=vc->codebooks[vf->book_list[book_idx]];
1025
1026         while (lsp_len<vf->order) {
1027             int vec_off;
1028
1029             AV_DEBUG( "floor0 dec: book dimension: %d\n", codebook.dimensions );
1030             AV_DEBUG( "floor0 dec: maximum depth: %d\n", codebook.maxdepth );
1031             /* read temp vector */
1032             vec_off=get_vlc2(&vc->gb,
1033                              codebook.vlc.table,
1034                              codebook.nb_bits,
1035                              codebook.maxdepth ) *
1036                              codebook.dimensions;
1037             AV_DEBUG( "floor0 dec: vector offset: %d\n", vec_off );
1038             /* copy each vector component and add last to it */
1039             for (idx=0; idx<codebook.dimensions; ++idx) {
1040                 lsp[lsp_len+idx]=codebook.codevectors[vec_off+idx]+last;
1041             }
1042             last=lsp[lsp_len+idx-1]; /* set last to last vector component */
1043
1044             lsp_len += codebook.dimensions;
1045         }
1046 #ifdef V_DEBUG
1047         /* DEBUG: output lsp coeffs */
1048         {
1049             int idx;
1050             for ( idx = 0; idx < lsp_len; ++idx )
1051                 AV_DEBUG("floor0 dec: coeff at %d is %f\n", idx, lsp[idx] );
1052         }
1053 #endif
1054
1055         /* synthesize floor output vector */
1056         {
1057             int i;
1058             int order=vf->order;
1059             float wstep=M_PI/vf->bark_map_size;
1060
1061             for(i=0;i<order;i++) { lsp[i]=2.0f*cos(lsp[i]); }
1062
1063             AV_DEBUG("floor0 synth: map_size=%d; m=%d; wstep=%f\n",
1064                      vf->map_size, order, wstep);
1065
1066             i=0;
1067             while(i<vf->map_size[blockflag]) {
1068                 int j, iter_cond=vf->map[blockflag][i];
1069                 float p=0.5f;
1070                 float q=0.5f;
1071                 float two_cos_w=2.0f*cos(wstep*iter_cond); // needed all times
1072
1073                 /* similar part for the q and p products */
1074                 for(j=0;j<order;j+=2) {
1075                     q *= lsp[j]  -two_cos_w;
1076                     p *= lsp[j+1]-two_cos_w;
1077                 }
1078                 if(j==order) { // even order
1079                     p *= p*(2.0f-two_cos_w);
1080                     q *= q*(2.0f+two_cos_w);
1081                 }
1082                 else { // odd order
1083                     q *= two_cos_w-lsp[j]; // one more time for q
1084
1085                     /* final step and square */
1086                     p *= p*(4.f-two_cos_w*two_cos_w);
1087                     q *= q;
1088                 }
1089
1090                 /* calculate linear floor value */
1091                 {
1092                     q=exp( (
1093                              ( (amplitude*vf->amplitude_offset)/
1094                                (((1<<vf->amplitude_bits)-1) * sqrt(p+q)) )
1095                              - vf->amplitude_offset ) * .11512925f
1096                          );
1097                 }
1098
1099                 /* fill vector */
1100                 do { vec[i]=q; ++i; }while(vf->map[blockflag][i]==iter_cond);
1101             }
1102         }
1103     }
1104     else {
1105         /* this channel is unused */
1106         return 1;
1107     }
1108
1109     AV_DEBUG(" Floor0 decoded\n");
1110
1111     return 0;
1112 }
1113 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *vfu, float *vec) {
1114     vorbis_floor1 * vf=&vfu->t1;
1115     GetBitContext *gb=&vc->gb;
1116     uint_fast16_t range_v[4]={ 256, 128, 86, 64 };
1117     uint_fast16_t range=range_v[vf->multiplier-1];
1118     uint_fast16_t floor1_Y[vf->x_list_dim];
1119     uint_fast16_t floor1_Y_final[vf->x_list_dim];
1120     uint_fast8_t floor1_flag[vf->x_list_dim];
1121     uint_fast8_t class_;
1122     uint_fast8_t cdim;
1123     uint_fast8_t cbits;
1124     uint_fast8_t csub;
1125     uint_fast8_t cval;
1126     int_fast16_t book;
1127     uint_fast16_t offset;
1128     uint_fast16_t i,j;
1129     uint_fast16_t *floor_x_sort=vf->x_list_order;
1130     /*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx= (unsigned)dy/adx ?
1131     int_fast16_t dy, err;
1132     uint_fast16_t lx,hx, ly, hy=0;
1133
1134
1135     if (!get_bits1(gb)) return 1; // silence
1136
1137 // Read values (or differences) for the floor's points
1138
1139     floor1_Y[0]=get_bits(gb, ilog(range-1));
1140     floor1_Y[1]=get_bits(gb, ilog(range-1));
1141
1142     AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);
1143
1144     offset=2;
1145     for(i=0;i<vf->partitions;++i) {
1146         class_=vf->partition_class[i];
1147         cdim=vf->class_dimensions[class_];
1148         cbits=vf->class_subclasses[class_];
1149         csub=(1<<cbits)-1;
1150         cval=0;
1151
1152         AV_DEBUG("Cbits %d \n", cbits);
1153
1154         if (cbits) { // this reads all subclasses for this partition's class
1155             cval=get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,
1156             vc->codebooks[vf->class_masterbook[class_]].nb_bits, 3);
1157         }
1158
1159         for(j=0;j<cdim;++j) {
1160             book=vf->subclass_books[class_][cval & csub];
1161
1162             AV_DEBUG("book %d Cbits %d cval %d  bits:%d \n", book, cbits, cval, get_bits_count(gb));
1163
1164             cval=cval>>cbits;
1165             if (book>0) {
1166                 floor1_Y[offset+j]=get_vlc2(gb, vc->codebooks[book].vlc.table,
1167                 vc->codebooks[book].nb_bits, 3);
1168             } else {
1169                 floor1_Y[offset+j]=0;
1170             }
1171
1172             AV_DEBUG(" floor(%d) = %d \n", vf->x_list[offset+j], floor1_Y[offset+j]);
1173         }
1174         offset+=cdim;
1175     }
1176
1177 // Amplitude calculation from the differences
1178
1179     floor1_flag[0]=1;
1180     floor1_flag[1]=1;
1181     floor1_Y_final[0]=floor1_Y[0];
1182     floor1_Y_final[1]=floor1_Y[1];
1183
1184     for(i=2;i<vf->x_list_dim;++i) {
1185         uint_fast16_t val, highroom, lowroom, room;
1186         uint_fast16_t high_neigh_offs;
1187         uint_fast16_t low_neigh_offs;
1188
1189         low_neigh_offs=vf->low_neighbour[i];
1190         high_neigh_offs=vf->high_neighbour[i];
1191         dy=floor1_Y_final[high_neigh_offs]-floor1_Y_final[low_neigh_offs];  // render_point begin
1192         adx=vf->x_list[high_neigh_offs]-vf->x_list[low_neigh_offs];
1193         ady= ABS(dy);
1194         err=ady*(vf->x_list[i]-vf->x_list[low_neigh_offs]);
1195         off=err/adx;
1196         if (dy<0) {
1197             predicted=floor1_Y_final[low_neigh_offs]-off;
1198         } else {
1199             predicted=floor1_Y_final[low_neigh_offs]+off;
1200         } // render_point end
1201
1202         val=floor1_Y[i];
1203         highroom=range-predicted;
1204         lowroom=predicted;
1205         if (highroom < lowroom) {
1206             room=highroom*2;
1207         } else {
1208             room=lowroom*2;   // SPEC mispelling
1209         }
1210         if (val) {
1211             floor1_flag[low_neigh_offs]=1;
1212             floor1_flag[high_neigh_offs]=1;
1213             floor1_flag[i]=1;
1214             if (val>=room) {
1215                 if (highroom > lowroom) {
1216                     floor1_Y_final[i]=val-lowroom+predicted;
1217                 } else {
1218                     floor1_Y_final[i]=predicted-val+highroom-1;
1219                 }
1220             } else {
1221                 if (val & 1) {
1222                     floor1_Y_final[i]=predicted-(val+1)/2;
1223                 } else {
1224                     floor1_Y_final[i]=predicted+val/2;
1225                 }
1226             }
1227         } else {
1228             floor1_flag[i]=0;
1229             floor1_Y_final[i]=predicted;
1230         }
1231
1232         AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->x_list[i], floor1_Y_final[i], val);
1233     }
1234
1235 // Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?
1236
1237     hx=0;
1238     lx=0;
1239     ly=floor1_Y_final[0]*vf->multiplier;  // conforms to SPEC
1240
1241     vec[0]=floor1_inverse_db_table[ly];
1242
1243     for(i=1;i<vf->x_list_dim;++i) {
1244         AV_DEBUG(" Looking at post %d \n", i);
1245
1246         if (floor1_flag[floor_x_sort[i]]) {   // SPEC mispelled
1247             int_fast16_t x, y, dy, base, sy; // if uncommented: dy = -32 adx = 2  base = 2blablabla ?????
1248
1249             hy=floor1_Y_final[floor_x_sort[i]]*vf->multiplier;
1250             hx=vf->x_list[floor_x_sort[i]];
1251
1252             dy=hy-ly;
1253             adx=hx-lx;
1254             ady= (dy<0) ? -dy:dy;//ABS(dy);
1255             base=dy/adx;
1256
1257             AV_DEBUG(" dy %d  adx %d base %d = %d \n", dy, adx, base, dy/adx);
1258
1259             x=lx;
1260             y=ly;
1261             err=0;
1262             if (dy<0) {
1263                 sy=base-1;
1264             } else {
1265                 sy=base+1;
1266             }
1267             ady=ady-(base<0 ? -base : base)*adx;
1268             vec[x]=floor1_inverse_db_table[y];
1269
1270             AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1271
1272             for(x=lx+1;(x<hx) && (x<vf->x_list[1]);++x) {
1273                 err+=ady;
1274                 if (err>=adx) {
1275                     err-=adx;
1276                     y+=sy;
1277                 } else {
1278                     y+=base;
1279                 }
1280                 vec[x]=floor1_inverse_db_table[y];
1281
1282                 AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1283             }
1284
1285 /*            for(j=1;j<hx-lx+1;++j) {  // iterating render_point
1286                 dy=hy-ly;
1287                 adx=hx-lx;
1288                 ady= dy<0 ? -dy : dy;
1289                 err=ady*j;
1290                 off=err/adx;
1291                 if (dy<0) {
1292                     predicted=ly-off;
1293                 } else {
1294                     predicted=ly+off;
1295                 }
1296                 if (lx+j < vf->x_list[1]) {
1297                     vec[lx+j]=floor1_inverse_db_table[predicted];
1298                 }
1299             }*/
1300
1301             lx=hx;
1302             ly=hy;
1303         }
1304     }
1305
1306     if (hx<vf->x_list[1]) {
1307         for(i=hx;i<vf->x_list[1];++i) {
1308             vec[i]=floor1_inverse_db_table[hy];
1309         }
1310     }
1311
1312     AV_DEBUG(" Floor decoded\n");
1313
1314     return 0;
1315 }
1316
1317 // Read and decode residue
1318
1319 static int vorbis_residue_decode(vorbis_context *vc, vorbis_residue *vr, uint_fast8_t ch, uint_fast8_t *do_not_decode, float *vec, uint_fast16_t vlen) {
1320     GetBitContext *gb=&vc->gb;
1321     uint_fast8_t c_p_c=vc->codebooks[vr->classbook].dimensions;
1322     uint_fast16_t n_to_read=vr->end-vr->begin;
1323     uint_fast16_t ptns_to_read=n_to_read/vr->partition_size;
1324     uint_fast8_t classifs[ptns_to_read*vc->audio_channels];
1325     uint_fast8_t pass;
1326     uint_fast8_t ch_used;
1327     uint_fast8_t i,j,l;
1328     uint_fast16_t k;
1329
1330     if (vr->type==2) {
1331         for(j=1;j<ch;++j) {
1332                 do_not_decode[0]&=do_not_decode[j];  // FIXME - clobbering input
1333         }
1334         if (do_not_decode[0]) return 0;
1335         ch_used=1;
1336     } else {
1337         ch_used=ch;
1338     }
1339
1340     AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d  cpc %d  \n", ch, c_p_c);
1341
1342     for(pass=0;pass<=vr->maxpass;++pass) { // FIXME OPTIMIZE?
1343         uint_fast16_t voffset;
1344         uint_fast16_t partition_count;
1345         uint_fast16_t j_times_ptns_to_read;
1346
1347         voffset=vr->begin;
1348         for(partition_count=0;partition_count<ptns_to_read;) {  // SPEC        error
1349             if (!pass) {
1350                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1351                     if (!do_not_decode[j]) {
1352                         uint_fast32_t temp=get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,
1353                         vc->codebooks[vr->classbook].nb_bits, 3);
1354
1355                         AV_DEBUG("Classword: %d \n", temp);
1356
1357                         assert(vr->classifications > 1 && temp<=65536); //needed for inverse[]
1358                         for(i=0;i<c_p_c;++i) {
1359                             uint_fast32_t temp2;
1360
1361                             temp2=(((uint_fast64_t)temp) * inverse[vr->classifications])>>32;
1362                             if (partition_count+c_p_c-1-i < ptns_to_read) {
1363                                 classifs[j_times_ptns_to_read+partition_count+c_p_c-1-i]=temp-temp2*vr->classifications;
1364                             }
1365                             temp=temp2;
1366                         }
1367                     }
1368                     j_times_ptns_to_read+=ptns_to_read;
1369                 }
1370             }
1371             for(i=0;(i<c_p_c) && (partition_count<ptns_to_read);++i) {
1372                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1373                     uint_fast16_t voffs;
1374
1375                     if (!do_not_decode[j]) {
1376                         uint_fast8_t vqclass=classifs[j_times_ptns_to_read+partition_count];
1377                         int_fast16_t vqbook=vr->books[vqclass][pass];
1378
1379                         if (vqbook>=0) {
1380                             uint_fast16_t coffs;
1381                             uint_fast16_t step=vr->partition_size/vc->codebooks[vqbook].dimensions;
1382                             vorbis_codebook codebook= vc->codebooks[vqbook];
1383
1384                             if (vr->type==0) {
1385
1386                                 voffs=voffset+j*vlen;
1387                                 for(k=0;k<step;++k) {
1388                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1389                                     for(l=0;l<codebook.dimensions;++l) {
1390                                         vec[voffs+k+l*step]+=codebook.codevectors[coffs+l];  // FPMATH
1391                                     }
1392                                 }
1393                             }
1394                             else if (vr->type==1) {
1395                                 voffs=voffset+j*vlen;
1396                                 for(k=0;k<step;++k) {
1397                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1398                                     for(l=0;l<codebook.dimensions;++l, ++voffs) {
1399                                         vec[voffs]+=codebook.codevectors[coffs+l];  // FPMATH
1400
1401                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d  \n", pass, voffs, vec[voffs], codebook.codevectors[coffs+l], coffs);
1402                                     }
1403                                 }
1404                             }
1405                             else if (vr->type==2 && ch==2 && (voffset&1)==0 && (codebook.dimensions&1)==0) { // most frequent case optimized
1406                                 voffs=voffset>>1;
1407
1408                                 for(k=0;k<step;++k) {
1409                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1410                                     for(l=0;l<codebook.dimensions;l+=2, voffs++) {
1411                                         vec[voffs     ]+=codebook.codevectors[coffs+l  ];  // FPMATH
1412                                         vec[voffs+vlen]+=codebook.codevectors[coffs+l+1];  // FPMATH
1413
1414                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d+%d  \n", pass, voffset/ch+(voffs%ch)*vlen, vec[voffset/ch+(voffs%ch)*vlen], codebook.codevectors[coffs+l], coffs, l);
1415                                     }
1416                                 }
1417
1418                             }
1419                             else if (vr->type==2) {
1420                                 voffs=voffset;
1421
1422                                 for(k=0;k<step;++k) {
1423                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1424                                     for(l=0;l<codebook.dimensions;++l, ++voffs) {
1425                                         vec[voffs/ch+(voffs%ch)*vlen]+=codebook.codevectors[coffs+l];  // FPMATH FIXME use if and counter instead of / and %
1426
1427                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d+%d  \n", pass, voffset/ch+(voffs%ch)*vlen, vec[voffset/ch+(voffs%ch)*vlen], codebook.codevectors[coffs+l], coffs, l);
1428                                     }
1429                                 }
1430                             } else {
1431                                 av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n");
1432                                 return 1;
1433                             }
1434                         }
1435                     }
1436                     j_times_ptns_to_read+=ptns_to_read;
1437                 }
1438                 ++partition_count;
1439                 voffset+=vr->partition_size;
1440             }
1441         }
1442     }
1443     return 0;
1444 }
1445
1446 // Decode the audio packet using the functions above
1447 #define BIAS 385
1448
1449 static int vorbis_parse_audio_packet(vorbis_context *vc) {
1450     GetBitContext *gb=&vc->gb;
1451
1452     uint_fast8_t previous_window=0,next_window=0;
1453     uint_fast8_t mode_number;
1454     uint_fast16_t blocksize;
1455     int_fast32_t i,j;
1456     uint_fast8_t no_residue[vc->audio_channels];
1457     uint_fast8_t do_not_decode[vc->audio_channels];
1458     vorbis_mapping *mapping;
1459     float *ch_res_ptr=vc->channel_residues;
1460     float *ch_floor_ptr=vc->channel_floors;
1461     uint_fast8_t res_chan[vc->audio_channels];
1462     uint_fast8_t res_num=0;
1463     int_fast16_t retlen=0;
1464     uint_fast16_t saved_start=0;
1465
1466     if (get_bits1(gb)) {
1467         av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n");
1468         return -1; // packet type not audio
1469     }
1470
1471     if (vc->mode_count==1) {
1472         mode_number=0;
1473     } else {
1474         mode_number=get_bits(gb, ilog(vc->mode_count-1));
1475     }
1476     vc->mode_number=mode_number;
1477     mapping=&vc->mappings[vc->modes[mode_number].mapping];
1478
1479     AV_DEBUG(" Mode number: %d , mapping: %d , blocktype %d \n", mode_number, vc->modes[mode_number].mapping, vc->modes[mode_number].blockflag);
1480
1481     if (vc->modes[mode_number].blockflag) {
1482         previous_window=get_bits1(gb);
1483         next_window=get_bits1(gb);
1484     }
1485
1486     blocksize=vc->modes[mode_number].blockflag ? vc->blocksize_1 : vc->blocksize_0;
1487     memset(ch_res_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1488     memset(ch_floor_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1489
1490 // Decode floor
1491
1492     for(i=0;i<vc->audio_channels;++i) {
1493         vorbis_floor *floor;
1494         if (mapping->submaps>1) {
1495             floor=&vc->floors[mapping->submap_floor[mapping->mux[i]]];
1496         } else {
1497             floor=&vc->floors[mapping->submap_floor[0]];
1498         }
1499
1500         no_residue[i]=floor->decode(vc, &floor->data, ch_floor_ptr);
1501         ch_floor_ptr+=blocksize/2;
1502     }
1503
1504 // Nonzero vector propagate
1505
1506     for(i=mapping->coupling_steps-1;i>=0;--i) {
1507         if (!(no_residue[mapping->magnitude[i]] & no_residue[mapping->angle[i]])) {
1508             no_residue[mapping->magnitude[i]]=0;
1509             no_residue[mapping->angle[i]]=0;
1510         }
1511     }
1512
1513 // Decode residue
1514
1515     for(i=0;i<mapping->submaps;++i) {
1516         vorbis_residue *residue;
1517         uint_fast8_t ch=0;
1518
1519         for(j=0;j<vc->audio_channels;++j) {
1520             if ((mapping->submaps==1) || (i=mapping->mux[j])) {
1521                 res_chan[j]=res_num;
1522                 if (no_residue[j]) {
1523                     do_not_decode[ch]=1;
1524                 } else {
1525                     do_not_decode[ch]=0;
1526                 }
1527                 ++ch;
1528                 ++res_num;
1529             }
1530         }
1531         residue=&vc->residues[mapping->submap_residue[i]];
1532         vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2);
1533
1534         ch_res_ptr+=ch*blocksize/2;
1535     }
1536
1537 // Inverse coupling
1538
1539     for(i=mapping->coupling_steps-1;i>=0;--i) { //warning: i has to be signed
1540         float *mag, *ang;
1541
1542         mag=vc->channel_residues+res_chan[mapping->magnitude[i]]*blocksize/2;
1543         ang=vc->channel_residues+res_chan[mapping->angle[i]]*blocksize/2;
1544         for(j=0;j<blocksize/2;++j) {
1545             float temp;
1546             if (mag[j]>0.0) {
1547                 if (ang[j]>0.0) {
1548                     ang[j]=mag[j]-ang[j];
1549                 } else {
1550                     temp=ang[j];
1551                     ang[j]=mag[j];
1552                     mag[j]+=temp;
1553                 }
1554             } else {
1555                 if (ang[j]>0.0) {
1556                     ang[j]+=mag[j];
1557                 } else {
1558                     temp=ang[j];
1559                     ang[j]=mag[j];
1560                     mag[j]-=temp;
1561                 }
1562             }
1563         }
1564     }
1565
1566 // Dotproduct
1567
1568     for(j=0, ch_floor_ptr=vc->channel_floors;j<vc->audio_channels;++j,ch_floor_ptr+=blocksize/2) {
1569         ch_res_ptr=vc->channel_residues+res_chan[j]*blocksize/2;
1570
1571         for(i=0;i<blocksize/2;++i) {
1572             ch_floor_ptr[i]*=ch_res_ptr[i]; //FPMATH
1573         }
1574     }
1575
1576 // MDCT, overlap/add, save data for next overlapping  FPMATH
1577
1578     for(j=0;j<vc->audio_channels;++j) {
1579         uint_fast8_t step=vc->audio_channels;
1580         uint_fast16_t k;
1581         float *saved=vc->saved+j*vc->blocksize_1/2;
1582         float *ret=vc->ret;
1583         const float *lwin=vc->lwin;
1584         const float *swin=vc->swin;
1585         float *buf=vc->buf;
1586         float *buf_tmp=vc->buf_tmp;
1587
1588         ch_floor_ptr=vc->channel_floors+j*blocksize/2;
1589
1590         saved_start=vc->saved_start;
1591
1592         ff_imdct_calc(vc->modes[mode_number].blockflag ? &vc->mdct1 : &vc->mdct0, buf, ch_floor_ptr, buf_tmp);
1593
1594         if (vc->modes[mode_number].blockflag) {
1595             // -- overlap/add
1596             if (previous_window) {
1597                 for(k=j, i=0;i<vc->blocksize_1/2;++i, k+=step) {
1598                     ret[k]=saved[i]+buf[i]*lwin[i]+BIAS;
1599                 }
1600                 retlen=vc->blocksize_1/2;
1601             } else {
1602                 buf += (vc->blocksize_1-vc->blocksize_0)/4;
1603                 for(k=j, i=0;i<vc->blocksize_0/2;++i, k+=step) {
1604                     ret[k]=saved[i]+buf[i]*swin[i]+BIAS;
1605                 }
1606                 buf += vc->blocksize_0/2;
1607                 for(i=0;i<(vc->blocksize_1-vc->blocksize_0)/4;++i, k+=step) {
1608                     ret[k]=buf[i]+BIAS;
1609                 }
1610                 buf=vc->buf;
1611                 retlen=vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4;
1612             }
1613             // -- save
1614             if (next_window) {
1615                 buf += vc->blocksize_1/2;
1616                 lwin += vc->blocksize_1/2-1;
1617                 for(i=0;i<vc->blocksize_1/2;++i) {
1618                     saved[i]=buf[i]*lwin[-i];
1619                 }
1620                 saved_start=0;
1621             } else {
1622                 saved_start=(vc->blocksize_1-vc->blocksize_0)/4;
1623                 buf += vc->blocksize_1/2;
1624                 for(i=0;i<saved_start;++i) {
1625                     saved[i]=buf[i];
1626                 }
1627                 swin += vc->blocksize_0/2-1;
1628                 for(i=0;i<vc->blocksize_0/2;++i) {
1629                     saved[saved_start+i]=buf[saved_start+i]*swin[-i];
1630                 }
1631             }
1632         } else {
1633             // --overlap/add
1634             for(k=j, i=0;i<saved_start;++i, k+=step) {
1635                 ret[k]=saved[i]+BIAS;
1636             }
1637             for(i=0;i<vc->blocksize_0/2;++i, k+=step) {
1638                 ret[k]=saved[saved_start+i]+buf[i]*swin[i]+BIAS;
1639             }
1640             retlen=saved_start+vc->blocksize_0/2;
1641             // -- save
1642             buf += vc->blocksize_0/2;
1643             swin += vc->blocksize_0/2-1;
1644             for(i=0;i<vc->blocksize_0/2;++i) {
1645                 saved[i]=buf[i]*swin[-i];
1646             }
1647             saved_start=0;
1648         }
1649     }
1650     vc->saved_start=saved_start;
1651
1652     return retlen*vc->audio_channels;
1653 }
1654
1655 // Return the decoded audio packet through the standard api
1656
1657 static int vorbis_decode_frame(AVCodecContext *avccontext,
1658                         void *data, int *data_size,
1659                         uint8_t *buf, int buf_size)
1660 {
1661     vorbis_context *vc = avccontext->priv_data ;
1662     GetBitContext *gb = &(vc->gb);
1663
1664     int_fast16_t i, len;
1665
1666     if(!buf_size){
1667         return 0;
1668     }
1669
1670     AV_DEBUG("packet length %d \n", buf_size);
1671
1672     init_get_bits(gb, buf, buf_size*8);
1673
1674     len=vorbis_parse_audio_packet(vc);
1675
1676     if (len<=0) {
1677         *data_size=0;
1678         return buf_size;
1679     }
1680
1681     if (!vc->first_frame) {
1682         vc->first_frame=1;
1683         *data_size=0;
1684         return buf_size ;
1685     }
1686
1687     AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
1688
1689     for(i=0;i<len;++i) {
1690         int_fast32_t tmp= ((int32_t*)vc->ret)[i];
1691         if(tmp & 0xf0000){
1692 //            tmp= (0x43c0ffff - tmp)>>31; //ask gcc devs why this is slower
1693             if(tmp > 0x43c0ffff) tmp= 0xFFFF;
1694             else                 tmp= 0;
1695         }
1696         ((int16_t*)data)[i]=tmp - 0x8000;
1697     }
1698
1699     *data_size=len*2;
1700
1701     return buf_size ;
1702 }
1703
1704 // Close decoder
1705
1706 static int vorbis_decode_close(AVCodecContext *avccontext) {
1707     vorbis_context *vc = avccontext->priv_data;
1708
1709     vorbis_free(vc);
1710
1711     return 0 ;
1712 }
1713
1714 AVCodec vorbis_decoder = {
1715     "vorbis",
1716     CODEC_TYPE_AUDIO,
1717     CODEC_ID_VORBIS,
1718     sizeof(vorbis_context),
1719     vorbis_decode_init,
1720     NULL,
1721     vorbis_decode_close,
1722     vorbis_decode_frame,
1723 };
1724