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