vorbis cosmetics: mdct0,mdct1 => mdct[2]
[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->mdct[0]);
165     ff_mdct_end(&vc->mdct[1]);
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     if(vc->exp_bias){
197         av_freep(&vc->win[0]);
198         av_freep(&vc->win[1]);
199     }
200 }
201
202 // Parse setup header -------------------------------------------------
203
204 // Process codebooks part
205
206 static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
207     uint_fast16_t cb;
208     uint_fast8_t *tmp_vlc_bits;
209     uint_fast32_t *tmp_vlc_codes;
210     GetBitContext *gb=&vc->gb;
211
212     vc->codebook_count=get_bits(gb,8)+1;
213
214     AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);
215
216     vc->codebooks=(vorbis_codebook *)av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
217     tmp_vlc_bits=(uint_fast8_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast8_t));
218     tmp_vlc_codes=(uint_fast32_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast32_t));
219
220     for(cb=0;cb<vc->codebook_count;++cb) {
221         vorbis_codebook *codebook_setup=&vc->codebooks[cb];
222         uint_fast8_t ordered;
223         uint_fast32_t t, used_entries=0;
224         uint_fast32_t entries;
225
226         AV_DEBUG(" %d. Codebook \n", cb);
227
228         if (get_bits(gb, 24)!=0x564342) {
229             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook setup data corrupt. \n", cb);
230             goto error;
231         }
232
233         codebook_setup->dimensions=get_bits(gb, 16);
234         if (codebook_setup->dimensions>16) {
235             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook's dimension is too large (%d). \n", cb, codebook_setup->dimensions);
236             goto error;
237         }
238         entries=get_bits(gb, 24);
239         if (entries>V_MAX_VLCS) {
240             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook has too many entries (%"PRIdFAST32"). \n", cb, entries);
241             goto error;
242         }
243
244         ordered=get_bits1(gb);
245
246         AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);
247
248         if (!ordered) {
249             uint_fast16_t ce;
250             uint_fast8_t flag;
251             uint_fast8_t sparse=get_bits1(gb);
252
253             AV_DEBUG(" not ordered \n");
254
255             if (sparse) {
256                 AV_DEBUG(" sparse \n");
257
258                 used_entries=0;
259                 for(ce=0;ce<entries;++ce) {
260                     flag=get_bits1(gb);
261                     if (flag) {
262                         tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
263                         ++used_entries;
264                     }
265                     else tmp_vlc_bits[ce]=0;
266                 }
267             } else {
268                 AV_DEBUG(" not sparse \n");
269
270                 used_entries=entries;
271                 for(ce=0;ce<entries;++ce) {
272                     tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
273                 }
274             }
275         } else {
276             uint_fast16_t current_entry=0;
277             uint_fast8_t current_length=get_bits(gb, 5)+1;
278
279             AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME
280
281             used_entries=entries;
282             for(;current_entry<used_entries;++current_length) {
283                 uint_fast16_t i, number;
284
285                 AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));
286
287                 number=get_bits(gb, ilog(entries - current_entry));
288
289                 AV_DEBUG(" number: %d \n", number);
290
291                 for(i=current_entry;i<number+current_entry;++i) {
292                     if (i<used_entries) tmp_vlc_bits[i]=current_length;
293                 }
294
295                 current_entry+=number;
296             }
297             if (current_entry>used_entries) {
298                 av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
299                 goto error;
300             }
301         }
302
303         codebook_setup->lookup_type=get_bits(gb, 4);
304
305         AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup" );
306
307 // If the codebook is used for (inverse) VQ, calculate codevectors.
308
309         if (codebook_setup->lookup_type==1) {
310             uint_fast16_t i, j, k;
311             uint_fast16_t codebook_lookup_values=nth_root(entries, codebook_setup->dimensions);
312             uint_fast16_t codebook_multiplicands[codebook_lookup_values];
313
314             float codebook_minimum_value=vorbisfloat2float(get_bits_long_le(gb, 32));
315             float codebook_delta_value=vorbisfloat2float(get_bits_long_le(gb, 32));
316             uint_fast8_t codebook_value_bits=get_bits(gb, 4)+1;
317             uint_fast8_t codebook_sequence_p=get_bits1(gb);
318
319             AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
320             AV_DEBUG("  delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);
321
322             for(i=0;i<codebook_lookup_values;++i) {
323                 codebook_multiplicands[i]=get_bits(gb, codebook_value_bits);
324
325                 AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
326                 AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
327             }
328
329 // Weed out unused vlcs and build codevector vector
330             codebook_setup->codevectors=(float *)av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float));
331             for(j=0, i=0;i<entries;++i) {
332                 uint_fast8_t dim=codebook_setup->dimensions;
333
334                 if (tmp_vlc_bits[i]) {
335                     float last=0.0;
336                     uint_fast32_t lookup_offset=i;
337
338 #ifdef V_DEBUG
339                     av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
340 #endif
341
342                     for(k=0;k<dim;++k) {
343                         uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
344                         codebook_setup->codevectors[j*dim+k]=codebook_multiplicands[multiplicand_offset]*codebook_delta_value+codebook_minimum_value+last;
345                         if (codebook_sequence_p) {
346                             last=codebook_setup->codevectors[j*dim+k];
347                         }
348                         lookup_offset/=codebook_lookup_values;
349                     }
350                     tmp_vlc_bits[j]=tmp_vlc_bits[i];
351
352 #ifdef V_DEBUG
353                     av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
354                     for(k=0;k<dim;++k) {
355                         av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j*dim+k]);
356                     }
357                     av_log(vc->avccontext, AV_LOG_INFO, "\n");
358 #endif
359
360                     ++j;
361                 }
362             }
363             if (j!=used_entries) {
364                 av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
365                 goto error;
366             }
367             entries=used_entries;
368         }
369         else if (codebook_setup->lookup_type>=2) {
370             av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
371             goto error;
372         }
373
374 // Initialize VLC table
375         if (vorbis_len2vlc(vc, tmp_vlc_bits, tmp_vlc_codes, entries)) {
376             av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
377             goto error;
378         }
379         codebook_setup->maxdepth=0;
380         for(t=0;t<entries;++t)
381             if (tmp_vlc_bits[t]>=codebook_setup->maxdepth) codebook_setup->maxdepth=tmp_vlc_bits[t];
382
383         if(codebook_setup->maxdepth > 3*V_NB_BITS) codebook_setup->nb_bits=V_NB_BITS2;
384         else                                       codebook_setup->nb_bits=V_NB_BITS;
385
386         codebook_setup->maxdepth=(codebook_setup->maxdepth+codebook_setup->nb_bits-1)/codebook_setup->nb_bits;
387
388         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)) {
389             av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
390             goto error;
391         }
392     }
393
394     av_free(tmp_vlc_bits);
395     av_free(tmp_vlc_codes);
396     return 0;
397
398 // Error:
399 error:
400     av_free(tmp_vlc_bits);
401     av_free(tmp_vlc_codes);
402     return 1;
403 }
404
405 // Process time domain transforms part (unused in Vorbis I)
406
407 static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc) {
408     GetBitContext *gb=&vc->gb;
409     uint_fast8_t i;
410     uint_fast8_t vorbis_time_count=get_bits(gb, 6)+1;
411
412     for(i=0;i<vorbis_time_count;++i) {
413         uint_fast16_t vorbis_tdtransform=get_bits(gb, 16);
414
415         AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);
416
417         if (vorbis_tdtransform) {
418             av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
419             return 1;
420         }
421     }
422     return 0;
423 }
424
425 // Process floors part
426
427 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
428                                          vorbis_floor_data *vfu, float *vec);
429 static void create_map( vorbis_context * vc, uint_fast8_t floor_number );
430 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc,
431                                          vorbis_floor_data *vfu, float *vec);
432 static int vorbis_parse_setup_hdr_floors(vorbis_context *vc) {
433     GetBitContext *gb=&vc->gb;
434     uint_fast16_t i,j,k;
435
436     vc->floor_count=get_bits(gb, 6)+1;
437
438     vc->floors=(vorbis_floor *)av_mallocz(vc->floor_count * sizeof(vorbis_floor));
439
440     for (i=0;i<vc->floor_count;++i) {
441         vorbis_floor *floor_setup=&vc->floors[i];
442
443         floor_setup->floor_type=get_bits(gb, 16);
444
445         AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);
446
447         if (floor_setup->floor_type==1) {
448             uint_fast8_t maximum_class=0;
449             uint_fast8_t rangebits;
450             uint_fast16_t floor1_values=2;
451
452             floor_setup->decode=vorbis_floor1_decode;
453
454             floor_setup->data.t1.partitions=get_bits(gb, 5);
455
456             AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->data.t1.partitions);
457
458             for(j=0;j<floor_setup->data.t1.partitions;++j) {
459                 floor_setup->data.t1.partition_class[j]=get_bits(gb, 4);
460                 if (floor_setup->data.t1.partition_class[j]>maximum_class) maximum_class=floor_setup->data.t1.partition_class[j];
461
462                 AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->data.t1.partition_class[j]);
463
464             }
465
466             AV_DEBUG(" maximum class %d \n", maximum_class);
467
468             floor_setup->data.t1.maximum_class=maximum_class;
469
470             for(j=0;j<=maximum_class;++j) {
471                 floor_setup->data.t1.class_dimensions[j]=get_bits(gb, 3)+1;
472                 floor_setup->data.t1.class_subclasses[j]=get_bits(gb, 2);
473
474                 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]);
475
476                 if (floor_setup->data.t1.class_subclasses[j]) {
477                     floor_setup->data.t1.class_masterbook[j]=get_bits(gb, 8);
478
479                     AV_DEBUG("   masterbook: %d \n", floor_setup->data.t1.class_masterbook[j]);
480                 }
481
482                 for(k=0;k<(1<<floor_setup->data.t1.class_subclasses[j]);++k) {
483                     floor_setup->data.t1.subclass_books[j][k]=(int16_t)get_bits(gb, 8)-1;
484
485                     AV_DEBUG("    book %d. : %d \n", k, floor_setup->data.t1.subclass_books[j][k]);
486                 }
487             }
488
489             floor_setup->data.t1.multiplier=get_bits(gb, 2)+1;
490             floor_setup->data.t1.x_list_dim=2;
491
492             for(j=0;j<floor_setup->data.t1.partitions;++j) {
493                 floor_setup->data.t1.x_list_dim+=floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];
494             }
495
496             floor_setup->data.t1.x_list=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
497             floor_setup->data.t1.x_list_order=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
498             floor_setup->data.t1.low_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
499             floor_setup->data.t1.high_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
500
501
502             rangebits=get_bits(gb, 4);
503             floor_setup->data.t1.x_list[0] = 0;
504             floor_setup->data.t1.x_list[1] = (1<<rangebits);
505
506             for(j=0;j<floor_setup->data.t1.partitions;++j) {
507                 for(k=0;k<floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];++k,++floor1_values) {
508                     floor_setup->data.t1.x_list[floor1_values]=get_bits(gb, rangebits);
509
510                     AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->data.t1.x_list[floor1_values]);
511                 }
512             }
513
514 // Precalculate order of x coordinates - needed for decode
515
516             for(k=0;k<floor_setup->data.t1.x_list_dim;++k) {
517                 floor_setup->data.t1.x_list_order[k]=k;
518             }
519
520             for(k=0;k<floor_setup->data.t1.x_list_dim-1;++k) {   // FIXME optimize sorting ?
521                 for(j=k+1;j<floor_setup->data.t1.x_list_dim;++j) {
522                     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]]) {
523                         uint_fast16_t tmp=floor_setup->data.t1.x_list_order[k];
524                         floor_setup->data.t1.x_list_order[k]=floor_setup->data.t1.x_list_order[j];
525                         floor_setup->data.t1.x_list_order[j]=tmp;
526                     }
527                 }
528             }
529
530 // Precalculate low and high neighbours
531
532             for(k=2;k<floor_setup->data.t1.x_list_dim;++k) {
533                 floor_setup->data.t1.low_neighbour[k]=0;
534                 floor_setup->data.t1.high_neighbour[k]=1;  // correct according to SPEC requirements
535
536                 for (j=0;j<k;++j) {
537                     if ((floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[k]) &&
538                       (floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[floor_setup->data.t1.low_neighbour[k]])) {
539                         floor_setup->data.t1.low_neighbour[k]=j;
540                     }
541                     if ((floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[k]) &&
542                       (floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[floor_setup->data.t1.high_neighbour[k]])) {
543                         floor_setup->data.t1.high_neighbour[k]=j;
544                     }
545                 }
546             }
547         }
548         else if(floor_setup->floor_type==0) {
549             uint_fast8_t max_codebook_dim=0;
550
551             floor_setup->decode=vorbis_floor0_decode;
552
553             floor_setup->data.t0.order=get_bits(gb, 8);
554             floor_setup->data.t0.rate=get_bits(gb, 16);
555             floor_setup->data.t0.bark_map_size=get_bits(gb, 16);
556             floor_setup->data.t0.amplitude_bits=get_bits(gb, 6);
557             /* zero would result in a div by zero later *
558              * 2^0 - 1 == 0                             */
559             if (floor_setup->data.t0.amplitude_bits == 0) {
560               av_log(vc->avccontext, AV_LOG_ERROR,
561                      "Floor 0 amplitude bits is 0.\n");
562               return 1;
563             }
564             floor_setup->data.t0.amplitude_offset=get_bits(gb, 8);
565             floor_setup->data.t0.num_books=get_bits(gb, 4)+1;
566
567             /* allocate mem for booklist */
568             floor_setup->data.t0.book_list=
569                 av_malloc(floor_setup->data.t0.num_books);
570             if(!floor_setup->data.t0.book_list) { return 1; }
571             /* read book indexes */
572             {
573                 int idx;
574                 uint_fast8_t book_idx;
575                 for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
576                     book_idx=get_bits(gb, 8);
577                     floor_setup->data.t0.book_list[idx]=book_idx;
578                     if (vc->codebooks[book_idx].dimensions > max_codebook_dim)
579                         max_codebook_dim=vc->codebooks[book_idx].dimensions;
580
581                     if (floor_setup->data.t0.book_list[idx]>vc->codebook_count)
582                         return 1;
583                 }
584             }
585
586             create_map( vc, i );
587
588             /* allocate mem for lsp coefficients */
589             {
590                 /* codebook dim is for padding if codebook dim doesn't *
591                  * divide order+1 then we need to read more data       */
592                 floor_setup->data.t0.lsp=
593                     av_malloc((floor_setup->data.t0.order+1 + max_codebook_dim)
594                               * sizeof(float));
595                 if(!floor_setup->data.t0.lsp) { return 1; }
596             }
597
598 #ifdef V_DEBUG /* debug output parsed headers */
599             AV_DEBUG("floor0 order: %u\n", floor_setup->data.t0.order);
600             AV_DEBUG("floor0 rate: %u\n", floor_setup->data.t0.rate);
601             AV_DEBUG("floor0 bark map size: %u\n",
602               floor_setup->data.t0.bark_map_size);
603             AV_DEBUG("floor0 amplitude bits: %u\n",
604               floor_setup->data.t0.amplitude_bits);
605             AV_DEBUG("floor0 amplitude offset: %u\n",
606               floor_setup->data.t0.amplitude_offset);
607             AV_DEBUG("floor0 number of books: %u\n",
608               floor_setup->data.t0.num_books);
609             AV_DEBUG("floor0 book list pointer: %p\n",
610               floor_setup->data.t0.book_list);
611             {
612               int idx;
613               for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
614                 AV_DEBUG( "  Book %d: %u\n",
615                   idx+1,
616                   floor_setup->data.t0.book_list[idx] );
617               }
618             }
619 #endif
620         }
621         else {
622             av_log(vc->avccontext, AV_LOG_ERROR, "Invalid floor type!\n");
623             return 1;
624         }
625     }
626     return 0;
627 }
628
629 // Process residues part
630
631 static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
632     GetBitContext *gb=&vc->gb;
633     uint_fast8_t i, j, k;
634
635     vc->residue_count=get_bits(gb, 6)+1;
636     vc->residues=(vorbis_residue *)av_mallocz(vc->residue_count * sizeof(vorbis_residue));
637
638     AV_DEBUG(" There are %d residues. \n", vc->residue_count);
639
640     for(i=0;i<vc->residue_count;++i) {
641         vorbis_residue *res_setup=&vc->residues[i];
642         uint_fast8_t cascade[64];
643         uint_fast8_t high_bits;
644         uint_fast8_t low_bits;
645
646         res_setup->type=get_bits(gb, 16);
647
648         AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);
649
650         res_setup->begin=get_bits(gb, 24);
651         res_setup->end=get_bits(gb, 24);
652         res_setup->partition_size=get_bits(gb, 24)+1;
653         res_setup->classifications=get_bits(gb, 6)+1;
654         res_setup->classbook=get_bits(gb, 8);
655
656         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,
657           res_setup->classifications, res_setup->classbook);
658
659         for(j=0;j<res_setup->classifications;++j) {
660             high_bits=0;
661             low_bits=get_bits(gb, 3);
662             if (get_bits1(gb)) {
663                 high_bits=get_bits(gb, 5);
664             }
665             cascade[j]=(high_bits<<3)+low_bits;
666
667             AV_DEBUG("     %d class casscade depth: %d \n", j, ilog(cascade[j]));
668         }
669
670         res_setup->maxpass=0;
671         for(j=0;j<res_setup->classifications;++j) {
672             for(k=0;k<8;++k) {
673                 if (cascade[j]&(1<<k)) {
674                         res_setup->books[j][k]=get_bits(gb, 8);
675
676                     AV_DEBUG("     %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);
677
678                     if (k>res_setup->maxpass) {
679                         res_setup->maxpass=k;
680                     }
681                 } else {
682                     res_setup->books[j][k]=-1;
683                 }
684             }
685         }
686     }
687     return 0;
688 }
689
690 // Process mappings part
691
692 static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc) {
693     GetBitContext *gb=&vc->gb;
694     uint_fast8_t i, j;
695
696     vc->mapping_count=get_bits(gb, 6)+1;
697     vc->mappings=(vorbis_mapping *)av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));
698
699     AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);
700
701     for(i=0;i<vc->mapping_count;++i) {
702         vorbis_mapping *mapping_setup=&vc->mappings[i];
703
704         if (get_bits(gb, 16)) {
705             av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
706             return 1;
707         }
708         if (get_bits1(gb)) {
709             mapping_setup->submaps=get_bits(gb, 4)+1;
710         } else {
711             mapping_setup->submaps=1;
712         }
713
714         if (get_bits1(gb)) {
715             mapping_setup->coupling_steps=get_bits(gb, 8)+1;
716             mapping_setup->magnitude=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
717             mapping_setup->angle=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
718             for(j=0;j<mapping_setup->coupling_steps;++j) {
719                 mapping_setup->magnitude[j]=get_bits(gb, ilog(vc->audio_channels-1));
720                 mapping_setup->angle[j]=get_bits(gb, ilog(vc->audio_channels-1));
721                 // FIXME: sanity checks
722             }
723         } else {
724             mapping_setup->coupling_steps=0;
725         }
726
727         AV_DEBUG("   %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);
728
729         if(get_bits(gb, 2)) {
730             av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
731             return 1; // following spec.
732         }
733
734         if (mapping_setup->submaps>1) {
735             mapping_setup->mux=(uint_fast8_t *)av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
736             for(j=0;j<vc->audio_channels;++j) {
737                 mapping_setup->mux[j]=get_bits(gb, 4);
738             }
739         }
740
741         for(j=0;j<mapping_setup->submaps;++j) {
742             get_bits(gb, 8); // FIXME check?
743             mapping_setup->submap_floor[j]=get_bits(gb, 8);
744             mapping_setup->submap_residue[j]=get_bits(gb, 8);
745
746             AV_DEBUG("   %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
747         }
748     }
749     return 0;
750 }
751
752 // Process modes part
753
754 static void create_map( vorbis_context * vc, uint_fast8_t floor_number )
755 {
756     vorbis_floor * floors=vc->floors;
757     vorbis_floor0 * vf;
758     int idx;
759     int_fast8_t blockflag;
760     int_fast32_t * map;
761     int_fast32_t n; //TODO: could theoretically be smaller?
762
763     for (blockflag=0;blockflag<2;++blockflag)
764     {
765     n=(blockflag ? vc->blocksize[1] : vc->blocksize[0]) / 2;
766     floors[floor_number].data.t0.map[blockflag]=
767         av_malloc((n+1) * sizeof(int_fast32_t)); // n+sentinel
768
769     map=floors[floor_number].data.t0.map[blockflag];
770     vf=&floors[floor_number].data.t0;
771
772     for (idx=0; idx<n;++idx) {
773         map[idx]=floor( BARK((vf->rate*idx)/(2.0f*n)) *
774                               ((vf->bark_map_size)/
775                                BARK(vf->rate/2.0f )) );
776         if (vf->bark_map_size-1 < map[idx]) {
777             map[idx]=vf->bark_map_size-1;
778         }
779     }
780     map[n]=-1;
781     vf->map_size[blockflag]=n;
782     }
783
784 #   ifdef V_DEBUG
785     for(idx=0;idx<=n;++idx) {
786         AV_DEBUG("floor0 map: map at pos %d is %d\n",
787                  idx, map[idx]);
788     }
789 #   endif
790 }
791
792 static int vorbis_parse_setup_hdr_modes(vorbis_context *vc) {
793     GetBitContext *gb=&vc->gb;
794     uint_fast8_t i;
795
796     vc->mode_count=get_bits(gb, 6)+1;
797     vc->modes=(vorbis_mode *)av_mallocz(vc->mode_count * sizeof(vorbis_mode));
798
799     AV_DEBUG(" There are %d modes.\n", vc->mode_count);
800
801     for(i=0;i<vc->mode_count;++i) {
802         vorbis_mode *mode_setup=&vc->modes[i];
803
804         mode_setup->blockflag=get_bits(gb, 1);
805         mode_setup->windowtype=get_bits(gb, 16); //FIXME check
806         mode_setup->transformtype=get_bits(gb, 16); //FIXME check
807         mode_setup->mapping=get_bits(gb, 8); //FIXME check
808
809         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);
810     }
811     return 0;
812 }
813
814 // Process the whole setup header using the functions above
815
816 static int vorbis_parse_setup_hdr(vorbis_context *vc) {
817     GetBitContext *gb=&vc->gb;
818
819     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
820     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
821     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
822         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
823         return 1;
824     }
825
826     if (vorbis_parse_setup_hdr_codebooks(vc)) {
827         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
828         return 2;
829     }
830     if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
831         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
832         return 3;
833     }
834     if (vorbis_parse_setup_hdr_floors(vc)) {
835         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
836         return 4;
837     }
838     if (vorbis_parse_setup_hdr_residues(vc)) {
839         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
840         return 5;
841     }
842     if (vorbis_parse_setup_hdr_mappings(vc)) {
843         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
844         return 6;
845     }
846     if (vorbis_parse_setup_hdr_modes(vc)) {
847         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
848         return 7;
849     }
850     if (!get_bits1(gb)) {
851         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
852         return 8; // framing flag bit unset error
853     }
854
855     return 0;
856 }
857
858 // Process the identification header
859
860 static int vorbis_parse_id_hdr(vorbis_context *vc){
861     GetBitContext *gb=&vc->gb;
862     uint_fast8_t bl0, bl1;
863     const float *vwin[8]={ vwin64, vwin128, vwin256, vwin512, vwin1024, vwin2048, vwin4096, vwin8192 };
864
865     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
866     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
867     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
868         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
869         return 1;
870     }
871
872     vc->version=get_bits_long_le(gb, 32);    //FIXME check 0
873     vc->audio_channels=get_bits(gb, 8);   //FIXME check >0
874     vc->audio_samplerate=get_bits_long_le(gb, 32);   //FIXME check >0
875     vc->bitrate_maximum=get_bits_long_le(gb, 32);
876     vc->bitrate_nominal=get_bits_long_le(gb, 32);
877     vc->bitrate_minimum=get_bits_long_le(gb, 32);
878     bl0=get_bits(gb, 4);
879     bl1=get_bits(gb, 4);
880     vc->blocksize[0]=(1<<bl0);
881     vc->blocksize[1]=(1<<bl1);
882     if (bl0>13 || bl0<6 || bl1>13 || bl1<6 || bl1<bl0) {
883         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
884         return 3;
885     }
886     // output format int16
887     if (vc->blocksize[1]/2 * vc->audio_channels * 2 >
888                                              AVCODEC_MAX_AUDIO_FRAME_SIZE) {
889         av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis channel count makes "
890                "output packets too large.\n");
891         return 4;
892     }
893     vc->win[0]=vwin[bl0-6];
894     vc->win[1]=vwin[bl1-6];
895
896     if(vc->exp_bias){
897         int i, j;
898         for(j=0; j<2; j++){
899             float *win = av_malloc(vc->blocksize[j]/2 * sizeof(float));
900             for(i=0; i<vc->blocksize[j]/2; i++)
901                 win[i] = vc->win[j][i] * (1<<15);
902             vc->win[j] = win;
903         }
904     }
905
906     if ((get_bits1(gb)) == 0) {
907         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
908         return 2;
909     }
910
911     vc->channel_residues=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
912     vc->channel_floors=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
913     vc->saved=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
914     vc->ret=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
915     vc->buf=(float *)av_malloc(vc->blocksize[1] * sizeof(float));
916     vc->buf_tmp=(float *)av_malloc(vc->blocksize[1] * sizeof(float));
917     vc->saved_start=0;
918
919     ff_mdct_init(&vc->mdct[0], bl0, 1);
920     ff_mdct_init(&vc->mdct[1], bl1, 1);
921
922     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 ",
923             vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize[0], vc->blocksize[1]);
924
925 /*
926     BLK=vc->blocksize[0];
927     for(i=0;i<BLK/2;++i) {
928         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)));
929     }
930 */
931
932     return 0;
933 }
934
935 // Process the extradata using the functions above (identification header, setup header)
936
937 static int vorbis_decode_init(AVCodecContext *avccontext) {
938     vorbis_context *vc = avccontext->priv_data ;
939     uint8_t *headers = avccontext->extradata;
940     int headers_len=avccontext->extradata_size;
941     uint8_t *header_start[3];
942     int header_len[3];
943     GetBitContext *gb = &(vc->gb);
944     int i, j, hdr_type;
945
946     vc->avccontext = avccontext;
947     dsputil_init(&vc->dsp, avccontext);
948
949     if(vc->dsp.float_to_int16 == ff_float_to_int16_c) {
950         vc->add_bias = 385;
951         vc->exp_bias = 0;
952     } else {
953         vc->add_bias = 0;
954         vc->exp_bias = 15<<23;
955     }
956
957     if (!headers_len) {
958         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
959         return -1;
960     }
961
962     if(headers[0] == 0 && headers[1] == 30) {
963         for(i = 0; i < 3; i++){
964             header_len[i] = *headers++ << 8;
965             header_len[i] += *headers++;
966             header_start[i] = headers;
967             headers += header_len[i];
968         }
969     } else if(headers[0] == 2) {
970         for(j=1,i=0;i<2;++i, ++j) {
971             header_len[i]=0;
972             while(j<headers_len && headers[j]==0xff) {
973                 header_len[i]+=0xff;
974                 ++j;
975             }
976             if (j>=headers_len) {
977                 av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
978                 return -1;
979             }
980             header_len[i]+=headers[j];
981         }
982         header_len[2]=headers_len-header_len[0]-header_len[1]-j;
983         headers+=j;
984         header_start[0] = headers;
985         header_start[1] = header_start[0] + header_len[0];
986         header_start[2] = header_start[1] + header_len[1];
987     } else {
988         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
989         return -1;
990     }
991
992     init_get_bits(gb, header_start[0], header_len[0]*8);
993     hdr_type=get_bits(gb, 8);
994     if (hdr_type!=1) {
995         av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
996         return -1;
997     }
998     if (vorbis_parse_id_hdr(vc)) {
999         av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
1000         vorbis_free(vc);
1001         return -1;
1002     }
1003
1004     init_get_bits(gb, header_start[2], header_len[2]*8);
1005     hdr_type=get_bits(gb, 8);
1006     if (hdr_type!=5) {
1007         av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
1008         return -1;
1009     }
1010     if (vorbis_parse_setup_hdr(vc)) {
1011         av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
1012         vorbis_free(vc);
1013         return -1;
1014     }
1015
1016     avccontext->channels = vc->audio_channels;
1017     avccontext->sample_rate = vc->audio_samplerate;
1018
1019     return 0 ;
1020 }
1021
1022 // Decode audiopackets -------------------------------------------------
1023
1024 // Read and decode floor
1025
1026 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
1027                                          vorbis_floor_data *vfu, float *vec) {
1028     vorbis_floor0 * vf=&vfu->t0;
1029     float * lsp=vf->lsp;
1030     uint_fast32_t amplitude;
1031     uint_fast32_t book_idx;
1032     uint_fast8_t blockflag=vc->modes[vc->mode_number].blockflag;
1033
1034     amplitude=get_bits(&vc->gb, vf->amplitude_bits);
1035     if (amplitude>0) {
1036         float last = 0;
1037         uint_fast16_t lsp_len = 0;
1038         uint_fast16_t idx;
1039         vorbis_codebook codebook;
1040
1041         book_idx=get_bits(&vc->gb, ilog(vf->num_books));
1042         if ( book_idx >= vf->num_books ) {
1043             av_log( vc->avccontext, AV_LOG_ERROR,
1044                     "floor0 dec: booknumber too high!\n" );
1045             //FIXME: look above
1046         }
1047         AV_DEBUG( "floor0 dec: booknumber: %u\n", book_idx );
1048         codebook=vc->codebooks[vf->book_list[book_idx]];
1049
1050         while (lsp_len<vf->order) {
1051             int vec_off;
1052
1053             AV_DEBUG( "floor0 dec: book dimension: %d\n", codebook.dimensions );
1054             AV_DEBUG( "floor0 dec: maximum depth: %d\n", codebook.maxdepth );
1055             /* read temp vector */
1056             vec_off=get_vlc2(&vc->gb,
1057                              codebook.vlc.table,
1058                              codebook.nb_bits,
1059                              codebook.maxdepth ) *
1060                              codebook.dimensions;
1061             AV_DEBUG( "floor0 dec: vector offset: %d\n", vec_off );
1062             /* copy each vector component and add last to it */
1063             for (idx=0; idx<codebook.dimensions; ++idx) {
1064                 lsp[lsp_len+idx]=codebook.codevectors[vec_off+idx]+last;
1065             }
1066             last=lsp[lsp_len+idx-1]; /* set last to last vector component */
1067
1068             lsp_len += codebook.dimensions;
1069         }
1070 #ifdef V_DEBUG
1071         /* DEBUG: output lsp coeffs */
1072         {
1073             int idx;
1074             for ( idx = 0; idx < lsp_len; ++idx )
1075                 AV_DEBUG("floor0 dec: coeff at %d is %f\n", idx, lsp[idx] );
1076         }
1077 #endif
1078
1079         /* synthesize floor output vector */
1080         {
1081             int i;
1082             int order=vf->order;
1083             float wstep=M_PI/vf->bark_map_size;
1084
1085             for(i=0;i<order;i++) { lsp[i]=2.0f*cos(lsp[i]); }
1086
1087             AV_DEBUG("floor0 synth: map_size=%d; m=%d; wstep=%f\n",
1088                      vf->map_size, order, wstep);
1089
1090             i=0;
1091             while(i<vf->map_size[blockflag]) {
1092                 int j, iter_cond=vf->map[blockflag][i];
1093                 float p=0.5f;
1094                 float q=0.5f;
1095                 float two_cos_w=2.0f*cos(wstep*iter_cond); // needed all times
1096
1097                 /* similar part for the q and p products */
1098                 for(j=0;j<order;j+=2) {
1099                     q *= lsp[j]  -two_cos_w;
1100                     p *= lsp[j+1]-two_cos_w;
1101                 }
1102                 if(j==order) { // even order
1103                     p *= p*(2.0f-two_cos_w);
1104                     q *= q*(2.0f+two_cos_w);
1105                 }
1106                 else { // odd order
1107                     q *= two_cos_w-lsp[j]; // one more time for q
1108
1109                     /* final step and square */
1110                     p *= p*(4.f-two_cos_w*two_cos_w);
1111                     q *= q;
1112                 }
1113
1114                 /* calculate linear floor value */
1115                 {
1116                     q=exp( (
1117                              ( (amplitude*vf->amplitude_offset)/
1118                                (((1<<vf->amplitude_bits)-1) * sqrt(p+q)) )
1119                              - vf->amplitude_offset ) * .11512925f
1120                          );
1121                 }
1122
1123                 /* fill vector */
1124                 do { vec[i]=q; ++i; }while(vf->map[blockflag][i]==iter_cond);
1125             }
1126         }
1127     }
1128     else {
1129         /* this channel is unused */
1130         return 1;
1131     }
1132
1133     AV_DEBUG(" Floor0 decoded\n");
1134
1135     return 0;
1136 }
1137 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *vfu, float *vec) {
1138     vorbis_floor1 * vf=&vfu->t1;
1139     GetBitContext *gb=&vc->gb;
1140     uint_fast16_t range_v[4]={ 256, 128, 86, 64 };
1141     uint_fast16_t range=range_v[vf->multiplier-1];
1142     uint_fast16_t floor1_Y[vf->x_list_dim];
1143     uint_fast16_t floor1_Y_final[vf->x_list_dim];
1144     uint_fast8_t floor1_flag[vf->x_list_dim];
1145     uint_fast8_t class_;
1146     uint_fast8_t cdim;
1147     uint_fast8_t cbits;
1148     uint_fast8_t csub;
1149     uint_fast8_t cval;
1150     int_fast16_t book;
1151     uint_fast16_t offset;
1152     uint_fast16_t i,j;
1153     uint_fast16_t *floor_x_sort=vf->x_list_order;
1154     /*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx= (unsigned)dy/adx ?
1155     int_fast16_t dy, err;
1156     uint_fast16_t lx,hx, ly, hy=0;
1157
1158
1159     if (!get_bits1(gb)) return 1; // silence
1160
1161 // Read values (or differences) for the floor's points
1162
1163     floor1_Y[0]=get_bits(gb, ilog(range-1));
1164     floor1_Y[1]=get_bits(gb, ilog(range-1));
1165
1166     AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);
1167
1168     offset=2;
1169     for(i=0;i<vf->partitions;++i) {
1170         class_=vf->partition_class[i];
1171         cdim=vf->class_dimensions[class_];
1172         cbits=vf->class_subclasses[class_];
1173         csub=(1<<cbits)-1;
1174         cval=0;
1175
1176         AV_DEBUG("Cbits %d \n", cbits);
1177
1178         if (cbits) { // this reads all subclasses for this partition's class
1179             cval=get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,
1180             vc->codebooks[vf->class_masterbook[class_]].nb_bits, 3);
1181         }
1182
1183         for(j=0;j<cdim;++j) {
1184             book=vf->subclass_books[class_][cval & csub];
1185
1186             AV_DEBUG("book %d Cbits %d cval %d  bits:%d \n", book, cbits, cval, get_bits_count(gb));
1187
1188             cval=cval>>cbits;
1189             if (book>0) {
1190                 floor1_Y[offset+j]=get_vlc2(gb, vc->codebooks[book].vlc.table,
1191                 vc->codebooks[book].nb_bits, 3);
1192             } else {
1193                 floor1_Y[offset+j]=0;
1194             }
1195
1196             AV_DEBUG(" floor(%d) = %d \n", vf->x_list[offset+j], floor1_Y[offset+j]);
1197         }
1198         offset+=cdim;
1199     }
1200
1201 // Amplitude calculation from the differences
1202
1203     floor1_flag[0]=1;
1204     floor1_flag[1]=1;
1205     floor1_Y_final[0]=floor1_Y[0];
1206     floor1_Y_final[1]=floor1_Y[1];
1207
1208     for(i=2;i<vf->x_list_dim;++i) {
1209         uint_fast16_t val, highroom, lowroom, room;
1210         uint_fast16_t high_neigh_offs;
1211         uint_fast16_t low_neigh_offs;
1212
1213         low_neigh_offs=vf->low_neighbour[i];
1214         high_neigh_offs=vf->high_neighbour[i];
1215         dy=floor1_Y_final[high_neigh_offs]-floor1_Y_final[low_neigh_offs];  // render_point begin
1216         adx=vf->x_list[high_neigh_offs]-vf->x_list[low_neigh_offs];
1217         ady= ABS(dy);
1218         err=ady*(vf->x_list[i]-vf->x_list[low_neigh_offs]);
1219         off=(int16_t)err/(int16_t)adx;
1220         if (dy<0) {
1221             predicted=floor1_Y_final[low_neigh_offs]-off;
1222         } else {
1223             predicted=floor1_Y_final[low_neigh_offs]+off;
1224         } // render_point end
1225
1226         val=floor1_Y[i];
1227         highroom=range-predicted;
1228         lowroom=predicted;
1229         if (highroom < lowroom) {
1230             room=highroom*2;
1231         } else {
1232             room=lowroom*2;   // SPEC mispelling
1233         }
1234         if (val) {
1235             floor1_flag[low_neigh_offs]=1;
1236             floor1_flag[high_neigh_offs]=1;
1237             floor1_flag[i]=1;
1238             if (val>=room) {
1239                 if (highroom > lowroom) {
1240                     floor1_Y_final[i]=val-lowroom+predicted;
1241                 } else {
1242                     floor1_Y_final[i]=predicted-val+highroom-1;
1243                 }
1244             } else {
1245                 if (val & 1) {
1246                     floor1_Y_final[i]=predicted-(val+1)/2;
1247                 } else {
1248                     floor1_Y_final[i]=predicted+val/2;
1249                 }
1250             }
1251         } else {
1252             floor1_flag[i]=0;
1253             floor1_Y_final[i]=predicted;
1254         }
1255
1256         AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->x_list[i], floor1_Y_final[i], val);
1257     }
1258
1259 // Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?
1260
1261     hx=0;
1262     lx=0;
1263     ly=floor1_Y_final[0]*vf->multiplier;  // conforms to SPEC
1264
1265     vec[0]=floor1_inverse_db_table[ly];
1266
1267     for(i=1;i<vf->x_list_dim;++i) {
1268         AV_DEBUG(" Looking at post %d \n", i);
1269
1270         if (floor1_flag[floor_x_sort[i]]) {   // SPEC mispelled
1271             int_fast16_t x, y, dy, base, sy; // if uncommented: dy = -32 adx = 2  base = 2blablabla ?????
1272
1273             hy=floor1_Y_final[floor_x_sort[i]]*vf->multiplier;
1274             hx=vf->x_list[floor_x_sort[i]];
1275
1276             dy=hy-ly;
1277             adx=hx-lx;
1278             ady= (dy<0) ? -dy:dy;//ABS(dy);
1279             base=(int16_t)dy/(int16_t)adx;
1280
1281             AV_DEBUG(" dy %d  adx %d base %d = %d \n", dy, adx, base, dy/adx);
1282
1283             x=lx;
1284             y=ly;
1285             err=0;
1286             if (dy<0) {
1287                 sy=base-1;
1288             } else {
1289                 sy=base+1;
1290             }
1291             ady=ady-(base<0 ? -base : base)*adx;
1292             vec[x]=floor1_inverse_db_table[y];
1293
1294             AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1295
1296             for(x=lx+1;(x<hx) && (x<vf->x_list[1]);++x) {
1297                 err+=ady;
1298                 if (err>=adx) {
1299                     err-=adx;
1300                     y+=sy;
1301                 } else {
1302                     y+=base;
1303                 }
1304                 vec[x]=floor1_inverse_db_table[y];
1305
1306                 AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1307             }
1308
1309 /*            for(j=1;j<hx-lx+1;++j) {  // iterating render_point
1310                 dy=hy-ly;
1311                 adx=hx-lx;
1312                 ady= dy<0 ? -dy : dy;
1313                 err=ady*j;
1314                 off=err/adx;
1315                 if (dy<0) {
1316                     predicted=ly-off;
1317                 } else {
1318                     predicted=ly+off;
1319                 }
1320                 if (lx+j < vf->x_list[1]) {
1321                     vec[lx+j]=floor1_inverse_db_table[predicted];
1322                 }
1323             }*/
1324
1325             lx=hx;
1326             ly=hy;
1327         }
1328     }
1329
1330     if (hx<vf->x_list[1]) {
1331         for(i=hx;i<vf->x_list[1];++i) {
1332             vec[i]=floor1_inverse_db_table[hy];
1333         }
1334     }
1335
1336     AV_DEBUG(" Floor decoded\n");
1337
1338     return 0;
1339 }
1340
1341 // Read and decode residue
1342
1343 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) {
1344     GetBitContext *gb=&vc->gb;
1345     uint_fast8_t c_p_c=vc->codebooks[vr->classbook].dimensions;
1346     uint_fast16_t n_to_read=vr->end-vr->begin;
1347     uint_fast16_t ptns_to_read=n_to_read/vr->partition_size;
1348     uint_fast8_t classifs[ptns_to_read*vc->audio_channels];
1349     uint_fast8_t pass;
1350     uint_fast8_t ch_used;
1351     uint_fast8_t i,j,l;
1352     uint_fast16_t k;
1353
1354     if (vr->type==2) {
1355         for(j=1;j<ch;++j) {
1356                 do_not_decode[0]&=do_not_decode[j];  // FIXME - clobbering input
1357         }
1358         if (do_not_decode[0]) return 0;
1359         ch_used=1;
1360     } else {
1361         ch_used=ch;
1362     }
1363
1364     AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d  cpc %d  \n", ch, c_p_c);
1365
1366     for(pass=0;pass<=vr->maxpass;++pass) { // FIXME OPTIMIZE?
1367         uint_fast16_t voffset;
1368         uint_fast16_t partition_count;
1369         uint_fast16_t j_times_ptns_to_read;
1370
1371         voffset=vr->begin;
1372         for(partition_count=0;partition_count<ptns_to_read;) {  // SPEC        error
1373             if (!pass) {
1374                 uint_fast32_t inverse_class = inverse[vr->classifications];
1375                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1376                     if (!do_not_decode[j]) {
1377                         uint_fast32_t temp=get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,
1378                         vc->codebooks[vr->classbook].nb_bits, 3);
1379
1380                         AV_DEBUG("Classword: %d \n", temp);
1381
1382                         assert(vr->classifications > 1 && temp<=65536); //needed for inverse[]
1383                         for(i=0;i<c_p_c;++i) {
1384                             uint_fast32_t temp2;
1385
1386                             temp2=(((uint_fast64_t)temp) * inverse_class)>>32;
1387                             if (partition_count+c_p_c-1-i < ptns_to_read) {
1388                                 classifs[j_times_ptns_to_read+partition_count+c_p_c-1-i]=temp-temp2*vr->classifications;
1389                             }
1390                             temp=temp2;
1391                         }
1392                     }
1393                     j_times_ptns_to_read+=ptns_to_read;
1394                 }
1395             }
1396             for(i=0;(i<c_p_c) && (partition_count<ptns_to_read);++i) {
1397                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1398                     uint_fast16_t voffs;
1399
1400                     if (!do_not_decode[j]) {
1401                         uint_fast8_t vqclass=classifs[j_times_ptns_to_read+partition_count];
1402                         int_fast16_t vqbook=vr->books[vqclass][pass];
1403
1404                         if (vqbook>=0) {
1405                             uint_fast16_t coffs;
1406                             unsigned dim= vc->codebooks[vqbook].dimensions; // not uint_fast8_t: 64bit is slower here on amd64
1407                             uint_fast16_t step= dim==1 ? vr->partition_size
1408                                               : FASTDIV(vr->partition_size, dim);
1409                             vorbis_codebook codebook= vc->codebooks[vqbook];
1410
1411                             if (vr->type==0) {
1412
1413                                 voffs=voffset+j*vlen;
1414                                 for(k=0;k<step;++k) {
1415                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1416                                     for(l=0;l<dim;++l) {
1417                                         vec[voffs+k+l*step]+=codebook.codevectors[coffs+l];  // FPMATH
1418                                     }
1419                                 }
1420                             }
1421                             else if (vr->type==1) {
1422                                 voffs=voffset+j*vlen;
1423                                 for(k=0;k<step;++k) {
1424                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1425                                     for(l=0;l<dim;++l, ++voffs) {
1426                                         vec[voffs]+=codebook.codevectors[coffs+l];  // FPMATH
1427
1428                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d  \n", pass, voffs, vec[voffs], codebook.codevectors[coffs+l], coffs);
1429                                     }
1430                                 }
1431                             }
1432                             else if (vr->type==2 && ch==2 && (voffset&1)==0 && (dim&1)==0) { // most frequent case optimized
1433                                 voffs=voffset>>1;
1434
1435                                 if(dim==2) {
1436                                     for(k=0;k<step;++k) {
1437                                         coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * 2;
1438                                         vec[voffs+k     ]+=codebook.codevectors[coffs  ];  // FPMATH
1439                                         vec[voffs+k+vlen]+=codebook.codevectors[coffs+1];  // FPMATH
1440                                     }
1441                                 } else
1442                                 for(k=0;k<step;++k) {
1443                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1444                                     for(l=0;l<dim;l+=2, voffs++) {
1445                                         vec[voffs     ]+=codebook.codevectors[coffs+l  ];  // FPMATH
1446                                         vec[voffs+vlen]+=codebook.codevectors[coffs+l+1];  // FPMATH
1447
1448                                         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);
1449                                     }
1450                                 }
1451
1452                             }
1453                             else if (vr->type==2) {
1454                                 voffs=voffset;
1455
1456                                 for(k=0;k<step;++k) {
1457                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
1458                                     for(l=0;l<dim;++l, ++voffs) {
1459                                         vec[voffs/ch+(voffs%ch)*vlen]+=codebook.codevectors[coffs+l];  // FPMATH FIXME use if and counter instead of / and %
1460
1461                                         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);
1462                                     }
1463                                 }
1464                             } else {
1465                                 av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n");
1466                                 return 1;
1467                             }
1468                         }
1469                     }
1470                     j_times_ptns_to_read+=ptns_to_read;
1471                 }
1472                 ++partition_count;
1473                 voffset+=vr->partition_size;
1474             }
1475         }
1476     }
1477     return 0;
1478 }
1479
1480 void vorbis_inverse_coupling(float *mag, float *ang, int blocksize)
1481 {
1482     int i;
1483     for(i=0; i<blocksize; i++)
1484     {
1485         if (mag[i]>0.0) {
1486             if (ang[i]>0.0) {
1487                 ang[i]=mag[i]-ang[i];
1488             } else {
1489                 float temp=ang[i];
1490                 ang[i]=mag[i];
1491                 mag[i]+=temp;
1492             }
1493         } else {
1494             if (ang[i]>0.0) {
1495                 ang[i]+=mag[i];
1496             } else {
1497                 float temp=ang[i];
1498                 ang[i]=mag[i];
1499                 mag[i]-=temp;
1500             }
1501         }
1502     }
1503 }
1504
1505 // Decode the audio packet using the functions above
1506
1507 static int vorbis_parse_audio_packet(vorbis_context *vc) {
1508     GetBitContext *gb=&vc->gb;
1509
1510     uint_fast8_t previous_window=0,next_window=0;
1511     uint_fast8_t mode_number;
1512     uint_fast16_t blocksize;
1513     int_fast32_t i,j;
1514     uint_fast8_t no_residue[vc->audio_channels];
1515     uint_fast8_t do_not_decode[vc->audio_channels];
1516     vorbis_mapping *mapping;
1517     float *ch_res_ptr=vc->channel_residues;
1518     float *ch_floor_ptr=vc->channel_floors;
1519     uint_fast8_t res_chan[vc->audio_channels];
1520     uint_fast8_t res_num=0;
1521     int_fast16_t retlen=0;
1522     uint_fast16_t saved_start=0;
1523     float fadd_bias = vc->add_bias;
1524
1525     if (get_bits1(gb)) {
1526         av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n");
1527         return -1; // packet type not audio
1528     }
1529
1530     if (vc->mode_count==1) {
1531         mode_number=0;
1532     } else {
1533         mode_number=get_bits(gb, ilog(vc->mode_count-1));
1534     }
1535     vc->mode_number=mode_number;
1536     mapping=&vc->mappings[vc->modes[mode_number].mapping];
1537
1538     AV_DEBUG(" Mode number: %d , mapping: %d , blocktype %d \n", mode_number, vc->modes[mode_number].mapping, vc->modes[mode_number].blockflag);
1539
1540     if (vc->modes[mode_number].blockflag) {
1541         previous_window=get_bits1(gb);
1542         next_window=get_bits1(gb);
1543     }
1544
1545     blocksize=vc->blocksize[vc->modes[mode_number].blockflag];
1546     memset(ch_res_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1547     memset(ch_floor_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1548
1549 // Decode floor
1550
1551     for(i=0;i<vc->audio_channels;++i) {
1552         vorbis_floor *floor;
1553         if (mapping->submaps>1) {
1554             floor=&vc->floors[mapping->submap_floor[mapping->mux[i]]];
1555         } else {
1556             floor=&vc->floors[mapping->submap_floor[0]];
1557         }
1558
1559         no_residue[i]=floor->decode(vc, &floor->data, ch_floor_ptr);
1560         ch_floor_ptr+=blocksize/2;
1561     }
1562
1563 // Nonzero vector propagate
1564
1565     for(i=mapping->coupling_steps-1;i>=0;--i) {
1566         if (!(no_residue[mapping->magnitude[i]] & no_residue[mapping->angle[i]])) {
1567             no_residue[mapping->magnitude[i]]=0;
1568             no_residue[mapping->angle[i]]=0;
1569         }
1570     }
1571
1572 // Decode residue
1573
1574     for(i=0;i<mapping->submaps;++i) {
1575         vorbis_residue *residue;
1576         uint_fast8_t ch=0;
1577
1578         for(j=0;j<vc->audio_channels;++j) {
1579             if ((mapping->submaps==1) || (i=mapping->mux[j])) {
1580                 res_chan[j]=res_num;
1581                 if (no_residue[j]) {
1582                     do_not_decode[ch]=1;
1583                 } else {
1584                     do_not_decode[ch]=0;
1585                 }
1586                 ++ch;
1587                 ++res_num;
1588             }
1589         }
1590         residue=&vc->residues[mapping->submap_residue[i]];
1591         vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2);
1592
1593         ch_res_ptr+=ch*blocksize/2;
1594     }
1595
1596 // Inverse coupling
1597
1598     for(i=mapping->coupling_steps-1;i>=0;--i) { //warning: i has to be signed
1599         float *mag, *ang;
1600
1601         mag=vc->channel_residues+res_chan[mapping->magnitude[i]]*blocksize/2;
1602         ang=vc->channel_residues+res_chan[mapping->angle[i]]*blocksize/2;
1603         vc->dsp.vorbis_inverse_coupling(mag, ang, blocksize/2);
1604     }
1605
1606 // Dotproduct
1607
1608     for(j=0, ch_floor_ptr=vc->channel_floors;j<vc->audio_channels;++j,ch_floor_ptr+=blocksize/2) {
1609         ch_res_ptr=vc->channel_residues+res_chan[j]*blocksize/2;
1610         vc->dsp.vector_fmul(ch_floor_ptr, ch_res_ptr, blocksize/2);
1611     }
1612
1613 // MDCT, overlap/add, save data for next overlapping  FPMATH
1614
1615     for(j=0;j<vc->audio_channels;++j) {
1616         uint_fast8_t step=vc->audio_channels;
1617         uint_fast16_t k;
1618         float *saved=vc->saved+j*vc->blocksize[1]/2;
1619         float *ret=vc->ret;
1620         const float *lwin=vc->win[1];
1621         const float *swin=vc->win[0];
1622         float *buf=vc->buf;
1623         float *buf_tmp=vc->buf_tmp;
1624
1625         ch_floor_ptr=vc->channel_floors+j*blocksize/2;
1626
1627         saved_start=vc->saved_start;
1628
1629         vc->mdct[0].fft.imdct_calc(&vc->mdct[vc->modes[mode_number].blockflag], buf, ch_floor_ptr, buf_tmp);
1630
1631         //FIXME process channels together, to allow faster simd vector_fmul_add_add?
1632         if (vc->modes[mode_number].blockflag) {
1633             // -- overlap/add
1634             if (previous_window) {
1635                 vc->dsp.vector_fmul_add_add(ret+j, buf, lwin, saved, vc->add_bias, vc->blocksize[1]/2, step);
1636                 retlen=vc->blocksize[1]/2;
1637             } else {
1638                 int len = (vc->blocksize[1]-vc->blocksize[0])/4;
1639                 buf += len;
1640                 vc->dsp.vector_fmul_add_add(ret+j, buf, swin, saved, vc->add_bias, vc->blocksize[0]/2, step);
1641                 k = vc->blocksize[0]/2*step + j;
1642                 buf += vc->blocksize[0]/2;
1643                 if(vc->exp_bias){
1644                     for(i=0; i<len; i++, k+=step)
1645                         ((uint32_t*)ret)[k] = ((uint32_t*)buf)[i] + vc->exp_bias; // ret[k]=buf[i]*(1<<bias)
1646                 } else {
1647                     for(i=0; i<len; i++, k+=step)
1648                         ret[k] = buf[i] + fadd_bias;
1649                 }
1650                 buf=vc->buf;
1651                 retlen=vc->blocksize[0]/2+len;
1652             }
1653             // -- save
1654             if (next_window) {
1655                 buf += vc->blocksize[1]/2;
1656                 vc->dsp.vector_fmul_reverse(saved, buf, lwin, vc->blocksize[1]/2);
1657                 saved_start=0;
1658             } else {
1659                 saved_start=(vc->blocksize[1]-vc->blocksize[0])/4;
1660                 buf += vc->blocksize[1]/2;
1661                 for(i=0; i<saved_start; i++)
1662                     ((uint32_t*)saved)[i] = ((uint32_t*)buf)[i] + vc->exp_bias;
1663                 vc->dsp.vector_fmul_reverse(saved+saved_start, buf+saved_start, swin, vc->blocksize[0]/2);
1664             }
1665         } else {
1666             // --overlap/add
1667             if(vc->add_bias) {
1668                 for(k=j, i=0;i<saved_start;++i, k+=step)
1669                     ret[k] = saved[i] + fadd_bias;
1670             } else {
1671                 for(k=j, i=0;i<saved_start;++i, k+=step)
1672                     ret[k] = saved[i];
1673             }
1674             vc->dsp.vector_fmul_add_add(ret+k, buf, swin, saved+saved_start, vc->add_bias, vc->blocksize[0]/2, step);
1675             retlen=saved_start+vc->blocksize[0]/2;
1676             // -- save
1677             buf += vc->blocksize[0]/2;
1678             vc->dsp.vector_fmul_reverse(saved, buf, swin, vc->blocksize[0]/2);
1679             saved_start=0;
1680         }
1681     }
1682     vc->saved_start=saved_start;
1683
1684     return retlen*vc->audio_channels;
1685 }
1686
1687 // Return the decoded audio packet through the standard api
1688
1689 static int vorbis_decode_frame(AVCodecContext *avccontext,
1690                         void *data, int *data_size,
1691                         uint8_t *buf, int buf_size)
1692 {
1693     vorbis_context *vc = avccontext->priv_data ;
1694     GetBitContext *gb = &(vc->gb);
1695
1696     int_fast16_t i, len;
1697
1698     if(!buf_size){
1699         return 0;
1700     }
1701
1702     AV_DEBUG("packet length %d \n", buf_size);
1703
1704     init_get_bits(gb, buf, buf_size*8);
1705
1706     len=vorbis_parse_audio_packet(vc);
1707
1708     if (len<=0) {
1709         *data_size=0;
1710         return buf_size;
1711     }
1712
1713     if (!vc->first_frame) {
1714         vc->first_frame=1;
1715         *data_size=0;
1716         return buf_size ;
1717     }
1718
1719     AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
1720
1721     vc->dsp.float_to_int16(data, vc->ret, len);
1722     *data_size=len*2;
1723
1724     return buf_size ;
1725 }
1726
1727 // Close decoder
1728
1729 static int vorbis_decode_close(AVCodecContext *avccontext) {
1730     vorbis_context *vc = avccontext->priv_data;
1731
1732     vorbis_free(vc);
1733
1734     return 0 ;
1735 }
1736
1737 AVCodec vorbis_decoder = {
1738     "vorbis",
1739     CODEC_TYPE_AUDIO,
1740     CODEC_ID_VORBIS,
1741     sizeof(vorbis_context),
1742     vorbis_decode_init,
1743     NULL,
1744     vorbis_decode_close,
1745     vorbis_decode_frame,
1746 };
1747