git.sesse.net Git - ffmpeg/blob - libavcodec/vorbis.c

   1 /**
   2  * @file vorbis.c
   3  * Vorbis I decoder
   4  * @author Denes Balatoni  ( dbalatoni programozo hu )
   5
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  *
  20  */
  21
  22 #undef V_DEBUG
  23 //#define V_DEBUG
  24 //#define AV_DEBUG(...) av_log(NULL, AV_LOG_INFO, __VA_ARGS__)
  25
  26 #include <math.h>
  27
  28 #define ALT_BITSTREAM_READER_LE
  29 #include "avcodec.h"
  30 #include "bitstream.h"
  31 #include "dsputil.h"
  32
  33 #include "vorbis.h"
  34
  35 #define V_NB_BITS 8
  36 #define V_NB_BITS2 11
  37 #define V_MAX_VLCS (1<<16)
  38
  39 #ifndef V_DEBUG
  40 #define AV_DEBUG(...)
  41 #endif
  42
  43 #undef NDEBUG
  44 #include <assert.h>
  45
  46 /* Helper functions */
  47
  48 /**
  49  *  reads 0-32 bits when using the ALT_BITSTREAM_READER_LE bitstream reader
  50  */
  51 static unsigned int get_bits_long_le(GetBitContext *s, int n){
  52     if(n<=17) return get_bits(s, n);
  53     else{
  54         int ret= get_bits(s, 16);
  55         return ret | (get_bits(s, n-16) << 16);
  56     }
  57 }
  58
  59 #define ilog(i) av_log2(2*(i))
  60
  61 #define BARK(x) \
  62     (13.1f*atan(0.00074f*(x))+2.24f*atan(1.85e-8f*(x)*(x))+1e-4f*(x))
  63
  64 static unsigned int nth_root(unsigned int x, unsigned int n) {   // x^(1/n)
  65     unsigned int ret=0, i, j;
  66
  67     do {
  68         ++ret;
  69         for(i=0,j=ret;i<n-1;i++) j*=ret;
  70     } while (j<=x);
  71
  72     return (ret-1);
  73 }
  74
  75 static float vorbisfloat2float(uint_fast32_t val) {
  76     double mant=val&0x1fffff;
  77     long exp=(val&0x7fe00000L)>>21;
  78     if (val&0x80000000) mant=-mant;
  79     return(ldexp(mant, exp-20-768));
  80 }
  81
  82
  83 // Generate vlc codes from vorbis huffman code lengths
  84
  85 static int vorbis_len2vlc(vorbis_context *vc, uint_fast8_t *bits, uint_fast32_t *codes, uint_fast32_t num) {
  86     uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
  87         0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};
  88
  89     uint_fast8_t i,j;
  90     uint_fast32_t code,p;
  91
  92 #ifdef V_DEBUG
  93     GetBitContext gb;
  94 #endif
  95
  96     for(p=0;(bits[p]==0) && (p<num);++p);
  97     if (p==num) {
  98 //        av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
  99         return 0;
 100     }
 101
 102     codes[p]=0;
 103     for(i=0;i<bits[p];++i) {
 104         exit_at_level[i+1]=1<<i;
 105     }
 106
 107 #ifdef V_DEBUG
 108     av_log(vc->avccontext, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]);
 109     init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
 110     for(i=0;i<bits[p];++i) {
 111         av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
 112     }
 113     av_log(vc->avccontext, AV_LOG_INFO, "\n");
 114 #endif
 115
 116     ++p;
 117
 118     for(;p<num;++p) {
 119         if (bits[p]==0) continue;
 120         // find corresponding exit(node which the tree can grow further from)
 121         for(i=bits[p];i>0;--i) {
 122             if (exit_at_level[i]) break;
 123         }
 124         if (!i) return 1; // overspecified tree
 125         code=exit_at_level[i];
 126         exit_at_level[i]=0;
 127         // construct code (append 0s to end) and introduce new exits
 128         for(j=i+1;j<=bits[p];++j) {
 129             exit_at_level[j]=code+(1<<(j-1));
 130         }
 131         codes[p]=code;
 132
 133 #ifdef V_DEBUG
 134         av_log(vc->avccontext, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
 135         init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
 136         for(i=0;i<bits[p];++i) {
 137             av_log(vc->avccontext, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
 138         }
 139         av_log(vc->avccontext, AV_LOG_INFO, "\n");
 140 #endif
 141
 142     }
 143
 144     //FIXME no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
 145
 146     return 0;
 147 }
 148
 149 // Free all allocated memory -----------------------------------------
 150
 151 static void vorbis_free(vorbis_context *vc) {
 152     int_fast16_t i;
 153
 154     av_freep(&vc->channel_residues);
 155     av_freep(&vc->channel_floors);
 156     av_freep(&vc->saved);
 157     av_freep(&vc->ret);
 158     av_freep(&vc->buf);
 159     av_freep(&vc->buf_tmp);
 160
 161     av_freep(&vc->residues);
 162     av_freep(&vc->modes);
 163
 164     ff_mdct_end(&vc->mdct0);
 165     ff_mdct_end(&vc->mdct1);
 166
 167     for(i=0;i<vc->codebook_count;++i) {
 168         av_free(vc->codebooks[i].codevectors);
 169         free_vlc(&vc->codebooks[i].vlc);
 170     }
 171     av_freep(&vc->codebooks);
 172
 173     for(i=0;i<vc->floor_count;++i) {
 174         if(vc->floors[i].floor_type==0) {
 175             av_free(vc->floors[i].data.t0.map[0]);
 176             av_free(vc->floors[i].data.t0.map[1]);
 177             av_free(vc->floors[i].data.t0.book_list);
 178             av_free(vc->floors[i].data.t0.lsp);
 179         }
 180         else {
 181             av_free(vc->floors[i].data.t1.x_list);
 182             av_free(vc->floors[i].data.t1.x_list_order);
 183             av_free(vc->floors[i].data.t1.low_neighbour);
 184             av_free(vc->floors[i].data.t1.high_neighbour);
 185         }
 186     }
 187     av_freep(&vc->floors);
 188
 189     for(i=0;i<vc->mapping_count;++i) {
 190         av_free(vc->mappings[i].magnitude);
 191         av_free(vc->mappings[i].angle);
 192         av_free(vc->mappings[i].mux);
 193     }
 194     av_freep(&vc->mappings);
 195 }
 196
 197 // Parse setup header -------------------------------------------------
 198
 199 // Process codebooks part
 200
 201 static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
 202     uint_fast16_t cb;
 203     uint_fast8_t *tmp_vlc_bits;
 204     uint_fast32_t *tmp_vlc_codes;
 205     GetBitContext *gb=&vc->gb;
 206
 207     vc->codebook_count=get_bits(gb,8)+1;
 208
 209     AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);
 210
 211     vc->codebooks=(vorbis_codebook *)av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
 212     tmp_vlc_bits=(uint_fast8_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast8_t));
 213     tmp_vlc_codes=(uint_fast32_t *)av_mallocz(V_MAX_VLCS * sizeof(uint_fast32_t));
 214
 215     for(cb=0;cb<vc->codebook_count;++cb) {
 216         vorbis_codebook *codebook_setup=&vc->codebooks[cb];
 217         uint_fast8_t ordered;
 218         uint_fast32_t t, used_entries=0;
 219         uint_fast32_t entries;
 220
 221         AV_DEBUG(" %d. Codebook \n", cb);
 222
 223         if (get_bits(gb, 24)!=0x564342) {
 224             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook setup data corrupt. \n", cb);
 225             goto error;
 226         }
 227
 228         codebook_setup->dimensions=get_bits(gb, 16);
 229         if (codebook_setup->dimensions>16) {
 230             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook's dimension is too large (%d). \n", cb, codebook_setup->dimensions);
 231             goto error;
 232         }
 233         entries=get_bits(gb, 24);
 234         if (entries>V_MAX_VLCS) {
 235             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook has too many entries (%"PRIdFAST32"). \n", cb, entries);
 236             goto error;
 237         }
 238
 239         ordered=get_bits1(gb);
 240
 241         AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);
 242
 243         if (!ordered) {
 244             uint_fast16_t ce;
 245             uint_fast8_t flag;
 246             uint_fast8_t sparse=get_bits1(gb);
 247
 248             AV_DEBUG(" not ordered \n");
 249
 250             if (sparse) {
 251                 AV_DEBUG(" sparse \n");
 252
 253                 used_entries=0;
 254                 for(ce=0;ce<entries;++ce) {
 255                     flag=get_bits1(gb);
 256                     if (flag) {
 257                         tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
 258                         ++used_entries;
 259                     }
 260                     else tmp_vlc_bits[ce]=0;
 261                 }
 262             } else {
 263                 AV_DEBUG(" not sparse \n");
 264
 265                 used_entries=entries;
 266                 for(ce=0;ce<entries;++ce) {
 267                     tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
 268                 }
 269             }
 270         } else {
 271             uint_fast16_t current_entry=0;
 272             uint_fast8_t current_length=get_bits(gb, 5)+1;
 273
 274             AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME
 275
 276             used_entries=entries;
 277             for(;current_entry<used_entries;++current_length) {
 278                 uint_fast16_t i, number;
 279
 280                 AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));
 281
 282                 number=get_bits(gb, ilog(entries - current_entry));
 283
 284                 AV_DEBUG(" number: %d \n", number);
 285
 286                 for(i=current_entry;i<number+current_entry;++i) {
 287                     if (i<used_entries) tmp_vlc_bits[i]=current_length;
 288                 }
 289
 290                 current_entry+=number;
 291             }
 292             if (current_entry>used_entries) {
 293                 av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
 294                 goto error;
 295             }
 296         }
 297
 298         codebook_setup->lookup_type=get_bits(gb, 4);
 299
 300         AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup" );
 301
 302 // If the codebook is used for (inverse) VQ, calculate codevectors.
 303
 304         if (codebook_setup->lookup_type==1) {
 305             uint_fast16_t i, j, k;
 306             uint_fast16_t codebook_lookup_values=nth_root(entries, codebook_setup->dimensions);
 307             uint_fast16_t codebook_multiplicands[codebook_lookup_values];
 308
 309             float codebook_minimum_value=vorbisfloat2float(get_bits_long_le(gb, 32));
 310             float codebook_delta_value=vorbisfloat2float(get_bits_long_le(gb, 32));
 311             uint_fast8_t codebook_value_bits=get_bits(gb, 4)+1;
 312             uint_fast8_t codebook_sequence_p=get_bits1(gb);
 313
 314             AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
 315             AV_DEBUG("  delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);
 316
 317             for(i=0;i<codebook_lookup_values;++i) {
 318                 codebook_multiplicands[i]=get_bits(gb, codebook_value_bits);
 319
 320                 AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
 321                 AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
 322             }
 323
 324 // Weed out unused vlcs and build codevector vector
 325             codebook_setup->codevectors=(float *)av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float));
 326             for(j=0, i=0;i<entries;++i) {
 327                 uint_fast8_t dim=codebook_setup->dimensions;
 328
 329                 if (tmp_vlc_bits[i]) {
 330                     float last=0.0;
 331                     uint_fast32_t lookup_offset=i;
 332
 333 #ifdef V_DEBUG
 334                     av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
 335 #endif
 336
 337                     for(k=0;k<dim;++k) {
 338                         uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
 339                         codebook_setup->codevectors[j*dim+k]=codebook_multiplicands[multiplicand_offset]*codebook_delta_value+codebook_minimum_value+last;
 340                         if (codebook_sequence_p) {
 341                             last=codebook_setup->codevectors[j*dim+k];
 342                         }
 343                         lookup_offset/=codebook_lookup_values;
 344                     }
 345                     tmp_vlc_bits[j]=tmp_vlc_bits[i];
 346
 347 #ifdef V_DEBUG
 348                     av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
 349                     for(k=0;k<dim;++k) {
 350                         av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j*dim+k]);
 351                     }
 352                     av_log(vc->avccontext, AV_LOG_INFO, "\n");
 353 #endif
 354
 355                     ++j;
 356                 }
 357             }
 358             if (j!=used_entries) {
 359                 av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
 360                 goto error;
 361             }
 362             entries=used_entries;
 363         }
 364         else if (codebook_setup->lookup_type>=2) {
 365             av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
 366             goto error;
 367         }
 368
 369 // Initialize VLC table
 370         if (vorbis_len2vlc(vc, tmp_vlc_bits, tmp_vlc_codes, entries)) {
 371             av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
 372             goto error;
 373         }
 374         codebook_setup->maxdepth=0;
 375         for(t=0;t<entries;++t)
 376             if (tmp_vlc_bits[t]>=codebook_setup->maxdepth) codebook_setup->maxdepth=tmp_vlc_bits[t];
 377
 378         if(codebook_setup->maxdepth > 3*V_NB_BITS) codebook_setup->nb_bits=V_NB_BITS2;
 379         else                                       codebook_setup->nb_bits=V_NB_BITS;
 380
 381         codebook_setup->maxdepth=(codebook_setup->maxdepth+codebook_setup->nb_bits-1)/codebook_setup->nb_bits;
 382
 383         if (init_vlc(&codebook_setup->vlc, codebook_setup->nb_bits, entries, tmp_vlc_bits, sizeof(*tmp_vlc_bits), sizeof(*tmp_vlc_bits), tmp_vlc_codes, sizeof(*tmp_vlc_codes), sizeof(*tmp_vlc_codes), INIT_VLC_LE)) {
 384             av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
 385             goto error;
 386         }
 387     }
 388
 389     av_free(tmp_vlc_bits);
 390     av_free(tmp_vlc_codes);
 391     return 0;
 392
 393 // Error:
 394 error:
 395     av_free(tmp_vlc_bits);
 396     av_free(tmp_vlc_codes);
 397     return 1;
 398 }
 399
 400 // Process time domain transforms part (unused in Vorbis I)
 401
 402 static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc) {
 403     GetBitContext *gb=&vc->gb;
 404     uint_fast8_t i;
 405     uint_fast8_t vorbis_time_count=get_bits(gb, 6)+1;
 406
 407     for(i=0;i<vorbis_time_count;++i) {
 408         uint_fast16_t vorbis_tdtransform=get_bits(gb, 16);
 409
 410         AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);
 411
 412         if (vorbis_tdtransform) {
 413             av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
 414             return 1;
 415         }
 416     }
 417     return 0;
 418 }
 419
 420 // Process floors part
 421
 422 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
 423                                          vorbis_floor_data *vfu, float *vec);
 424 static void create_map( vorbis_context * vc, uint_fast8_t floor_number );
 425 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc,
 426                                          vorbis_floor_data *vfu, float *vec);
 427 static int vorbis_parse_setup_hdr_floors(vorbis_context *vc) {
 428     GetBitContext *gb=&vc->gb;
 429     uint_fast16_t i,j,k;
 430
 431     vc->floor_count=get_bits(gb, 6)+1;
 432
 433     vc->floors=(vorbis_floor *)av_mallocz(vc->floor_count * sizeof(vorbis_floor));
 434
 435     for (i=0;i<vc->floor_count;++i) {
 436         vorbis_floor *floor_setup=&vc->floors[i];
 437
 438         floor_setup->floor_type=get_bits(gb, 16);
 439
 440         AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);
 441
 442         if (floor_setup->floor_type==1) {
 443             uint_fast8_t maximum_class=0;
 444             uint_fast8_t rangebits;
 445             uint_fast16_t floor1_values=2;
 446
 447             floor_setup->decode=vorbis_floor1_decode;
 448
 449             floor_setup->data.t1.partitions=get_bits(gb, 5);
 450
 451             AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->data.t1.partitions);
 452
 453             for(j=0;j<floor_setup->data.t1.partitions;++j) {
 454                 floor_setup->data.t1.partition_class[j]=get_bits(gb, 4);
 455                 if (floor_setup->data.t1.partition_class[j]>maximum_class) maximum_class=floor_setup->data.t1.partition_class[j];
 456
 457                 AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->data.t1.partition_class[j]);
 458
 459             }
 460
 461             AV_DEBUG(" maximum class %d \n", maximum_class);
 462
 463             floor_setup->data.t1.maximum_class=maximum_class;
 464
 465             for(j=0;j<=maximum_class;++j) {
 466                 floor_setup->data.t1.class_dimensions[j]=get_bits(gb, 3)+1;
 467                 floor_setup->data.t1.class_subclasses[j]=get_bits(gb, 2);
 468
 469                 AV_DEBUG(" %d floor %d class dim: %d subclasses %d \n", i, j, floor_setup->data.t1.class_dimensions[j], floor_setup->data.t1.class_subclasses[j]);
 470
 471                 if (floor_setup->data.t1.class_subclasses[j]) {
 472                     floor_setup->data.t1.class_masterbook[j]=get_bits(gb, 8);
 473
 474                     AV_DEBUG("   masterbook: %d \n", floor_setup->data.t1.class_masterbook[j]);
 475                 }
 476
 477                 for(k=0;k<(1<<floor_setup->data.t1.class_subclasses[j]);++k) {
 478                     floor_setup->data.t1.subclass_books[j][k]=(int16_t)get_bits(gb, 8)-1;
 479
 480                     AV_DEBUG("    book %d. : %d \n", k, floor_setup->data.t1.subclass_books[j][k]);
 481                 }
 482             }
 483
 484             floor_setup->data.t1.multiplier=get_bits(gb, 2)+1;
 485             floor_setup->data.t1.x_list_dim=2;
 486
 487             for(j=0;j<floor_setup->data.t1.partitions;++j) {
 488                 floor_setup->data.t1.x_list_dim+=floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];
 489             }
 490
 491             floor_setup->data.t1.x_list=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
 492             floor_setup->data.t1.x_list_order=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
 493             floor_setup->data.t1.low_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
 494             floor_setup->data.t1.high_neighbour=(uint_fast16_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(uint_fast16_t));
 495
 496
 497             rangebits=get_bits(gb, 4);
 498             floor_setup->data.t1.x_list[0] = 0;
 499             floor_setup->data.t1.x_list[1] = (1<<rangebits);
 500
 501             for(j=0;j<floor_setup->data.t1.partitions;++j) {
 502                 for(k=0;k<floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];++k,++floor1_values) {
 503                     floor_setup->data.t1.x_list[floor1_values]=get_bits(gb, rangebits);
 504
 505                     AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->data.t1.x_list[floor1_values]);
 506                 }
 507             }
 508
 509 // Precalculate order of x coordinates - needed for decode
 510
 511             for(k=0;k<floor_setup->data.t1.x_list_dim;++k) {
 512                 floor_setup->data.t1.x_list_order[k]=k;
 513             }
 514
 515             for(k=0;k<floor_setup->data.t1.x_list_dim-1;++k) {   // FIXME optimize sorting ?
 516                 for(j=k+1;j<floor_setup->data.t1.x_list_dim;++j) {
 517                     if(floor_setup->data.t1.x_list[floor_setup->data.t1.x_list_order[k]]>floor_setup->data.t1.x_list[floor_setup->data.t1.x_list_order[j]]) {
 518                         uint_fast16_t tmp=floor_setup->data.t1.x_list_order[k];
 519                         floor_setup->data.t1.x_list_order[k]=floor_setup->data.t1.x_list_order[j];
 520                         floor_setup->data.t1.x_list_order[j]=tmp;
 521                     }
 522                 }
 523             }
 524
 525 // Precalculate low and high neighbours
 526
 527             for(k=2;k<floor_setup->data.t1.x_list_dim;++k) {
 528                 floor_setup->data.t1.low_neighbour[k]=0;
 529                 floor_setup->data.t1.high_neighbour[k]=1;  // correct according to SPEC requirements
 530
 531                 for (j=0;j<k;++j) {
 532                     if ((floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[k]) &&
 533                       (floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[floor_setup->data.t1.low_neighbour[k]])) {
 534                         floor_setup->data.t1.low_neighbour[k]=j;
 535                     }
 536                     if ((floor_setup->data.t1.x_list[j]>floor_setup->data.t1.x_list[k]) &&
 537                       (floor_setup->data.t1.x_list[j]<floor_setup->data.t1.x_list[floor_setup->data.t1.high_neighbour[k]])) {
 538                         floor_setup->data.t1.high_neighbour[k]=j;
 539                     }
 540                 }
 541             }
 542         }
 543         else if(floor_setup->floor_type==0) {
 544             uint_fast8_t max_codebook_dim=0;
 545
 546             floor_setup->decode=vorbis_floor0_decode;
 547
 548             floor_setup->data.t0.order=get_bits(gb, 8);
 549             floor_setup->data.t0.rate=get_bits(gb, 16);
 550             floor_setup->data.t0.bark_map_size=get_bits(gb, 16);
 551             floor_setup->data.t0.amplitude_bits=get_bits(gb, 6);
 552             /* zero would result in a div by zero later *
 553              * 2^0 - 1 == 0                             */
 554             if (floor_setup->data.t0.amplitude_bits == 0) {
 555               av_log(vc->avccontext, AV_LOG_ERROR,
 556                      "Floor 0 amplitude bits is 0.\n");
 557               return 1;
 558             }
 559             floor_setup->data.t0.amplitude_offset=get_bits(gb, 8);
 560             floor_setup->data.t0.num_books=get_bits(gb, 4)+1;
 561
 562             /* allocate mem for booklist */
 563             floor_setup->data.t0.book_list=
 564                 av_malloc(floor_setup->data.t0.num_books);
 565             if(!floor_setup->data.t0.book_list) { return 1; }
 566             /* read book indexes */
 567             {
 568                 int idx;
 569                 uint_fast8_t book_idx;
 570                 for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
 571                     book_idx=get_bits(gb, 8);
 572                     floor_setup->data.t0.book_list[idx]=book_idx;
 573                     if (vc->codebooks[book_idx].dimensions > max_codebook_dim)
 574                         max_codebook_dim=vc->codebooks[book_idx].dimensions;
 575
 576                     if (floor_setup->data.t0.book_list[idx]>vc->codebook_count)
 577                         return 1;
 578                 }
 579             }
 580
 581             create_map( vc, i );
 582
 583             /* allocate mem for lsp coefficients */
 584             {
 585                 /* codebook dim is for padding if codebook dim doesn't *
 586                  * divide order+1 then we need to read more data       */
 587                 floor_setup->data.t0.lsp=
 588                     av_malloc((floor_setup->data.t0.order+1 + max_codebook_dim)
 589                               * sizeof(float));
 590                 if(!floor_setup->data.t0.lsp) { return 1; }
 591             }
 592
 593 #ifdef V_DEBUG /* debug output parsed headers */
 594             AV_DEBUG("floor0 order: %u\n", floor_setup->data.t0.order);
 595             AV_DEBUG("floor0 rate: %u\n", floor_setup->data.t0.rate);
 596             AV_DEBUG("floor0 bark map size: %u\n",
 597               floor_setup->data.t0.bark_map_size);
 598             AV_DEBUG("floor0 amplitude bits: %u\n",
 599               floor_setup->data.t0.amplitude_bits);
 600             AV_DEBUG("floor0 amplitude offset: %u\n",
 601               floor_setup->data.t0.amplitude_offset);
 602             AV_DEBUG("floor0 number of books: %u\n",
 603               floor_setup->data.t0.num_books);
 604             AV_DEBUG("floor0 book list pointer: %p\n",
 605               floor_setup->data.t0.book_list);
 606             {
 607               int idx;
 608               for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
 609                 AV_DEBUG( "  Book %d: %u\n",
 610                   idx+1,
 611                   floor_setup->data.t0.book_list[idx] );
 612               }
 613             }
 614 #endif
 615         }
 616         else {
 617             av_log(vc->avccontext, AV_LOG_ERROR, "Invalid floor type!\n");
 618             return 1;
 619         }
 620     }
 621     return 0;
 622 }
 623
 624 // Process residues part
 625
 626 static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
 627     GetBitContext *gb=&vc->gb;
 628     uint_fast8_t i, j, k;
 629
 630     vc->residue_count=get_bits(gb, 6)+1;
 631     vc->residues=(vorbis_residue *)av_mallocz(vc->residue_count * sizeof(vorbis_residue));
 632
 633     AV_DEBUG(" There are %d residues. \n", vc->residue_count);
 634
 635     for(i=0;i<vc->residue_count;++i) {
 636         vorbis_residue *res_setup=&vc->residues[i];
 637         uint_fast8_t cascade[64];
 638         uint_fast8_t high_bits;
 639         uint_fast8_t low_bits;
 640
 641         res_setup->type=get_bits(gb, 16);
 642
 643         AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);
 644
 645         res_setup->begin=get_bits(gb, 24);
 646         res_setup->end=get_bits(gb, 24);
 647         res_setup->partition_size=get_bits(gb, 24)+1;
 648         res_setup->classifications=get_bits(gb, 6)+1;
 649         res_setup->classbook=get_bits(gb, 8);
 650
 651         AV_DEBUG("    begin %d end %d part.size %d classif.s %d classbook %d \n", res_setup->begin, res_setup->end, res_setup->partition_size,
 652           res_setup->classifications, res_setup->classbook);
 653
 654         for(j=0;j<res_setup->classifications;++j) {
 655             high_bits=0;
 656             low_bits=get_bits(gb, 3);
 657             if (get_bits1(gb)) {
 658                 high_bits=get_bits(gb, 5);
 659             }
 660             cascade[j]=(high_bits<<3)+low_bits;
 661
 662             AV_DEBUG("     %d class casscade depth: %d \n", j, ilog(cascade[j]));
 663         }
 664
 665         res_setup->maxpass=0;
 666         for(j=0;j<res_setup->classifications;++j) {
 667             for(k=0;k<8;++k) {
 668                 if (cascade[j]&(1<<k)) {
 669                         res_setup->books[j][k]=get_bits(gb, 8);
 670
 671                     AV_DEBUG("     %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);
 672
 673                     if (k>res_setup->maxpass) {
 674                         res_setup->maxpass=k;
 675                     }
 676                 } else {
 677                     res_setup->books[j][k]=-1;
 678                 }
 679             }
 680         }
 681     }
 682     return 0;
 683 }
 684
 685 // Process mappings part
 686
 687 static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc) {
 688     GetBitContext *gb=&vc->gb;
 689     uint_fast8_t i, j;
 690
 691     vc->mapping_count=get_bits(gb, 6)+1;
 692     vc->mappings=(vorbis_mapping *)av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));
 693
 694     AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);
 695
 696     for(i=0;i<vc->mapping_count;++i) {
 697         vorbis_mapping *mapping_setup=&vc->mappings[i];
 698
 699         if (get_bits(gb, 16)) {
 700             av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
 701             return 1;
 702         }
 703         if (get_bits1(gb)) {
 704             mapping_setup->submaps=get_bits(gb, 4)+1;
 705         } else {
 706             mapping_setup->submaps=1;
 707         }
 708
 709         if (get_bits1(gb)) {
 710             mapping_setup->coupling_steps=get_bits(gb, 8)+1;
 711             mapping_setup->magnitude=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
 712             mapping_setup->angle=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
 713             for(j=0;j<mapping_setup->coupling_steps;++j) {
 714                 mapping_setup->magnitude[j]=get_bits(gb, ilog(vc->audio_channels-1));
 715                 mapping_setup->angle[j]=get_bits(gb, ilog(vc->audio_channels-1));
 716                 // FIXME: sanity checks
 717             }
 718         } else {
 719             mapping_setup->coupling_steps=0;
 720         }
 721
 722         AV_DEBUG("   %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);
 723
 724         if(get_bits(gb, 2)) {
 725             av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
 726             return 1; // following spec.
 727         }
 728
 729         if (mapping_setup->submaps>1) {
 730             mapping_setup->mux=(uint_fast8_t *)av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
 731             for(j=0;j<vc->audio_channels;++j) {
 732                 mapping_setup->mux[j]=get_bits(gb, 4);
 733             }
 734         }
 735
 736         for(j=0;j<mapping_setup->submaps;++j) {
 737             get_bits(gb, 8); // FIXME check?
 738             mapping_setup->submap_floor[j]=get_bits(gb, 8);
 739             mapping_setup->submap_residue[j]=get_bits(gb, 8);
 740
 741             AV_DEBUG("   %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
 742         }
 743     }
 744     return 0;
 745 }
 746
 747 // Process modes part
 748
 749 static void create_map( vorbis_context * vc, uint_fast8_t floor_number )
 750 {
 751     vorbis_floor * floors=vc->floors;
 752     vorbis_floor0 * vf;
 753     int idx;
 754     int_fast8_t blockflag;
 755     int_fast32_t * map;
 756     int_fast32_t n; //TODO: could theoretically be smaller?
 757
 758     for (blockflag=0;blockflag<2;++blockflag)
 759     {
 760     n=(blockflag ? vc->blocksize_1 : vc->blocksize_0) / 2;
 761     floors[floor_number].data.t0.map[blockflag]=
 762         av_malloc((n+1) * sizeof(int_fast32_t)); // n+sentinel
 763
 764     map=floors[floor_number].data.t0.map[blockflag];
 765     vf=&floors[floor_number].data.t0;
 766
 767     for (idx=0; idx<n;++idx) {
 768         map[idx]=floor( BARK((vf->rate*idx)/(2.0f*n)) *
 769                               ((vf->bark_map_size)/
 770                                BARK(vf->rate/2.0f )) );
 771         if (vf->bark_map_size-1 < map[idx]) {
 772             map[idx]=vf->bark_map_size-1;
 773         }
 774     }
 775     map[n]=-1;
 776     vf->map_size[blockflag]=n;
 777     }
 778
 779 #   ifdef V_DEBUG
 780     for(idx=0;idx<=n;++idx) {
 781         AV_DEBUG("floor0 map: map at pos %d is %d\n",
 782                  idx, map[idx]);
 783     }
 784 #   endif
 785 }
 786
 787 static int vorbis_parse_setup_hdr_modes(vorbis_context *vc) {
 788     GetBitContext *gb=&vc->gb;
 789     uint_fast8_t i;
 790
 791     vc->mode_count=get_bits(gb, 6)+1;
 792     vc->modes=(vorbis_mode *)av_mallocz(vc->mode_count * sizeof(vorbis_mode));
 793
 794     AV_DEBUG(" There are %d modes.\n", vc->mode_count);
 795
 796     for(i=0;i<vc->mode_count;++i) {
 797         vorbis_mode *mode_setup=&vc->modes[i];
 798
 799         mode_setup->blockflag=get_bits(gb, 1);
 800         mode_setup->windowtype=get_bits(gb, 16); //FIXME check
 801         mode_setup->transformtype=get_bits(gb, 16); //FIXME check
 802         mode_setup->mapping=get_bits(gb, 8); //FIXME check
 803
 804         AV_DEBUG(" %d mode: blockflag %d, windowtype %d, transformtype %d, mapping %d \n", i, mode_setup->blockflag, mode_setup->windowtype, mode_setup->transformtype, mode_setup->mapping);
 805     }
 806     return 0;
 807 }
 808
 809 // Process the whole setup header using the functions above
 810
 811 static int vorbis_parse_setup_hdr(vorbis_context *vc) {
 812     GetBitContext *gb=&vc->gb;
 813
 814     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
 815     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
 816     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
 817         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
 818         return 1;
 819     }
 820
 821     if (vorbis_parse_setup_hdr_codebooks(vc)) {
 822         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
 823         return 2;
 824     }
 825     if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
 826         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
 827         return 3;
 828     }
 829     if (vorbis_parse_setup_hdr_floors(vc)) {
 830         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
 831         return 4;
 832     }
 833     if (vorbis_parse_setup_hdr_residues(vc)) {
 834         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
 835         return 5;
 836     }
 837     if (vorbis_parse_setup_hdr_mappings(vc)) {
 838         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
 839         return 6;
 840     }
 841     if (vorbis_parse_setup_hdr_modes(vc)) {
 842         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
 843         return 7;
 844     }
 845     if (!get_bits1(gb)) {
 846         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
 847         return 8; // framing flag bit unset error
 848     }
 849
 850     return 0;
 851 }
 852
 853 // Process the identification header
 854
 855 static int vorbis_parse_id_hdr(vorbis_context *vc){
 856     GetBitContext *gb=&vc->gb;
 857     uint_fast8_t bl0, bl1;
 858     const float *vwin[8]={ vwin64, vwin128, vwin256, vwin512, vwin1024, vwin2048, vwin4096, vwin8192 };
 859
 860     if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
 861     (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
 862     (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
 863         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
 864         return 1;
 865     }
 866
 867     vc->version=get_bits_long_le(gb, 32);    //FIXME check 0
 868     vc->audio_channels=get_bits(gb, 8);   //FIXME check >0
 869     vc->audio_samplerate=get_bits_long_le(gb, 32);   //FIXME check >0
 870     vc->bitrate_maximum=get_bits_long_le(gb, 32);
 871     vc->bitrate_nominal=get_bits_long_le(gb, 32);
 872     vc->bitrate_minimum=get_bits_long_le(gb, 32);
 873     bl0=get_bits(gb, 4);
 874     bl1=get_bits(gb, 4);
 875     vc->blocksize_0=(1<<bl0);
 876     vc->blocksize_1=(1<<bl1);
 877     if (bl0>13 || bl0<6 || bl1>13 || bl1<6 || bl1<bl0) {
 878         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
 879         return 3;
 880     }
 881     // output format int16
 882     if (vc->blocksize_1/2 * vc->audio_channels * 2 >
 883                                              AVCODEC_MAX_AUDIO_FRAME_SIZE) {
 884         av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis channel count makes "
 885                "output packets too large.\n");
 886         return 4;
 887     }
 888     vc->swin=vwin[bl0-6];
 889     vc->lwin=vwin[bl1-6];
 890
 891     if ((get_bits1(gb)) == 0) {
 892         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
 893         return 2;
 894     }
 895
 896     vc->channel_residues=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
 897     vc->channel_floors=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
 898     vc->saved=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
 899     vc->ret=(float *)av_malloc((vc->blocksize_1/2)*vc->audio_channels * sizeof(float));
 900     vc->buf=(float *)av_malloc(vc->blocksize_1 * sizeof(float));
 901     vc->buf_tmp=(float *)av_malloc(vc->blocksize_1 * sizeof(float));
 902     vc->saved_start=0;
 903
 904     ff_mdct_init(&vc->mdct0, bl0, 1);
 905     ff_mdct_init(&vc->mdct1, bl1, 1);
 906
 907     AV_DEBUG(" vorbis version %d \n audio_channels %d \n audio_samplerate %d \n bitrate_max %d \n bitrate_nom %d \n bitrate_min %d \n blk_0 %d blk_1 %d \n ",
 908             vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize_0, vc->blocksize_1);
 909
 910 /*
 911     BLK=vc->blocksize_0;
 912     for(i=0;i<BLK/2;++i) {
 913         vc->swin[i]=sin(0.5*3.14159265358*(sin(((float)i+0.5)/(float)BLK*3.14159265358))*(sin(((float)i+0.5)/(float)BLK*3.14159265358)));
 914     }
 915 */
 916
 917     return 0;
 918 }
 919
 920 // Process the extradata using the functions above (identification header, setup header)
 921
 922 static int vorbis_decode_init(AVCodecContext *avccontext) {
 923     vorbis_context *vc = avccontext->priv_data ;
 924     uint8_t *headers = avccontext->extradata;
 925     int headers_len=avccontext->extradata_size;
 926     uint8_t *header_start[3];
 927     int header_len[3];
 928     GetBitContext *gb = &(vc->gb);
 929     int i, j, hdr_type;
 930
 931     vc->avccontext = avccontext;
 932     dsputil_init(&vc->dsp, avccontext);
 933
 934     if (!headers_len) {
 935         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
 936         return -1;
 937     }
 938
 939     if(headers[0] == 0 && headers[1] == 30) {
 940         for(i = 0; i < 3; i++){
 941             header_len[i] = *headers++ << 8;
 942             header_len[i] += *headers++;
 943             header_start[i] = headers;
 944             headers += header_len[i];
 945         }
 946     } else if(headers[0] == 2) {
 947         for(j=1,i=0;i<2;++i, ++j) {
 948             header_len[i]=0;
 949             while(j<headers_len && headers[j]==0xff) {
 950                 header_len[i]+=0xff;
 951                 ++j;
 952             }
 953             if (j>=headers_len) {
 954                 av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
 955                 return -1;
 956             }
 957             header_len[i]+=headers[j];
 958         }
 959         header_len[2]=headers_len-header_len[0]-header_len[1]-j;
 960         headers+=j;
 961         header_start[0] = headers;
 962         header_start[1] = header_start[0] + header_len[0];
 963         header_start[2] = header_start[1] + header_len[1];
 964     } else {
 965         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
 966         return -1;
 967     }
 968
 969     init_get_bits(gb, header_start[0], header_len[0]*8);
 970     hdr_type=get_bits(gb, 8);
 971     if (hdr_type!=1) {
 972         av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
 973         return -1;
 974     }
 975     if (vorbis_parse_id_hdr(vc)) {
 976         av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
 977         vorbis_free(vc);
 978         return -1;
 979     }
 980
 981     init_get_bits(gb, header_start[2], header_len[2]*8);
 982     hdr_type=get_bits(gb, 8);
 983     if (hdr_type!=5) {
 984         av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
 985         return -1;
 986     }
 987     if (vorbis_parse_setup_hdr(vc)) {
 988         av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
 989         vorbis_free(vc);
 990         return -1;
 991     }
 992
 993     avccontext->channels = vc->audio_channels;
 994     avccontext->sample_rate = vc->audio_samplerate;
 995
 996     return 0 ;
 997 }
 998
 999 // Decode audiopackets -------------------------------------------------
1000
1001 // Read and decode floor
1002
1003 static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
1004                                          vorbis_floor_data *vfu, float *vec) {
1005     vorbis_floor0 * vf=&vfu->t0;
1006     float * lsp=vf->lsp;
1007     uint_fast32_t amplitude;
1008     uint_fast32_t book_idx;
1009     uint_fast8_t blockflag=vc->modes[vc->mode_number].blockflag;
1010
1011     amplitude=get_bits(&vc->gb, vf->amplitude_bits);
1012     if (amplitude>0) {
1013         float last = 0;
1014         uint_fast16_t lsp_len = 0;
1015         uint_fast16_t idx;
1016         vorbis_codebook codebook;
1017
1018         book_idx=get_bits(&vc->gb, ilog(vf->num_books));
1019         if ( book_idx >= vf->num_books ) {
1020             av_log( vc->avccontext, AV_LOG_ERROR,
1021                     "floor0 dec: booknumber too high!\n" );
1022             //FIXME: look above
1023         }
1024         AV_DEBUG( "floor0 dec: booknumber: %u\n", book_idx );
1025         codebook=vc->codebooks[vf->book_list[book_idx]];
1026
1027         while (lsp_len<vf->order) {
1028             int vec_off;
1029
1030             AV_DEBUG( "floor0 dec: book dimension: %d\n", codebook.dimensions );
1031             AV_DEBUG( "floor0 dec: maximum depth: %d\n", codebook.maxdepth );
1032             /* read temp vector */
1033             vec_off=get_vlc2(&vc->gb,
1034                              codebook.vlc.table,
1035                              codebook.nb_bits,
1036                              codebook.maxdepth ) *
1037                              codebook.dimensions;
1038             AV_DEBUG( "floor0 dec: vector offset: %d\n", vec_off );
1039             /* copy each vector component and add last to it */
1040             for (idx=0; idx<codebook.dimensions; ++idx) {
1041                 lsp[lsp_len+idx]=codebook.codevectors[vec_off+idx]+last;
1042             }
1043             last=lsp[lsp_len+idx-1]; /* set last to last vector component */
1044
1045             lsp_len += codebook.dimensions;
1046         }
1047 #ifdef V_DEBUG
1048         /* DEBUG: output lsp coeffs */
1049         {
1050             int idx;
1051             for ( idx = 0; idx < lsp_len; ++idx )
1052                 AV_DEBUG("floor0 dec: coeff at %d is %f\n", idx, lsp[idx] );
1053         }
1054 #endif
1055
1056         /* synthesize floor output vector */
1057         {
1058             int i;
1059             int order=vf->order;
1060             float wstep=M_PI/vf->bark_map_size;
1061
1062             for(i=0;i<order;i++) { lsp[i]=2.0f*cos(lsp[i]); }
1063
1064             AV_DEBUG("floor0 synth: map_size=%d; m=%d; wstep=%f\n",
1065                      vf->map_size, order, wstep);
1066
1067             i=0;
1068             while(i<vf->map_size[blockflag]) {
1069                 int j, iter_cond=vf->map[blockflag][i];
1070                 float p=0.5f;
1071                 float q=0.5f;
1072                 float two_cos_w=2.0f*cos(wstep*iter_cond); // needed all times
1073
1074                 /* similar part for the q and p products */
1075                 for(j=0;j<order;j+=2) {
1076                     q *= lsp[j]  -two_cos_w;
1077                     p *= lsp[j+1]-two_cos_w;
1078                 }
1079                 if(j==order) { // even order
1080                     p *= p*(2.0f-two_cos_w);
1081                     q *= q*(2.0f+two_cos_w);
1082                 }
1083                 else { // odd order
1084                     q *= two_cos_w-lsp[j]; // one more time for q
1085
1086                     /* final step and square */
1087                     p *= p*(4.f-two_cos_w*two_cos_w);
1088                     q *= q;
1089                 }
1090
1091                 /* calculate linear floor value */
1092                 {
1093                     q=exp( (
1094                              ( (amplitude*vf->amplitude_offset)/
1095                                (((1<<vf->amplitude_bits)-1) * sqrt(p+q)) )
1096                              - vf->amplitude_offset ) * .11512925f
1097                          );
1098                 }
1099
1100                 /* fill vector */
1101                 do { vec[i]=q; ++i; }while(vf->map[blockflag][i]==iter_cond);
1102             }
1103         }
1104     }
1105     else {
1106         /* this channel is unused */
1107         return 1;
1108     }
1109
1110     AV_DEBUG(" Floor0 decoded\n");
1111
1112     return 0;
1113 }
1114 static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *vfu, float *vec) {
1115     vorbis_floor1 * vf=&vfu->t1;
1116     GetBitContext *gb=&vc->gb;
1117     uint_fast16_t range_v[4]={ 256, 128, 86, 64 };
1118     uint_fast16_t range=range_v[vf->multiplier-1];
1119     uint_fast16_t floor1_Y[vf->x_list_dim];
1120     uint_fast16_t floor1_Y_final[vf->x_list_dim];
1121     uint_fast8_t floor1_flag[vf->x_list_dim];
1122     uint_fast8_t class_;
1123     uint_fast8_t cdim;
1124     uint_fast8_t cbits;
1125     uint_fast8_t csub;
1126     uint_fast8_t cval;
1127     int_fast16_t book;
1128     uint_fast16_t offset;
1129     uint_fast16_t i,j;
1130     uint_fast16_t *floor_x_sort=vf->x_list_order;
1131     /*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx= (unsigned)dy/adx ?
1132     int_fast16_t dy, err;
1133     uint_fast16_t lx,hx, ly, hy=0;
1134
1135
1136     if (!get_bits1(gb)) return 1; // silence
1137
1138 // Read values (or differences) for the floor's points
1139
1140     floor1_Y[0]=get_bits(gb, ilog(range-1));
1141     floor1_Y[1]=get_bits(gb, ilog(range-1));
1142
1143     AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);
1144
1145     offset=2;
1146     for(i=0;i<vf->partitions;++i) {
1147         class_=vf->partition_class[i];
1148         cdim=vf->class_dimensions[class_];
1149         cbits=vf->class_subclasses[class_];
1150         csub=(1<<cbits)-1;
1151         cval=0;
1152
1153         AV_DEBUG("Cbits %d \n", cbits);
1154
1155         if (cbits) { // this reads all subclasses for this partition's class
1156             cval=get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,
1157             vc->codebooks[vf->class_masterbook[class_]].nb_bits, 3);
1158         }
1159
1160         for(j=0;j<cdim;++j) {
1161             book=vf->subclass_books[class_][cval & csub];
1162
1163             AV_DEBUG("book %d Cbits %d cval %d  bits:%d \n", book, cbits, cval, get_bits_count(gb));
1164
1165             cval=cval>>cbits;
1166             if (book>0) {
1167                 floor1_Y[offset+j]=get_vlc2(gb, vc->codebooks[book].vlc.table,
1168                 vc->codebooks[book].nb_bits, 3);
1169             } else {
1170                 floor1_Y[offset+j]=0;
1171             }
1172
1173             AV_DEBUG(" floor(%d) = %d \n", vf->x_list[offset+j], floor1_Y[offset+j]);
1174         }
1175         offset+=cdim;
1176     }
1177
1178 // Amplitude calculation from the differences
1179
1180     floor1_flag[0]=1;
1181     floor1_flag[1]=1;
1182     floor1_Y_final[0]=floor1_Y[0];
1183     floor1_Y_final[1]=floor1_Y[1];
1184
1185     for(i=2;i<vf->x_list_dim;++i) {
1186         uint_fast16_t val, highroom, lowroom, room;
1187         uint_fast16_t high_neigh_offs;
1188         uint_fast16_t low_neigh_offs;
1189
1190         low_neigh_offs=vf->low_neighbour[i];
1191         high_neigh_offs=vf->high_neighbour[i];
1192         dy=floor1_Y_final[high_neigh_offs]-floor1_Y_final[low_neigh_offs];  // render_point begin
1193         adx=vf->x_list[high_neigh_offs]-vf->x_list[low_neigh_offs];
1194         ady= ABS(dy);
1195         err=ady*(vf->x_list[i]-vf->x_list[low_neigh_offs]);
1196         off=(int16_t)err/(int16_t)adx;
1197         if (dy<0) {
1198             predicted=floor1_Y_final[low_neigh_offs]-off;
1199         } else {
1200             predicted=floor1_Y_final[low_neigh_offs]+off;
1201         } // render_point end
1202
1203         val=floor1_Y[i];
1204         highroom=range-predicted;
1205         lowroom=predicted;
1206         if (highroom < lowroom) {
1207             room=highroom*2;
1208         } else {
1209             room=lowroom*2;   // SPEC mispelling
1210         }
1211         if (val) {
1212             floor1_flag[low_neigh_offs]=1;
1213             floor1_flag[high_neigh_offs]=1;
1214             floor1_flag[i]=1;
1215             if (val>=room) {
1216                 if (highroom > lowroom) {
1217                     floor1_Y_final[i]=val-lowroom+predicted;
1218                 } else {
1219                     floor1_Y_final[i]=predicted-val+highroom-1;
1220                 }
1221             } else {
1222                 if (val & 1) {
1223                     floor1_Y_final[i]=predicted-(val+1)/2;
1224                 } else {
1225                     floor1_Y_final[i]=predicted+val/2;
1226                 }
1227             }
1228         } else {
1229             floor1_flag[i]=0;
1230             floor1_Y_final[i]=predicted;
1231         }
1232
1233         AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->x_list[i], floor1_Y_final[i], val);
1234     }
1235
1236 // Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?
1237
1238     hx=0;
1239     lx=0;
1240     ly=floor1_Y_final[0]*vf->multiplier;  // conforms to SPEC
1241
1242     vec[0]=floor1_inverse_db_table[ly];
1243
1244     for(i=1;i<vf->x_list_dim;++i) {
1245         AV_DEBUG(" Looking at post %d \n", i);
1246
1247         if (floor1_flag[floor_x_sort[i]]) {   // SPEC mispelled
1248             int_fast16_t x, y, dy, base, sy; // if uncommented: dy = -32 adx = 2  base = 2blablabla ?????
1249
1250             hy=floor1_Y_final[floor_x_sort[i]]*vf->multiplier;
1251             hx=vf->x_list[floor_x_sort[i]];
1252
1253             dy=hy-ly;
1254             adx=hx-lx;
1255             ady= (dy<0) ? -dy:dy;//ABS(dy);
1256             base=(int16_t)dy/(int16_t)adx;
1257
1258             AV_DEBUG(" dy %d  adx %d base %d = %d \n", dy, adx, base, dy/adx);
1259
1260             x=lx;
1261             y=ly;
1262             err=0;
1263             if (dy<0) {
1264                 sy=base-1;
1265             } else {
1266                 sy=base+1;
1267             }
1268             ady=ady-(base<0 ? -base : base)*adx;
1269             vec[x]=floor1_inverse_db_table[y];
1270
1271             AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1272
1273             for(x=lx+1;(x<hx) && (x<vf->x_list[1]);++x) {
1274                 err+=ady;
1275                 if (err>=adx) {
1276                     err-=adx;
1277                     y+=sy;
1278                 } else {
1279                     y+=base;
1280                 }
1281                 vec[x]=floor1_inverse_db_table[y];
1282
1283                 AV_DEBUG(" vec[ %d ] = %d \n", x, y);
1284             }
1285
1286 /*            for(j=1;j<hx-lx+1;++j) {  // iterating render_point
1287                 dy=hy-ly;
1288                 adx=hx-lx;
1289                 ady= dy<0 ? -dy : dy;
1290                 err=ady*j;
1291                 off=err/adx;
1292                 if (dy<0) {
1293                     predicted=ly-off;
1294                 } else {
1295                     predicted=ly+off;
1296                 }
1297                 if (lx+j < vf->x_list[1]) {
1298                     vec[lx+j]=floor1_inverse_db_table[predicted];
1299                 }
1300             }*/
1301
1302             lx=hx;
1303             ly=hy;
1304         }
1305     }
1306
1307     if (hx<vf->x_list[1]) {
1308         for(i=hx;i<vf->x_list[1];++i) {
1309             vec[i]=floor1_inverse_db_table[hy];
1310         }
1311     }
1312
1313     AV_DEBUG(" Floor decoded\n");
1314
1315     return 0;
1316 }
1317
1318 // Read and decode residue
1319
1320 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) {
1321     GetBitContext *gb=&vc->gb;
1322     uint_fast8_t c_p_c=vc->codebooks[vr->classbook].dimensions;
1323     uint_fast16_t n_to_read=vr->end-vr->begin;
1324     uint_fast16_t ptns_to_read=n_to_read/vr->partition_size;
1325     uint_fast8_t classifs[ptns_to_read*vc->audio_channels];
1326     uint_fast8_t pass;
1327     uint_fast8_t ch_used;
1328     uint_fast8_t i,j,l;
1329     uint_fast16_t k;
1330
1331     if (vr->type==2) {
1332         for(j=1;j<ch;++j) {
1333                 do_not_decode[0]&=do_not_decode[j];  // FIXME - clobbering input
1334         }
1335         if (do_not_decode[0]) return 0;
1336         ch_used=1;
1337     } else {
1338         ch_used=ch;
1339     }
1340
1341     AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d  cpc %d  \n", ch, c_p_c);
1342
1343     for(pass=0;pass<=vr->maxpass;++pass) { // FIXME OPTIMIZE?
1344         uint_fast16_t voffset;
1345         uint_fast16_t partition_count;
1346         uint_fast16_t j_times_ptns_to_read;
1347
1348         voffset=vr->begin;
1349         for(partition_count=0;partition_count<ptns_to_read;) {  // SPEC        error
1350             if (!pass) {
1351                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1352                     if (!do_not_decode[j]) {
1353                         uint_fast32_t temp=get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,
1354                         vc->codebooks[vr->classbook].nb_bits, 3);
1355
1356                         AV_DEBUG("Classword: %d \n", temp);
1357
1358                         assert(vr->classifications > 1 && temp<=65536); //needed for inverse[]
1359                         for(i=0;i<c_p_c;++i) {
1360                             uint_fast32_t temp2;
1361
1362                             temp2=(((uint_fast64_t)temp) * inverse[vr->classifications])>>32;
1363                             if (partition_count+c_p_c-1-i < ptns_to_read) {
1364                                 classifs[j_times_ptns_to_read+partition_count+c_p_c-1-i]=temp-temp2*vr->classifications;
1365                             }
1366                             temp=temp2;
1367                         }
1368                     }
1369                     j_times_ptns_to_read+=ptns_to_read;
1370                 }
1371             }
1372             for(i=0;(i<c_p_c) && (partition_count<ptns_to_read);++i) {
1373                 for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {
1374                     uint_fast16_t voffs;
1375
1376                     if (!do_not_decode[j]) {
1377                         uint_fast8_t vqclass=classifs[j_times_ptns_to_read+partition_count];
1378                         int_fast16_t vqbook=vr->books[vqclass][pass];
1379
1380                         if (vqbook>=0) {
1381                             uint_fast16_t coffs;
1382                             uint_fast8_t dim= vc->codebooks[vqbook].dimensions;
1383                             uint_fast16_t step= dim==1 ? vr->partition_size
1384                                               : FASTDIV(vr->partition_size, dim);
1385                             vorbis_codebook codebook= vc->codebooks[vqbook];
1386
1387                             if (vr->type==0) {
1388
1389                                 voffs=voffset+j*vlen;
1390                                 for(k=0;k<step;++k) {
1391                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1392                                     for(l=0;l<codebook.dimensions;++l) {
1393                                         vec[voffs+k+l*step]+=codebook.codevectors[coffs+l];  // FPMATH
1394                                     }
1395                                 }
1396                             }
1397                             else if (vr->type==1) {
1398                                 voffs=voffset+j*vlen;
1399                                 for(k=0;k<step;++k) {
1400                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1401                                     for(l=0;l<codebook.dimensions;++l, ++voffs) {
1402                                         vec[voffs]+=codebook.codevectors[coffs+l];  // FPMATH
1403
1404                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d  \n", pass, voffs, vec[voffs], codebook.codevectors[coffs+l], coffs);
1405                                     }
1406                                 }
1407                             }
1408                             else if (vr->type==2 && ch==2 && (voffset&1)==0 && (codebook.dimensions&1)==0) { // most frequent case optimized
1409                                 voffs=voffset>>1;
1410
1411                                 for(k=0;k<step;++k) {
1412                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1413                                     for(l=0;l<codebook.dimensions;l+=2, voffs++) {
1414                                         vec[voffs     ]+=codebook.codevectors[coffs+l  ];  // FPMATH
1415                                         vec[voffs+vlen]+=codebook.codevectors[coffs+l+1];  // FPMATH
1416
1417                                         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);
1418                                     }
1419                                 }
1420
1421                             }
1422                             else if (vr->type==2) {
1423                                 voffs=voffset;
1424
1425                                 for(k=0;k<step;++k) {
1426                                     coffs=get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * codebook.dimensions;
1427                                     for(l=0;l<codebook.dimensions;++l, ++voffs) {
1428                                         vec[voffs/ch+(voffs%ch)*vlen]+=codebook.codevectors[coffs+l];  // FPMATH FIXME use if and counter instead of / and %
1429
1430                                         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);
1431                                     }
1432                                 }
1433                             } else {
1434                                 av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n");
1435                                 return 1;
1436                             }
1437                         }
1438                     }
1439                     j_times_ptns_to_read+=ptns_to_read;
1440                 }
1441                 ++partition_count;
1442                 voffset+=vr->partition_size;
1443             }
1444         }
1445     }
1446     return 0;
1447 }
1448
1449 void vorbis_inverse_coupling(float *mag, float *ang, int blocksize)
1450 {
1451     int i;
1452     for(i=0; i<blocksize; i++)
1453     {
1454         if (mag[i]>0.0) {
1455             if (ang[i]>0.0) {
1456                 ang[i]=mag[i]-ang[i];
1457             } else {
1458                 float temp=ang[i];
1459                 ang[i]=mag[i];
1460                 mag[i]+=temp;
1461             }
1462         } else {
1463             if (ang[i]>0.0) {
1464                 ang[i]+=mag[i];
1465             } else {
1466                 float temp=ang[i];
1467                 ang[i]=mag[i];
1468                 mag[i]-=temp;
1469             }
1470         }
1471     }
1472 }
1473
1474 // Decode the audio packet using the functions above
1475 #define BIAS 385
1476
1477 static int vorbis_parse_audio_packet(vorbis_context *vc) {
1478     GetBitContext *gb=&vc->gb;
1479
1480     uint_fast8_t previous_window=0,next_window=0;
1481     uint_fast8_t mode_number;
1482     uint_fast16_t blocksize;
1483     int_fast32_t i,j;
1484     uint_fast8_t no_residue[vc->audio_channels];
1485     uint_fast8_t do_not_decode[vc->audio_channels];
1486     vorbis_mapping *mapping;
1487     float *ch_res_ptr=vc->channel_residues;
1488     float *ch_floor_ptr=vc->channel_floors;
1489     uint_fast8_t res_chan[vc->audio_channels];
1490     uint_fast8_t res_num=0;
1491     int_fast16_t retlen=0;
1492     uint_fast16_t saved_start=0;
1493
1494     if (get_bits1(gb)) {
1495         av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n");
1496         return -1; // packet type not audio
1497     }
1498
1499     if (vc->mode_count==1) {
1500         mode_number=0;
1501     } else {
1502         mode_number=get_bits(gb, ilog(vc->mode_count-1));
1503     }
1504     vc->mode_number=mode_number;
1505     mapping=&vc->mappings[vc->modes[mode_number].mapping];
1506
1507     AV_DEBUG(" Mode number: %d , mapping: %d , blocktype %d \n", mode_number, vc->modes[mode_number].mapping, vc->modes[mode_number].blockflag);
1508
1509     if (vc->modes[mode_number].blockflag) {
1510         previous_window=get_bits1(gb);
1511         next_window=get_bits1(gb);
1512     }
1513
1514     blocksize=vc->modes[mode_number].blockflag ? vc->blocksize_1 : vc->blocksize_0;
1515     memset(ch_res_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1516     memset(ch_floor_ptr, 0, sizeof(float)*vc->audio_channels*blocksize/2); //FIXME can this be removed ?
1517
1518 // Decode floor
1519
1520     for(i=0;i<vc->audio_channels;++i) {
1521         vorbis_floor *floor;
1522         if (mapping->submaps>1) {
1523             floor=&vc->floors[mapping->submap_floor[mapping->mux[i]]];
1524         } else {
1525             floor=&vc->floors[mapping->submap_floor[0]];
1526         }
1527
1528         no_residue[i]=floor->decode(vc, &floor->data, ch_floor_ptr);
1529         ch_floor_ptr+=blocksize/2;
1530     }
1531
1532 // Nonzero vector propagate
1533
1534     for(i=mapping->coupling_steps-1;i>=0;--i) {
1535         if (!(no_residue[mapping->magnitude[i]] & no_residue[mapping->angle[i]])) {
1536             no_residue[mapping->magnitude[i]]=0;
1537             no_residue[mapping->angle[i]]=0;
1538         }
1539     }
1540
1541 // Decode residue
1542
1543     for(i=0;i<mapping->submaps;++i) {
1544         vorbis_residue *residue;
1545         uint_fast8_t ch=0;
1546
1547         for(j=0;j<vc->audio_channels;++j) {
1548             if ((mapping->submaps==1) || (i=mapping->mux[j])) {
1549                 res_chan[j]=res_num;
1550                 if (no_residue[j]) {
1551                     do_not_decode[ch]=1;
1552                 } else {
1553                     do_not_decode[ch]=0;
1554                 }
1555                 ++ch;
1556                 ++res_num;
1557             }
1558         }
1559         residue=&vc->residues[mapping->submap_residue[i]];
1560         vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2);
1561
1562         ch_res_ptr+=ch*blocksize/2;
1563     }
1564
1565 // Inverse coupling
1566
1567     for(i=mapping->coupling_steps-1;i>=0;--i) { //warning: i has to be signed
1568         float *mag, *ang;
1569
1570         mag=vc->channel_residues+res_chan[mapping->magnitude[i]]*blocksize/2;
1571         ang=vc->channel_residues+res_chan[mapping->angle[i]]*blocksize/2;
1572         vc->dsp.vorbis_inverse_coupling(mag, ang, blocksize/2);
1573     }
1574
1575 // Dotproduct
1576
1577     for(j=0, ch_floor_ptr=vc->channel_floors;j<vc->audio_channels;++j,ch_floor_ptr+=blocksize/2) {
1578         ch_res_ptr=vc->channel_residues+res_chan[j]*blocksize/2;
1579
1580         for(i=0;i<blocksize/2;++i) {
1581             ch_floor_ptr[i]*=ch_res_ptr[i]; //FPMATH
1582         }
1583     }
1584
1585 // MDCT, overlap/add, save data for next overlapping  FPMATH
1586
1587     for(j=0;j<vc->audio_channels;++j) {
1588         uint_fast8_t step=vc->audio_channels;
1589         uint_fast16_t k;
1590         float *saved=vc->saved+j*vc->blocksize_1/2;
1591         float *ret=vc->ret;
1592         const float *lwin=vc->lwin;
1593         const float *swin=vc->swin;
1594         float *buf=vc->buf;
1595         float *buf_tmp=vc->buf_tmp;
1596
1597         ch_floor_ptr=vc->channel_floors+j*blocksize/2;
1598
1599         saved_start=vc->saved_start;
1600
1601         vc->mdct0.fft.imdct_calc(vc->modes[mode_number].blockflag ? &vc->mdct1 : &vc->mdct0, buf, ch_floor_ptr, buf_tmp);
1602
1603         if (vc->modes[mode_number].blockflag) {
1604             // -- overlap/add
1605             if (previous_window) {
1606                 for(k=j, i=0;i<vc->blocksize_1/2;++i, k+=step) {
1607                     ret[k]=saved[i]+buf[i]*lwin[i]+BIAS;
1608                 }
1609                 retlen=vc->blocksize_1/2;
1610             } else {
1611                 buf += (vc->blocksize_1-vc->blocksize_0)/4;
1612                 for(k=j, i=0;i<vc->blocksize_0/2;++i, k+=step) {
1613                     ret[k]=saved[i]+buf[i]*swin[i]+BIAS;
1614                 }
1615                 buf += vc->blocksize_0/2;
1616                 for(i=0;i<(vc->blocksize_1-vc->blocksize_0)/4;++i, k+=step) {
1617                     ret[k]=buf[i]+BIAS;
1618                 }
1619                 buf=vc->buf;
1620                 retlen=vc->blocksize_0/2+(vc->blocksize_1-vc->blocksize_0)/4;
1621             }
1622             // -- save
1623             if (next_window) {
1624                 buf += vc->blocksize_1/2;
1625                 lwin += vc->blocksize_1/2-1;
1626                 for(i=0;i<vc->blocksize_1/2;++i) {
1627                     saved[i]=buf[i]*lwin[-i];
1628                 }
1629                 saved_start=0;
1630             } else {
1631                 saved_start=(vc->blocksize_1-vc->blocksize_0)/4;
1632                 buf += vc->blocksize_1/2;
1633                 for(i=0;i<saved_start;++i) {
1634                     saved[i]=buf[i];
1635                 }
1636                 swin += vc->blocksize_0/2-1;
1637                 for(i=0;i<vc->blocksize_0/2;++i) {
1638                     saved[saved_start+i]=buf[saved_start+i]*swin[-i];
1639                 }
1640             }
1641         } else {
1642             // --overlap/add
1643             for(k=j, i=0;i<saved_start;++i, k+=step) {
1644                 ret[k]=saved[i]+BIAS;
1645             }
1646             for(i=0;i<vc->blocksize_0/2;++i, k+=step) {
1647                 ret[k]=saved[saved_start+i]+buf[i]*swin[i]+BIAS;
1648             }
1649             retlen=saved_start+vc->blocksize_0/2;
1650             // -- save
1651             buf += vc->blocksize_0/2;
1652             swin += vc->blocksize_0/2-1;
1653             for(i=0;i<vc->blocksize_0/2;++i) {
1654                 saved[i]=buf[i]*swin[-i];
1655             }
1656             saved_start=0;
1657         }
1658     }
1659     vc->saved_start=saved_start;
1660
1661     return retlen*vc->audio_channels;
1662 }
1663
1664 // Return the decoded audio packet through the standard api
1665
1666 static int vorbis_decode_frame(AVCodecContext *avccontext,
1667                         void *data, int *data_size,
1668                         uint8_t *buf, int buf_size)
1669 {
1670     vorbis_context *vc = avccontext->priv_data ;
1671     GetBitContext *gb = &(vc->gb);
1672
1673     int_fast16_t i, len;
1674
1675     if(!buf_size){
1676         return 0;
1677     }
1678
1679     AV_DEBUG("packet length %d \n", buf_size);
1680
1681     init_get_bits(gb, buf, buf_size*8);
1682
1683     len=vorbis_parse_audio_packet(vc);
1684
1685     if (len<=0) {
1686         *data_size=0;
1687         return buf_size;
1688     }
1689
1690     if (!vc->first_frame) {
1691         vc->first_frame=1;
1692         *data_size=0;
1693         return buf_size ;
1694     }
1695
1696     AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
1697
1698     for(i=0;i<len;++i) {
1699         int_fast32_t tmp= ((int32_t*)vc->ret)[i];
1700         if(tmp & 0xf0000){
1701 //            tmp= (0x43c0ffff - tmp)>>31; //ask gcc devs why this is slower
1702             if(tmp > 0x43c0ffff) tmp= 0xFFFF;
1703             else                 tmp= 0;
1704         }
1705         ((int16_t*)data)[i]=tmp - 0x8000;
1706     }
1707
1708     *data_size=len*2;
1709
1710     return buf_size ;
1711 }
1712
1713 // Close decoder
1714
1715 static int vorbis_decode_close(AVCodecContext *avccontext) {
1716     vorbis_context *vc = avccontext->priv_data;
1717
1718     vorbis_free(vc);
1719
1720     return 0 ;
1721 }
1722
1723 AVCodec vorbis_decoder = {
1724     "vorbis",
1725     CODEC_TYPE_AUDIO,
1726     CODEC_ID_VORBIS,
1727     sizeof(vorbis_context),
1728     vorbis_decode_init,
1729     NULL,
1730     vorbis_decode_close,
1731     vorbis_decode_frame,
1732 };
1733