vorbis.c

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/**
 * @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"

#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))

unsigned int ff_vorbis_nth_root(unsigned int x, unsigned int n) {   // x^(1/n)
    unsigned int ret=0, i, j;

    do {
        ++ret;
        for(i=0,j=ret;i<n-1;i++) j*=ret;
    } while (j<=x);

    return (ret-1);
}

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));
}


// Generate vlc codes from vorbis huffman code lengths

int ff_vorbis_len2vlc(uint8_t *bits, uint32_t *codes, uint_fast32_t num) {
    uint_fast32_t exit_at_level[33]={404,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
        0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0};

    uint_fast8_t i,j;
    uint_fast32_t code,p;

#ifdef V_DEBUG
    GetBitContext gb;
#endif

    for(p=0;(bits[p]==0) && (p<num);++p);
    if (p==num) {
//        av_log(vc->avccontext, AV_LOG_INFO, "An empty codebook. Heh?! \n");
        return 0;
    }

    codes[p]=0;
    for(i=0;i<bits[p];++i) {
        exit_at_level[i+1]=1<<i;
    }

#ifdef V_DEBUG
    av_log(NULL, AV_LOG_INFO, " %d. of %d code len %d code %d - ", p, num, bits[p], codes[p]);
    init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
    for(i=0;i<bits[p];++i) {
        av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
    }
    av_log(NULL, AV_LOG_INFO, "\n");
#endif

    ++p;

    for(;p<num;++p) {
        if (bits[p]==0) continue;
        // find corresponding exit(node which the tree can grow further from)
        for(i=bits[p];i>0;--i) {
            if (exit_at_level[i]) break;
        }
        if (!i) return 1; // overspecified tree
        code=exit_at_level[i];
        exit_at_level[i]=0;
        // construct code (append 0s to end) and introduce new exits
        for(j=i+1;j<=bits[p];++j) {
            exit_at_level[j]=code+(1<<(j-1));
        }
        codes[p]=code;

#ifdef V_DEBUG
        av_log(NULL, AV_LOG_INFO, " %d. code len %d code %d - ", p, bits[p], codes[p]);
        init_get_bits(&gb, (uint_fast8_t *)&codes[p], bits[p]);
        for(i=0;i<bits[p];++i) {
            av_log(NULL, AV_LOG_INFO, "%s", get_bits1(&gb) ? "1" : "0");
        }
        av_log(NULL, AV_LOG_INFO, "\n");
#endif

    }

    //no exits should be left (underspecified tree - ie. unused valid vlcs - not allowed by SPEC)
    for (p=1; p<33; p++)
        if (exit_at_level[p]) return 1;

    return 0;
}

void ff_vorbis_ready_floor1_list(floor1_entry_t * list, int values) {
    int i;
    list[0].sort = 0;
    list[1].sort = 1;
    for (i = 2; i < values; i++) {
        int j;
        list[i].low = 0;
        list[i].high = 1;
        list[i].sort = i;
        for (j = 2; j < i; j++) {
            int tmp = list[j].x;
            if (tmp < list[i].x) {
                if (tmp > list[list[i].low].x) list[i].low = j;
            } else {
                if (tmp < list[list[i].high].x) list[i].high = j;
            }
        }
    }
    for (i = 0; i < values - 1; i++) {
        int j;
        for (j = i + 1; j < values; j++) {
            if (list[list[i].sort].x > list[list[j].sort].x) {
                int tmp = list[i].sort;
                list[i].sort = list[j].sort;
                list[j].sort = tmp;
            }
        }
    }
}

// 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;