PeerStreamer

/**

 * @file vorbis_dec.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

    uint_fast8_t previous_window;

    float *channel_residues;

    float *channel_floors;

    float *saved;

    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=av_mallocz(vc->codebook_count * sizeof(vorbis_codebook));

    tmp_vlc_bits =av_mallocz(V_MAX_VLCS * sizeof(uint8_t));

    tmp_vlc_codes=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=used_entries ? av_mallocz(used_entries*codebook_setup->dimensions * sizeof(float)) : NULL;

            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=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=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=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=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=av_mallocz(mapping_setup->coupling_steps * sizeof(uint_fast8_t));

            mapping_setup->angle    =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=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) {

            skip_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=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_bits1(gb);

        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= av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));

    vc->channel_floors  = av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));

    vc->saved           = av_mallocz((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));

    vc->ret             = av_malloc((vc->blocksize[1]/2)*vc->audio_channels * sizeof(float));

    vc->buf             = av_malloc( vc->blocksize[1]                       * sizeof(float));

    vc->buf_tmp         = av_malloc( vc->blocksize[1]                       * sizeof(float));

    vc->previous_window=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 av_cold 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;

    avccontext->frame_size  = FFMIN(vc->blocksize[0], vc->blocksize[1])>>2;

    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) {

        float last = 0;

        uint_fast16_t lsp_len = 0;

        uint_fast16_t idx;

        vorbis_codebook codebook;

        book_idx=get_bits(&vc->gb, ilog(vf->num_books));

        if ( book_idx >= vf->num_books ) {

            av_log( vc->avccontext, AV_LOG_ERROR,

                    "floor0 dec: booknumber too high!\n" );

            book_idx= 0;

            //FIXME: look above

        }

        AV_DEBUG( "floor0 dec: booknumber: %u\n", book_idx );

        codebook=vc->codebooks[vf->book_list[book_idx]];

        while (lsp_len<vf->order) {

            int vec_off;

            AV_DEBUG( "floor0 dec: book dimension: %d\n", codebook.dimensions );

            AV_DEBUG( "floor0 dec: maximum depth: %d\n", codebook.maxdepth );

            /* read temp vector */

            vec_off=get_vlc2(&vc->gb,

                             codebook.vlc.table,

                             codebook.nb_bits,

                             codebook.maxdepth ) *

                             codebook.dimensions;

            AV_DEBUG( "floor0 dec: vector offset: %d\n", vec_off );

            /* copy each vector component and add last to it */

            for (idx=0; idx<codebook.dimensions; ++idx) {

                lsp[lsp_len+idx]=codebook.codevectors[vec_off+idx]+last;

            }

            last=lsp[lsp_len+idx-1]; /* set last to last vector component */

            lsp_len += codebook.dimensions;

        }

#ifdef V_DEBUG

        /* DEBUG: output lsp coeffs */

        {

            int idx;

            for ( idx = 0; idx < lsp_len; ++idx )

                AV_DEBUG("floor0 dec: coeff at %d is %f\n", idx, lsp[idx] );

        }

#endif

        /* synthesize floor output vector */

        {

            int i;

            int order=vf->order;

            float wstep=M_PI/vf->bark_map_size;

            for(i=0;i<order;i++) { lsp[i]=2.0f*cos(lsp[i]); }

            AV_DEBUG("floor0 synth: map_size=%d; m=%d; wstep=%f\n",

                     vf->map_size, order, wstep);

            i=0;

            while(i<vf->map_size[blockflag]) {

                int j, iter_cond=vf->map[blockflag][i];

                float p=0.5f;

                float q=0.5f;

                float two_cos_w=2.0f*cos(wstep*iter_cond); // needed all times

                /* similar part for the q and p products */

                for(j=0;j<order;j+=2) {

                    q *= lsp[j]  -two_cos_w;

                    p *= lsp[j+1]-two_cos_w;

                }

                if(j==order) { // even order

                    p *= p*(2.0f-two_cos_w);

                    q *= q*(2.0f+two_cos_w);

                }

                else { // odd order

                    q *= two_cos_w-lsp[j]; // one more time for q

                    /* final step and square */

                    p *= p*(4.f-two_cos_w*two_cos_w);

                    q *= q;

                }

                /* calculate linear floor value */

                {

                    q=exp( (

                             ( (amplitude*vf->amplitude_offset)/

                               (((1<<vf->amplitude_bits)-1) * sqrt(p+q)) )

                             - vf->amplitude_offset ) * .11512925f

                         );

                }

                /* fill vector */

                do { vec[i]=q; ++i; }while(vf->map[blockflag][i]==iter_cond);

            }

        }

    }

    else {

        /* this channel is unused */

        return 1;

    }

    AV_DEBUG(" Floor0 decoded\n");

    return 0;

}

static uint_fast8_t vorbis_floor1_decode(vorbis_context *vc, vorbis_floor_data *vfu, float *vec) {

    vorbis_floor1 * vf=&vfu->t1;

    GetBitContext *gb=&vc->gb;

    uint_fast16_t range_v[4]={ 256, 128, 86, 64 };

    uint_fast16_t range=range_v[vf->multiplier-1];

    uint_fast16_t floor1_Y[vf->x_list_dim];

    uint_fast16_t floor1_Y_final[vf->x_list_dim];

    int floor1_flag[vf->x_list_dim];

    uint_fast8_t class_;

    uint_fast8_t cdim;

    uint_fast8_t cbits;

    uint_fast8_t csub;

    uint_fast8_t cval;

    int_fast16_t book;

    uint_fast16_t offset;

    uint_fast16_t i,j;

    /*u*/int_fast16_t adx, ady, off, predicted; // WTF ? dy/adx= (unsigned)dy/adx ?

    int_fast16_t dy, err;

    if (!get_bits1(gb)) return 1; // silence

// Read values (or differences) for the floor's points

    floor1_Y[0]=get_bits(gb, ilog(range-1));

    floor1_Y[1]=get_bits(gb, ilog(range-1));

    AV_DEBUG("floor 0 Y %d floor 1 Y %d \n", floor1_Y[0], floor1_Y[1]);

    offset=2;

    for(i=0;i<vf->partitions;++i) {

        class_=vf->partition_class[i];

        cdim=vf->class_dimensions[class_];

        cbits=vf->class_subclasses[class_];

        csub=(1<<cbits)-1;

        cval=0;

        AV_DEBUG("Cbits %d \n", cbits);

        if (cbits) { // this reads all subclasses for this partition's class

            cval=get_vlc2(gb, vc->codebooks[vf->class_masterbook[class_]].vlc.table,

            vc->codebooks[vf->class_masterbook[class_]].nb_bits, 3);

        }

        for(j=0;j<cdim;++j) {

            book=vf->subclass_books[class_][cval & csub];

            AV_DEBUG("book %d Cbits %d cval %d  bits:%d \n", book, cbits, cval, get_bits_count(gb));

            cval=cval>>cbits;

            if (book>-1) {

                floor1_Y[offset+j]=get_vlc2(gb, vc->codebooks[book].vlc.table,

                vc->codebooks[book].nb_bits, 3);

            } else {

                floor1_Y[offset+j]=0;

            }

            AV_DEBUG(" floor(%d) = %d \n", vf->list[offset+j].x, floor1_Y[offset+j]);

        }

        offset+=cdim;

    }

// Amplitude calculation from the differences

    floor1_flag[0]=1;

    floor1_flag[1]=1;

    floor1_Y_final[0]=floor1_Y[0];

    floor1_Y_final[1]=floor1_Y[1];

    for(i=2;i<vf->x_list_dim;++i) {

        uint_fast16_t val, highroom, lowroom, room;

        uint_fast16_t high_neigh_offs;

        uint_fast16_t low_neigh_offs;

        low_neigh_offs=vf->list[i].low;

        high_neigh_offs=vf->list[i].high;

        dy=floor1_Y_final[high_neigh_offs]-floor1_Y_final[low_neigh_offs];  // render_point begin

        adx=vf->list[high_neigh_offs].x-vf->list[low_neigh_offs].x;

        ady= FFABS(dy);

        err=ady*(vf->list[i].x-vf->list[low_neigh_offs].x);

        off=(int16_t)err/(int16_t)adx;

        if (dy<0) {

            predicted=floor1_Y_final[low_neigh_offs]-off;

        } else {

            predicted=floor1_Y_final[low_neigh_offs]+off;

        } // render_point end

        val=floor1_Y[i];

        highroom=range-predicted;

        lowroom=predicted;

        if (highroom < lowroom) {

            room=highroom*2;

        } else {

            room=lowroom*2;   // SPEC mispelling

        }

        if (val) {

            floor1_flag[low_neigh_offs]=1;

            floor1_flag[high_neigh_offs]=1;

            floor1_flag[i]=1;

            if (val>=room) {

                if (highroom > lowroom) {

                    floor1_Y_final[i]=val-lowroom+predicted;

                } else {

                    floor1_Y_final[i]=predicted-val+highroom-1;

                }

            } else {

                if (val & 1) {

                    floor1_Y_final[i]=predicted-(val+1)/2;

                } else {

                    floor1_Y_final[i]=predicted+val/2;

                }

            }

        } else {

            floor1_flag[i]=0;

            floor1_Y_final[i]=predicted;

        }

        AV_DEBUG(" Decoded floor(%d) = %d / val %d \n", vf->list[i].x, floor1_Y_final[i], val);

    }

// Curve synth - connect the calculated dots and convert from dB scale FIXME optimize ?

    ff_vorbis_floor1_render_list(vf->list, vf->x_list_dim, floor1_Y_final, floor1_flag, vf->multiplier, vec, vf->list[1].x);

    AV_DEBUG(" Floor decoded\n");

    return 0;

}

// Read and decode residue

static int vorbis_residue_decode(vorbis_context *vc, vorbis_residue *vr, uint_fast8_t ch, uint_fast8_t *do_not_decode, float *vec, uint_fast16_t vlen) {

    GetBitContext *gb=&vc->gb;

    uint_fast8_t c_p_c=vc->codebooks[vr->classbook].dimensions;

    uint_fast16_t n_to_read=vr->end-vr->begin;

    uint_fast16_t ptns_to_read=n_to_read/vr->partition_size;

    uint_fast8_t classifs[ptns_to_read*vc->audio_channels];

    uint_fast8_t pass;

    uint_fast8_t ch_used;

    uint_fast8_t i,j,l;

    uint_fast16_t k;

    if (vr->type==2) {

        for(j=1;j<ch;++j) {

                do_not_decode[0]&=do_not_decode[j];  // FIXME - clobbering input

        }

        if (do_not_decode[0]) return 0;

        ch_used=1;

    } else {

        ch_used=ch;

    }

    AV_DEBUG(" residue type 0/1/2 decode begin, ch: %d  cpc %d  \n", ch, c_p_c);

    for(pass=0;pass<=vr->maxpass;++pass) { // FIXME OPTIMIZE?

        uint_fast16_t voffset;

        uint_fast16_t partition_count;

        uint_fast16_t j_times_ptns_to_read;

        voffset=vr->begin;

        for(partition_count=0;partition_count<ptns_to_read;) {  // SPEC        error

            if (!pass) {

                uint_fast32_t inverse_class = ff_inverse[vr->classifications];

                for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {

                    if (!do_not_decode[j]) {

                        uint_fast32_t temp=get_vlc2(gb, vc->codebooks[vr->classbook].vlc.table,

                        vc->codebooks[vr->classbook].nb_bits, 3);

                        AV_DEBUG("Classword: %d \n", temp);

                        assert(vr->classifications > 1 && temp<=65536); //needed for inverse[]

                        for(i=0;i<c_p_c;++i) {

                            uint_fast32_t temp2;

                            temp2=(((uint_fast64_t)temp) * inverse_class)>>32;

                            if (partition_count+c_p_c-1-i < ptns_to_read) {

                                classifs[j_times_ptns_to_read+partition_count+c_p_c-1-i]=temp-temp2*vr->classifications;

                            }

                            temp=temp2;

                        }

                    }

                    j_times_ptns_to_read+=ptns_to_read;

                }

            }

            for(i=0;(i<c_p_c) && (partition_count<ptns_to_read);++i) {

                for(j_times_ptns_to_read=0, j=0;j<ch_used;++j) {

                    uint_fast16_t voffs;

                    if (!do_not_decode[j]) {

                        uint_fast8_t vqclass=classifs[j_times_ptns_to_read+partition_count];

                        int_fast16_t vqbook=vr->books[vqclass][pass];

                        if (vqbook>=0 && vc->codebooks[vqbook].codevectors) {

                            uint_fast16_t coffs;

                            unsigned dim= vc->codebooks[vqbook].dimensions; // not uint_fast8_t: 64bit is slower here on amd64

                            uint_fast16_t step= dim==1 ? vr->partition_size

                                              : FASTDIV(vr->partition_size, dim);

                            vorbis_codebook codebook= vc->codebooks[vqbook];

                            if (vr->type==0) {