1e12272e89ef36a9f2a16c63c183262992b1c7b1
[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 #define ilog(i) av_log2(2*(i))
49
50 #define BARK(x) \
51     (13.1f*atan(0.00074f*(x))+2.24f*atan(1.85e-8f*(x)*(x))+1e-4f*(x))
52
53 static unsigned int nth_root(unsigned int x, unsigned int n) {   // x^(1/n)
54     unsigned int ret=0, i, j;
55
56     do {
57         ++ret;
58         for(i=0,j=ret;i<n-1;i++) j*=ret;
59     } while (j<=x);
60
61     return (ret-1);
62 }
63
64 static float vorbisfloat2float(uint_fast32_t val) {
65     double mant=val&0x1fffff;
66     long exp=(val&0x7fe00000L)>>21;
67     if (val&0x80000000) mant=-mant;
68     return(ldexp(mant, exp-20-768));
69 }
70
71
72 // Generate vlc codes from vorbis huffman code lengths
73
74 static int vorbis_len2vlc(vorbis_context *vc, uint_fast8_t *bits, uint_fast32_t *codes, uint_fast32_t num) {
75     uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
76         0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
77
78     uint_fast8_t i,j;
79     uint_fast32_t code,p;
80
81 #ifdef V_DEBUG
82     GetBitContext gb;
83 #endif
84
85     for(p=0;(bits[p]==0) && (p<num);++p);
86     if (p==num) {
87 //        av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
88         return 0;
89     }
90
91     codes[p]=0;
92     for(i=0;i<bits[p];++i) {
93         exit_at_level[i+1]=1<<i;
94     }
95
96 #ifdef V_DEBUG
97     av_log(vc->avccontext, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]);
98     init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
99     for(i=0;i<bits[p];++i) {
100         av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
101     }
102     av_log(vc->avccontext, AV_LOG_INFO, "\n");
103 #endif
104
105     ++p;
106
107     for(;p<num;++p) {
108         if (bits[p]==0) continue;
109         // find corresponding exit(node which the tree can grow further from)
110         for(i=bits[p];i>0;--i) {
111             if (exit_at_level[i]) break;
112         }
113         if (!i) return 1; // overspecified tree
114         code=exit_at_level[i];
115         exit_at_level[i]=0;
116         // construct code (append 0s to end) and introduce new exits
117         for(j=i+1;j<=bits[p];++j) {
118             exit_at_level[j]=code+(1<<(j-1));
119         }
120         codes[p]=code;
121
122 #ifdef V_DEBUG
123         av_log(vc->avccontext, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
124         init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
125         for(i=0;i<bits[p];++i) {
126             av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
127         }
128         av_log(vc->avccontext, AV_LOG_INFO, "\n");
129 #endif
130
131     }
132
133     //FIXME no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
134
135     return 0;
136 }
137
138 // Free all allocated memory -----------------------------------------
139
140 static void vorbis_free(vorbis_context *vc) {
141     int_fast16_t i;
142
143     av_freep(&vc->channel_residues);
144     av_freep(&vc->channel_floors);
145     av_freep(&vc->saved);
146     av_freep(&vc->ret);
147     av_freep(&vc->buf);
148     av_freep(&vc->buf_tmp);
149
150     av_freep(&vc->residues);
151     av_freep(&vc->modes);
152
153     ff_mdct_end(&vc->mdct[0]);
154     ff_mdct_end(&vc->mdct[1]);
155
156     for(i=0;i<vc->codebook_count;++i) {
157         av_free(vc->codebooks[i].codevectors);
158         free_vlc(&vc->codebooks[i].vlc);
159     }
160     av_freep(&vc->codebooks);
161
162     for(i=0;i<vc->floor_count;++i) {
163         if(vc->floors[i].floor_type==0) {
164             av_free(vc->floors[i].data.t0.map[0]);
165             av_free(vc->floors[i].data.t0.map[1]);
166             av_free(vc->floors[i].data.t0.book_list);
167             av_free(vc->floors[i].data.t0.lsp);
168         }
169         else {
170             av_free(vc->floors[i].data.t1.x_list);
171             av_free(vc->floors[i].data.t1.x_list_order);
172             av_free(vc->floors[i].data.t1.low_neighbour);
173             av_free(vc->floors[i].data.t1.high_neighbour);
174         }
175     }
176     av_freep(&vc->floors);
177
178     for(i=0;i<vc->mapping_count;++i) {
179         av_free(vc->mappings[i].magnitude);
180         av_free(vc->mappings[i].angle);
181         av_free(vc->mappings[i].mux);
182     }
183     av_freep(&vc->mappings);
184
185     if(vc->exp_bias){
186         av_freep(&vc->win[0]);
187         av_freep(&vc->win[1]);
188     }
189 }
190
191 // Parse setup header -------------------------------------------------
192
193 // Process codebooks part
194
195 static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
196     uint_fast16_t cb;
197     uint_fast8_t *tmp_vlc_bits;
198     uint_fast32_t *tmp_vlc_codes;
199     GetBitContext *gb=&vc->gb;
200
201     vc->codebook_count=get_bits(gb,8)+1;
202
203     AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);
204
205     vc->codebooks=(vorbis_codebook *)av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
206     tmp_vlc_bits=(uint_fast8_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast8_t));
207     tmp_vlc_codes=(uint_fast32_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast32_t));
208
209     for(cb=0;cb<vc->codebook_count;++cb) {
210         vorbis_codebook *codebook_setup=&vc->codebooks[cb];
211         uint_fast8_t ordered;
212         uint_fast32_t t, used_entries=0;
213         uint_fast32_t entries;
214
215         AV_DEBUG(" %d. Codebook \n", cb);
216
217         if (get_bits(gb, 24)!=0x564342) {
218             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook setup data corrupt. \n", cb);
219             goto error;
220         }
221
222         codebook_setup->dimensions=get_bits(gb, 16);
223         if (codebook_setup->dimensions>16) {
224             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook's dimension is too large (%d). \n", cb, codebook_setup->dimensions);
225             goto error;
226         }
227         entries=get_bits(gb, 24);
228         if (entries>V_MAX_VLCS) {
229             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook has too many entries (%"PRIdFAST32"). \n", cb, entries);
230             goto error;
231         }
232
233         ordered=get_bits1(gb);
234
235         AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);
236
237         if (!ordered) {
238             uint_fast16_t ce;
239             uint_fast8_t flag;
240             uint_fast8_t sparse=get_bits1(gb);
241
242             AV_DEBUG(" not ordered \n");
243
244             if (sparse) {
245                 AV_DEBUG(" sparse \n");
246
247                 used_entries=0;
248                 for(ce=0;ce<entries;++ce) {
249                     flag=get_bits1(gb);
250                     if (flag) {
251                         tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
252                         ++used_entries;
253                     }
254                     else tmp_vlc_bits[ce]=0;
255                 }
256             } else {
257                 AV_DEBUG(" not sparse \n");
258
259                 used_entries=entries;
260                 for(ce=0;ce<entries;++ce) {
261                     tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
262                 }
263             }
264         } else {
265             uint_fast16_t current_entry=0;
266             uint_fast8_t current_length=get_bits(gb, 5)+1;
267
268             AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME
269
270             used_entries=entries;
271             for(;current_entry<used_entries;++current_length) {
272                 uint_fast16_t i, number;
273
274                 AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));
275
276                 number=get_bits(gb, ilog(entries - current_entry));
277
278                 AV_DEBUG(" number: %d \n", number);
279
280                 for(i=current_entry;i<number+current_entry;++i) {
281                     if (i<used_entries) tmp_vlc_bits[i]=current_length;
282                 }
283
284                 current_entry+=number;
285             }
286             if (current_entry>used_entries) {
287                 av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
288                 goto error;
289             }
290         }
291
292         codebook_setup->lookup_type=get_bits(gb, 4);
293
294         AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup" );
295
296 // If the codebook is used for (inverse) VQ, calculate codevectors.
297
298         if (codebook_setup->lookup_type==1) {
299             uint_fast16_t i, j, k;
300             uint_fast16_t codebook_lookup_values=nth_root(entries, codebook_setup->dimensions);
301             uint_fast16_t codebook_multiplicands[codebook_lookup_values];
302
303             float codebook_minimum_value=vorbisfloat2float(get_bits_long(gb, 32));
304             float codebook_delta_value=vorbisfloat2float(get_bits_long(gb, 32));
305             uint_fast8_t codebook_value_bits=get_bits(gb, 4)+1;
306             uint_fast8_t codebook_sequence_p=get_bits1(gb);
307
308             AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
309             AV_DEBUG("  delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);
310
311             for(i=0;i<codebook_lookup_values;++i) {
312                 codebook_multiplicands[i]=get_bits(gb, codebook_value_bits);
313
314                 AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
315                 AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
316             }
317
318 // Weed out unused vlcs and build codevector vector
319             codebook_setup->codevectors=(float *)av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float));
320             for(j=0, i=0;i<entries;++i) {
321                 uint_fast8_t dim=codebook_setup->dimensions;
322
323                 if (tmp_vlc_bits[i]) {
324                     float last=0.0;
325                     uint_fast32_t lookup_offset=i;
326
327 #ifdef V_DEBUG
328                     av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
329 #endif
330
331                     for(k=0;k<dim;++k) {
332                         uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
333                         codebook_setup->codevectors[j*dim+k]=codebook_multiplicands[multiplicand_offset]*codebook_delta_value+codebook_minimum_value+last;
334                         if (codebook_sequence_p) {
335                             last=codebook_setup->codevectors[j*dim+k];
336                         }
337                         lookup_offset/=codebook_lookup_values;
338                     }
339                     tmp_vlc_bits[j]=tmp_vlc_bits[i];
340
341 #ifdef V_DEBUG
342                     av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
343                     for(k=0;k<dim;++k) {
344                         av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j*dim+k]);
345                     }
346                     av_log(vc->avccontext, AV_LOG_INFO, "\n");
347 #endif
348
349                     ++j;
350                 }
351             }
352             if (j!=used_entries) {
353                 av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
354                 goto error;
355             }
356             entries=used_entries;
357         }
358         else if (codebook_setup->lookup_type>=2) {
359             av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
360             goto error;
361         }
362
363 // Initialize VLC table
364         if (vorbis_len2vlc(vc, tmp_vlc_bits, tmp_vlc_codes, entries)) {
365             av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
366             goto error;
367         }
368         codebook_setup->maxdepth=0;
369         for(t=0;t<entries;++t)
370             if (tmp_vlc_bits[t]>=codebook_setup->maxdepth) codebook_setup->maxdepth=tmp_vlc_bits[t];
371
372         if(codebook_setup->maxdepth > 3*V_NB_BITS) codebook_setup->nb_bits=V_NB_BITS2;
373         else                                       codebook_setup->nb_bits=V_NB_BITS;
374
375         codebook_setup->maxdepth=(codebook_setup->maxdepth+codebook_setup->nb_bits-1)/codebook_setup->nb_bits;
376
377         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)) {
378             av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
379             goto error;
380         }
381     }
382
383     av_free(tmp_vlc_bits);
384     av_free(tmp_vlc_codes);
385     return 0;
386
387 // Error:
388 error:
389     av_free(tmp_vlc_bits);
390     av_free(tmp_vlc_codes);
391     return 1;
392 }
393
394 // Process time domain transforms part (unused in Vorbis I)
395
396 static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc) {
397     GetBitContext *gb=&vc->gb;
398     uint_fast8_t i;
399     uint_fast8_t vorbis_time_count=get_bits(gb, 6)+1;
400
401     for(i=0;i<vorbis_time_count;++i) {
402         uint_fast16_t vorbis_tdtransform=get_bits(gb, 16);
403
404         AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);
405
406         if (vorbis_tdtransform) {
407             av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
408             return 1;
409         }
410     }
411     return 0;
412 }
413
414 // Process floors part
415
416 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
417                                          vorbis_floor_data *vfu, float *vec);
418 static void create_map( vorbis_context * vc, uint_fast8_t floor_number );
419 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc,
420                                          vorbis_floor_data *vfu, float *vec);
421 static int vorbis_parse_setup_hdr_floors(vorbis_context *vc) {
422     GetBitContext *gb=&vc->gb;
423     uint_fast16_t i,j,k;
424
425     vc->floor_count=get_bits(gb, 6)+1;
426
427     vc->floors=(vorbis_floor *)av_mallocz(vc->floor_count * sizeof(vorbis_floor));
428
429     for (i=0;i<vc->floor_count;++i) {
430         vorbis_floor *floor_setup=&vc->floors[i];
431
432         floor_setup->floor_type=get_bits(gb, 16);
433
434         AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);
435
436         if (floor_setup->floor_type==1) {
437             uint_fast8_t maximum_class=0;
438             uint_fast8_t rangebits;
439             uint_fast16_t floor1_values=2;
440
441             floor_setup->decode=vorbis_floor1_decode;
442
443             floor_setup->data.t1.partitions=get_bits(gb, 5);
444
445             AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->data.t1.partitions);
446
447             for(j=0;j<floor_setup->data.t1.partitions;++j) {
448                 floor_setup->data.t1.partition_class[j]=get_bits(gb, 4);
449                 if (floor_setup->data.t1.partition_class[j]>maximum_class) maximum_class=floor_setup->data.t1.partition_class[j];
450
451                 AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->data.t1.partition_class[j]);
452
453             }
454
455             AV_DEBUG(" maximum class %d \n", maximum_class);
456
457             floor_setup->data.t1.maximum_class=maximum_class;
458
459             for(j=0;j<=maximum_class;++j) {
460                 floor_setup->data.t1.class_dimensions[j]=get_bits(gb, 3)+1;
461                 floor_setup->data.t1.class_subclasses[j]=get_bits(gb, 2);
462
463                 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]);
464
465                 if (floor_setup->data.t1.class_subclasses[j]) {
466                     floor_setup->data.t1.class_masterbook[j]=get_bits(gb, 8);
467
468                     AV_DEBUG("   masterbook: %d \n", floor_setup->data.t1.class_masterbook[j]);
469                 }
470
471                 for(k=0;k<(1<<floor_setup->data.t1.class_subclasses[j]);++k) {
472                     floor_setup->data.t1.subclass_books[j][k]=(int16_t)get_bits(gb, 8)-1;
473
474                     AV_DEBUG("    book %d. : %d \n", k, floor_setup->data.t1.subclass_books[j][k]);
475                 }
476             }
477
478             floor_setup->data.t1.multiplier=get_bits(gb, 2)+1;
479             floor_setup->data.t1.x_list_dim=2;
480
481             for(j=0;j<floor_setup->data.t1.partitions;++j) {
482                 floor_setup->data.t1.x_list_dim+=floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];
483             }
484
485             floor_setup->data.t1.x_list=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
486             floor_setup->data.t1.x_list_order=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
487             floor_setup->data.t1.low_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
488             floor_setup->data.t1.high_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
489
490
491             rangebits=get_bits(gb, 4);
492             floor_setup->data.t1.x_list[0] = 0;
493             floor_setup->data.t1.x_list[1] = (1<<rangebits);
494
495             for(j=0;j<floor_setup->data.t1.partitions;++j) {
496                 for(k=0;k<floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];++k,++floor1_values) {
497                     floor_setup->data.t1.x_list[floor1_values]=get_bits(gb, rangebits);
498
499                     AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->data.t1.x_list[floor1_values]);
500                 }
501             }
502
503 // Precalculate order of x coordinates - needed for decode
504
505             for(k=0;k<floor_setup->data.t1.x_list_dim;++k) {
506                 floor_setup->data.t1.x_list_order[k]=k;
507             }
508
509             for(k=0;k<floor_setup->data.t1.x_list_dim-1;++k) {   // FIXME optimize sorting ?
510                 for(j=k+1;j<floor_setup->data.t1.x_list_dim;++j) {
511                     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]]) {
512                         uint_fast16_t tmp=floor_setup->data.t1.x_list_order[k];
513                         floor_setup->data.t1.x_list_order[k]=floor_setup->data.t1.x_list_order[j];
514                         floor_setup->data.t1.x_list_order[j]=tmp;
515                     }
516                 }
517             }
518
519 // Precalculate low and high neighbours
520
521             for(k=2;k<floor_setup->data.t1.x_list_dim;++k) {
522                 floor_setup->data.t1.low_neighbour[k]=0;
523                 floor_setup->data.t1.high_neighbour[k]=1;  // correct according to SPEC requirements
524
525                 for (j=0;j<k;++j) {
526                     if ((floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[k]) &&
527                       (floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[floor_setup->data.t1.low_neighbour[k]])) {
528                         floor_setup->data.t1.low_neighbour[k]=j;
529                     }
530                     if ((floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[k]) &&
531                       (floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[floor_setup->data.t1.high_neighbour[k]])) {
532                         floor_setup->data.t1.high_neighbour[k]=j;
533                     }
534                 }
535             }
536         }
537         else if(floor_setup->floor_type==0) {
538             uint_fast8_t max_codebook_dim=0;
539
540             floor_setup->decode=vorbis_floor0_decode;
541
542             floor_setup->data.t0.order=get_bits(gb, 8);
543             floor_setup->data.t0.rate=get_bits(gb, 16);
544             floor_setup->data.t0.bark_map_size=get_bits(gb, 16);
545             floor_setup->data.t0.amplitude_bits=get_bits(gb, 6);
546             /* zero would result in a div by zero later *
547              * 2^0 - 1 == 0                             */
548             if (floor_setup->data.t0.amplitude_bits == 0) {
549               av_log(vc->avccontext, AV_LOG_ERROR,
550                      "Floor 0 amplitude bits is 0.\n");
551               return 1;
552             }
553             floor_setup->data.t0.amplitude_offset=get_bits(gb, 8);
554             floor_setup->data.t0.num_books=get_bits(gb, 4)+1;
555
556             /* allocate mem for booklist */
557             floor_setup->data.t0.book_list=
558                 av_malloc(floor_setup->data.t0.num_books);
559             if(!floor_setup->data.t0.book_list) { return 1; }
560             /* read book indexes */
561             {
562                 int idx;
563                 uint_fast8_t book_idx;
564                 for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
565                     book_idx=get_bits(gb, 8);
566                     floor_setup->data.t0.book_list[idx]=book_idx;
567                     if (vc->codebooks[book_idx].dimensions > max_codebook_dim)
568                         max_codebook_dim=vc->codebooks[book_idx].dimensions;
569
570                     if (floor_setup->data.t0.book_list[idx]>vc->codebook_count)
571                         return 1;
572                 }
573             }
574
575             create_map( vc, i );
576
577             /* allocate mem for lsp coefficients */
578             {
579                 /* codebook dim is for padding if codebook dim doesn't *
580                  * divide order+1 then we need to read more data       */
581                 floor_setup->data.t0.lsp=
582                     av_malloc((floor_setup->data.t0.order+1 + max_codebook_dim)
583                               * sizeof(float));
584                 if(!floor_setup->data.t0.lsp) { return 1; }
585             }
586
587 #ifdef V_DEBUG /* debug output parsed headers */
588             AV_DEBUG("floor0 order: %u\n", floor_setup->data.t0.order);
589             AV_DEBUG("floor0 rate: %u\n", floor_setup->data.t0.rate);
590             AV_DEBUG("floor0 bark map size: %u\n",
591               floor_setup->data.t0.bark_map_size);
592             AV_DEBUG("floor0 amplitude bits: %u\n",
593               floor_setup->data.t0.amplitude_bits);
594             AV_DEBUG("floor0 amplitude offset: %u\n",
595               floor_setup->data.t0.amplitude_offset);
596             AV_DEBUG("floor0 number of books: %u\n",
597               floor_setup->data.t0.num_books);
598             AV_DEBUG("floor0 book list pointer: %p\n",
599               floor_setup->data.t0.book_list);
600             {
601               int idx;
602               for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
603                 AV_DEBUG( "  Book %d: %u\n",
604                   idx+1,
605                   floor_setup->data.t0.book_list[idx] );
606               }
607             }
608 #endif
609         }
610         else {
611             av_log(vc->avccontext, AV_LOG_ERROR, "Invalid floor type!\n");
612             return 1;
613         }
614     }
615     return 0;
616 }
617
618 // Process residues part
619
620 static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
621     GetBitContext *gb=&vc->gb;
622     uint_fast8_t i, j, k;
623
624     vc->residue_count=get_bits(gb, 6)+1;
625     vc->residues=(vorbis_residue *)av_mallocz(vc->residue_count * sizeof(vorbis_residue));
626
627     AV_DEBUG(" There are %d residues. \n", vc->residue_count);
628
629     for(i=0;i<vc->residue_count;++i) {
630         vorbis_residue *res_setup=&vc->residues[i];
631         uint_fast8_t cascade[64];
632         uint_fast8_t high_bits;
633         uint_fast8_t low_bits;
634
635         res_setup->type=get_bits(gb, 16);
636
637         AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);
638
639         res_setup->begin=get_bits(gb, 24);
640         res_setup->end=get_bits(gb, 24);
641         res_setup->partition_size=get_bits(gb, 24)+1;
642         res_setup->classifications=get_bits(gb, 6)+1;
643         res_setup->classbook=get_bits(gb, 8);
644
645         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,
646           res_setup->classifications, res_setup->classbook);
647
648         for(j=0;j<res_setup->classifications;++j) {
649             high_bits=0;
650             low_bits=get_bits(gb, 3);
651             if (get_bits1(gb)) {
652                 high_bits=get_bits(gb, 5);
653             }
654             cascade[j]=(high_bits<<3)+low_bits;
655
656             AV_DEBUG("     %d class casscade depth: %d \n", j, ilog(cascade[j]));
657         }
658
659         res_setup->maxpass=0;
660         for(j=0;j<res_setup->classifications;++j) {
661             for(k=0;k<8;++k) {
662                 if (cascade[j]&(1<<k)) {
663                         res_setup->books[j][k]=get_bits(gb, 8);
664
665                     AV_DEBUG("     %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);
666
667                     if (k>res_setup->maxpass) {
668                         res_setup->maxpass=k;
669                     }
670                 } else {
671                     res_setup->books[j][k]=-1;
672                 }
673             }
674         }
675     }
676     return 0;
677 }
678
679 // Process mappings part
680
681 static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc) {
682     GetBitContext *gb=&vc->gb;
683     uint_fast8_t i, j;
684
685     vc->mapping_count=get_bits(gb, 6)+1;
686     vc->mappings=(vorbis_mapping *)av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));
687
688     AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);
689
690     for(i=0;i<vc->mapping_count;++i) {
691         vorbis_mapping *mapping_setup=&vc->mappings[i];
692
693         if (get_bits(gb, 16)) {
694             av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
695             return 1;
696         }
697         if (get_bits1(gb)) {
698             mapping_setup->submaps=get_bits(gb, 4)+1;
699         } else {
700             mapping_setup->submaps=1;
701         }
702
703         if (get_bits1(gb)) {
704             mapping_setup->coupling_steps=get_bits(gb, 8)+1;
705             mapping_setup->magnitude=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
706             mapping_setup->angle=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
707             for(j=0;j<mapping_setup->coupling_steps;++j) {
708                 mapping_setup->magnitude[j]=get_bits(gb, ilog(vc->audio_channels-1));
709                 mapping_setup->angle[j]=get_bits(gb, ilog(vc->audio_channels-1));
710                 // FIXME: sanity checks
711             }
712         } else {
713             mapping_setup->coupling_steps=0;
714         }
715
716         AV_DEBUG("   %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);
717
718         if(get_bits(gb, 2)) {
719             av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
720             return 1; // following spec.
721         }
722
723         if (mapping_setup->submaps>1) {
724             mapping_setup->mux=(uint_fast8_t *)av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
725             for(j=0;j<vc->audio_channels;++j) {
726                 mapping_setup->mux[j]=get_bits(gb, 4);
727             }
728         }
729
730         for(j=0;j<mapping_setup->submaps;++j) {
731             get_bits(gb, 8); // FIXME check?
732             mapping_setup->submap_floor[j]=get_bits(gb, 8);
733             mapping_setup->submap_residue[j]=get_bits(gb, 8);
734
735             AV_DEBUG("   %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
736         }
737     }
738     return 0;
739 }
740
741 // Process modes part
742
743 static void create_map( vorbis_context * vc, uint_fast8_t floor_number )
744 {
745     vorbis_floor * floors=vc->floors;
746     vorbis_floor0 * vf;
747     int idx;
748     int_fast8_t blockflag;
749     int_fast32_t * map;
750     int_fast32_t n; //TODO: could theoretically be smaller?
751
752     for (blockflag=0;blockflag<2;++blockflag)
753     {
754     n=vc->blocksize[blockflag]/2;
755     floors[floor_number].data.t0.map[blockflag]=
756         av_malloc((n+1) * sizeof(int_fast32_t)); // n+sentinel
757
758     map=floors[floor_number].data.t0.map[blockflag];
759     vf=&floors[floor_number].data.t0;
760
761     for (idx=0; idx<n;++idx) {
762         map[idx]=floor( BARK((vf->rate*idx)/(2.0f*n)) *
763                               ((vf->bark_map_size)/
764                                BARK(vf->rate/2.0f )) );
765         if (vf->bark_map_size-1 < map[idx]) {
766             map[idx]=vf->bark_map_size-1;
767         }
768     }
769     map[n]=-1;
770     vf->map_size[blockflag]=n;
771     }
772
773 #   ifdef V_DEBUG
774     for(idx=0;idx<=n;++idx) {
775         AV_DEBUG("floor0 map: map at pos %d is %d\n",
776                  idx, map[idx]);
777     }
778 #   endif
779 }
780
781 static int vorbis_parse_setup_hdr_modes(vorbis_context *vc) {
782     GetBitContext *gb=&vc->gb;
783     uint_fast8_t i;
784
785     vc->mode_count=get_bits(gb, 6)+1;
786     vc->modes=(vorbis_mode *)av_mallocz(vc->mode_count * sizeof(vorbis_mode));
787
788     AV_DEBUG(" There are %d modes.\n", vc->mode_count);
789
790     for(i=0;i<vc->mode_count;++i) {
791         vorbis_mode *mode_setup=&vc->modes[i];
792
793         mode_setup->blockflag=get_bits(gb, 1);
794         mode_setup->windowtype=get_bits(gb, 16); //FIXME check
795         mode_setup->transformtype=get_bits(gb, 16); //FIXME check
796         mode_setup->mapping=get_bits(gb, 8); //FIXME check
797
798         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);
799     }
800     return 0;
801 }
802
803 // Process the whole setup header using the functions above
804
805 static int vorbis_parse_setup_hdr(vorbis_context *vc) {
806     GetBitContext *gb=&vc->gb;
807
808     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
809     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
810     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
811         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
812         return 1;
813     }
814
815     if (vorbis_parse_setup_hdr_codebooks(vc)) {
816         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
817         return 2;
818     }
819     if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
820         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
821         return 3;
822     }
823     if (vorbis_parse_setup_hdr_floors(vc)) {
824         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
825         return 4;
826     }
827     if (vorbis_parse_setup_hdr_residues(vc)) {
828         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
829         return 5;
830     }
831     if (vorbis_parse_setup_hdr_mappings(vc)) {
832         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
833         return 6;
834     }
835     if (vorbis_parse_setup_hdr_modes(vc)) {
836         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
837         return 7;
838     }
839     if (!get_bits1(gb)) {
840         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
841         return 8; // framing flag bit unset error
842     }
843
844     return 0;
845 }
846
847 // Process the identification header
848
849 static int vorbis_parse_id_hdr(vorbis_context *vc){
850     GetBitContext *gb=&vc->gb;
851     uint_fast8_t bl0, bl1;
852     const float *vwin[8]={ vwin64, vwin128, vwin256, vwin512, vwin1024, vwin2048, vwin4096, vwin8192 };
853
854     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
855     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
856     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
857         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
858         return 1;
859     }
860
861     vc->version=get_bits_long(gb, 32);    //FIXME check 0
862     vc->audio_channels=get_bits(gb, 8);   //FIXME check >0
863     vc->audio_samplerate=get_bits_long(gb, 32);   //FIXME check >0
864     vc->bitrate_maximum=get_bits_long(gb, 32);
865     vc->bitrate_nominal=get_bits_long(gb, 32);
866     vc->bitrate_minimum=get_bits_long(gb, 32);
867     bl0=get_bits(gb, 4);
868     bl1=get_bits(gb, 4);
869     vc->blocksize[0]=(1<<bl0);
870     vc->blocksize[1]=(1<<bl1);
871     if (bl0>13 || bl0<6 || bl1>13 || bl1<6 || bl1<bl0) {
872         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
873         return 3;
874     }
875     // output format int16
876     if (vc->blocksize[1]/2 * vc->audio_channels * 2 >
877                                              AVCODEC_MAX_AUDIO_FRAME_SIZE) {
878         av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis channel count makes "
879                "output packets too large.\n");
880         return 4;
881     }
882     vc->win[0]=vwin[bl0-6];
883     vc->win[1]=vwin[bl1-6];
884
885     if(vc->exp_bias){
886         int i, j;
887         for(j=0; j<2; j++){
888             float *win = av_malloc(vc->blocksize[j]/2 * sizeof(float));
889             for(i=0; i<vc->blocksize[j]/2; i++)
890                 win[i] = vc->win[j][i] * (1<<15);
891             vc->win[j] = win;
892         }
893     }
894
895     if ((get_bits1(gb)) == 0) {
896         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
897         return 2;
898     }
899
900     vc->channel_residues=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
901     vc->channel_floors=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
902     vc->saved=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
903     vc->ret=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
904     vc->buf=(float *)av_malloc(vc->blocksize[1] * sizeof(float));
905     vc->buf_tmp=(float *)av_malloc(vc->blocksize[1] * sizeof(float));
906     vc->saved_start=0;
907
908     ff_mdct_init(&vc->mdct[0], bl0, 1);
909     ff_mdct_init(&vc->mdct[1], bl1, 1);
910
911     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 ",
912             vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize[0], vc->blocksize[1]);
913
914 /*
915     BLK=vc->blocksize[0];
916     for(i=0;i<BLK/2;++i) {
917         vc->win[0][i]=sin(0.5*3.14159265358*(sin(((float)i+0.5)/(float)BLK*3.14159265358))*(sin(((float)i+0.5)/(float)BLK*3.14159265358)));
918     }
919 */
920
921     return 0;
922 }
923
924 // Process the extradata using the functions above (identification header, setup header)
925
926 static int vorbis_decode_init(AVCodecContext *avccontext) {
927     vorbis_context *vc = avccontext->priv_data ;
928     uint8_t *headers = avccontext->extradata;
929     int headers_len=avccontext->extradata_size;
930     uint8_t *header_start[3];
931     int header_len[3];
932     GetBitContext *gb = &(vc->gb);
933     int i, j, hdr_type;
934
935     vc->avccontext = avccontext;
936     dsputil_init(&vc->dsp, avccontext);
937
938     if(vc->dsp.float_to_int16 == ff_float_to_int16_c) {
939         vc->add_bias = 385;
940         vc->exp_bias = 0;
941     } else {
942         vc->add_bias = 0;
943         vc->exp_bias = 15<<23;
944     }
945
946     if (!headers_len) {
947         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
948         return -1;
949     }
950
951     if(headers[0] == 0 && headers[1] == 30) {
952         for(i = 0; i < 3; i++){
953             header_len[i] = *headers++ << 8;
954             header_len[i] += *headers++;
955             header_start[i] = headers;
956             headers += header_len[i];
957         }
958     } else if(headers[0] == 2) {
959         for(j=1,i=0;i<2;++i, ++j) {
960             header_len[i]=0;
961             while(j<headers_len && headers[j]==0xff) {
962                 header_len[i]+=0xff;
963                 ++j;
964             }
965             if (j>=headers_len) {
966                 av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
967                 return -1;
968             }
969             header_len[i]+=headers[j];
970         }
971         header_len[2]=headers_len-header_len[0]-header_len[1]-j;
972         headers+=j;
973         header_start[0] = headers;
974         header_start[1] = header_start[0] + header_len[0];
975         header_start[2] = header_start[1] + header_len[1];
976     } else {
977         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
978         return -1;
979     }
980
981     init_get_bits(gb, header_start[0], header_len[0]*8);
982     hdr_type=get_bits(gb, 8);
983     if (hdr_type!=1) {
984         av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
985         return -1;
986     }
987     if (vorbis_parse_id_hdr(vc)) {
988         av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
989         vorbis_free(vc);
990         return -1;
991     }
992
993     init_get_bits(gb, header_start[2], header_len[2]*8);
994     hdr_type=get_bits(gb, 8);
995     if (hdr_type!=5) {
996         av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
997         return -1;
998     }
999     if (vorbis_parse_setup_hdr(vc)) {
1000         av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
1001         vorbis_free(vc);
1002         return -1;
1003     }
1004
1005     avccontext->channels = vc->audio_channels;
1006     avccontext->sample_rate = vc->audio_samplerate;
1007
1008     return 0 ;
1009 }
1010
1011 // Decode audiopackets -------------------------------------------------
1012
1013 // Read and decode floor
1014
1015 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
1016                                          vorbis_floor_data *vfu, float *vec) {
1017     vorbis_floor0 * vf=&vfu->t0;
1018     float * lsp=vf->lsp;
1019     uint_fast32_t amplitude;
1020     uint_fast32_t book_idx;
1021     uint_fast8_t blockflag=vc->modes[vc->mode_number].blockflag;
1022
1023     amplitude=get_bits(&vc->gb, vf->amplitude_bits);
1024     if (amplitude>0) {
1025         float last = 0;
1026         uint_fast16_t lsp_len = 0;
1027         uint_fast16_t idx;
1028         vorbis_codebook codebook;
1029
1030         book_idx=get_bits(&vc->gb, ilog(vf->num_books));
1031         if ( book_idx >= vf->num_books ) {
1032             av_log( vc->avccontext, AV_LOG_ERROR,
1033                     "floor0 dec: booknumber too high!\n" );
1034             //FIXME: look above
1035         }
1036         AV_DEBUG( "floor0 dec: booknumber: %u\n", book_idx );
1037         codebook=vc->codebooks[vf->book_list[book_idx]];
1038
1039         while (lsp_len<vf->order) {
1040             int vec_off;
1041
1042             AV_DEBUG( "floor0 dec: book dimension: %d\n", codebook.dimensions );
1043             AV_DEBUG( "floor0 dec: maximum depth: %d\n", codebook.maxdepth );
1044             /* read temp vector */
1045             vec_off=get_vlc2(&vc->gb,
1046                              codebook.vlc.table,
1047                              codebook.nb_bits,
1048                              codebook.maxdepth ) *
1049                              codebook.dimensions;
1050             AV_DEBUG( "floor0 dec: vector offset: %d\n", vec_off );
1051             /* copy each vector component and add last to it */
1052             for (idx=0; idx<codebook.dimensions; ++idx) {
1053                 lsp[lsp_len+idx]=codebook.codevectors[vec_off+idx]+last;
1054             }
1055             last=lsp[lsp_len+idx-1]; /* set last to last vector component */
1056
1057             lsp_len += codebook.dimensions;
1058         }
1059 #ifdef V_DEBUG
1060         /* DEBUG: output lsp coeffs */
1061         {
1062             int idx;
1063             for ( idx = 0; idx < lsp_len; ++idx )
1064                 AV_DEBUG("floor0 dec: coeff at %d is %f\n", idx, lsp[idx] );
1065         }
1066 #endif
1067
1068         /* synthesize floor output vector */
1069         {
1070             int i;
1071             int order=vf->order;
1072             float wstep=M_PI/vf->bark_map_size;
1073
1074             for(i=0;i<order;i++) { lsp[i]=2.0f*cos(lsp[i]); }
1075
1076             AV_DEBUG("floor0 synth: map_size=%d; m=%d; wstep=%f\n",
1077                      vf->map_size, order, wstep);
1078
1079             i=0;
1080             while(i<vf->map_size[blockflag]) {
1081                 int j, iter_cond=vf->map[blockflag][i];
1082                 float p=0.5f;
1083                 float q=0.5f;
1084                 float two_cos_w=2.0f*cos(wstep*iter_cond); // needed all times
1085
1086                 /* similar part for the q and p products */
1087                 for(j=0;j<order;j+=2) {
1088                     q *= lsp[j]  -two_cos_w;
1089                     p *= lsp[j+1]-two_cos_w;
1090                 }
1091                 if(j==order) { // even order
1092                     p *= p*(2.0f-two_cos_w);
1093                     q *= q*(2.0f+two_cos_w);
1094                 }
1095                 else { // odd order
1096                     q *= two_cos_w-lsp[j]; // one more time for q
1097
1098                     /* final step and square */
1099                     p *= p*(4.f-two_cos_w*two_cos_w);
1100                     q *= q;
1101                 }
1102
1103                 /* calculate linear floor value */
1104                 {
1105                     q=exp( (
1106                              ( (amplitude*vf->amplitude_offset)/
1107                                (((1<<vf->amplitude_bits)-1) * sqrt(p+q)) )
1108                              - vf->amplitude_offset ) * .11512925f
1109                          );
1110                 }
1111
1112                 /* fill vector */
1113                 do { vec[i]=q; ++i; }while(vf->map[blockflag][i]==iter_cond);
1114             }
1115         }
1116     }
1117     else {
1118         /* this channel is unused */
1119         return 1;
1120     }
1121
1122     AV_DEBUG(" Floor0 decoded\n");
1123
1124     return 0;
1125 }
1126 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *vfu, float *vec) {
1127     vorbis_floor1 * vf=&vfu->t1;
1128     GetBitContext *gb=&vc->gb;
1129     uint_fast16_t range_v[4]={ 256, 128, 86, 64 };
1130     uint_fast16_t range=range_v[vf->multiplier-1];
1131     uint_fast16_t floor1_Y[vf->x_list_dim];
1132     uint_fast16_t floor1_Y_final[vf->x_list_dim];
1133     uint_fast8_t floor1_flag[vf->x_list_dim];
1134     uint_fast8_t class_;
1135     uint_fast8_t cdim;
1136     uint_fast8_t cbits;
1137     uint_fast8_t csub;
1138     uint_fast8_t cval;
1139     int_fast16_t book;
1140     uint_fast16_t offset;
1141     uint_fast16_t i,j;
1142     uint_fast16_t *floor_x_sort=vf->x_list_order;
1143     /*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx= (unsigned)dy/adx ?
1144     int_fast16_t dy, err;
1145     uint_fast16_t lx,hx, ly, hy=0;
1146
1147
1148     if (!get_bits1(gb)) return 1; // silence
1149
1150 // Read values (or differences) for the floor's points
1151
1152     floor1_Y[0]=get_bits(gb, ilog(range-1));
1153     floor1_Y[1]=get_bits(gb, ilog(range-1));
1154
1155     AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);
1156
1157     offset=2;
1158     for(i=0;i<vf->partitions;++i) {
1159         class_=vf->partition_class[i];
1160         cdim=vf->class_dimensions[class_];
1161         cbits=vf->class_subclasses[class_];
1162         csub=(1<<cbits)-1;
1163         cval=0;
1164
1165         AV_DEBUG("Cbits %d \n", cbits);
1166
1167         if (cbits) { // this reads all subclasses for this partition's class
1168             cval=get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,
1169             vc->codebooks[vf->class_masterbook[class_]].nb_bits, 3);
1170         }
1171
1172         for(j=0;j<cdim;++j) {
1173             book=vf->subclass_books[class_][cval & csub];
1174
1175             AV_DEBUG("book %d Cbits %d cval %d  bits:%d \n", book, cbits, cval, get_bits_count(gb));
1176
1177             cval=cval>>cbits;
1178             if (book>-1) {
1179                 floor1_Y[offset+j]=get_vlc2(gb, vc->codebooks[book].vlc.table,
1180                 vc->codebooks[book].nb_bits, 3);
1181             } else {
1182                 floor1_Y[offset+j]=0;
1183             }
1184
1185             AV_DEBUG(" floor(%d) = %d \n", vf->x_list[offset+j], floor1_Y[offset+j]);
1186         }
1187         offset+=cdim;
1188     }
1189
1190 // Amplitude calculation from the differences
1191
1192     floor1_flag[0]=1;
1193     floor1_flag[1]=1;
1194     floor1_Y_final[0]=floor1_Y[0];
1195     floor1_Y_final[1]=floor1_Y[1];
1196
1197     for(i=2;i<vf->x_list_dim;++i) {
1198         uint_fast16_t val, highroom, lowroom, room;
1199         uint_fast16_t high_neigh_offs;
1200         uint_fast16_t low_neigh_offs;
1201
1202         low_neigh_offs=vf->low_neighbour[i];
1203         high_neigh_offs=vf->high_neighbour[i];
1204         dy=floor1_Y_final[high_neigh_offs]-floor1_Y_final[low_neigh_offs];  // render_point begin
1205         adx=vf->x_list[high_neigh_offs]-vf->x_list[low_neigh_offs];
1206         ady= ABS(dy);
1207         err=ady*(vf->x_list[i]-vf->x_list[low_neigh_offs]);
1208         off=(int16_t)err/(int16_t)adx;
1209         if (dy<0) {
1210             predicted=floor1_Y_final[low_neigh_offs]-off;
1211         } else {
1212             predicted=floor1_Y_final[low_neigh_offs]+off;
1213         } // render_point end
1214
1215         val=floor1_Y[i];
1216         highroom=range-predicted;
1217         lowroom=predicted;
1218         if (highroom < lowroom) {
1219             room=highroom*2;
1220         } else {
1221             room=lowroom*2;   // SPEC mispelling
1222         }
1223         if (val) {
1224             floor1_flag[low_neigh_offs]=1;
1225             floor1_flag[high_neigh_offs]=1;
1226             floor1_flag[i]=1;
1227             if (val>=room) {
1228                 if (highroom > lowroom) {
1229                     floor1_Y_final[i]=val-lowroom+predicted;
1230                 } else {
1231                     floor1_Y_final[i]=predicted-val+highroom-1;
1232                 }
1233             } else {
1234                 if (val & 1) {
1235                     floor1_Y_final[i]=predicted-(val+1)/2;
1236                 } else {
1237                     floor1_Y_final[i]=predicted+val/2;
1238                 }
1239             }
1240         } else {
1241             floor1_flag[i]=0;
1242             floor1_Y_final[i]=predicted;
1243         }
1244
1245         AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->x_list[i], floor1_Y_final[i], val);
1246     }
1247
1248 // Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?
1249
1250     hx=0;
1251     lx=0;
1252     ly=floor1_Y_final[0]*vf->multiplier;  // conforms to SPEC
1253
1254     vec[0]=floor1_inverse_db_table[ly];
1255
1256     for(i=1;i<vf->x_list_dim;++i) {
1257         AV_DEBUG(" Looking at post %d \n", i);
1258
1259         if (floor1_flag[floor_x_sort[i]]) {   // SPEC mispelled
1260             int_fast16_t x, y, dy, base, sy; // if uncommented: dy = -32 adx = 2  base = 2blablabla ?????
1261
1262             hy=floor1_Y_final[floor_x_sort[i]]*vf->multiplier;
1263             hx=vf->x_list[floor_x_sort[i]];
1264
1265             dy=hy-ly;
1266             adx=hx-lx;
1267             ady= (dy<0) ? -dy:dy;//ABS(dy);
1268             base=(int16_t)dy/(int16_t)adx;
1269
1270             AV_DEBUG(" dy %d  adx %d base %d = %d \n", dy, adx, base, dy/adx);
1271
1272             x=lx;
1273             y=ly;
1274             err=0;
1275             if (dy<0) {
1276                 sy=base-1;
1277             } else {
1278                 sy=base+1;
1279             }
1280             ady=ady-(base<0 ? -base : base)*adx;
1281             vec[x]=floor1_inverse_db_table[y];
1282
1283             AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1284
1285             for(x=lx+1;(x<hx) && (x<vf->x_list[1]);++x) {
1286                 err+=ady;
1287                 if (err>=adx) {
1288                     err-=adx;
1289                     y+=sy;
1290                 } else {
1291                     y+=base;
1292                 }
1293                 vec[x]=floor1_inverse_db_table[y];
1294
1295                 AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1296             }
1297
1298 /*            for(j=1;j<hx-lx+1;++j) {  // iterating render_point
1299                 dy=hy-ly;
1300                 adx=hx-lx;
1301                 ady= dy<0 ? -dy : dy;
1302                 err=ady*j;
1303                 off=err/adx;
1304                 if (dy<0) {
1305                     predicted=ly-off;
1306                 } else {
1307                     predicted=ly+off;
1308                 }
1309                 if (lx+j < vf->x_list[1]) {
1310                     vec[lx+j]=floor1_inverse_db_table[predicted];
1311                 }
1312             }*/
1313
1314             lx=hx;
1315             ly=hy;
1316         }
1317     }
1318
1319     if (hx<vf->x_list[1]) {
1320         for(i=hx;i<vf->x_list[1];++i) {
1321             vec[i]=floor1_inverse_db_table[hy];
1322         }
1323     }
1324
1325     AV_DEBUG(" Floor decoded\n");
1326
1327     return 0;
1328 }
1329
1330 // Read and decode residue
1331
1332 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) {
1333     GetBitContext *gb=&vc->gb;
1334     uint_fast8_t c_p_c=vc->codebooks[vr->classbook].dimensions;
1335     uint_fast16_t n_to_read=vr->end-vr->begin;
1336     uint_fast16_t ptns_to_read=n_to_read/vr->partition_size;
1337     uint_fast8_t classifs[ptns_to_read*vc->audio_channels];
1338     uint_fast8_t pass;
1339     uint_fast8_t ch_used;
1340     uint_fast8_t i,j,l;
1341     uint_fast16_t k;
1342
1343     if (vr->type==2) {
1344         for(j=1;j<ch;++j) {
1345                 do_not_decode[0]&=do_not_decode[j];  // FIXME - clobbering input
1346         }
1347         if (do_not_decode[0]) return 0;
1348         ch_used=1;
1349     } else {
1350         ch_used=ch;
1351     }
1352
1353     AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d  cpc %d  \n", ch, c_p_c);
1354
1355     for(pass=0;pass<=vr->maxpass;++pass) { // FIXME OPTIMIZE?
1356         uint_fast16_t voffset;
1357         uint_fast16_t partition_count;
1358         uint_fast16_t j_times_ptns_to_read;
1359
1360         voffset=vr->begin;
1361         for(partition_count=0;partition_count<ptns_to_read;) {  // SPEC        error
1362             if (!pass) {
1363                 uint_fast32_t inverse_class = inverse[vr->classifications];
1364                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1365                     if (!do_not_decode[j]) {
1366                         uint_fast32_t temp=get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,
1367                         vc->codebooks[vr->classbook].nb_bits, 3);
1368
1369                         AV_DEBUG("Classword: %d \n", temp);
1370
1371                         assert(vr->classifications > 1 && temp<=65536); //needed for inverse[]
1372                         for(i=0;i<c_p_c;++i) {
1373                             uint_fast32_t temp2;
1374
1375                             temp2=(((uint_fast64_t)temp) * inverse_class)>>32;
1376                             if (partition_count+c_p_c-1-i < ptns_to_read) {
1377                                 classifs[j_times_ptns_to_read+partition_count+c_p_c-1-i]=temp-temp2*vr->classifications;
1378                             }
1379                             temp=temp2;
1380                         }
1381                     }
1382                     j_times_ptns_to_read+=ptns_to_read;
1383                 }
1384             }
1385             for(i=0;(i<c_p_c) && (partition_count<ptns_to_read);++i) {
1386                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1387                     uint_fast16_t voffs;
1388
1389                     if (!do_not_decode[j]) {
1390                         uint_fast8_t vqclass=classifs[j_times_ptns_to_read+partition_count];
1391                         int_fast16_t vqbook=vr->books[vqclass][pass];
1392
1393                         if (vqbook>=0) {
1394                             uint_fast16_t coffs;
1395                             unsigned dim= vc->codebooks[vqbook].dimensions; // not uint_fast8_t: 64bit is slower here on amd64
1396                             uint_fast16_t step= dim==1 ? vr->partition_size
1397                                               : FASTDIV(vr->partition_size, dim);
1398                             vorbis_codebook codebook= vc->codebooks[vqbook];
1399
1400                             if (vr->type==0) {
1401
1402                                 voffs=voffset+j*vlen;
1403                                 for(k=0;k<step;++k) {
1404                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1405                                     for(l=0;l<dim;++l) {
1406                                         vec[voffs+k+l*step]+=codebook.codevectors[coffs+l];  // FPMATH
1407                                     }
1408                                 }
1409                             }
1410                             else if (vr->type==1) {
1411                                 voffs=voffset+j*vlen;
1412                                 for(k=0;k<step;++k) {
1413                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1414                                     for(l=0;l<dim;++l, ++voffs) {
1415                                         vec[voffs]+=codebook.codevectors[coffs+l];  // FPMATH
1416
1417                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d  \n", pass, voffs, vec[voffs], codebook.codevectors[coffs+l], coffs);
1418                                     }
1419                                 }
1420                             }
1421                             else if (vr->type==2 && ch==2 && (voffset&1)==0 && (dim&1)==0) { // most frequent case optimized
1422                                 voffs=voffset>>1;
1423
1424                                 if(dim==2) {
1425                                     for(k=0;k<step;++k) {
1426                                         coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * 2;
1427                                         vec[voffs+k     ]+=codebook.codevectors[coffs  ];  // FPMATH
1428                                         vec[voffs+k+vlen]+=codebook.codevectors[coffs+1];  // FPMATH
1429                                     }
1430                                 } else
1431                                 for(k=0;k<step;++k) {
1432                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1433                                     for(l=0;l<dim;l+=2, voffs++) {
1434                                         vec[voffs     ]+=codebook.codevectors[coffs+l  ];  // FPMATH
1435                                         vec[voffs+vlen]+=codebook.codevectors[coffs+l+1];  // FPMATH
1436
1437                                         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);
1438                                     }
1439                                 }
1440
1441                             }
1442                             else if (vr->type==2) {
1443                                 voffs=voffset;
1444
1445                                 for(k=0;k<step;++k) {
1446                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1447                                     for(l=0;l<dim;++l, ++voffs) {
1448                                         vec[voffs/ch+(voffs%ch)*vlen]+=codebook.codevectors[coffs+l];  // FPMATH FIXME use if and counter instead of / and %
1449
1450                                         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);
1451                                     }
1452                                 }
1453                             } else {
1454                                 av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n");
1455                                 return 1;
1456                             }
1457                         }
1458                     }
1459                     j_times_ptns_to_read+=ptns_to_read;
1460                 }
1461                 ++partition_count;
1462                 voffset+=vr->partition_size;
1463             }
1464         }
1465     }
1466     return 0;
1467 }
1468
1469 void vorbis_inverse_coupling(float *mag, float *ang, int blocksize)
1470 {
1471     int i;
1472     for(i=0; i<blocksize; i++)
1473     {
1474         if (mag[i]>0.0) {
1475             if (ang[i]>0.0) {
1476                 ang[i]=mag[i]-ang[i];
1477             } else {
1478                 float temp=ang[i];
1479                 ang[i]=mag[i];
1480                 mag[i]+=temp;
1481             }
1482         } else {
1483             if (ang[i]>0.0) {
1484                 ang[i]+=mag[i];
1485             } else {
1486                 float temp=ang[i];
1487                 ang[i]=mag[i];
1488                 mag[i]-=temp;
1489             }
1490         }
1491     }
1492 }
1493
1494 // Decode the audio packet using the functions above
1495
1496 static int vorbis_parse_audio_packet(vorbis_context *vc) {
1497     GetBitContext *gb=&vc->gb;
1498
1499     uint_fast8_t previous_window=0,next_window=0;
1500     uint_fast8_t mode_number;
1501     uint_fast16_t blocksize;
1502     int_fast32_t i,j;
1503     uint_fast8_t no_residue[vc->audio_channels];
1504     uint_fast8_t do_not_decode[vc->audio_channels];
1505     vorbis_mapping *mapping;
1506     float *ch_res_ptr=vc->channel_residues;
1507     float *ch_floor_ptr=vc->channel_floors;
1508     uint_fast8_t res_chan[vc->audio_channels];
1509     uint_fast8_t res_num=0;
1510     int_fast16_t retlen=0;
1511     uint_fast16_t saved_start=0;
1512     float fadd_bias = vc->add_bias;
1513
1514     if (get_bits1(gb)) {
1515         av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n");
1516         return -1; // packet type not audio
1517     }
1518
1519     if (vc->mode_count==1) {
1520         mode_number=0;
1521     } else {
1522         mode_number=get_bits(gb, ilog(vc->mode_count-1));
1523     }
1524     vc->mode_number=mode_number;
1525     mapping=&vc->mappings[vc->modes[mode_number].mapping];
1526
1527     AV_DEBUG(" Mode number: %d , mapping: %d , blocktype %d \n", mode_number, vc->modes[mode_number].mapping, vc->modes[mode_number].blockflag);
1528
1529     if (vc->modes[mode_number].blockflag) {
1530         previous_window=get_bits1(gb);
1531         next_window=get_bits1(gb);
1532     }
1533
1534     blocksize=vc->blocksize[vc->modes[mode_number].blockflag];
1535     memset(ch_res_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1536     memset(ch_floor_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1537
1538 // Decode floor
1539
1540     for(i=0;i<vc->audio_channels;++i) {
1541         vorbis_floor *floor;
1542         if (mapping->submaps>1) {
1543             floor=&vc->floors[mapping->submap_floor[mapping->mux[i]]];
1544         } else {
1545             floor=&vc->floors[mapping->submap_floor[0]];
1546         }
1547
1548         no_residue[i]=floor->decode(vc, &floor->data, ch_floor_ptr);
1549         ch_floor_ptr+=blocksize/2;
1550     }
1551
1552 // Nonzero vector propagate
1553
1554     for(i=mapping->coupling_steps-1;i>=0;--i) {
1555         if (!(no_residue[mapping->magnitude[i]] & no_residue[mapping->angle[i]])) {
1556             no_residue[mapping->magnitude[i]]=0;
1557             no_residue[mapping->angle[i]]=0;
1558         }
1559     }
1560
1561 // Decode residue
1562
1563     for(i=0;i<mapping->submaps;++i) {
1564         vorbis_residue *residue;
1565         uint_fast8_t ch=0;
1566
1567         for(j=0;j<vc->audio_channels;++j) {
1568             if ((mapping->submaps==1) || (i=mapping->mux[j])) {
1569                 res_chan[j]=res_num;
1570                 if (no_residue[j]) {
1571                     do_not_decode[ch]=1;
1572                 } else {
1573                     do_not_decode[ch]=0;
1574                 }
1575                 ++ch;
1576                 ++res_num;
1577             }
1578         }
1579         residue=&vc->residues[mapping->submap_residue[i]];
1580         vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2);
1581
1582         ch_res_ptr+=ch*blocksize/2;
1583     }
1584
1585 // Inverse coupling
1586
1587     for(i=mapping->coupling_steps-1;i>=0;--i) { //warning: i has to be signed
1588         float *mag, *ang;
1589
1590         mag=vc->channel_residues+res_chan[mapping->magnitude[i]]*blocksize/2;
1591         ang=vc->channel_residues+res_chan[mapping->angle[i]]*blocksize/2;
1592         vc->dsp.vorbis_inverse_coupling(mag, ang, blocksize/2);
1593     }
1594
1595 // Dotproduct
1596
1597     for(j=0, ch_floor_ptr=vc->channel_floors;j<vc->audio_channels;++j,ch_floor_ptr+=blocksize/2) {
1598         ch_res_ptr=vc->channel_residues+res_chan[j]*blocksize/2;
1599         vc->dsp.vector_fmul(ch_floor_ptr, ch_res_ptr, blocksize/2);
1600     }
1601
1602 // MDCT, overlap/add, save data for next overlapping  FPMATH
1603
1604     for(j=0;j<vc->audio_channels;++j) {
1605         uint_fast8_t step=vc->audio_channels;
1606         uint_fast16_t k;
1607         float *saved=vc->saved+j*vc->blocksize[1]/2;
1608         float *ret=vc->ret;
1609         const float *lwin=vc->win[1];
1610         const float *swin=vc->win[0];
1611         float *buf=vc->buf;
1612         float *buf_tmp=vc->buf_tmp;
1613
1614         ch_floor_ptr=vc->channel_floors+j*blocksize/2;
1615
1616         saved_start=vc->saved_start;
1617
1618         vc->mdct[0].fft.imdct_calc(&vc->mdct[vc->modes[mode_number].blockflag], buf, ch_floor_ptr, buf_tmp);
1619
1620         //FIXME process channels together, to allow faster simd vector_fmul_add_add?
1621         if (vc->modes[mode_number].blockflag) {
1622             // -- overlap/add
1623             if (previous_window) {
1624                 vc->dsp.vector_fmul_add_add(ret+j, buf, lwin, saved, vc->add_bias, vc->blocksize[1]/2, step);
1625                 retlen=vc->blocksize[1]/2;
1626             } else {
1627                 int len = (vc->blocksize[1]-vc->blocksize[0])/4;
1628                 buf += len;
1629                 vc->dsp.vector_fmul_add_add(ret+j, buf, swin, saved, vc->add_bias, vc->blocksize[0]/2, step);
1630                 k = vc->blocksize[0]/2*step + j;
1631                 buf += vc->blocksize[0]/2;
1632                 if(vc->exp_bias){
1633                     for(i=0; i<len; i++, k+=step)
1634                         ((uint32_t*)ret)[k] = ((uint32_t*)buf)[i] + vc->exp_bias; // ret[k]=buf[i]*(1<<bias)
1635                 } else {
1636                     for(i=0; i<len; i++, k+=step)
1637                         ret[k] = buf[i] + fadd_bias;
1638                 }
1639                 buf=vc->buf;
1640                 retlen=vc->blocksize[0]/2+len;
1641             }
1642             // -- save
1643             if (next_window) {
1644                 buf += vc->blocksize[1]/2;
1645                 vc->dsp.vector_fmul_reverse(saved, buf, lwin, vc->blocksize[1]/2);
1646                 saved_start=0;
1647             } else {
1648                 saved_start=(vc->blocksize[1]-vc->blocksize[0])/4;
1649                 buf += vc->blocksize[1]/2;
1650                 for(i=0; i<saved_start; i++)
1651                     ((uint32_t*)saved)[i] = ((uint32_t*)buf)[i] + vc->exp_bias;
1652                 vc->dsp.vector_fmul_reverse(saved+saved_start, buf+saved_start, swin, vc->blocksize[0]/2);
1653             }
1654         } else {
1655             // --overlap/add
1656             if(vc->add_bias) {
1657                 for(k=j, i=0;i<saved_start;++i, k+=step)
1658                     ret[k] = saved[i] + fadd_bias;
1659             } else {
1660                 for(k=j, i=0;i<saved_start;++i, k+=step)
1661                     ret[k] = saved[i];
1662             }
1663             vc->dsp.vector_fmul_add_add(ret+k, buf, swin, saved+saved_start, vc->add_bias, vc->blocksize[0]/2, step);
1664             retlen=saved_start+vc->blocksize[0]/2;
1665             // -- save
1666             buf += vc->blocksize[0]/2;
1667             vc->dsp.vector_fmul_reverse(saved, buf, swin, vc->blocksize[0]/2);
1668             saved_start=0;
1669         }
1670     }
1671     vc->saved_start=saved_start;
1672
1673     return retlen*vc->audio_channels;
1674 }
1675
1676 // Return the decoded audio packet through the standard api
1677
1678 static int vorbis_decode_frame(AVCodecContext *avccontext,
1679                         void *data, int *data_size,
1680                         uint8_t *buf, int buf_size)
1681 {
1682     vorbis_context *vc = avccontext->priv_data ;
1683     GetBitContext *gb = &(vc->gb);
1684
1685     int_fast16_t len;
1686
1687     if(!buf_size){
1688         return 0;
1689     }
1690
1691     AV_DEBUG("packet length %d \n", buf_size);
1692
1693     init_get_bits(gb, buf, buf_size*8);
1694
1695     len=vorbis_parse_audio_packet(vc);
1696
1697     if (len<=0) {
1698         *data_size=0;
1699         return buf_size;
1700     }
1701
1702     if (!vc->first_frame) {
1703         vc->first_frame=1;
1704         *data_size=0;
1705         return buf_size ;
1706     }
1707
1708     AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
1709
1710     vc->dsp.float_to_int16(data, vc->ret, len);
1711     *data_size=len*2;
1712
1713     return buf_size ;
1714 }
1715
1716 // Close decoder
1717
1718 static int vorbis_decode_close(AVCodecContext *avccontext) {
1719     vorbis_context *vc = avccontext->priv_data;
1720
1721     vorbis_free(vc);
1722
1723     return 0 ;
1724 }
1725
1726 AVCodec vorbis_decoder = {
1727     "vorbis",
1728     CODEC_TYPE_AUDIO,
1729     CODEC_ID_VORBIS,
1730     sizeof(vorbis_context),
1731     vorbis_decode_init,
1732     NULL,
1733     vorbis_decode_close,
1734     vorbis_decode_frame,
1735 };
1736