/*

 * copyright (c) 2006 Oded Shimon <ods15@ods15.dyndns.org>

 *

 * 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

 */

/**

 * @file

 * Native Vorbis encoder.

 * @author Oded Shimon <ods15@ods15.dyndns.org>

 */

#include <float.h>

#include "libavutil/float_dsp.h"

#include "libavutil/mem.h"

#include "libavutil/tx.h"

#include "avcodec.h"

#include "codec_internal.h"

#include "encode.h"

#include "mathops.h"

#include "vorbis.h"

#include "vorbis_data.h"

#include "vorbis_enc_data.h"

#include "audio_frame_queue.h"

#include "libavfilter/bufferqueue.h"

#define BITSTREAM_WRITER_LE

#include "put_bits.h"

#undef NDEBUG

#include <assert.h>

typedef struct vorbis_enc_codebook {

    int nentries;

    uint8_t *lens;

    uint32_t *codewords;

    int ndimensions;

    float min;

    float delta;

    int seq_p;

    int lookup;

    int *quantlist;

    float *dimensions;

    float *pow2;

} vorbis_enc_codebook;

typedef struct vorbis_enc_floor_class {

    int dim;

    int subclass;

    int masterbook;

    int *books;

} vorbis_enc_floor_class;

typedef struct vorbis_enc_floor {

    int partitions;

    int *partition_to_class;

    int nclasses;

    vorbis_enc_floor_class *classes;

    int multiplier;

    int rangebits;

    int values;

    vorbis_floor1_entry *list;

} vorbis_enc_floor;

typedef struct vorbis_enc_residue {

    int type;

    int begin;

    int end;

    int partition_size;

    int classifications;

    int classbook;

    int8_t (*books)[8];

    float (*maxes)[2];

} vorbis_enc_residue;

typedef struct vorbis_enc_mapping {

    int submaps;

    int *mux;

    int *floor;

    int *residue;

    int coupling_steps;

    int *magnitude;

    int *angle;

} vorbis_enc_mapping;

typedef struct vorbis_enc_mode {

    int blockflag;

    int mapping;

} vorbis_enc_mode;

typedef struct vorbis_enc_context {

    int channels;

    int sample_rate;

    int log2_blocksize[2];

    AVTXContext *mdct[2];

    av_tx_fn mdct_fn[2];

    const float *win[2];

    int have_saved;

    float *saved;

    float *samples;

    float *floor;  // also used for tmp values for mdct

    float *coeffs; // also used for residue after floor

    float *scratch; // used for tmp values for psy model

    float quality;

    AudioFrameQueue afq;

    struct FFBufQueue bufqueue;

    int ncodebooks;

    vorbis_enc_codebook *codebooks;

    int nfloors;

    vorbis_enc_floor *floors;

    int nresidues;

    vorbis_enc_residue *residues;

    int nmappings;

    vorbis_enc_mapping *mappings;

    int nmodes;

    vorbis_enc_mode *modes;

    int64_t next_pts;

    AVFloatDSPContext *fdsp;

} vorbis_enc_context;

#define MAX_CHANNELS     2

#define MAX_CODEBOOK_DIM 8

#define MAX_FLOOR_CLASS_DIM  4

#define NUM_FLOOR_PARTITIONS 8

#define MAX_FLOOR_VALUES     (MAX_FLOOR_CLASS_DIM*NUM_FLOOR_PARTITIONS+2)

#define RESIDUE_SIZE           1600

#define RESIDUE_PART_SIZE      32

#define NUM_RESIDUE_PARTITIONS (RESIDUE_SIZE/RESIDUE_PART_SIZE)

static inline int put_codeword(PutBitContext *pb, vorbis_enc_codebook *cb,

                               int entry)

{

    av_assert2(entry >= 0);

    av_assert2(entry < cb->nentries);

    av_assert2(cb->lens[entry]);

    if (put_bits_left(pb) < cb->lens[entry])

        return AVERROR(EINVAL);

    put_bits(pb, cb->lens[entry], cb->codewords[entry]);

    return 0;

}

static int cb_lookup_vals(int lookup, int dimensions, int entries)

{

    if (lookup == 1)

        return ff_vorbis_nth_root(entries, dimensions);

    else if (lookup == 2)

        return dimensions *entries;

    return 0;

}

static int ready_codebook(vorbis_enc_codebook *cb)

{

    int i;

    ff_vorbis_len2vlc(cb->lens, cb->codewords, cb->nentries);

    if (!cb->lookup) {

        cb->pow2 = cb->dimensions = NULL;

    } else {

        int vals = cb_lookup_vals(cb->lookup, cb->ndimensions, cb->nentries);

        cb->dimensions = av_malloc_array(cb->nentries, sizeof(float) * cb->ndimensions);

        cb->pow2 = av_calloc(cb->nentries, sizeof(*cb->pow2));

        if (!cb->dimensions || !cb->pow2)

            return AVERROR(ENOMEM);

        for (i = 0; i < cb->nentries; i++) {

            float last = 0;

            int j;

            int div = 1;

            for (j = 0; j < cb->ndimensions; j++) {

                int off;

                if (cb->lookup == 1)

                    off = (i / div) % vals; // lookup type 1

                else

                    off = i * cb->ndimensions + j; // lookup type 2

                cb->dimensions[i * cb->ndimensions + j] = last + cb->min + cb->quantlist[off] * cb->delta;

                if (cb->seq_p)

                    last = cb->dimensions[i * cb->ndimensions + j];

                cb->pow2[i] += cb->dimensions[i * cb->ndimensions + j] * cb->dimensions[i * cb->ndimensions + j];

                div *= vals;

            }

            cb->pow2[i] /= 2.0;

        }

    }

    return 0;

}

static int ready_residue(vorbis_enc_residue *rc, vorbis_enc_context *venc)

{

    int i;

    av_assert0(rc->type == 2);

    rc->maxes = av_calloc(rc->classifications, sizeof(*rc->maxes));

    if (!rc->maxes)

        return AVERROR(ENOMEM);

    for (i = 0; i < rc->classifications; i++) {

        int j;

        vorbis_enc_codebook * cb;

        for (j = 0; j < 8; j++)

            if (rc->books[i][j] != -1)

                break;

        if (j == 8) // zero

            continue;

        cb = &venc->codebooks[rc->books[i][j]];

        assert(cb->ndimensions >= 2);

        assert(cb->lookup);

        for (j = 0; j < cb->nentries; j++) {

            float a;

            if (!cb->lens[j])

                continue;

            a = fabs(cb->dimensions[j * cb->ndimensions]);

            if (a > rc->maxes[i][0])

                rc->maxes[i][0] = a;

            a = fabs(cb->dimensions[j * cb->ndimensions + 1]);

            if (a > rc->maxes[i][1])

                rc->maxes[i][1] = a;

        }

    }

    // small bias

    for (i = 0; i < rc->classifications; i++) {

        rc->maxes[i][0] += 0.8;

        rc->maxes[i][1] += 0.8;

    }

    return 0;

}

static av_cold int dsp_init(AVCodecContext *avctx, vorbis_enc_context *venc)

{

    int ret = 0;

    float scale = 1.0f;

    venc->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);

    if (!venc->fdsp)

        return AVERROR(ENOMEM);

    // init windows

    venc->win[0] = ff_vorbis_vwin[venc->log2_blocksize[0] - 6];

    venc->win[1] = ff_vorbis_vwin[venc->log2_blocksize[1] - 6];

    if ((ret = av_tx_init(&venc->mdct[0], &venc->mdct_fn[0], AV_TX_FLOAT_MDCT,

                          0, 1 << (venc->log2_blocksize[0] - 1), &scale, 0)) < 0)

        return ret;

    if ((ret = av_tx_init(&venc->mdct[1], &venc->mdct_fn[1], AV_TX_FLOAT_MDCT,

                          0, 1 << (venc->log2_blocksize[1] - 1), &scale, 0)) < 0)

        return ret;

    return 0;

}

static int create_vorbis_context(vorbis_enc_context *venc,

                                 AVCodecContext *avctx)

{

    vorbis_enc_floor   *fc;

    vorbis_enc_residue *rc;

    vorbis_enc_mapping *mc;

    const uint8_t *clens, *quant;

    int i, book, ret;

    venc->channels    = avctx->ch_layout.nb_channels;

    venc->sample_rate = avctx->sample_rate;

    venc->log2_blocksize[0] = venc->log2_blocksize[1] = 11;

    venc->ncodebooks = FF_ARRAY_ELEMS(cvectors);

    venc->codebooks  = av_mallocz(sizeof(vorbis_enc_codebook) * venc->ncodebooks);

    if (!venc->codebooks)

        return AVERROR(ENOMEM);

    // codebook 0..14 - floor1 book, values 0..255

    // codebook 15 residue masterbook

    // codebook 16..29 residue

    clens = codebooks;

    quant = quant_tables;

    for (book = 0; book < venc->ncodebooks; book++) {

        vorbis_enc_codebook *cb = &venc->codebooks[book];

        int vals;

        cb->ndimensions = cvectors[book].dim;

        cb->nentries    = cvectors[book].real_len;

        cb->min         = cvectors[book].min;

        cb->delta       = cvectors[book].delta;

        cb->lookup      = cvectors[book].lookup;

        cb->seq_p       = 0;

        cb->lens      = av_malloc_array(cb->nentries, sizeof(uint8_t));

        cb->codewords = av_malloc_array(cb->nentries, sizeof(uint32_t));

        if (!cb->lens || !cb->codewords)

            return AVERROR(ENOMEM);

        memcpy(cb->lens, clens, cvectors[book].len);

        memset(cb->lens + cvectors[book].len, 0, cb->nentries - cvectors[book].len);

        clens += cvectors[book].len;

        if (cb->lookup) {

            vals = cb_lookup_vals(cb->lookup, cb->ndimensions, cb->nentries);

            cb->quantlist = av_malloc_array(vals, sizeof(int));

            if (!cb->quantlist)

                return AVERROR(ENOMEM);

            for (i = 0; i < vals; i++)

                cb->quantlist[i] = *quant++;

        } else {

            cb->quantlist = NULL;

        }

        if ((ret = ready_codebook(cb)) < 0)

            return ret;

    }

    venc->nfloors = 1;

    venc->floors  = av_mallocz(sizeof(vorbis_enc_floor) * venc->nfloors);

    if (!venc->floors)

        return AVERROR(ENOMEM);

    // just 1 floor

    fc = &venc->floors[0];

    fc->partitions         = NUM_FLOOR_PARTITIONS;

    fc->partition_to_class = av_malloc(sizeof(int) * fc->partitions);

    if (!fc->partition_to_class)

        return AVERROR(ENOMEM);

    fc->nclasses           = 0;

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

        static const int a[] = {0, 1, 2, 2, 3, 3, 4, 4};

        fc->partition_to_class[i] = a[i];

        fc->nclasses = FFMAX(fc->nclasses, fc->partition_to_class[i]);

    }

    fc->nclasses++;

    fc->classes = av_calloc(fc->nclasses, sizeof(vorbis_enc_floor_class));

    if (!fc->classes)

        return AVERROR(ENOMEM);

    for (i = 0; i < fc->nclasses; i++) {

        vorbis_enc_floor_class * c = &fc->classes[i];

        int j, books;

        c->dim        = floor_classes[i].dim;

        c->subclass   = floor_classes[i].subclass;

        c->masterbook = floor_classes[i].masterbook;

        books         = (1 << c->subclass);

        c->books      = av_malloc_array(books, sizeof(int));

        if (!c->books)

            return AVERROR(ENOMEM);

        for (j = 0; j < books; j++)

            c->books[j] = floor_classes[i].nbooks[j];

    }

    fc->multiplier = 2;

    fc->rangebits  = venc->log2_blocksize[1] - 1;

    fc->values = 2;

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

        fc->values += fc->classes[fc->partition_to_class[i]].dim;

    fc->list = av_malloc_array(fc->values, sizeof(vorbis_floor1_entry));

    if (!fc->list)

        return AVERROR(ENOMEM);

    fc->list[0].x = 0;

    fc->list[1].x = 1 << fc->rangebits;

    for (i = 2; i < fc->values; i++) {

        static const int a[] = {

             93, 23,372,  6, 46,186,750, 14, 33, 65,

            130,260,556,  3, 10, 18, 28, 39, 55, 79,

            111,158,220,312,464,650,850

        };

        fc->list[i].x = a[i - 2];

    }

    if (ff_vorbis_ready_floor1_list(avctx, fc->list, fc->values))

        return AVERROR_BUG;

    venc->nresidues = 1;

    venc->residues  = av_mallocz(sizeof(vorbis_enc_residue) * venc->nresidues);

    if (!venc->residues)

        return AVERROR(ENOMEM);

    // single residue

    rc = &venc->residues[0];

    rc->type            = 2;

    rc->begin           = 0;

    rc->end             = 1600;

    rc->partition_size  = 32;

    rc->classifications = 10;

    rc->classbook       = 15;

    rc->books           = av_malloc(sizeof(*rc->books) * rc->classifications);

    if (!rc->books)

        return AVERROR(ENOMEM);

    {

        static const int8_t a[10][8] = {

            { -1, -1, -1, -1, -1, -1, -1, -1, },

            { -1, -1, 16, -1, -1, -1, -1, -1, },

            { -1, -1, 17, -1, -1, -1, -1, -1, },

            { -1, -1, 18, -1, -1, -1, -1, -1, },

            { -1, -1, 19, -1, -1, -1, -1, -1, },

            { -1, -1, 20, -1, -1, -1, -1, -1, },

            { -1, -1, 21, -1, -1, -1, -1, -1, },

            { 22, 23, -1, -1, -1, -1, -1, -1, },

            { 24, 25, -1, -1, -1, -1, -1, -1, },

            { 26, 27, 28, -1, -1, -1, -1, -1, },

        };

        memcpy(rc->books, a, sizeof a);

    }

    if ((ret = ready_residue(rc, venc)) < 0)

        return ret;

    venc->nmappings = 1;

    venc->mappings  = av_mallocz(sizeof(vorbis_enc_mapping) * venc->nmappings);

    if (!venc->mappings)

        return AVERROR(ENOMEM);

    // single mapping

    mc = &venc->mappings[0];

    mc->submaps = 1;

    mc->mux     = av_malloc(sizeof(int) * venc->channels);

    if (!mc->mux)

        return AVERROR(ENOMEM);

    for (i = 0; i < venc->channels; i++)

        mc->mux[i] = 0;

    mc->floor   = av_malloc(sizeof(int) * mc->submaps);

    mc->residue = av_malloc(sizeof(int) * mc->submaps);

    if (!mc->floor || !mc->residue)

        return AVERROR(ENOMEM);

    for (i = 0; i < mc->submaps; i++) {

        mc->floor[i]   = 0;

        mc->residue[i] = 0;

    }

    mc->coupling_steps = venc->channels == 2 ? 1 : 0;

    mc->magnitude      = av_malloc(sizeof(int) * mc->coupling_steps);

    mc->angle          = av_malloc(sizeof(int) * mc->coupling_steps);

    if (!mc->magnitude || !mc->angle)

        return AVERROR(ENOMEM);

    if (mc->coupling_steps) {

        mc->magnitude[0] = 0;

        mc->angle[0]     = 1;

    }

    venc->nmodes = 2;

    venc->modes  = av_malloc(sizeof(vorbis_enc_mode) * venc->nmodes);

    if (!venc->modes)

        return AVERROR(ENOMEM);

    // Short block

    venc->modes[0].blockflag = 0;

    venc->modes[0].mapping   = 0;

    // Long block

    venc->modes[1].blockflag = 1;

    venc->modes[1].mapping   = 0;

    venc->have_saved = 0;

    venc->saved      = av_malloc_array((1 << venc->log2_blocksize[1]) / 2, sizeof(float) * venc->channels);

    venc->samples    = av_malloc_array((1 << venc->log2_blocksize[1]), sizeof(float) * venc->channels);

    venc->floor      = av_malloc_array((1 << venc->log2_blocksize[1]) / 2, sizeof(float) * venc->channels);

    venc->coeffs     = av_malloc_array((1 << venc->log2_blocksize[1]) / 2, sizeof(float) * venc->channels);

    venc->scratch    = av_malloc_array((1 << venc->log2_blocksize[1]), sizeof(float) * venc->channels);

    if (!venc->saved || !venc->samples || !venc->floor || !venc->coeffs || !venc->scratch)

        return AVERROR(ENOMEM);

    if ((ret = dsp_init(avctx, venc)) < 0)

        return ret;

    return 0;

}

static void put_float(PutBitContext *pb, float f)

{

    int exp, mant;

    uint32_t res = 0;

    mant = (int)ldexp(frexp(f, &exp), 20);

    exp += 788 - 20;

    if (mant < 0) {

        res |= (1U << 31);

        mant = -mant;

    }

    res |= mant | (exp << 21);

    put_bits32(pb, res);

}

static void put_codebook_header(PutBitContext *pb, vorbis_enc_codebook *cb)

{

    int i;

    int ordered = 0;

    put_bits(pb, 24, 0x564342); //magic

    put_bits(pb, 16, cb->ndimensions);

    put_bits(pb, 24, cb->nentries);

    for (i = 1; i < cb->nentries; i++)

        if (cb->lens[i] < cb->lens[i-1])

            break;

    if (i == cb->nentries)

        ordered = 1;

    put_bits(pb, 1, ordered);

    if (ordered) {

        int len = cb->lens[0];

        put_bits(pb, 5, len - 1);

        i = 0;

        while (i < cb->nentries) {

            int j;

            for (j = 0; j+i < cb->nentries; j++)

                if (cb->lens[j+i] != len)

                    break;

            put_bits(pb, ilog(cb->nentries - i), j);

            i += j;

            len++;

        }

    } else {

        int sparse = 0;

        for (i = 0; i < cb->nentries; i++)

            if (!cb->lens[i])

                break;

        if (i != cb->nentries)

            sparse = 1;

        put_bits(pb, 1, sparse);

        for (i = 0; i < cb->nentries; i++) {

            if (sparse)

                put_bits(pb, 1, !!cb->lens[i]);

            if (cb->lens[i])

                put_bits(pb, 5, cb->lens[i] - 1);

        }

    }

    put_bits(pb, 4, cb->lookup);

    if (cb->lookup) {

        int tmp  = cb_lookup_vals(cb->lookup, cb->ndimensions, cb->nentries);

        int bits = ilog(cb->quantlist[0]);

        for (i = 1; i < tmp; i++)

            bits = FFMAX(bits, ilog(cb->quantlist[i]));

        put_float(pb, cb->min);

        put_float(pb, cb->delta);

        put_bits(pb, 4, bits - 1);

        put_bits(pb, 1, cb->seq_p);

        for (i = 0; i < tmp; i++)

            put_bits(pb, bits, cb->quantlist[i]);

    }

}

static void put_floor_header(PutBitContext *pb, vorbis_enc_floor *fc)

{

    int i;

    put_bits(pb, 16, 1); // type, only floor1 is supported

    put_bits(pb, 5, fc->partitions);

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

        put_bits(pb, 4, fc->partition_to_class[i]);

    for (i = 0; i < fc->nclasses; i++) {

        int j, books;

        put_bits(pb, 3, fc->classes[i].dim - 1);

        put_bits(pb, 2, fc->classes[i].subclass);

        if (fc->classes[i].subclass)

            put_bits(pb, 8, fc->classes[i].masterbook);

        books = (1 << fc->classes[i].subclass);

        for (j = 0; j < books; j++)

            put_bits(pb, 8, fc->classes[i].books[j] + 1);

    }

    put_bits(pb, 2, fc->multiplier - 1);

    put_bits(pb, 4, fc->rangebits);

    for (i = 2; i < fc->values; i++)

        put_bits(pb, fc->rangebits, fc->list[i].x);

}

static void put_residue_header(PutBitContext *pb, vorbis_enc_residue *rc)

{

    int i;

    put_bits(pb, 16, rc->type);

    put_bits(pb, 24, rc->begin);

    put_bits(pb, 24, rc->end);

    put_bits(pb, 24, rc->partition_size - 1);

    put_bits(pb, 6, rc->classifications - 1);

    put_bits(pb, 8, rc->classbook);

    for (i = 0; i < rc->classifications; i++) {

        int j, tmp = 0;

        for (j = 0; j < 8; j++)

            tmp |= (rc->books[i][j] != -1) << j;

        put_bits(pb, 3, tmp & 7);

        put_bits(pb, 1, tmp > 7);

        if (tmp > 7)

            put_bits(pb, 5, tmp >> 3);

    }

    for (i = 0; i < rc->classifications; i++) {

        int j;

        for (j = 0; j < 8; j++)

            if (rc->books[i][j] != -1)

                put_bits(pb, 8, rc->books[i][j]);

    }

}

static int put_main_header(vorbis_enc_context *venc, uint8_t **out)

{

    int i;

    PutBitContext pb;

    int len, hlens[3];

    int buffer_len = 50000;

    uint8_t *buffer = av_mallocz(buffer_len), *p = buffer;

    if (!buffer)

        return AVERROR(ENOMEM);

    // identification header

    init_put_bits(&pb, p, buffer_len);

    put_bits(&pb, 8, 1); //magic

    for (i = 0; "vorbis"[i]; i++)

        put_bits(&pb, 8, "vorbis"[i]);

    put_bits32(&pb, 0); // version

    put_bits(&pb,  8, venc->channels);

    put_bits32(&pb, venc->sample_rate);

    put_bits32(&pb, 0); // bitrate

    put_bits32(&pb, 0); // bitrate

    put_bits32(&pb, 0); // bitrate

    put_bits(&pb,  4, venc->log2_blocksize[0]);

    put_bits(&pb,  4, venc->log2_blocksize[1]);

    put_bits(&pb,  1, 1); // framing

    flush_put_bits(&pb);

    hlens[0] = put_bytes_output(&pb);

    buffer_len -= hlens[0];

    p += hlens[0];

    // comment header

    init_put_bits(&pb, p, buffer_len);

    put_bits(&pb, 8, 3); //magic

    for (i = 0; "vorbis"[i]; i++)

        put_bits(&pb, 8, "vorbis"[i]);

    put_bits32(&pb, 0); // vendor length TODO

    put_bits32(&pb, 0); // amount of comments

    put_bits(&pb,  1, 1); // framing

    flush_put_bits(&pb);

    hlens[1] = put_bytes_output(&pb);

    buffer_len -= hlens[1];

    p += hlens[1];

    // setup header

    init_put_bits(&pb, p, buffer_len);

    put_bits(&pb, 8, 5); //magic

    for (i = 0; "vorbis"[i]; i++)

        put_bits(&pb, 8, "vorbis"[i]);

    // codebooks

    put_bits(&pb, 8, venc->ncodebooks - 1);

    for (i = 0; i < venc->ncodebooks; i++)

        put_codebook_header(&pb, &venc->codebooks[i]);

    // time domain, reserved, zero

    put_bits(&pb,  6, 0);

    put_bits(&pb, 16, 0);

    // floors

    put_bits(&pb, 6, venc->nfloors - 1);

    for (i = 0; i < venc->nfloors; i++)

        put_floor_header(&pb, &venc->floors[i]);

    // residues

    put_bits(&pb, 6, venc->nresidues - 1);

    for (i = 0; i < venc->nresidues; i++)

        put_residue_header(&pb, &venc->residues[i]);

    // mappings

    put_bits(&pb, 6, venc->nmappings - 1);

    for (i = 0; i < venc->nmappings; i++) {

        vorbis_enc_mapping *mc = &venc->mappings[i];

        int j;

        put_bits(&pb, 16, 0); // mapping type

        put_bits(&pb, 1, mc->submaps > 1);

        if (mc->submaps > 1)

            put_bits(&pb, 4, mc->submaps - 1);

        put_bits(&pb, 1, !!mc->coupling_steps);

        if (mc->coupling_steps) {

            put_bits(&pb, 8, mc->coupling_steps - 1);

            for (j = 0; j < mc->coupling_steps; j++) {

                put_bits(&pb, ilog(venc->channels - 1), mc->magnitude[j]);

                put_bits(&pb, ilog(venc->channels - 1), mc->angle[j]);

            }

        }

        put_bits(&pb, 2, 0); // reserved

        if (mc->submaps > 1)

            for (j = 0; j < venc->channels; j++)

                put_bits(&pb, 4, mc->mux[j]);

        for (j = 0; j < mc->submaps; j++) {

            put_bits(&pb, 8, 0); // reserved time configuration

            put_bits(&pb, 8, mc->floor[j]);

            put_bits(&pb, 8, mc->residue[j]);

        }

    }

    // modes

    put_bits(&pb, 6, venc->nmodes - 1);

    for (i = 0; i < venc->nmodes; i++) {

        put_bits(&pb, 1, venc->modes[i].blockflag);

        put_bits(&pb, 16, 0); // reserved window type

        put_bits(&pb, 16, 0); // reserved transform type

        put_bits(&pb, 8, venc->modes[i].mapping);

    }

    put_bits(&pb, 1, 1); // framing

    flush_put_bits(&pb);

    hlens[2] = put_bytes_output(&pb);

    len = hlens[0] + hlens[1] + hlens[2];

    p = *out = av_mallocz(64 + len + len/255);

    if (!p) {

        av_freep(&buffer);

        return AVERROR(ENOMEM);

    }

    *p++ = 2;

    p += av_xiphlacing(p, hlens[0]);

    p += av_xiphlacing(p, hlens[1]);

    buffer_len = 0;

    for (i = 0; i < 3; i++) {

        memcpy(p, buffer + buffer_len, hlens[i]);

        p += hlens[i];

        buffer_len += hlens[i];

    }

    av_freep(&buffer);

    return p - *out;

}

static float get_floor_average(vorbis_enc_floor * fc, float *coeffs, int i)

{

    int begin = fc->list[fc->list[FFMAX(i-1, 0)].sort].x;

    int end   = fc->list[fc->list[FFMIN(i+1, fc->values - 1)].sort].x;

    int j;

    float average = 0;

    for (j = begin; j < end; j++)

        average += fabs(coeffs[j]);

    return average / (end - begin);

}

static void floor_fit(vorbis_enc_context *venc, vorbis_enc_floor *fc,

                      float *coeffs, uint16_t *posts, int samples)

{

    int range = 255 / fc->multiplier + 1;

    int i;

    float tot_average = 0.0;

    float averages[MAX_FLOOR_VALUES];

    for (i = 0; i < fc->values; i++) {

        averages[i] = get_floor_average(fc, coeffs, i);

        tot_average += averages[i];

    }

    tot_average /= fc->values;

    tot_average /= venc->quality;

    for (i = 0; i < fc->values; i++) {

        int position  = fc->list[fc->list[i].sort].x;

        float average = averages[i];

        int j;

        average = sqrt(tot_average * average) * pow(1.25f, position*0.005f); // MAGIC!

        for (j = 0; j < range - 1; j++)

            if (ff_vorbis_floor1_inverse_db_table[j * fc->multiplier] > average)

                break;

        posts[fc->list[i].sort] = j;

    }

}

static int render_point(int x0, int y0, int x1, int y1, int x)

{

    return y0 +  (x - x0) * (y1 - y0) / (x1 - x0);

}

static int floor_encode(vorbis_enc_context *venc, vorbis_enc_floor *fc,

                        PutBitContext *pb, uint16_t *posts,

                        float *floor, int samples)

{

    int range = 255 / fc->multiplier + 1;

    int coded[MAX_FLOOR_VALUES]; // first 2 values are unused

    int i, counter;

    if (put_bits_left(pb) < 1 + 2 * ilog(range - 1))

        return AVERROR(EINVAL);

    put_bits(pb, 1, 1); // non zero

    put_bits(pb, ilog(range - 1), posts[0]);

    put_bits(pb, ilog(range - 1), posts[1]);

    coded[0] = coded[1] = 1;

    for (i = 2; i < fc->values; i++) {

        int predicted = render_point(fc->list[fc->list[i].low].x,

                                     posts[fc->list[i].low],

                                     fc->list[fc->list[i].high].x,

                                     posts[fc->list[i].high],

                                     fc->list[i].x);

        int highroom = range - predicted;

        int lowroom = predicted;

        int room = FFMIN(highroom, lowroom);

        if (predicted == posts[i]) {

            coded[i] = 0; // must be used later as flag!

            continue;

        } else {

            if (!coded[fc->list[i].low ])

                coded[fc->list[i].low ] = -1;

            if (!coded[fc->list[i].high])

                coded[fc->list[i].high] = -1;

        }

        if (posts[i] > predicted) {

            if (posts[i] - predicted > room)

                coded[i] = posts[i] - predicted + lowroom;

            else

                coded[i] = (posts[i] - predicted) << 1;

        } else {

            if (predicted - posts[i] > room)

                coded[i] = predicted - posts[i] + highroom - 1;

            else

                coded[i] = ((predicted - posts[i]) << 1) - 1;

        }

    }

    counter = 2;

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

        vorbis_enc_floor_class * c = &fc->classes[fc->partition_to_class[i]];

        int k, cval = 0, csub = 1<<c->subclass;

        if (c->subclass) {

            vorbis_enc_codebook * book = &venc->codebooks[c->masterbook];

            int cshift = 0;

            for (k = 0; k < c->dim; k++) {

                int l;

                for (l = 0; l < csub; l++) {

                    int maxval = 1;

                    if (c->books[l] != -1)

                        maxval = venc->codebooks[c->books[l]].nentries;

                    // coded could be -1, but this still works, cause that is 0

                    if (coded[counter + k] < maxval)

                        break;

                }

                assert(l != csub);