vorbis_dec.c

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/**
 * @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
    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=used_entries ? (float *)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;