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libavcodec/vorbis_dec.c

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00001 
00023 #undef V_DEBUG
00024 //#define V_DEBUG
00025 //#define AV_DEBUG(...) av_log(NULL, AV_LOG_INFO, __VA_ARGS__)
00026 
00027 #include <math.h>
00028 
00029 #define ALT_BITSTREAM_READER_LE
00030 #include "avcodec.h"
00031 #include "get_bits.h"
00032 #include "dsputil.h"
00033 #include "fft.h"
00034 
00035 #include "vorbis.h"
00036 #include "xiph.h"
00037 
00038 #define V_NB_BITS 8
00039 #define V_NB_BITS2 11
00040 #define V_MAX_VLCS (1 << 16)
00041 #define V_MAX_PARTITIONS (1 << 20)
00042 
00043 #ifndef V_DEBUG
00044 #define AV_DEBUG(...)
00045 #endif
00046 
00047 #undef NDEBUG
00048 #include <assert.h>
00049 
00050 typedef struct {
00051     uint_fast8_t dimensions;
00052     uint_fast8_t lookup_type;
00053     uint_fast8_t maxdepth;
00054     VLC vlc;
00055     float *codevectors;
00056     unsigned int nb_bits;
00057 } vorbis_codebook;
00058 
00059 typedef union  vorbis_floor_u  vorbis_floor_data;
00060 typedef struct vorbis_floor0_s vorbis_floor0;
00061 typedef struct vorbis_floor1_s vorbis_floor1;
00062 struct vorbis_context_s;
00063 typedef
00064 int (* vorbis_floor_decode_func)
00065     (struct vorbis_context_s *, vorbis_floor_data *, float *);
00066 typedef struct {
00067     uint_fast8_t floor_type;
00068     vorbis_floor_decode_func decode;
00069     union vorbis_floor_u {
00070         struct vorbis_floor0_s {
00071             uint_fast8_t  order;
00072             uint_fast16_t rate;
00073             uint_fast16_t bark_map_size;
00074             int_fast32_t *map[2];
00075             uint_fast32_t map_size[2];
00076             uint_fast8_t  amplitude_bits;
00077             uint_fast8_t  amplitude_offset;
00078             uint_fast8_t  num_books;
00079             uint_fast8_t *book_list;
00080             float        *lsp;
00081         } t0;
00082         struct vorbis_floor1_s {
00083             uint_fast8_t partitions;
00084             uint_fast8_t maximum_class;
00085             uint_fast8_t partition_class[32];
00086             uint_fast8_t class_dimensions[16];
00087             uint_fast8_t class_subclasses[16];
00088             uint_fast8_t class_masterbook[16];
00089             int_fast16_t subclass_books[16][8];
00090             uint_fast8_t multiplier;
00091             uint_fast16_t x_list_dim;
00092             vorbis_floor1_entry *list;
00093         } t1;
00094     } data;
00095 } vorbis_floor;
00096 
00097 typedef struct {
00098     uint_fast16_t type;
00099     uint_fast32_t begin;
00100     uint_fast32_t end;
00101     uint_fast32_t partition_size;
00102     uint_fast8_t  classifications;
00103     uint_fast8_t  classbook;
00104     int_fast16_t  books[64][8];
00105     uint_fast8_t  maxpass;
00106 } vorbis_residue;
00107 
00108 typedef struct {
00109     uint_fast8_t  submaps;
00110     uint_fast16_t coupling_steps;
00111     uint_fast8_t *magnitude;
00112     uint_fast8_t *angle;
00113     uint_fast8_t *mux;
00114     uint_fast8_t  submap_floor[16];
00115     uint_fast8_t  submap_residue[16];
00116 } vorbis_mapping;
00117 
00118 typedef struct {
00119     uint_fast8_t  blockflag;
00120     uint_fast16_t windowtype;
00121     uint_fast16_t transformtype;
00122     uint_fast8_t  mapping;
00123 } vorbis_mode;
00124 
00125 typedef struct vorbis_context_s {
00126     AVCodecContext *avccontext;
00127     GetBitContext gb;
00128     DSPContext dsp;
00129 
00130     FFTContext mdct[2];
00131     uint_fast8_t  first_frame;
00132     uint_fast32_t version;
00133     uint_fast8_t  audio_channels;
00134     uint_fast32_t audio_samplerate;
00135     uint_fast32_t bitrate_maximum;
00136     uint_fast32_t bitrate_nominal;
00137     uint_fast32_t bitrate_minimum;
00138     uint_fast32_t blocksize[2];
00139     const float  *win[2];
00140     uint_fast16_t codebook_count;
00141     vorbis_codebook *codebooks;
00142     uint_fast8_t  floor_count;
00143     vorbis_floor *floors;
00144     uint_fast8_t  residue_count;
00145     vorbis_residue *residues;
00146     uint_fast8_t  mapping_count;
00147     vorbis_mapping *mappings;
00148     uint_fast8_t  mode_count;
00149     vorbis_mode  *modes;
00150     uint_fast8_t  mode_number; // mode number for the current packet
00151     uint_fast8_t  previous_window;
00152     float        *channel_residues;
00153     float        *channel_floors;
00154     float        *saved;
00155     uint_fast32_t add_bias; // for float->int conversion
00156     uint_fast32_t exp_bias;
00157 } vorbis_context;
00158 
00159 /* Helper functions */
00160 
00161 #define BARK(x) \
00162     (13.1f * atan(0.00074f * (x)) + 2.24f * atan(1.85e-8f * (x) * (x)) + 1e-4f * (x))
00163 
00164 static const char idx_err_str[] = "Index value %d out of range (0 - %d) for %s at %s:%i\n";
00165 #define VALIDATE_INDEX(idx, limit) \
00166     if (idx >= limit) {\
00167         av_log(vc->avccontext, AV_LOG_ERROR,\
00168                idx_err_str,\
00169                (int)(idx), (int)(limit - 1), #idx, __FILE__, __LINE__);\
00170         return -1;\
00171     }
00172 #define GET_VALIDATED_INDEX(idx, bits, limit) \
00173     {\
00174         idx = get_bits(gb, bits);\
00175         VALIDATE_INDEX(idx, limit)\
00176     }
00177 
00178 static float vorbisfloat2float(uint_fast32_t val)
00179 {
00180     double mant = val & 0x1fffff;
00181     long exp    = (val & 0x7fe00000L) >> 21;
00182     if (val & 0x80000000)
00183         mant = -mant;
00184     return ldexp(mant, exp - 20 - 768);
00185 }
00186 
00187 
00188 // Free all allocated memory -----------------------------------------
00189 
00190 static void vorbis_free(vorbis_context *vc)
00191 {
00192     int_fast16_t i;
00193 
00194     av_freep(&vc->channel_residues);
00195     av_freep(&vc->channel_floors);
00196     av_freep(&vc->saved);
00197 
00198     av_freep(&vc->residues);
00199     av_freep(&vc->modes);
00200 
00201     ff_mdct_end(&vc->mdct[0]);
00202     ff_mdct_end(&vc->mdct[1]);
00203 
00204     for (i = 0; i < vc->codebook_count; ++i) {
00205         av_free(vc->codebooks[i].codevectors);
00206         free_vlc(&vc->codebooks[i].vlc);
00207     }
00208     av_freep(&vc->codebooks);
00209 
00210     for (i = 0; i < vc->floor_count; ++i) {
00211         if (vc->floors[i].floor_type == 0) {
00212             av_free(vc->floors[i].data.t0.map[0]);
00213             av_free(vc->floors[i].data.t0.map[1]);
00214             av_free(vc->floors[i].data.t0.book_list);
00215             av_free(vc->floors[i].data.t0.lsp);
00216         } else {
00217             av_free(vc->floors[i].data.t1.list);
00218         }
00219     }
00220     av_freep(&vc->floors);
00221 
00222     for (i = 0; i < vc->mapping_count; ++i) {
00223         av_free(vc->mappings[i].magnitude);
00224         av_free(vc->mappings[i].angle);
00225         av_free(vc->mappings[i].mux);
00226     }
00227     av_freep(&vc->mappings);
00228 }
00229 
00230 // Parse setup header -------------------------------------------------
00231 
00232 // Process codebooks part
00233 
00234 static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc)
00235 {
00236     uint_fast16_t cb;
00237     uint8_t  *tmp_vlc_bits;
00238     uint32_t *tmp_vlc_codes;
00239     GetBitContext *gb = &vc->gb;
00240 
00241     vc->codebook_count = get_bits(gb, 8) + 1;
00242 
00243     AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);
00244 
00245     vc->codebooks = av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
00246     tmp_vlc_bits  = av_mallocz(V_MAX_VLCS * sizeof(uint8_t));
00247     tmp_vlc_codes = av_mallocz(V_MAX_VLCS * sizeof(uint32_t));
00248 
00249     for (cb = 0; cb < vc->codebook_count; ++cb) {
00250         vorbis_codebook *codebook_setup = &vc->codebooks[cb];
00251         uint_fast8_t ordered;
00252         uint_fast32_t t, used_entries = 0;
00253         uint_fast32_t entries;
00254 
00255         AV_DEBUG(" %d. Codebook \n", cb);
00256 
00257         if (get_bits(gb, 24) != 0x564342) {
00258             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook setup data corrupt. \n", cb);
00259             goto error;
00260         }
00261 
00262         codebook_setup->dimensions=get_bits(gb, 16);
00263         if (codebook_setup->dimensions > 16 || codebook_setup->dimensions == 0) {
00264             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook's dimension is invalid (%d). \n", cb, codebook_setup->dimensions);
00265             goto error;
00266         }
00267         entries = get_bits(gb, 24);
00268         if (entries > V_MAX_VLCS) {
00269             av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook has too many entries (%"PRIdFAST32"). \n", cb, entries);
00270             goto error;
00271         }
00272 
00273         ordered = get_bits1(gb);
00274 
00275         AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);
00276 
00277         if (!ordered) {
00278             uint_fast16_t ce;
00279             uint_fast8_t  flag;
00280             uint_fast8_t  sparse = get_bits1(gb);
00281 
00282             AV_DEBUG(" not ordered \n");
00283 
00284             if (sparse) {
00285                 AV_DEBUG(" sparse \n");
00286 
00287                 used_entries = 0;
00288                 for (ce = 0; ce < entries; ++ce) {
00289                     flag = get_bits1(gb);
00290                     if (flag) {
00291                         tmp_vlc_bits[ce] = get_bits(gb, 5) + 1;
00292                         ++used_entries;
00293                     } else
00294                         tmp_vlc_bits[ce] = 0;
00295                 }
00296             } else {
00297                 AV_DEBUG(" not sparse \n");
00298 
00299                 used_entries = entries;
00300                 for (ce = 0; ce < entries; ++ce)
00301                     tmp_vlc_bits[ce] = get_bits(gb, 5) + 1;
00302             }
00303         } else {
00304             uint_fast16_t current_entry = 0;
00305             uint_fast8_t current_length = get_bits(gb, 5)+1;
00306 
00307             AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME
00308 
00309             used_entries = entries;
00310             for (; current_entry < used_entries && current_length <= 32; ++current_length) {
00311                 uint_fast16_t i, number;
00312 
00313                 AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));
00314 
00315                 number = get_bits(gb, ilog(entries - current_entry));
00316 
00317                 AV_DEBUG(" number: %d \n", number);
00318 
00319                 for (i = current_entry; i < number+current_entry; ++i)
00320                     if (i < used_entries)
00321                         tmp_vlc_bits[i] = current_length;
00322 
00323                 current_entry+=number;
00324             }
00325             if (current_entry>used_entries) {
00326                 av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
00327                 goto error;
00328             }
00329         }
00330 
00331         codebook_setup->lookup_type = get_bits(gb, 4);
00332 
00333         AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup");
00334 
00335 // If the codebook is used for (inverse) VQ, calculate codevectors.
00336 
00337         if (codebook_setup->lookup_type == 1) {
00338             uint_fast16_t i, j, k;
00339             uint_fast16_t codebook_lookup_values = ff_vorbis_nth_root(entries, codebook_setup->dimensions);
00340             uint_fast16_t codebook_multiplicands[codebook_lookup_values];
00341 
00342             float codebook_minimum_value = vorbisfloat2float(get_bits_long(gb, 32));
00343             float codebook_delta_value   = vorbisfloat2float(get_bits_long(gb, 32));
00344             uint_fast8_t codebook_value_bits = get_bits(gb, 4)+1;
00345             uint_fast8_t codebook_sequence_p = get_bits1(gb);
00346 
00347             AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
00348             AV_DEBUG("  delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);
00349 
00350             for (i = 0; i < codebook_lookup_values; ++i) {
00351                 codebook_multiplicands[i] = get_bits(gb, codebook_value_bits);
00352 
00353                 AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
00354                 AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
00355             }
00356 
00357 // Weed out unused vlcs and build codevector vector
00358             codebook_setup->codevectors = used_entries ? av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float)) : NULL;
00359             for (j = 0, i = 0; i < entries; ++i) {
00360                 uint_fast8_t dim = codebook_setup->dimensions;
00361 
00362                 if (tmp_vlc_bits[i]) {
00363                     float last = 0.0;
00364                     uint_fast32_t lookup_offset = i;
00365 
00366 #ifdef V_DEBUG
00367                     av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
00368 #endif
00369 
00370                     for (k = 0; k < dim; ++k) {
00371                         uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
00372                         codebook_setup->codevectors[j * dim + k] = codebook_multiplicands[multiplicand_offset] * codebook_delta_value + codebook_minimum_value + last;
00373                         if (codebook_sequence_p)
00374                             last = codebook_setup->codevectors[j * dim + k];
00375                         lookup_offset/=codebook_lookup_values;
00376                     }
00377                     tmp_vlc_bits[j] = tmp_vlc_bits[i];
00378 
00379 #ifdef V_DEBUG
00380                     av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
00381                     for (k = 0; k < dim; ++k)
00382                         av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j * dim + k]);
00383                     av_log(vc->avccontext, AV_LOG_INFO, "\n");
00384 #endif
00385 
00386                     ++j;
00387                 }
00388             }
00389             if (j != used_entries) {
00390                 av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
00391                 goto error;
00392             }
00393             entries = used_entries;
00394         } else if (codebook_setup->lookup_type >= 2) {
00395             av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
00396             goto error;
00397         }
00398 
00399 // Initialize VLC table
00400         if (ff_vorbis_len2vlc(tmp_vlc_bits, tmp_vlc_codes, entries)) {
00401             av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
00402             goto error;
00403         }
00404         codebook_setup->maxdepth = 0;
00405         for (t = 0; t < entries; ++t)
00406             if (tmp_vlc_bits[t] >= codebook_setup->maxdepth)
00407                 codebook_setup->maxdepth = tmp_vlc_bits[t];
00408 
00409         if (codebook_setup->maxdepth > 3 * V_NB_BITS)
00410             codebook_setup->nb_bits = V_NB_BITS2;
00411         else
00412             codebook_setup->nb_bits = V_NB_BITS;
00413 
00414         codebook_setup->maxdepth = (codebook_setup->maxdepth+codebook_setup->nb_bits - 1) / codebook_setup->nb_bits;
00415 
00416         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)) {
00417             av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
00418             goto error;
00419         }
00420     }
00421 
00422     av_free(tmp_vlc_bits);
00423     av_free(tmp_vlc_codes);
00424     return 0;
00425 
00426 // Error:
00427 error:
00428     av_free(tmp_vlc_bits);
00429     av_free(tmp_vlc_codes);
00430     return -1;
00431 }
00432 
00433 // Process time domain transforms part (unused in Vorbis I)
00434 
00435 static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc)
00436 {
00437     GetBitContext *gb = &vc->gb;
00438     uint_fast8_t i;
00439     uint_fast8_t vorbis_time_count = get_bits(gb, 6) + 1;
00440 
00441     for (i = 0; i < vorbis_time_count; ++i) {
00442         uint_fast16_t vorbis_tdtransform = get_bits(gb, 16);
00443 
00444         AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);
00445 
00446         if (vorbis_tdtransform) {
00447             av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
00448             return -1;
00449         }
00450     }
00451     return 0;
00452 }
00453 
00454 // Process floors part
00455 
00456 static int vorbis_floor0_decode(vorbis_context *vc,
00457                                 vorbis_floor_data *vfu, float *vec);
00458 static void create_map(vorbis_context *vc, uint_fast8_t floor_number);
00459 static int vorbis_floor1_decode(vorbis_context *vc,
00460                                 vorbis_floor_data *vfu, float *vec);
00461 static int vorbis_parse_setup_hdr_floors(vorbis_context *vc)
00462 {
00463     GetBitContext *gb = &vc->gb;
00464     uint_fast16_t i,j,k;
00465 
00466     vc->floor_count = get_bits(gb, 6) + 1;
00467 
00468     vc->floors = av_mallocz(vc->floor_count * sizeof(vorbis_floor));
00469 
00470     for (i = 0; i < vc->floor_count; ++i) {
00471         vorbis_floor *floor_setup = &vc->floors[i];
00472 
00473         floor_setup->floor_type = get_bits(gb, 16);
00474 
00475         AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);
00476 
00477         if (floor_setup->floor_type == 1) {
00478             uint_fast8_t  maximum_class = 0;
00479             uint_fast8_t  rangebits;
00480             uint_fast32_t rangemax;
00481             uint_fast16_t floor1_values = 2;
00482 
00483             floor_setup->decode = vorbis_floor1_decode;
00484 
00485             floor_setup->data.t1.partitions = get_bits(gb, 5);
00486 
00487             AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->data.t1.partitions);
00488 
00489             for (j = 0; j < floor_setup->data.t1.partitions; ++j) {
00490                 floor_setup->data.t1.partition_class[j] = get_bits(gb, 4);
00491                 if (floor_setup->data.t1.partition_class[j] > maximum_class)
00492                     maximum_class = floor_setup->data.t1.partition_class[j];
00493 
00494                 AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->data.t1.partition_class[j]);
00495 
00496             }
00497 
00498             AV_DEBUG(" maximum class %d \n", maximum_class);
00499 
00500             floor_setup->data.t1.maximum_class = maximum_class;
00501 
00502             for (j = 0; j <= maximum_class; ++j) {
00503                 floor_setup->data.t1.class_dimensions[j] = get_bits(gb, 3) + 1;
00504                 floor_setup->data.t1.class_subclasses[j] = get_bits(gb, 2);
00505 
00506                 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]);
00507 
00508                 if (floor_setup->data.t1.class_subclasses[j]) {
00509                     GET_VALIDATED_INDEX(floor_setup->data.t1.class_masterbook[j], 8, vc->codebook_count)
00510 
00511                     AV_DEBUG("   masterbook: %d \n", floor_setup->data.t1.class_masterbook[j]);
00512                 }
00513 
00514                 for (k = 0; k < (1 << floor_setup->data.t1.class_subclasses[j]); ++k) {
00515                     int16_t bits = get_bits(gb, 8) - 1;
00516                     if (bits != -1)
00517                         VALIDATE_INDEX(bits, vc->codebook_count)
00518                     floor_setup->data.t1.subclass_books[j][k] = bits;
00519 
00520                     AV_DEBUG("    book %d. : %d \n", k, floor_setup->data.t1.subclass_books[j][k]);
00521                 }
00522             }
00523 
00524             floor_setup->data.t1.multiplier = get_bits(gb, 2) + 1;
00525             floor_setup->data.t1.x_list_dim = 2;
00526 
00527             for (j = 0; j < floor_setup->data.t1.partitions; ++j)
00528                 floor_setup->data.t1.x_list_dim+=floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];
00529 
00530             floor_setup->data.t1.list = av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(vorbis_floor1_entry));
00531 
00532 
00533             rangebits = get_bits(gb, 4);
00534             rangemax = (1 << rangebits);
00535             if (rangemax > vc->blocksize[1] / 2) {
00536                 av_log(vc->avccontext, AV_LOG_ERROR,
00537                        "Floor value is too large for blocksize: %d (%d)\n",
00538                        rangemax, vc->blocksize[1] / 2);
00539                 return -1;
00540             }
00541             floor_setup->data.t1.list[0].x = 0;
00542             floor_setup->data.t1.list[1].x = rangemax;
00543 
00544             for (j = 0; j < floor_setup->data.t1.partitions; ++j) {
00545                 for (k = 0; k < floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]]; ++k, ++floor1_values) {
00546                     floor_setup->data.t1.list[floor1_values].x = get_bits(gb, rangebits);
00547 
00548                     AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->data.t1.list[floor1_values].x);
00549                 }
00550             }
00551 
00552 // Precalculate order of x coordinates - needed for decode
00553             ff_vorbis_ready_floor1_list(floor_setup->data.t1.list, floor_setup->data.t1.x_list_dim);
00554         } else if (floor_setup->floor_type == 0) {
00555             uint_fast8_t max_codebook_dim = 0;
00556 
00557             floor_setup->decode = vorbis_floor0_decode;
00558 
00559             floor_setup->data.t0.order          = get_bits(gb,  8);
00560             floor_setup->data.t0.rate           = get_bits(gb, 16);
00561             floor_setup->data.t0.bark_map_size  = get_bits(gb, 16);
00562             floor_setup->data.t0.amplitude_bits = get_bits(gb,  6);
00563             /* zero would result in a div by zero later *
00564              * 2^0 - 1 == 0                             */
00565             if (floor_setup->data.t0.amplitude_bits == 0) {
00566               av_log(vc->avccontext, AV_LOG_ERROR,
00567                      "Floor 0 amplitude bits is 0.\n");
00568               return -1;
00569             }
00570             floor_setup->data.t0.amplitude_offset = get_bits(gb, 8);
00571             floor_setup->data.t0.num_books        = get_bits(gb, 4) + 1;
00572 
00573             /* allocate mem for booklist */
00574             floor_setup->data.t0.book_list =
00575                 av_malloc(floor_setup->data.t0.num_books);
00576             if (!floor_setup->data.t0.book_list)
00577                 return -1;
00578             /* read book indexes */
00579             {
00580                 int idx;
00581                 uint_fast8_t book_idx;
00582                 for (idx = 0; idx < floor_setup->data.t0.num_books; ++idx) {
00583                     GET_VALIDATED_INDEX(floor_setup->data.t0.book_list[idx], 8, vc->codebook_count)
00584                     if (vc->codebooks[book_idx].dimensions > max_codebook_dim)
00585                         max_codebook_dim = vc->codebooks[book_idx].dimensions;
00586                 }
00587             }
00588 
00589             create_map(vc, i);
00590 
00591             /* allocate mem for lsp coefficients */
00592             {
00593                 /* codebook dim is for padding if codebook dim doesn't *
00594                  * divide order+1 then we need to read more data       */
00595                 floor_setup->data.t0.lsp =
00596                     av_malloc((floor_setup->data.t0.order+1 + max_codebook_dim)
00597                               * sizeof(float));
00598                 if (!floor_setup->data.t0.lsp)
00599                     return -1;
00600             }
00601 
00602 #ifdef V_DEBUG /* debug output parsed headers */
00603             AV_DEBUG("floor0 order: %u\n", floor_setup->data.t0.order);
00604             AV_DEBUG("floor0 rate: %u\n", floor_setup->data.t0.rate);
00605             AV_DEBUG("floor0 bark map size: %u\n",
00606               floor_setup->data.t0.bark_map_size);
00607             AV_DEBUG("floor0 amplitude bits: %u\n",
00608               floor_setup->data.t0.amplitude_bits);
00609             AV_DEBUG("floor0 amplitude offset: %u\n",
00610               floor_setup->data.t0.amplitude_offset);
00611             AV_DEBUG("floor0 number of books: %u\n",
00612               floor_setup->data.t0.num_books);
00613             AV_DEBUG("floor0 book list pointer: %p\n",
00614               floor_setup->data.t0.book_list);
00615             {
00616               int idx;
00617               for (idx = 0; idx < floor_setup->data.t0.num_books; ++idx) {
00618                   AV_DEBUG("  Book %d: %u\n",
00619                            idx+1,
00620                            floor_setup->data.t0.book_list[idx]);
00621               }
00622             }
00623 #endif
00624         } else {
00625             av_log(vc->avccontext, AV_LOG_ERROR, "Invalid floor type!\n");
00626             return -1;
00627         }
00628     }
00629     return 0;
00630 }
00631 
00632 // Process residues part
00633 
00634 static int vorbis_parse_setup_hdr_residues(vorbis_context *vc)
00635 {
00636     GetBitContext *gb = &vc->gb;
00637     uint_fast8_t i, j, k;
00638 
00639     vc->residue_count = get_bits(gb, 6)+1;
00640     vc->residues      = av_mallocz(vc->residue_count * sizeof(vorbis_residue));
00641 
00642     AV_DEBUG(" There are %d residues. \n", vc->residue_count);
00643 
00644     for (i = 0; i < vc->residue_count; ++i) {
00645         vorbis_residue *res_setup = &vc->residues[i];
00646         uint_fast8_t cascade[64];
00647         uint_fast8_t high_bits;
00648         uint_fast8_t low_bits;
00649 
00650         res_setup->type = get_bits(gb, 16);
00651 
00652         AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);
00653 
00654         res_setup->begin          = get_bits(gb, 24);
00655         res_setup->end            = get_bits(gb, 24);
00656         res_setup->partition_size = get_bits(gb, 24) + 1;
00657         /* Validations to prevent a buffer overflow later. */
00658         if (res_setup->begin>res_setup->end ||
00659             res_setup->end>vc->blocksize[1] / (res_setup->type == 2 ? 1 : 2) ||
00660             (res_setup->end-res_setup->begin) / res_setup->partition_size > V_MAX_PARTITIONS) {
00661             av_log(vc->avccontext, AV_LOG_ERROR, "partition out of bounds: type, begin, end, size, blocksize: %"PRIdFAST16", %"PRIdFAST32", %"PRIdFAST32", %"PRIdFAST32", %"PRIdFAST32"\n", res_setup->type, res_setup->begin, res_setup->end, res_setup->partition_size, vc->blocksize[1] / 2);
00662             return -1;
00663         }
00664 
00665         res_setup->classifications = get_bits(gb, 6) + 1;
00666         GET_VALIDATED_INDEX(res_setup->classbook, 8, vc->codebook_count)
00667 
00668         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,
00669           res_setup->classifications, res_setup->classbook);
00670 
00671         for (j = 0; j < res_setup->classifications; ++j) {
00672             high_bits = 0;
00673             low_bits  = get_bits(gb, 3);
00674             if (get_bits1(gb))
00675                 high_bits = get_bits(gb, 5);
00676             cascade[j] = (high_bits << 3) + low_bits;
00677 
00678             AV_DEBUG("     %d class casscade depth: %d \n", j, ilog(cascade[j]));
00679         }
00680 
00681         res_setup->maxpass = 0;
00682         for (j = 0; j < res_setup->classifications; ++j) {
00683             for (k = 0; k < 8; ++k) {
00684                 if (cascade[j]&(1 << k)) {
00685                     GET_VALIDATED_INDEX(res_setup->books[j][k], 8, vc->codebook_count)
00686 
00687                     AV_DEBUG("     %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);
00688 
00689                     if (k>res_setup->maxpass)
00690                         res_setup->maxpass = k;
00691                 } else {
00692                     res_setup->books[j][k] = -1;
00693                 }
00694             }
00695         }
00696     }
00697     return 0;
00698 }
00699 
00700 // Process mappings part
00701 
00702 static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc)
00703 {
00704     GetBitContext *gb = &vc->gb;
00705     uint_fast8_t i, j;
00706 
00707     vc->mapping_count = get_bits(gb, 6)+1;
00708     vc->mappings      = av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));
00709 
00710     AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);
00711 
00712     for (i = 0; i < vc->mapping_count; ++i) {
00713         vorbis_mapping *mapping_setup = &vc->mappings[i];
00714 
00715         if (get_bits(gb, 16)) {
00716             av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
00717             return -1;
00718         }
00719         if (get_bits1(gb)) {
00720             mapping_setup->submaps = get_bits(gb, 4) + 1;
00721         } else {
00722             mapping_setup->submaps = 1;
00723         }
00724 
00725         if (get_bits1(gb)) {
00726             mapping_setup->coupling_steps = get_bits(gb, 8) + 1;
00727             mapping_setup->magnitude      = av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
00728             mapping_setup->angle          = av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
00729             for (j = 0; j < mapping_setup->coupling_steps; ++j) {
00730                 GET_VALIDATED_INDEX(mapping_setup->magnitude[j], ilog(vc->audio_channels - 1), vc->audio_channels)
00731                 GET_VALIDATED_INDEX(mapping_setup->angle[j],     ilog(vc->audio_channels - 1), vc->audio_channels)
00732             }
00733         } else {
00734             mapping_setup->coupling_steps = 0;
00735         }
00736 
00737         AV_DEBUG("   %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);
00738 
00739         if (get_bits(gb, 2)) {
00740             av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
00741             return -1; // following spec.
00742         }
00743 
00744         if (mapping_setup->submaps>1) {
00745             mapping_setup->mux = av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
00746             for (j = 0; j < vc->audio_channels; ++j)
00747                 mapping_setup->mux[j] = get_bits(gb, 4);
00748         }
00749 
00750         for (j = 0; j < mapping_setup->submaps; ++j) {
00751             skip_bits(gb, 8); // FIXME check?
00752             GET_VALIDATED_INDEX(mapping_setup->submap_floor[j],   8, vc->floor_count)
00753             GET_VALIDATED_INDEX(mapping_setup->submap_residue[j], 8, vc->residue_count)
00754 
00755             AV_DEBUG("   %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
00756         }
00757     }
00758     return 0;
00759 }
00760 
00761 // Process modes part
00762 
00763 static void create_map(vorbis_context *vc, uint_fast8_t floor_number)
00764 {
00765     vorbis_floor *floors = vc->floors;
00766     vorbis_floor0 *vf;
00767     int idx;
00768     int_fast8_t blockflag;
00769     int_fast32_t *map;
00770     int_fast32_t n; //TODO: could theoretically be smaller?
00771 
00772     for (blockflag = 0; blockflag < 2; ++blockflag) {
00773         n = vc->blocksize[blockflag] / 2;
00774         floors[floor_number].data.t0.map[blockflag] =
00775             av_malloc((n+1) * sizeof(int_fast32_t)); // n + sentinel
00776 
00777         map =  floors[floor_number].data.t0.map[blockflag];
00778         vf  = &floors[floor_number].data.t0;
00779 
00780         for (idx = 0; idx < n; ++idx) {
00781             map[idx] = floor(BARK((vf->rate * idx) / (2.0f * n)) *
00782                              ((vf->bark_map_size) /
00783                               BARK(vf->rate / 2.0f)));
00784             if (vf->bark_map_size-1 < map[idx])
00785                 map[idx] = vf->bark_map_size - 1;
00786         }
00787         map[n] = -1;
00788         vf->map_size[blockflag] = n;
00789     }
00790 
00791 #   ifdef V_DEBUG
00792     for (idx = 0; idx <= n; ++idx) {
00793         AV_DEBUG("floor0 map: map at pos %d is %d\n",
00794                  idx, map[idx]);
00795     }
00796 #   endif
00797 }
00798 
00799 static int vorbis_parse_setup_hdr_modes(vorbis_context *vc)
00800 {
00801     GetBitContext *gb = &vc->gb;
00802     uint_fast8_t i;
00803 
00804     vc->mode_count = get_bits(gb, 6) + 1;
00805     vc->modes      = av_mallocz(vc->mode_count * sizeof(vorbis_mode));
00806 
00807     AV_DEBUG(" There are %d modes.\n", vc->mode_count);
00808 
00809     for (i = 0; i < vc->mode_count; ++i) {
00810         vorbis_mode *mode_setup = &vc->modes[i];
00811 
00812         mode_setup->blockflag     = get_bits1(gb);
00813         mode_setup->windowtype    = get_bits(gb, 16); //FIXME check
00814         mode_setup->transformtype = get_bits(gb, 16); //FIXME check
00815         GET_VALIDATED_INDEX(mode_setup->mapping, 8, vc->mapping_count);
00816 
00817         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);
00818     }
00819     return 0;
00820 }
00821 
00822 // Process the whole setup header using the functions above
00823 
00824 static int vorbis_parse_setup_hdr(vorbis_context *vc)
00825 {
00826     GetBitContext *gb = &vc->gb;
00827 
00828     if ((get_bits(gb, 8) != 'v') || (get_bits(gb, 8) != 'o') ||
00829         (get_bits(gb, 8) != 'r') || (get_bits(gb, 8) != 'b') ||
00830         (get_bits(gb, 8) != 'i') || (get_bits(gb, 8) != 's')) {
00831         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
00832         return -1;
00833     }
00834 
00835     if (vorbis_parse_setup_hdr_codebooks(vc)) {
00836         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
00837         return -2;
00838     }
00839     if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
00840         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
00841         return -3;
00842     }
00843     if (vorbis_parse_setup_hdr_floors(vc)) {
00844         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
00845         return -4;
00846     }
00847     if (vorbis_parse_setup_hdr_residues(vc)) {
00848         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
00849         return -5;
00850     }
00851     if (vorbis_parse_setup_hdr_mappings(vc)) {
00852         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
00853         return -6;
00854     }
00855     if (vorbis_parse_setup_hdr_modes(vc)) {
00856         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
00857         return -7;
00858     }
00859     if (!get_bits1(gb)) {
00860         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
00861         return -8; // framing flag bit unset error
00862     }
00863 
00864     return 0;
00865 }
00866 
00867 // Process the identification header
00868 
00869 static int vorbis_parse_id_hdr(vorbis_context *vc)
00870 {
00871     GetBitContext *gb = &vc->gb;
00872     uint_fast8_t bl0, bl1;
00873 
00874     if ((get_bits(gb, 8) != 'v') || (get_bits(gb, 8) != 'o') ||
00875         (get_bits(gb, 8) != 'r') || (get_bits(gb, 8) != 'b') ||
00876         (get_bits(gb, 8) != 'i') || (get_bits(gb, 8) != 's')) {
00877         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
00878         return -1;
00879     }
00880 
00881     vc->version        = get_bits_long(gb, 32);    //FIXME check 0
00882     vc->audio_channels = get_bits(gb, 8);
00883     if (vc->audio_channels <= 0) {
00884         av_log(vc->avccontext, AV_LOG_ERROR, "Invalid number of channels\n");
00885         return -1;
00886     }
00887     vc->audio_samplerate = get_bits_long(gb, 32);
00888     if (vc->audio_samplerate <= 0) {
00889         av_log(vc->avccontext, AV_LOG_ERROR, "Invalid samplerate\n");
00890         return -1;
00891     }
00892     vc->bitrate_maximum = get_bits_long(gb, 32);
00893     vc->bitrate_nominal = get_bits_long(gb, 32);
00894     vc->bitrate_minimum = get_bits_long(gb, 32);
00895     bl0 = get_bits(gb, 4);
00896     bl1 = get_bits(gb, 4);
00897     vc->blocksize[0] = (1 << bl0);
00898     vc->blocksize[1] = (1 << bl1);
00899     if (bl0 > 13 || bl0 < 6 || bl1 > 13 || bl1 < 6 || bl1 < bl0) {
00900         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
00901         return -3;
00902     }
00903     // output format int16
00904     if (vc->blocksize[1] / 2 * vc->audio_channels * 2 > AVCODEC_MAX_AUDIO_FRAME_SIZE) {
00905         av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis channel count makes "
00906                "output packets too large.\n");
00907         return -4;
00908     }
00909     vc->win[0] = ff_vorbis_vwin[bl0 - 6];
00910     vc->win[1] = ff_vorbis_vwin[bl1 - 6];
00911 
00912     if ((get_bits1(gb)) == 0) {
00913         av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
00914         return -2;
00915     }
00916 
00917     vc->channel_residues =  av_malloc((vc->blocksize[1]  / 2) * vc->audio_channels * sizeof(float));
00918     vc->channel_floors   =  av_malloc((vc->blocksize[1]  / 2) * vc->audio_channels * sizeof(float));
00919     vc->saved            =  av_mallocz((vc->blocksize[1] / 4) * vc->audio_channels * sizeof(float));
00920     vc->previous_window  = 0;
00921 
00922     ff_mdct_init(&vc->mdct[0], bl0, 1, vc->exp_bias ? -(1 << 15) : -1.0);
00923     ff_mdct_init(&vc->mdct[1], bl1, 1, vc->exp_bias ? -(1 << 15) : -1.0);
00924 
00925     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 ",
00926             vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize[0], vc->blocksize[1]);
00927 
00928 /*
00929     BLK = vc->blocksize[0];
00930     for (i = 0; i < BLK / 2; ++i) {
00931         vc->win[0][i] = sin(0.5*3.14159265358*(sin(((float)i + 0.5) / (float)BLK*3.14159265358))*(sin(((float)i + 0.5) / (float)BLK*3.14159265358)));
00932     }
00933 */
00934 
00935     return 0;
00936 }
00937 
00938 // Process the extradata using the functions above (identification header, setup header)
00939 
00940 static av_cold int vorbis_decode_init(AVCodecContext *avccontext)
00941 {
00942     vorbis_context *vc = avccontext->priv_data ;
00943     uint8_t *headers   = avccontext->extradata;
00944     int headers_len    = avccontext->extradata_size;
00945     uint8_t *header_start[3];
00946     int header_len[3];
00947     GetBitContext *gb = &(vc->gb);
00948     int hdr_type;
00949 
00950     vc->avccontext = avccontext;
00951     dsputil_init(&vc->dsp, avccontext);
00952 
00953     if (vc->dsp.float_to_int16_interleave == ff_float_to_int16_interleave_c) {
00954         vc->add_bias = 385;
00955         vc->exp_bias = 0;
00956     } else {
00957         vc->add_bias = 0;
00958         vc->exp_bias = 15 << 23;
00959     }
00960 
00961     if (!headers_len) {
00962         av_log(avccontext, AV_LOG_ERROR, "Extradata missing.\n");
00963         return -1;
00964     }
00965 
00966     if (ff_split_xiph_headers(headers, headers_len, 30, header_start, header_len) < 0) {
00967         av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
00968         return -1;
00969     }
00970 
00971     init_get_bits(gb, header_start[0], header_len[0]*8);
00972     hdr_type = get_bits(gb, 8);
00973     if (hdr_type != 1) {
00974         av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
00975         return -1;
00976     }
00977     if (vorbis_parse_id_hdr(vc)) {
00978         av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
00979         vorbis_free(vc);
00980         return -1;
00981     }
00982 
00983     init_get_bits(gb, header_start[2], header_len[2]*8);
00984     hdr_type = get_bits(gb, 8);
00985     if (hdr_type != 5) {
00986         av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
00987         vorbis_free(vc);
00988         return -1;
00989     }
00990     if (vorbis_parse_setup_hdr(vc)) {
00991         av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
00992         vorbis_free(vc);
00993         return -1;
00994     }
00995 
00996     if (vc->audio_channels > 8)
00997         avccontext->channel_layout = 0;
00998     else
00999         avccontext->channel_layout = ff_vorbis_channel_layouts[vc->audio_channels - 1];
01000 
01001     avccontext->channels    = vc->audio_channels;
01002     avccontext->sample_rate = vc->audio_samplerate;
01003     avccontext->frame_size  = FFMIN(vc->blocksize[0], vc->blocksize[1]) >> 2;
01004     avccontext->sample_fmt  = SAMPLE_FMT_S16;
01005 
01006     return 0 ;
01007 }
01008 
01009 // Decode audiopackets -------------------------------------------------
01010 
01011 // Read and decode floor
01012 
01013 static int vorbis_floor0_decode(vorbis_context *vc,
01014                                 vorbis_floor_data *vfu, float *vec)
01015 {
01016     vorbis_floor0 *vf = &vfu->t0;
01017     float *lsp = vf->lsp;
01018     uint_fast32_t amplitude;
01019     uint_fast32_t book_idx;
01020     uint_fast8_t blockflag = vc->modes[vc->mode_number].blockflag;
01021 
01022     amplitude = get_bits(&vc->gb, vf->amplitude_bits);
01023     if (amplitude > 0) {
01024         float last = 0;
01025         uint_fast16_t lsp_len = 0;
01026         uint_fast16_t idx;
01027         vorbis_codebook codebook;
01028 
01029         book_idx = get_bits(&vc->gb, ilog(vf->num_books));
01030         if (book_idx >= vf->num_books) {
01031             av_log(vc->avccontext, AV_LOG_ERROR,
01032                     "floor0 dec: booknumber too high!\n");
01033             book_idx =  0;
01034             //FIXME: look above
01035         }
01036         AV_DEBUG("floor0 dec: booknumber: %u\n", book_idx);
01037         codebook = vc->codebooks[vf->book_list[book_idx]];
01038         /* Invalid codebook! */
01039         if (!codebook.codevectors)
01040             return -1;
01041 
01042         while (lsp_len<vf->order) {
01043             int vec_off;
01044 
01045             AV_DEBUG("floor0 dec: book dimension: %d\n", codebook.dimensions);
01046             AV_DEBUG("floor0 dec: maximum depth: %d\n", codebook.maxdepth);
01047             /* read temp vector */
01048             vec_off = get_vlc2(&vc->gb, codebook.vlc.table,
01049                                codebook.nb_bits, codebook.maxdepth)
01050                       * codebook.dimensions;
01051             AV_DEBUG("floor0 dec: vector offset: %d\n", vec_off);
01052             /* copy each vector component and add last to it */
01053             for (idx = 0; idx < codebook.dimensions; ++idx)
01054                 lsp[lsp_len+idx] = codebook.codevectors[vec_off+idx] + last;
01055             last = lsp[lsp_len+idx-1]; /* set last to last vector component */
01056 
01057             lsp_len += codebook.dimensions;
01058         }
01059 #ifdef V_DEBUG
01060         /* DEBUG: output lsp coeffs */
01061         {
01062             int idx;
01063             for (idx = 0; idx < lsp_len; ++idx)
01064                 AV_DEBUG("floor0 dec: coeff at %d is %f\n", idx, lsp[idx]);
01065         }
01066 #endif
01067 
01068         /* synthesize floor output vector */
01069         {
01070             int i;
01071             int order = vf->order;
01072             float wstep = M_PI / vf->bark_map_size;
01073 
01074             for (i = 0; i < order; i++)
01075                 lsp[i] = 2.0f * cos(lsp[i]);
01076 
01077             AV_DEBUG("floor0 synth: map_size = %d; m = %d; wstep = %f\n",
01078                      vf->map_size, order, wstep);
01079 
01080             i = 0;
01081             while (i < vf->map_size[blockflag]) {
01082                 int j, iter_cond = vf->map[blockflag][i];
01083                 float p = 0.5f;
01084                 float q = 0.5f;
01085                 float two_cos_w = 2.0f * cos(wstep * iter_cond); // needed all times
01086 
01087                 /* similar part for the q and p products */
01088                 for (j = 0; j + 1 < order; j += 2) {
01089                     q *= lsp[j]     - two_cos_w;
01090                     p *= lsp[j + 1] - two_cos_w;
01091                 }
01092                 if (j == order) { // even order
01093                     p *= p * (2.0f - two_cos_w);
01094                     q *= q * (2.0f + two_cos_w);
01095                 } else { // odd order
01096                     q *= two_cos_w-lsp[j]; // one more time for q
01097 
01098                     /* final step and square */
01099                     p *= p * (4.f - two_cos_w * two_cos_w);
01100                     q *= q;
01101                 }
01102 
01103                 /* calculate linear floor value */
01104                 {
01105                     q = exp((((amplitude*vf->amplitude_offset) /
01106                               (((1 << vf->amplitude_bits) - 1) * sqrt(p + q)))
01107                              - vf->amplitude_offset) * .11512925f);
01108                 }
01109 
01110                 /* fill vector */
01111                 do {
01112                     vec[i] = q; ++i;
01113                 } while (vf->map[blockflag][i] == iter_cond);
01114             }
01115         }
01116     } else {
01117         /* this channel is unused */
01118         return 1;
01119     }
01120 
01121     AV_DEBUG(" Floor0 decoded\n");
01122 
01123     return 0;
01124 }
01125 
01126 static int vorbis_floor1_decode(vorbis_context *vc,
01127                                 vorbis_floor_data *vfu, float *vec)
01128 {
01129     vorbis_floor1 *vf = &vfu->t1;
01130     GetBitContext *gb = &vc->gb;
01131     uint_fast16_t range_v[4] = { 256, 128, 86, 64 };
01132     uint_fast16_t range = range_v[vf->multiplier-1];
01133     uint_fast16_t floor1_Y[vf->x_list_dim];
01134     uint_fast16_t floor1_Y_final[vf->x_list_dim];
01135     int floor1_flag[vf->x_list_dim];
01136     uint_fast8_t class_;
01137     uint_fast8_t cdim;
01138     uint_fast8_t cbits;
01139     uint_fast8_t csub;
01140     uint_fast8_t cval;
01141     int_fast16_t book;
01142     uint_fast16_t offset;
01143     uint_fast16_t i,j;
01144     /*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx =  (unsigned)dy/adx ?
01145     int_fast16_t dy, err;
01146 
01147 
01148     if (!get_bits1(gb)) // silence
01149         return 1;
01150 
01151 // Read values (or differences) for the floor's points
01152 
01153     floor1_Y[0] = get_bits(gb, ilog(range - 1));
01154     floor1_Y[1] = get_bits(gb, ilog(range - 1));
01155 
01156     AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);
01157 
01158     offset = 2;
01159     for (i = 0; i < vf->partitions; ++i) {
01160         class_ = vf->partition_class[i];
01161         cdim   = vf->class_dimensions[class_];
01162         cbits  = vf->class_subclasses[class_];
01163         csub = (1 << cbits) - 1;
01164         cval = 0;
01165 
01166         AV_DEBUG("Cbits %d \n", cbits);
01167 
01168         if (cbits) // this reads all subclasses for this partition's class
01169             cval = get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,
01170                             vc->codebooks[vf->class_masterbook[class_]].nb_bits, 3);
01171 
01172         for (j = 0; j < cdim; ++j) {
01173             book = vf->subclass_books[class_][cval & csub];
01174 
01175             AV_DEBUG("book %d Cbits %d cval %d  bits:%d \n", book, cbits, cval, get_bits_count(gb));
01176 
01177             cval = cval >> cbits;
01178             if (book > -1) {
01179                 floor1_Y[offset+j] = get_vlc2(gb, vc->codebooks[book].vlc.table,
01180                 vc->codebooks[book].nb_bits, 3);
01181             } else {
01182                 floor1_Y[offset+j] = 0;
01183             }
01184 
01185             AV_DEBUG(" floor(%d) = %d \n", vf->list[offset+j].x, floor1_Y[offset+j]);
01186         }
01187         offset+=cdim;
01188     }
01189 
01190 // Amplitude calculation from the differences
01191 
01192     floor1_flag[0] = 1;
01193     floor1_flag[1] = 1;
01194     floor1_Y_final[0] = floor1_Y[0];
01195     floor1_Y_final[1] = floor1_Y[1];
01196 
01197     for (i = 2; i < vf->x_list_dim; ++i) {
01198         uint_fast16_t val, highroom, lowroom, room;
01199         uint_fast16_t high_neigh_offs;
01200         uint_fast16_t low_neigh_offs;
01201 
01202         low_neigh_offs  = vf->list[i].low;
01203         high_neigh_offs = vf->list[i].high;
01204         dy  = floor1_Y_final[high_neigh_offs] - floor1_Y_final[low_neigh_offs];  // render_point begin
01205         adx = vf->list[high_neigh_offs].x - vf->list[low_neigh_offs].x;
01206         ady = FFABS(dy);
01207         err = ady * (vf->list[i].x - vf->list[low_neigh_offs].x);
01208         off = (int16_t)err / (int16_t)adx;
01209         if (dy < 0) {
01210             predicted = floor1_Y_final[low_neigh_offs] - off;
01211         } else {
01212             predicted = floor1_Y_final[low_neigh_offs] + off;
01213         } // render_point end
01214 
01215         val = floor1_Y[i];
01216         highroom = range-predicted;
01217         lowroom  = predicted;
01218         if (highroom < lowroom) {
01219             room = highroom * 2;
01220         } else {
01221             room = lowroom * 2;   // SPEC mispelling
01222         }
01223         if (val) {
01224             floor1_flag[low_neigh_offs]  = 1;
01225             floor1_flag[high_neigh_offs] = 1;
01226             floor1_flag[i]               = 1;
01227             if (val >= room) {
01228                 if (highroom > lowroom) {
01229                     floor1_Y_final[i] = val - lowroom + predicted;
01230                 } else {
01231                     floor1_Y_final[i] = predicted - val + highroom - 1;
01232                 }
01233             } else {
01234                 if (val & 1) {
01235                     floor1_Y_final[i] = predicted - (val + 1) / 2;
01236                 } else {
01237                     floor1_Y_final[i] = predicted + val / 2;
01238                 }
01239             }
01240         } else {
01241             floor1_flag[i]    = 0;
01242             floor1_Y_final[i] = predicted;
01243         }
01244 
01245         AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->list[i].x, floor1_Y_final[i], val);
01246     }
01247 
01248 // Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?
01249 
01250     ff_vorbis_floor1_render_list(vf->list, vf->x_list_dim, floor1_Y_final, floor1_flag, vf->multiplier, vec, vf->list[1].x);
01251 
01252     AV_DEBUG(" Floor decoded\n");
01253 
01254     return 0;
01255 }
01256 
01257 // Read and decode residue
01258 
01259 static av_always_inline int vorbis_residue_decode_internal(vorbis_context *vc,
01260                                                            vorbis_residue *vr,
01261                                                            uint_fast8_t ch,
01262                                                            uint_fast8_t *do_not_decode,
01263                                                            float *vec,
01264                                                            uint_fast16_t vlen,
01265                                                            int vr_type)
01266 {
01267     GetBitContext *gb = &vc->gb;
01268     uint_fast8_t c_p_c = vc->codebooks[vr->classbook].dimensions;
01269     uint_fast16_t n_to_read = vr->end-vr->begin;
01270     uint_fast16_t ptns_to_read = n_to_read/vr->partition_size;
01271     uint_fast8_t classifs[ptns_to_read*vc->audio_channels];
01272     uint_fast8_t pass;
01273     uint_fast8_t ch_used;
01274     uint_fast8_t i,j,l;
01275     uint_fast16_t k;
01276 
01277     if (vr_type == 2) {
01278         for (j = 1; j < ch; ++j)
01279             do_not_decode[0] &= do_not_decode[j];  // FIXME - clobbering input
01280         if (do_not_decode[0])
01281             return 0;
01282         ch_used = 1;
01283     } else {
01284         ch_used = ch;
01285     }
01286 
01287     AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d  cpc %d  \n", ch, c_p_c);
01288 
01289     for (pass = 0; pass <= vr->maxpass; ++pass) { // FIXME OPTIMIZE?
01290         uint_fast16_t voffset;
01291         uint_fast16_t partition_count;
01292         uint_fast16_t j_times_ptns_to_read;
01293 
01294         voffset = vr->begin;
01295         for (partition_count = 0; partition_count < ptns_to_read;) {  // SPEC        error
01296             if (!pass) {
01297                 uint_fast32_t inverse_class = ff_inverse[vr->classifications];
01298                 for (j_times_ptns_to_read = 0, j = 0; j < ch_used; ++j) {
01299                     if (!do_not_decode[j]) {
01300                         uint_fast32_t temp = get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,
01301                         vc->codebooks[vr->classbook].nb_bits, 3);
01302 
01303                         AV_DEBUG("Classword: %d \n", temp);
01304 
01305                         assert(vr->classifications > 1 && temp <= 65536); //needed for inverse[]
01306                         for (i = 0; i < c_p_c; ++i) {
01307                             uint_fast32_t temp2;
01308 
01309                             temp2 = (((uint_fast64_t)temp) * inverse_class) >> 32;
01310                             if (partition_count + c_p_c - 1 - i < ptns_to_read)
01311                                 classifs[j_times_ptns_to_read + partition_count + c_p_c - 1 - i] = temp - temp2 * vr->classifications;
01312                             temp = temp2;
01313                         }
01314                     }
01315                     j_times_ptns_to_read += ptns_to_read;
01316                 }
01317             }
01318             for (i = 0; (i < c_p_c) && (partition_count < ptns_to_read); ++i) {
01319                 for (j_times_ptns_to_read = 0, j = 0; j < ch_used; ++j) {
01320                     uint_fast16_t voffs;
01321 
01322                     if (!do_not_decode[j]) {
01323                         uint_fast8_t vqclass = classifs[j_times_ptns_to_read+partition_count];
01324                         int_fast16_t vqbook = vr->books[vqclass][pass];
01325 
01326                         if (vqbook >= 0 && vc->codebooks[vqbook].codevectors) {
01327                             uint_fast16_t coffs;
01328                             unsigned dim =  vc->codebooks[vqbook].dimensions; // not uint_fast8_t: 64bit is slower here on amd64
01329                             uint_fast16_t step = dim == 1 ? vr->partition_size
01330                                                           : FASTDIV(vr->partition_size, dim);
01331                             vorbis_codebook codebook = vc->codebooks[vqbook];
01332 
01333                             if (vr_type == 0) {
01334 
01335                                 voffs = voffset+j*vlen;
01336                                 for (k = 0; k < step; ++k) {
01337                                     coffs = get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
01338                                     for (l = 0; l < dim; ++l)
01339                                         vec[voffs + k + l * step] += codebook.codevectors[coffs + l];  // FPMATH
01340                                 }
01341                             } else if (vr_type == 1) {
01342                                 voffs = voffset + j * vlen;
01343                                 for (k = 0; k < step; ++k) {
01344                                     coffs = get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
01345                                     for (l = 0; l < dim; ++l, ++voffs) {
01346                                         vec[voffs]+=codebook.codevectors[coffs+l];  // FPMATH
01347 
01348                                         AV_DEBUG(" pass %d offs: %d curr: %f change: %f cv offs.: %d  \n", pass, voffs, vec[voffs], codebook.codevectors[coffs+l], coffs);
01349                                     }
01350                                 }
01351                             } else if (vr_type == 2 && ch == 2 && (voffset & 1) == 0 && (dim & 1) == 0) { // most frequent case optimized
01352                                 voffs = voffset >> 1;
01353 
01354                                 if (dim == 2) {
01355                                     for (k = 0; k < step; ++k) {
01356                                         coffs = get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * 2;
01357                                         vec[voffs + k       ] += codebook.codevectors[coffs    ];  // FPMATH
01358                                         vec[voffs + k + vlen] += codebook.codevectors[coffs + 1];  // FPMATH
01359                                     }
01360                                 } else if (dim == 4) {
01361                                     for (k = 0; k < step; ++k, voffs += 2) {
01362                                         coffs = get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * 4;
01363                                         vec[voffs           ] += codebook.codevectors[coffs    ];  // FPMATH
01364                                         vec[voffs + 1       ] += codebook.codevectors[coffs + 2];  // FPMATH
01365                                         vec[voffs + vlen    ] += codebook.codevectors[coffs + 1];  // FPMATH
01366                                         vec[voffs + vlen + 1] += codebook.codevectors[coffs + 3];  // FPMATH
01367                                     }
01368                                 } else
01369                                 for (k = 0; k < step; ++k) {
01370                                     coffs = get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
01371                                     for (l = 0; l < dim; l += 2, voffs++) {
01372                                         vec[voffs       ] += codebook.codevectors[coffs + l    ];  // FPMATH
01373                                         vec[voffs + vlen] += codebook.codevectors[coffs + l + 1];  // FPMATH
01374 
01375                                         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);
01376                                     }
01377                                 }
01378 
01379                             } else if (vr_type == 2) {
01380                                 voffs = voffset;
01381 
01382                                 for (k = 0; k < step; ++k) {
01383                                     coffs = get_vlc2(gb, codebook.vlc.table, codebook.nb_bits, 3) * dim;
01384                                     for (l = 0; l < dim; ++l, ++voffs) {
01385                                         vec[voffs / ch + (voffs % ch) * vlen] += codebook.codevectors[coffs + l];  // FPMATH FIXME use if and counter instead of / and %
01386 
01387                                         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);
01388                                     }
01389                                 }
01390                             }
01391                         }
01392                     }
01393                     j_times_ptns_to_read += ptns_to_read;
01394                 }
01395                 ++partition_count;
01396                 voffset += vr->partition_size;
01397             }
01398         }
01399     }
01400     return 0;
01401 }
01402 
01403 static inline int vorbis_residue_decode(vorbis_context *vc, vorbis_residue *vr,
01404                                         uint_fast8_t ch,
01405                                         uint_fast8_t *do_not_decode,
01406                                         float *vec, uint_fast16_t vlen)
01407 {
01408     if (vr->type == 2)
01409         return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, 2);
01410     else if (vr->type == 1)
01411         return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, 1);
01412     else if (vr->type == 0)
01413         return vorbis_residue_decode_internal(vc, vr, ch, do_not_decode, vec, vlen, 0);
01414     else {
01415         av_log(vc->avccontext, AV_LOG_ERROR, " Invalid residue type while residue decode?! \n");
01416         return -1;
01417     }
01418 }
01419 
01420 void vorbis_inverse_coupling(float *mag, float *ang, int blocksize)
01421 {
01422     int i;
01423     for (i = 0;  i < blocksize;  i++) {
01424         if (mag[i] > 0.0) {
01425             if (ang[i] > 0.0) {
01426                 ang[i] = mag[i] - ang[i];
01427             } else {
01428                 float temp = ang[i];
01429                 ang[i]     = mag[i];
01430                 mag[i]    += temp;
01431             }
01432         } else {
01433             if (ang[i] > 0.0) {
01434                 ang[i] += mag[i];
01435             } else {
01436                 float temp = ang[i];
01437                 ang[i]     = mag[i];
01438                 mag[i]    -= temp;
01439             }
01440         }
01441     }
01442 }
01443 
01444 static void copy_normalize(float *dst, float *src, int len, int exp_bias,
01445                            float add_bias)
01446 {
01447     int i;
01448     if (exp_bias) {
01449         memcpy(dst, src, len * sizeof(float));
01450     } else {
01451         for (i = 0; i < len; i++)
01452             dst[i] = src[i] + add_bias;
01453     }
01454 }
01455 
01456 // Decode the audio packet using the functions above
01457 
01458 static int vorbis_parse_audio_packet(vorbis_context *vc)
01459 {
01460     GetBitContext *gb = &vc->gb;
01461 
01462     uint_fast8_t previous_window = vc->previous_window;
01463     uint_fast8_t mode_number;
01464     uint_fast8_t blockflag;
01465     uint_fast16_t blocksize;
01466     int_fast32_t i,j;
01467     uint_fast8_t no_residue[vc->audio_channels];
01468     uint_fast8_t do_not_decode[vc->audio_channels];
01469     vorbis_mapping *mapping;
01470     float *ch_res_ptr   = vc->channel_residues;
01471     float *ch_floor_ptr = vc->channel_floors;
01472     uint_fast8_t res_chan[vc->audio_channels];
01473     uint_fast8_t res_num = 0;
01474     int_fast16_t retlen  = 0;
01475     float fadd_bias = vc->add_bias;
01476 
01477     if (get_bits1(gb)) {
01478         av_log(vc->avccontext, AV_LOG_ERROR, "Not a Vorbis I audio packet.\n");
01479         return -1; // packet type not audio
01480     }
01481 
01482     if (vc->mode_count == 1) {
01483         mode_number = 0;
01484     } else {
01485         GET_VALIDATED_INDEX(mode_number, ilog(vc->mode_count-1), vc->mode_count)
01486     }
01487     vc->mode_number = mode_number;
01488     mapping = &vc->mappings[vc->modes[mode_number].mapping];
01489 
01490     AV_DEBUG(" Mode number: %d , mapping: %d , blocktype %d \n", mode_number, vc->modes[mode_number].mapping, vc->modes[mode_number].blockflag);
01491 
01492     blockflag = vc->modes[mode_number].blockflag;
01493     blocksize = vc->blocksize[blockflag];
01494     if (blockflag)
01495         skip_bits(gb, 2); // previous_window, next_window
01496 
01497     memset(ch_res_ptr,   0, sizeof(float) * vc->audio_channels * blocksize / 2); //FIXME can this be removed ?
01498     memset(ch_floor_ptr, 0, sizeof(float) * vc->audio_channels * blocksize / 2); //FIXME can this be removed ?
01499 
01500 // Decode floor
01501 
01502     for (i = 0; i < vc->audio_channels; ++i) {
01503         vorbis_floor *floor;
01504         int ret;
01505         if (mapping->submaps > 1) {
01506             floor = &vc->floors[mapping->submap_floor[mapping->mux[i]]];
01507         } else {
01508             floor = &vc->floors[mapping->submap_floor[0]];
01509         }
01510 
01511         ret = floor->decode(vc, &floor->data, ch_floor_ptr);
01512 
01513         if (ret < 0) {
01514             av_log(vc->avccontext, AV_LOG_ERROR, "Invalid codebook in vorbis_floor_decode.\n");
01515             return -1;
01516         }
01517         no_residue[i] = ret;
01518         ch_floor_ptr += blocksize / 2;
01519     }
01520 
01521 // Nonzero vector propagate
01522 
01523     for (i = mapping->coupling_steps - 1; i >= 0; --i) {
01524         if (!(no_residue[mapping->magnitude[i]] & no_residue[mapping->angle[i]])) {
01525             no_residue[mapping->magnitude[i]] = 0;
01526             no_residue[mapping->angle[i]]     = 0;
01527         }
01528     }
01529 
01530 // Decode residue
01531 
01532     for (i = 0; i < mapping->submaps; ++i) {
01533         vorbis_residue *residue;
01534         uint_fast8_t ch = 0;
01535 
01536         for (j = 0; j < vc->audio_channels; ++j) {
01537             if ((mapping->submaps == 1) || (i == mapping->mux[j])) {
01538                 res_chan[j] = res_num;
01539                 if (no_residue[j]) {
01540                     do_not_decode[ch] = 1;
01541                 } else {
01542                     do_not_decode[ch] = 0;
01543                 }
01544                 ++ch;
01545                 ++res_num;
01546             }
01547         }
01548         residue = &vc->residues[mapping->submap_residue[i]];
01549         vorbis_residue_decode(vc, residue, ch, do_not_decode, ch_res_ptr, blocksize/2);
01550 
01551         ch_res_ptr += ch * blocksize / 2;
01552     }
01553 
01554 // Inverse coupling
01555 
01556     for (i = mapping->coupling_steps - 1; i >= 0; --i) { //warning: i has to be signed
01557         float *mag, *ang;
01558 
01559         mag = vc->channel_residues+res_chan[mapping->magnitude[i]] * blocksize / 2;
01560         ang = vc->channel_residues+res_chan[mapping->angle[i]]     * blocksize / 2;
01561         vc->dsp.vorbis_inverse_coupling(mag, ang, blocksize / 2);
01562     }
01563 
01564 // Dotproduct, MDCT
01565 
01566     for (j = vc->audio_channels-1;j >= 0; j--) {
01567         ch_floor_ptr = vc->channel_floors   + j           * blocksize / 2;
01568         ch_res_ptr   = vc->channel_residues + res_chan[j] * blocksize / 2;
01569         vc->dsp.vector_fmul(ch_floor_ptr, ch_res_ptr, blocksize / 2);
01570         ff_imdct_half(&vc->mdct[blockflag], ch_res_ptr, ch_floor_ptr);
01571     }
01572 
01573 // Overlap/add, save data for next overlapping  FPMATH
01574 
01575     retlen = (blocksize + vc->blocksize[previous_window]) / 4;
01576     for (j = 0; j < vc->audio_channels; j++) {
01577         uint_fast16_t bs0 = vc->blocksize[0];
01578         uint_fast16_t bs1 = vc->blocksize[1];
01579         float *residue    = vc->channel_residues + res_chan[j] * blocksize / 2;
01580         float *saved      = vc->saved + j * bs1 / 4;
01581         float *ret        = vc->channel_floors + j * retlen;
01582         float *buf        = residue;
01583         const float *win  = vc->win[blockflag & previous_window];
01584 
01585         if (blockflag == previous_window) {
01586             vc->dsp.vector_fmul_window(ret, saved, buf, win, fadd_bias, blocksize / 4);
01587         } else if (blockflag > previous_window) {
01588             vc->dsp.vector_fmul_window(ret, saved, buf, win, fadd_bias, bs0 / 4);
01589             copy_normalize(ret+bs0/2, buf+bs0/4, (bs1-bs0)/4, vc->exp_bias, fadd_bias);
01590         } else {
01591             copy_normalize(ret, saved, (bs1 - bs0) / 4, vc->exp_bias, fadd_bias);
01592             vc->dsp.vector_fmul_window(ret + (bs1 - bs0) / 4, saved + (bs1 - bs0) / 4, buf, win, fadd_bias, bs0 / 4);
01593         }
01594         memcpy(saved, buf + blocksize / 4, blocksize / 4 * sizeof(float));
01595     }
01596 
01597     vc->previous_window = blockflag;
01598     return retlen;
01599 }
01600 
01601 // Return the decoded audio packet through the standard api
01602 
01603 static int vorbis_decode_frame(AVCodecContext *avccontext,
01604                                void *data, int *data_size,
01605                                AVPacket *avpkt)
01606 {
01607     const uint8_t *buf = avpkt->data;
01608     int buf_size       = avpkt->size;
01609     vorbis_context *vc = avccontext->priv_data ;
01610     GetBitContext *gb = &(vc->gb);
01611     const float *channel_ptrs[vc->audio_channels];
01612     int i;
01613 
01614     int_fast16_t len;
01615 
01616     if (!buf_size)
01617         return 0;
01618 
01619     AV_DEBUG("packet length %d \n", buf_size);
01620 
01621     init_get_bits(gb, buf, buf_size*8);
01622 
01623     len = vorbis_parse_audio_packet(vc);
01624 
01625     if (len <= 0) {
01626         *data_size = 0;
01627         return buf_size;
01628     }
01629 
01630     if (!vc->first_frame) {
01631         vc->first_frame = 1;
01632         *data_size = 0;
01633         return buf_size ;
01634     }
01635 
01636     AV_DEBUG("parsed %d bytes %d bits, returned %d samples (*ch*bits) \n", get_bits_count(gb)/8, get_bits_count(gb)%8, len);
01637 
01638     if (vc->audio_channels > 8) {
01639         for (i = 0; i < vc->audio_channels; i++)
01640             channel_ptrs[i] = vc->channel_floors + i * len;
01641     } else {
01642         for (i = 0; i < vc->audio_channels; i++)
01643             channel_ptrs[i] = vc->channel_floors +
01644                               len * ff_vorbis_channel_layout_offsets[vc->audio_channels - 1][i];
01645     }
01646 
01647     vc->dsp.float_to_int16_interleave(data, channel_ptrs, len, vc->audio_channels);
01648     *data_size = len * 2 * vc->audio_channels;
01649 
01650     return buf_size ;
01651 }
01652 
01653 // Close decoder
01654 
01655 static av_cold int vorbis_decode_close(AVCodecContext *avccontext)
01656 {
01657     vorbis_context *vc = avccontext->priv_data;
01658 
01659     vorbis_free(vc);
01660 
01661     return 0 ;
01662 }
01663 
01664 AVCodec vorbis_decoder = {
01665     "vorbis",
01666     AVMEDIA_TYPE_AUDIO,
01667     CODEC_ID_VORBIS,
01668     sizeof(vorbis_context),
01669     vorbis_decode_init,
01670     NULL,
01671     vorbis_decode_close,
01672     vorbis_decode_frame,
01673     .long_name = NULL_IF_CONFIG_SMALL("Vorbis"),
01674     .channel_layouts = ff_vorbis_channel_layouts,
01675 };
01676 

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