vorbis.c

/**
 * @file vorbis.c
 * Vorbis I decoder
 * @author Denes Balatoni  ( dbalatoni programozo hu )

 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 *
 */

#undef V_DEBUG
//#define V_DEBUG
//#define AV_DEBUG(...) av_log(NULL, AV_LOG_INFO, __VA_ARGS__)

#include <math.h>

#define ALT_BITSTREAM_READER_LE
#include "avcodec.h"
#include "bitstream.h"
#include "dsputil.h"

#include "vorbis.h"
#include "xiph.h"

#define V_NB_BITS 8
#define V_NB_BITS2 11
#define V_MAX_VLCS (1<<16)

#ifndef V_DEBUG
#define AV_DEBUG(...)
#endif

#undef NDEBUG
#include <assert.h>

typedef struct {
    uint_fast8_t dimensions;
    uint_fast8_t lookup_type;
    uint_fast8_t maxdepth;
    VLC vlc;
    float *codevectors;
    unsigned int nb_bits;
} vorbis_codebook;

typedef union vorbis_floor_u vorbis_floor_data;
typedef struct vorbis_floor0_s vorbis_floor0;
typedef struct vorbis_floor1_s vorbis_floor1;
struct vorbis_context_s;
typedef
uint_fast8_t (* vorbis_floor_decode_func)
             (struct vorbis_context_s *, vorbis_floor_data *, float *);
typedef struct {
    uint_fast8_t floor_type;
    vorbis_floor_decode_func decode;
    union vorbis_floor_u
    {
        struct vorbis_floor0_s
        {
            uint_fast8_t order;
            uint_fast16_t rate;
            uint_fast16_t bark_map_size;
            int_fast32_t * map[2];
            uint_fast32_t map_size[2];
            uint_fast8_t amplitude_bits;
            uint_fast8_t amplitude_offset;
            uint_fast8_t num_books;
            uint_fast8_t * book_list;
            float * lsp;
        } t0;
        struct vorbis_floor1_s
        {
            uint_fast8_t partitions;
            uint_fast8_t maximum_class;
            uint_fast8_t partition_class[32];
            uint_fast8_t class_dimensions[16];
            uint_fast8_t class_subclasses[16];
            uint_fast8_t class_masterbook[16];
            int_fast16_t subclass_books[16][8];
            uint_fast8_t multiplier;
            uint_fast16_t x_list_dim;
            floor1_entry_t * list;
        } t1;
    } data;
} vorbis_floor;

typedef struct {
    uint_fast16_t type;
    uint_fast32_t begin;
    uint_fast32_t end;
    uint_fast32_t partition_size;
    uint_fast8_t classifications;
    uint_fast8_t classbook;
    int_fast16_t books[64][8];
    uint_fast8_t maxpass;
} vorbis_residue;

typedef struct {
    uint_fast8_t submaps;
    uint_fast16_t coupling_steps;
    uint_fast8_t *magnitude;
    uint_fast8_t *angle;
    uint_fast8_t *mux;
    uint_fast8_t submap_floor[16];
    uint_fast8_t submap_residue[16];
} vorbis_mapping;

typedef struct {
    uint_fast8_t blockflag;
    uint_fast16_t windowtype;
    uint_fast16_t transformtype;
    uint_fast8_t mapping;
} vorbis_mode;

typedef struct vorbis_context_s {
    AVCodecContext *avccontext;
    GetBitContext gb;
    DSPContext dsp;

    MDCTContext mdct[2];
    uint_fast8_t first_frame;
    uint_fast32_t version;
    uint_fast8_t audio_channels;
    uint_fast32_t audio_samplerate;
    uint_fast32_t bitrate_maximum;
    uint_fast32_t bitrate_nominal;
    uint_fast32_t bitrate_minimum;
    uint_fast32_t blocksize[2];
    const float * win[2];
    uint_fast16_t codebook_count;
    vorbis_codebook *codebooks;
    uint_fast8_t floor_count;
    vorbis_floor *floors;
    uint_fast8_t residue_count;
    vorbis_residue *residues;
    uint_fast8_t mapping_count;
    vorbis_mapping *mappings;
    uint_fast8_t mode_count;
    vorbis_mode *modes;
    uint_fast8_t mode_number; // mode number for the current packet
    float *channel_residues;
    float *channel_floors;
    float *saved;
    uint_fast16_t saved_start;
    float *ret;
    float *buf;
    float *buf_tmp;
    uint_fast32_t add_bias; // for float->int conversion
    uint_fast32_t exp_bias;
} vorbis_context;

/* Helper functions */

#define BARK(x) \
    (13.1f*atan(0.00074f*(x))+2.24f*atan(1.85e-8f*(x)*(x))+1e-4f*(x))

static float vorbisfloat2float(uint_fast32_t val) {
    double mant=val&0x1fffff;
    long exp=(val&0x7fe00000L)>>21;
    if (val&0x80000000) mant=-mant;
    return(ldexp(mant, exp-20-768));
}


// Free all allocated memory -----------------------------------------

static void vorbis_free(vorbis_context *vc) {
    int_fast16_t i;

    av_freep(&vc->channel_residues);
    av_freep(&vc->channel_floors);
    av_freep(&vc->saved);
    av_freep(&vc->ret);
    av_freep(&vc->buf);
    av_freep(&vc->buf_tmp);

    av_freep(&vc->residues);
    av_freep(&vc->modes);

    ff_mdct_end(&vc->mdct[0]);
    ff_mdct_end(&vc->mdct[1]);

    for(i=0;i<vc->codebook_count;++i) {
        av_free(vc->codebooks[i].codevectors);
        free_vlc(&vc->codebooks[i].vlc);
    }
    av_freep(&vc->codebooks);

    for(i=0;i<vc->floor_count;++i) {
        if(vc->floors[i].floor_type==0) {
            av_free(vc->floors[i].data.t0.map[0]);
            av_free(vc->floors[i].data.t0.map[1]);
            av_free(vc->floors[i].data.t0.book_list);
            av_free(vc->floors[i].data.t0.lsp);
        }
        else {
            av_free(vc->floors[i].data.t1.list);
        }
    }
    av_freep(&vc->floors);

    for(i=0;i<vc->mapping_count;++i) {
        av_free(vc->mappings[i].magnitude);
        av_free(vc->mappings[i].angle);
        av_free(vc->mappings[i].mux);
    }
    av_freep(&vc->mappings);

    if(vc->exp_bias){
        av_freep(&vc->win[0]);
        av_freep(&vc->win[1]);
    }
}

// Parse setup header -------------------------------------------------

// Process codebooks part

static int vorbis_parse_setup_hdr_codebooks(vorbis_context *vc) {
    uint_fast16_t cb;
    uint8_t *tmp_vlc_bits;
    uint32_t *tmp_vlc_codes;
    GetBitContext *gb=&vc->gb;

    vc->codebook_count=get_bits(gb,8)+1;

    AV_DEBUG(" Codebooks: %d \n", vc->codebook_count);

    vc->codebooks=(vorbis_codebook *)av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));
    tmp_vlc_bits=(uint8_t *)av_mallocz(V_MAX_VLCS * sizeof(uint8_t));
    tmp_vlc_codes=(uint32_t *)av_mallocz(V_MAX_VLCS * sizeof(uint32_t));

    for(cb=0;cb<vc->codebook_count;++cb) {
        vorbis_codebook *codebook_setup=&vc->codebooks[cb];
        uint_fast8_t ordered;
        uint_fast32_t t, used_entries=0;
        uint_fast32_t entries;

        AV_DEBUG(" %d. Codebook \n", cb);

        if (get_bits(gb, 24)!=0x564342) {
            av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook setup data corrupt. \n", cb);
            goto error;
        }

        codebook_setup->dimensions=get_bits(gb, 16);
        if (codebook_setup->dimensions>16) {
            av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook's dimension is too large (%d). \n", cb, codebook_setup->dimensions);
            goto error;
        }
        entries=get_bits(gb, 24);
        if (entries>V_MAX_VLCS) {
            av_log(vc->avccontext, AV_LOG_ERROR, " %"PRIdFAST16". Codebook has too many entries (%"PRIdFAST32"). \n", cb, entries);
            goto error;
        }

        ordered=get_bits1(gb);

        AV_DEBUG(" codebook_dimensions %d, codebook_entries %d \n", codebook_setup->dimensions, entries);

        if (!ordered) {
            uint_fast16_t ce;
            uint_fast8_t flag;
            uint_fast8_t sparse=get_bits1(gb);

            AV_DEBUG(" not ordered \n");

            if (sparse) {
                AV_DEBUG(" sparse \n");

                used_entries=0;
                for(ce=0;ce<entries;++ce) {
                    flag=get_bits1(gb);
                    if (flag) {
                        tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
                        ++used_entries;
                    }
                    else tmp_vlc_bits[ce]=0;
                }
            } else {
                AV_DEBUG(" not sparse \n");

                used_entries=entries;
                for(ce=0;ce<entries;++ce) {
                    tmp_vlc_bits[ce]=get_bits(gb, 5)+1;
                }
            }
        } else {
            uint_fast16_t current_entry=0;
            uint_fast8_t current_length=get_bits(gb, 5)+1;

            AV_DEBUG(" ordered, current length: %d \n", current_length);  //FIXME

            used_entries=entries;
            for(;current_entry<used_entries;++current_length) {
                uint_fast16_t i, number;

                AV_DEBUG(" number bits: %d ", ilog(entries - current_entry));

                number=get_bits(gb, ilog(entries - current_entry));

                AV_DEBUG(" number: %d \n", number);

                for(i=current_entry;i<number+current_entry;++i) {
                    if (i<used_entries) tmp_vlc_bits[i]=current_length;
                }

                current_entry+=number;
            }
            if (current_entry>used_entries) {
                av_log(vc->avccontext, AV_LOG_ERROR, " More codelengths than codes in codebook. \n");
                goto error;
            }
        }

        codebook_setup->lookup_type=get_bits(gb, 4);

        AV_DEBUG(" lookup type: %d : %s \n", codebook_setup->lookup_type, codebook_setup->lookup_type ? "vq" : "no lookup" );

// If the codebook is used for (inverse) VQ, calculate codevectors.

        if (codebook_setup->lookup_type==1) {
            uint_fast16_t i, j, k;
            uint_fast16_t codebook_lookup_values=ff_vorbis_nth_root(entries, codebook_setup->dimensions);
            uint_fast16_t codebook_multiplicands[codebook_lookup_values];

            float codebook_minimum_value=vorbisfloat2float(get_bits_long(gb, 32));
            float codebook_delta_value=vorbisfloat2float(get_bits_long(gb, 32));
            uint_fast8_t codebook_value_bits=get_bits(gb, 4)+1;
            uint_fast8_t codebook_sequence_p=get_bits1(gb);

            AV_DEBUG(" We expect %d numbers for building the codevectors. \n", codebook_lookup_values);
            AV_DEBUG("  delta %f minmum %f \n", codebook_delta_value, codebook_minimum_value);

            for(i=0;i<codebook_lookup_values;++i) {
                codebook_multiplicands[i]=get_bits(gb, codebook_value_bits);

                AV_DEBUG(" multiplicands*delta+minmum : %e \n", (float)codebook_multiplicands[i]*codebook_delta_value+codebook_minimum_value);
                AV_DEBUG(" multiplicand %d \n", codebook_multiplicands[i]);
            }

// Weed out unused vlcs and build codevector vector
            codebook_setup->codevectors=(float *)av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float));
            for(j=0, i=0;i<entries;++i) {
                uint_fast8_t dim=codebook_setup->dimensions;

                if (tmp_vlc_bits[i]) {
                    float last=0.0;
                    uint_fast32_t lookup_offset=i;

#ifdef V_DEBUG
                    av_log(vc->avccontext, AV_LOG_INFO, "Lookup offset %d ,", i);
#endif

                    for(k=0;k<dim;++k) {
                        uint_fast32_t multiplicand_offset = lookup_offset % codebook_lookup_values;
                        codebook_setup->codevectors[j*dim+k]=codebook_multiplicands[multiplicand_offset]*codebook_delta_value+codebook_minimum_value+last;
                        if (codebook_sequence_p) {
                            last=codebook_setup->codevectors[j*dim+k];
                        }
                        lookup_offset/=codebook_lookup_values;
                    }
                    tmp_vlc_bits[j]=tmp_vlc_bits[i];

#ifdef V_DEBUG
                    av_log(vc->avccontext, AV_LOG_INFO, "real lookup offset %d, vector: ", j);
                    for(k=0;k<dim;++k) {
                        av_log(vc->avccontext, AV_LOG_INFO, " %f ", codebook_setup->codevectors[j*dim+k]);
                    }
                    av_log(vc->avccontext, AV_LOG_INFO, "\n");
#endif

                    ++j;
                }
            }
            if (j!=used_entries) {
                av_log(vc->avccontext, AV_LOG_ERROR, "Bug in codevector vector building code. \n");
                goto error;
            }
            entries=used_entries;
        }
        else if (codebook_setup->lookup_type>=2) {
            av_log(vc->avccontext, AV_LOG_ERROR, "Codebook lookup type not supported. \n");
            goto error;
        }

// Initialize VLC table
        if (ff_vorbis_len2vlc(tmp_vlc_bits, tmp_vlc_codes, entries)) {
            av_log(vc->avccontext, AV_LOG_ERROR, " Invalid code lengths while generating vlcs. \n");
            goto error;
        }
        codebook_setup->maxdepth=0;
        for(t=0;t<entries;++t)
            if (tmp_vlc_bits[t]>=codebook_setup->maxdepth) codebook_setup->maxdepth=tmp_vlc_bits[t];

        if(codebook_setup->maxdepth > 3*V_NB_BITS) codebook_setup->nb_bits=V_NB_BITS2;
        else                                       codebook_setup->nb_bits=V_NB_BITS;

        codebook_setup->maxdepth=(codebook_setup->maxdepth+codebook_setup->nb_bits-1)/codebook_setup->nb_bits;

        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)) {
            av_log(vc->avccontext, AV_LOG_ERROR, " Error generating vlc tables. \n");
            goto error;
        }
    }

    av_free(tmp_vlc_bits);
    av_free(tmp_vlc_codes);
    return 0;

// Error:
error:
    av_free(tmp_vlc_bits);
    av_free(tmp_vlc_codes);
    return 1;
}

// Process time domain transforms part (unused in Vorbis I)

static int vorbis_parse_setup_hdr_tdtransforms(vorbis_context *vc) {
    GetBitContext *gb=&vc->gb;
    uint_fast8_t i;
    uint_fast8_t vorbis_time_count=get_bits(gb, 6)+1;

    for(i=0;i<vorbis_time_count;++i) {
        uint_fast16_t vorbis_tdtransform=get_bits(gb, 16);

        AV_DEBUG(" Vorbis time domain transform %d: %d \n", vorbis_time_count, vorbis_tdtransform);

        if (vorbis_tdtransform) {
            av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis time domain transform data nonzero. \n");
            return 1;
        }
    }
    return 0;
}

// Process floors part

static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
                                         vorbis_floor_data *vfu, float *vec);
static void create_map( vorbis_context * vc, uint_fast8_t floor_number );
static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc,
                                         vorbis_floor_data *vfu, float *vec);
static int vorbis_parse_setup_hdr_floors(vorbis_context *vc) {
    GetBitContext *gb=&vc->gb;
    uint_fast16_t i,j,k;

    vc->floor_count=get_bits(gb, 6)+1;

    vc->floors=(vorbis_floor *)av_mallocz(vc->floor_count * sizeof(vorbis_floor));

    for (i=0;i<vc->floor_count;++i) {
        vorbis_floor *floor_setup=&vc->floors[i];

        floor_setup->floor_type=get_bits(gb, 16);

        AV_DEBUG(" %d. floor type %d \n", i, floor_setup->floor_type);

        if (floor_setup->floor_type==1) {
            uint_fast8_t maximum_class=0;
            uint_fast8_t rangebits;
            uint_fast16_t floor1_values=2;

            floor_setup->decode=vorbis_floor1_decode;

            floor_setup->data.t1.partitions=get_bits(gb, 5);

            AV_DEBUG(" %d.floor: %d partitions \n", i, floor_setup->data.t1.partitions);

            for(j=0;j<floor_setup->data.t1.partitions;++j) {
                floor_setup->data.t1.partition_class[j]=get_bits(gb, 4);
                if (floor_setup->data.t1.partition_class[j]>maximum_class) maximum_class=floor_setup->data.t1.partition_class[j];

                AV_DEBUG(" %d. floor %d partition class %d \n", i, j, floor_setup->data.t1.partition_class[j]);

            }

            AV_DEBUG(" maximum class %d \n", maximum_class);

            floor_setup->data.t1.maximum_class=maximum_class;

            for(j=0;j<=maximum_class;++j) {
                floor_setup->data.t1.class_dimensions[j]=get_bits(gb, 3)+1;
                floor_setup->data.t1.class_subclasses[j]=get_bits(gb, 2);

                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]);

                if (floor_setup->data.t1.class_subclasses[j]) {
                    floor_setup->data.t1.class_masterbook[j]=get_bits(gb, 8);

                    AV_DEBUG("   masterbook: %d \n", floor_setup->data.t1.class_masterbook[j]);
                }

                for(k=0;k<(1<<floor_setup->data.t1.class_subclasses[j]);++k) {
                    floor_setup->data.t1.subclass_books[j][k]=(int16_t)get_bits(gb, 8)-1;

                    AV_DEBUG("    book %d. : %d \n", k, floor_setup->data.t1.subclass_books[j][k]);
                }
            }

            floor_setup->data.t1.multiplier=get_bits(gb, 2)+1;
            floor_setup->data.t1.x_list_dim=2;

            for(j=0;j<floor_setup->data.t1.partitions;++j) {
                floor_setup->data.t1.x_list_dim+=floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];
            }

            floor_setup->data.t1.list=(floor1_entry_t *)av_mallocz(floor_setup->data.t1.x_list_dim * sizeof(floor1_entry_t));


            rangebits=get_bits(gb, 4);
            floor_setup->data.t1.list[0].x = 0;
            floor_setup->data.t1.list[1].x = (1<<rangebits);

            for(j=0;j<floor_setup->data.t1.partitions;++j) {
                for(k=0;k<floor_setup->data.t1.class_dimensions[floor_setup->data.t1.partition_class[j]];++k,++floor1_values) {
                    floor_setup->data.t1.list[floor1_values].x=get_bits(gb, rangebits);

                    AV_DEBUG(" %d. floor1 Y coord. %d \n", floor1_values, floor_setup->data.t1.list[floor1_values].x);
                }
            }

// Precalculate order of x coordinates - needed for decode
            ff_vorbis_ready_floor1_list(floor_setup->data.t1.list, floor_setup->data.t1.x_list_dim);
        }
        else if(floor_setup->floor_type==0) {
            uint_fast8_t max_codebook_dim=0;

            floor_setup->decode=vorbis_floor0_decode;

            floor_setup->data.t0.order=get_bits(gb, 8);
            floor_setup->data.t0.rate=get_bits(gb, 16);
            floor_setup->data.t0.bark_map_size=get_bits(gb, 16);
            floor_setup->data.t0.amplitude_bits=get_bits(gb, 6);
            /* zero would result in a div by zero later *
             * 2^0 - 1 == 0                             */
            if (floor_setup->data.t0.amplitude_bits == 0) {
              av_log(vc->avccontext, AV_LOG_ERROR,
                     "Floor 0 amplitude bits is 0.\n");
              return 1;
            }
            floor_setup->data.t0.amplitude_offset=get_bits(gb, 8);
            floor_setup->data.t0.num_books=get_bits(gb, 4)+1;

            /* allocate mem for booklist */
            floor_setup->data.t0.book_list=
                av_malloc(floor_setup->data.t0.num_books);
            if(!floor_setup->data.t0.book_list) { return 1; }
            /* read book indexes */
            {
                int idx;
                uint_fast8_t book_idx;
                for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
                    book_idx=get_bits(gb, 8);
                    floor_setup->data.t0.book_list[idx]=book_idx;
                    if (vc->codebooks[book_idx].dimensions > max_codebook_dim)
                        max_codebook_dim=vc->codebooks[book_idx].dimensions;

                    if (floor_setup->data.t0.book_list[idx]>vc->codebook_count)
                        return 1;
                }
            }

            create_map( vc, i );

            /* allocate mem for lsp coefficients */
            {
                /* codebook dim is for padding if codebook dim doesn't *
                 * divide order+1 then we need to read more data       */
                floor_setup->data.t0.lsp=
                    av_malloc((floor_setup->data.t0.order+1 + max_codebook_dim)
                              * sizeof(float));
                if(!floor_setup->data.t0.lsp) { return 1; }
            }

#ifdef V_DEBUG /* debug output parsed headers */
            AV_DEBUG("floor0 order: %u\n", floor_setup->data.t0.order);
            AV_DEBUG("floor0 rate: %u\n", floor_setup->data.t0.rate);
            AV_DEBUG("floor0 bark map size: %u\n",
              floor_setup->data.t0.bark_map_size);
            AV_DEBUG("floor0 amplitude bits: %u\n",
              floor_setup->data.t0.amplitude_bits);
            AV_DEBUG("floor0 amplitude offset: %u\n",
              floor_setup->data.t0.amplitude_offset);
            AV_DEBUG("floor0 number of books: %u\n",
              floor_setup->data.t0.num_books);
            AV_DEBUG("floor0 book list pointer: %p\n",
              floor_setup->data.t0.book_list);
            {
              int idx;
              for (idx=0;idx<floor_setup->data.t0.num_books;++idx) {
                AV_DEBUG( "  Book %d: %u\n",
                  idx+1,
                  floor_setup->data.t0.book_list[idx] );
              }
            }
#endif
        }
        else {
            av_log(vc->avccontext, AV_LOG_ERROR, "Invalid floor type!\n");
            return 1;
        }
    }
    return 0;
}

// Process residues part

static int vorbis_parse_setup_hdr_residues(vorbis_context *vc){
    GetBitContext *gb=&vc->gb;
    uint_fast8_t i, j, k;

    vc->residue_count=get_bits(gb, 6)+1;
    vc->residues=(vorbis_residue *)av_mallocz(vc->residue_count * sizeof(vorbis_residue));

    AV_DEBUG(" There are %d residues. \n", vc->residue_count);

    for(i=0;i<vc->residue_count;++i) {
        vorbis_residue *res_setup=&vc->residues[i];
        uint_fast8_t cascade[64];
        uint_fast8_t high_bits;
        uint_fast8_t low_bits;

        res_setup->type=get_bits(gb, 16);

        AV_DEBUG(" %d. residue type %d \n", i, res_setup->type);

        res_setup->begin=get_bits(gb, 24);
        res_setup->end=get_bits(gb, 24);
        res_setup->partition_size=get_bits(gb, 24)+1;
        res_setup->classifications=get_bits(gb, 6)+1;
        res_setup->classbook=get_bits(gb, 8);

        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,
          res_setup->classifications, res_setup->classbook);

        for(j=0;j<res_setup->classifications;++j) {
            high_bits=0;
            low_bits=get_bits(gb, 3);
            if (get_bits1(gb)) {
                high_bits=get_bits(gb, 5);
            }
            cascade[j]=(high_bits<<3)+low_bits;

            AV_DEBUG("     %d class casscade depth: %d \n", j, ilog(cascade[j]));
        }

        res_setup->maxpass=0;
        for(j=0;j<res_setup->classifications;++j) {
            for(k=0;k<8;++k) {
                if (cascade[j]&(1<<k)) {
                        res_setup->books[j][k]=get_bits(gb, 8);

                    AV_DEBUG("     %d class casscade depth %d book: %d \n", j, k, res_setup->books[j][k]);

                    if (k>res_setup->maxpass) {
                        res_setup->maxpass=k;
                    }
                } else {
                    res_setup->books[j][k]=-1;
                }
            }
        }
    }
    return 0;
}

// Process mappings part

static int vorbis_parse_setup_hdr_mappings(vorbis_context *vc) {
    GetBitContext *gb=&vc->gb;
    uint_fast8_t i, j;

    vc->mapping_count=get_bits(gb, 6)+1;
    vc->mappings=(vorbis_mapping *)av_mallocz(vc->mapping_count * sizeof(vorbis_mapping));

    AV_DEBUG(" There are %d mappings. \n", vc->mapping_count);

    for(i=0;i<vc->mapping_count;++i) {
        vorbis_mapping *mapping_setup=&vc->mappings[i];

        if (get_bits(gb, 16)) {
            av_log(vc->avccontext, AV_LOG_ERROR, "Other mappings than type 0 are not compliant with the Vorbis I specification. \n");
            return 1;
        }
        if (get_bits1(gb)) {
            mapping_setup->submaps=get_bits(gb, 4)+1;
        } else {
            mapping_setup->submaps=1;
        }

        if (get_bits1(gb)) {
            mapping_setup->coupling_steps=get_bits(gb, 8)+1;
            mapping_setup->magnitude=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
            mapping_setup->angle=(uint_fast8_t *)av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));
            for(j=0;j<mapping_setup->coupling_steps;++j) {
                mapping_setup->magnitude[j]=get_bits(gb, ilog(vc->audio_channels-1));
                mapping_setup->angle[j]=get_bits(gb, ilog(vc->audio_channels-1));
                // FIXME: sanity checks
            }
        } else {
            mapping_setup->coupling_steps=0;
        }

        AV_DEBUG("   %d mapping coupling steps: %d \n", i, mapping_setup->coupling_steps);

        if(get_bits(gb, 2)) {
            av_log(vc->avccontext, AV_LOG_ERROR, "%d. mapping setup data invalid. \n", i);
            return 1; // following spec.
        }

        if (mapping_setup->submaps>1) {
            mapping_setup->mux=(uint_fast8_t *)av_mallocz(vc->audio_channels * sizeof(uint_fast8_t));
            for(j=0;j<vc->audio_channels;++j) {
                mapping_setup->mux[j]=get_bits(gb, 4);
            }
        }

        for(j=0;j<mapping_setup->submaps;++j) {
            get_bits(gb, 8); // FIXME check?
            mapping_setup->submap_floor[j]=get_bits(gb, 8);
            mapping_setup->submap_residue[j]=get_bits(gb, 8);

            AV_DEBUG("   %d mapping %d submap : floor %d, residue %d \n", i, j, mapping_setup->submap_floor[j], mapping_setup->submap_residue[j]);
        }
    }
    return 0;
}

// Process modes part

static void create_map( vorbis_context * vc, uint_fast8_t floor_number )
{
    vorbis_floor * floors=vc->floors;
    vorbis_floor0 * vf;
    int idx;
    int_fast8_t blockflag;
    int_fast32_t * map;
    int_fast32_t n; //TODO: could theoretically be smaller?

    for (blockflag=0;blockflag<2;++blockflag)
    {
    n=vc->blocksize[blockflag]/2;
    floors[floor_number].data.t0.map[blockflag]=
        av_malloc((n+1) * sizeof(int_fast32_t)); // n+sentinel

    map=floors[floor_number].data.t0.map[blockflag];
    vf=&floors[floor_number].data.t0;

    for (idx=0; idx<n;++idx) {
        map[idx]=floor( BARK((vf->rate*idx)/(2.0f*n)) *
                              ((vf->bark_map_size)/
                               BARK(vf->rate/2.0f )) );
        if (vf->bark_map_size-1 < map[idx]) {
            map[idx]=vf->bark_map_size-1;
        }
    }
    map[n]=-1;
    vf->map_size[blockflag]=n;
    }

#   ifdef V_DEBUG
    for(idx=0;idx<=n;++idx) {
        AV_DEBUG("floor0 map: map at pos %d is %d\n",
                 idx, map[idx]);
    }
#   endif
}

static int vorbis_parse_setup_hdr_modes(vorbis_context *vc) {
    GetBitContext *gb=&vc->gb;
    uint_fast8_t i;

    vc->mode_count=get_bits(gb, 6)+1;
    vc->modes=(vorbis_mode *)av_mallocz(vc->mode_count * sizeof(vorbis_mode));

    AV_DEBUG(" There are %d modes.\n", vc->mode_count);

    for(i=0;i<vc->mode_count;++i) {
        vorbis_mode *mode_setup=&vc->modes[i];

        mode_setup->blockflag=get_bits(gb, 1);
        mode_setup->windowtype=get_bits(gb, 16); //FIXME check
        mode_setup->transformtype=get_bits(gb, 16); //FIXME check
        mode_setup->mapping=get_bits(gb, 8); //FIXME check

        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);
    }
    return 0;
}

// Process the whole setup header using the functions above

static int vorbis_parse_setup_hdr(vorbis_context *vc) {
    GetBitContext *gb=&vc->gb;

    if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
    (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
    (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (no vorbis signature). \n");
        return 1;
    }

    if (vorbis_parse_setup_hdr_codebooks(vc)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (codebooks). \n");
        return 2;
    }
    if (vorbis_parse_setup_hdr_tdtransforms(vc)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (time domain transforms). \n");
        return 3;
    }
    if (vorbis_parse_setup_hdr_floors(vc)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (floors). \n");
        return 4;
    }
    if (vorbis_parse_setup_hdr_residues(vc)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (residues). \n");
        return 5;
    }
    if (vorbis_parse_setup_hdr_mappings(vc)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (mappings). \n");
        return 6;
    }
    if (vorbis_parse_setup_hdr_modes(vc)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (modes). \n");
        return 7;
    }
    if (!get_bits1(gb)) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis setup header packet corrupt (framing flag). \n");
        return 8; // framing flag bit unset error
    }

    return 0;
}

// Process the identification header

static int vorbis_parse_id_hdr(vorbis_context *vc){
    GetBitContext *gb=&vc->gb;
    uint_fast8_t bl0, bl1;

    if ((get_bits(gb, 8)!='v') || (get_bits(gb, 8)!='o') ||
    (get_bits(gb, 8)!='r') || (get_bits(gb, 8)!='b') ||
    (get_bits(gb, 8)!='i') || (get_bits(gb, 8)!='s')) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (no vorbis signature). \n");
        return 1;
    }

    vc->version=get_bits_long(gb, 32);    //FIXME check 0
    vc->audio_channels=get_bits(gb, 8);   //FIXME check >0
    vc->audio_samplerate=get_bits_long(gb, 32);   //FIXME check >0
    vc->bitrate_maximum=get_bits_long(gb, 32);
    vc->bitrate_nominal=get_bits_long(gb, 32);
    vc->bitrate_minimum=get_bits_long(gb, 32);
    bl0=get_bits(gb, 4);
    bl1=get_bits(gb, 4);
    vc->blocksize[0]=(1<<bl0);
    vc->blocksize[1]=(1<<bl1);
    if (bl0>13 || bl0<6 || bl1>13 || bl1<6 || bl1<bl0) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (illegal blocksize). \n");
        return 3;
    }
    // output format int16
    if (vc->blocksize[1]/2 * vc->audio_channels * 2 >
                                             AVCODEC_MAX_AUDIO_FRAME_SIZE) {
        av_log(vc->avccontext, AV_LOG_ERROR, "Vorbis channel count makes "
               "output packets too large.\n");
        return 4;
    }
    vc->win[0]=ff_vorbis_vwin[bl0-6];
    vc->win[1]=ff_vorbis_vwin[bl1-6];

    if(vc->exp_bias){
        int i, j;
        for(j=0; j<2; j++){
            float *win = av_malloc(vc->blocksize[j]/2 * sizeof(float));
            for(i=0; i<vc->blocksize[j]/2; i++)
                win[i] = vc->win[j][i] * (1<<15);
            vc->win[j] = win;
        }
    }

    if ((get_bits1(gb)) == 0) {
        av_log(vc->avccontext, AV_LOG_ERROR, " Vorbis id header packet corrupt (framing flag not set). \n");
        return 2;
    }

    vc->channel_residues=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
    vc->channel_floors=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
    vc->saved=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
    vc->ret=(float *)av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));
    vc->buf=(float *)av_malloc(vc->blocksize[1] * sizeof(float));
    vc->buf_tmp=(float *)av_malloc(vc->blocksize[1] * sizeof(float));
    vc->saved_start=0;

    ff_mdct_init(&vc->mdct[0], bl0, 1);
    ff_mdct_init(&vc->mdct[1], bl1, 1);

    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 ",
            vc->version, vc->audio_channels, vc->audio_samplerate, vc->bitrate_maximum, vc->bitrate_nominal, vc->bitrate_minimum, vc->blocksize[0], vc->blocksize[1]);

/*
    BLK=vc->blocksize[0];
    for(i=0;i<BLK/2;++i) {
        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)));
    }
*/

    return 0;
}

// Process the extradata using the functions above (identification header, setup header)

static int vorbis_decode_init(AVCodecContext *avccontext) {
    vorbis_context *vc = avccontext->priv_data ;
    uint8_t *headers = avccontext->extradata;
    int headers_len=avccontext->extradata_size;
    uint8_t *header_start[3];
    int header_len[3];
    GetBitContext *gb = &(vc->gb);
    int hdr_type;

    vc->avccontext = avccontext;
    dsputil_init(&vc->dsp, avccontext);

    if(vc->dsp.float_to_int16 == ff_float_to_int16_c) {
        vc->add_bias = 385;
        vc->exp_bias = 0;
    } else {
        vc->add_bias = 0;
        vc->exp_bias = 15<<23;
    }

    if (!headers_len) {
        av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
        return -1;
    }

    if (ff_split_xiph_headers(headers, headers_len, 30, header_start, header_len) < 0) {
        av_log(avccontext, AV_LOG_ERROR, "Extradata corrupt.\n");
        return -1;
    }

    init_get_bits(gb, header_start[0], header_len[0]*8);
    hdr_type=get_bits(gb, 8);
    if (hdr_type!=1) {
        av_log(avccontext, AV_LOG_ERROR, "First header is not the id header.\n");
        return -1;
    }
    if (vorbis_parse_id_hdr(vc)) {
        av_log(avccontext, AV_LOG_ERROR, "Id header corrupt.\n");
        vorbis_free(vc);
        return -1;
    }

    init_get_bits(gb, header_start[2], header_len[2]*8);
    hdr_type=get_bits(gb, 8);
    if (hdr_type!=5) {
        av_log(avccontext, AV_LOG_ERROR, "Third header is not the setup header.\n");
        return -1;
    }
    if (vorbis_parse_setup_hdr(vc)) {
        av_log(avccontext, AV_LOG_ERROR, "Setup header corrupt.\n");
        vorbis_free(vc);
        return -1;
    }

    avccontext->channels = vc->audio_channels;
    avccontext->sample_rate = vc->audio_samplerate;

    return 0 ;
}

// Decode audiopackets -------------------------------------------------

// Read and decode floor

static uint_fast8_t vorbis_floor0_decode(vorbis_context *vc,
                                         vorbis_floor_data *vfu, float *vec) {
    vorbis_floor0 * vf=&vfu->t0;
    float * lsp=vf->lsp;
    uint_fast32_t amplitude;
    uint_fast32_t book_idx;
    uint_fast8_t blockflag=vc->modes[vc->mode_number].blockflag;

    amplitude=get_bits(&vc->gb, vf->amplitude_bits);
    if (amplitude>0) {