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/*

 * Voxware MetaSound decoder

 * Copyright (c) 2013 Konstantin Shishkov

 * based on TwinVQ decoder

 * Copyright (c) 2009 Vitor Sessak

 *

 * 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

 */

#include 

#include 

#define BITSTREAM_READER_LE

#include "libavutil/channel_layout.h"

#include "libavutil/float_dsp.h"

#include "avcodec.h"

#include "get_bits.h"

#include "fft.h"

#include "internal.h"

#include "lsp.h"

#include "sinewin.h"

#include "twinvq.h"

#include "metasound_data.h"

static void add_peak(float period, int width, const float *shape,

                     float ppc_gain, float *speech, int len)

{

    int i, j, center;

    const float *shape_end = shape + len;

    // First peak centered around zero

    for (i = 0; i < width / 2; i++)

        speech[i] += ppc_gain * *shape++;

    for (i = 1; i < ROUNDED_DIV(len, width); i++) {

        center = (int)(i * period + 0.5);

        for (j = -width / 2; j < (width + 1) / 2; j++)

            speech[j + center] += ppc_gain * *shape++;

    }

    // For the last block, be careful not to go beyond the end of the buffer

    center = (int)(i * period + 0.5);

    for (j = -width / 2; j < (width + 1) / 2 && shape < shape_end; j++)

        speech[j + center] += ppc_gain * *shape++;

}

static void decode_ppc(TwinVQContext *tctx, int period_coef, int g_coef,

                       const float *shape, float *speech)

{

    const TwinVQModeTab *mtab = tctx->mtab;

    int isampf       = tctx->avctx->sample_rate / 1000;

    int ibps         = tctx->avctx->bit_rate / (1000 * tctx->avctx->channels);

    int width;

    float ratio = (float)mtab->size / isampf;

    float min_period, max_period, period_range, period;

    float some_mult;

    float pgain_base, pgain_step, ppc_gain;

    if (tctx->avctx->channels == 1) {

        min_period = log2(ratio * 0.2);

        max_period = min_period + log2(6);

    } else {

        min_period = (int)(ratio * 0.2 * 400     + 0.5) / 400.0;

        max_period = (int)(ratio * 0.2 * 400 * 6 + 0.5) / 400.0;

    }

    period_range = max_period - min_period;

    period       = min_period + period_coef * period_range /

                   ((1 << mtab->ppc_period_bit) - 1);

    if (tctx->avctx->channels == 1)

        period = powf(2.0, period);

    else

        period = (int)(period * 400 + 0.5) / 400.0;

    switch (isampf) {

    case  8: some_mult = 2.0; break;

    case 11: some_mult = 3.0; break;

    case 16: some_mult = 3.0; break;

    case 22: some_mult = ibps == 32 ? 2.0 : 4.0; break;

    case 44: some_mult = 8.0; break;

    default: some_mult = 4.0;

    }

    width = (int)(some_mult / (mtab->size / period) * mtab->ppc_shape_len);

    if (isampf == 22 && ibps == 32)

        width = (int)((2.0 / period + 1) * width + 0.5);

    pgain_base = tctx->avctx->channels == 2 ? 25000.0 : 20000.0;

    pgain_step = pgain_base / ((1 << mtab->pgain_bit) - 1);

    ppc_gain   = 1.0 / 8192 *

                 twinvq_mulawinv(pgain_step * g_coef + pgain_step / 2,

                                 pgain_base, TWINVQ_PGAIN_MU);

    add_peak(period, width, shape, ppc_gain, speech, mtab->ppc_shape_len);

}

static void dec_bark_env(TwinVQContext *tctx, const uint8_t *in, int use_hist,

                         int ch, float *out, float gain,

                         enum TwinVQFrameType ftype)

{

    const TwinVQModeTab *mtab = tctx->mtab;

    int i, j;

    float *hist     = tctx->bark_hist[ftype][ch];

    float val       = ((const float []) { 0.4, 0.35, 0.28 })[ftype];

    int bark_n_coef = mtab->fmode[ftype].bark_n_coef;

    int fw_cb_len   = mtab->fmode[ftype].bark_env_size / bark_n_coef;

    int idx         = 0;

    if (tctx->avctx->channels == 1)

        val = 0.5;

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

        for (j = 0; j < bark_n_coef; j++, idx++) {

            float tmp2 = mtab->fmode[ftype].bark_cb[fw_cb_len * in[j] + i] *

                         (1.0 / 2048);

            float st;

            if (tctx->avctx->channels == 1)

                st = use_hist ?

                    tmp2 + val * hist[idx] + 1.0 : tmp2 + 1.0;

            else

                st = use_hist ? (1.0 - val) * tmp2 + val * hist[idx] + 1.0

                              : tmp2 + 1.0;

            hist[idx] = tmp2;

            if (st < 0.1)

                st = 0.1;

            twinvq_memset_float(out, st * gain,

                                mtab->fmode[ftype].bark_tab[idx]);

            out += mtab->fmode[ftype].bark_tab[idx];

        }

}

static void read_cb_data(TwinVQContext *tctx, GetBitContext *gb,

                         uint8_t *dst, enum TwinVQFrameType ftype)

{

    int i;

    for (i = 0; i < tctx->n_div[ftype]; i++) {

        int bs_second_part = (i >= tctx->bits_main_spec_change[ftype]);

        *dst++ = get_bits(gb, tctx->bits_main_spec[0][ftype][bs_second_part]);

        *dst++ = get_bits(gb, tctx->bits_main_spec[1][ftype][bs_second_part]);

    }

}

static int metasound_read_bitstream(AVCodecContext *avctx, TwinVQContext *tctx,

                                    const uint8_t *buf, int buf_size)

{

    TwinVQFrameData     *bits = &tctx->bits;

    const TwinVQModeTab *mtab = tctx->mtab;

    int channels              = tctx->avctx->channels;

    int sub;

    GetBitContext gb;

    int i, j, k;

    init_get_bits(&gb, buf, buf_size * 8);

    bits->window_type = get_bits(&gb, TWINVQ_WINDOW_TYPE_BITS);

    if (bits->window_type > 8) {

        av_log(avctx, AV_LOG_ERROR, "Invalid window type, broken sample?\n");

        return AVERROR_INVALIDDATA;

    }

    bits->ftype = ff_twinvq_wtype_to_ftype_table[tctx->bits.window_type];

    sub = mtab->fmode[bits->ftype].sub;

    if (bits->ftype != TWINVQ_FT_SHORT)

        get_bits(&gb, 2);

    read_cb_data(tctx, &gb, bits->main_coeffs, bits->ftype);

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

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

            for (k = 0; k < mtab->fmode[bits->ftype].bark_n_coef; k++)

                bits->bark1[i][j][k] =

                    get_bits(&gb, mtab->fmode[bits->ftype].bark_n_bit);

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

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

            bits->bark_use_hist[i][j] = get_bits1(&gb);

    if (bits->ftype == TWINVQ_FT_LONG) {

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

            bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);

    } else {

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

            bits->gain_bits[i] = get_bits(&gb, TWINVQ_GAIN_BITS);

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

                bits->sub_gain_bits[i * sub + j] =

                    get_bits(&gb, TWINVQ_SUB_GAIN_BITS);

        }

    }

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

        bits->lpc_hist_idx[i] = get_bits(&gb, mtab->lsp_bit0);

        bits->lpc_idx1[i]     = get_bits(&gb, mtab->lsp_bit1);

        for (j = 0; j < mtab->lsp_split; j++)

            bits->lpc_idx2[i][j] = get_bits(&gb, mtab->lsp_bit2);

    }

    if (bits->ftype == TWINVQ_FT_LONG) {

        read_cb_data(tctx, &gb, bits->ppc_coeffs, 3);

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

            bits->p_coef[i] = get_bits(&gb, mtab->ppc_period_bit);

            bits->g_coef[i] = get_bits(&gb, mtab->pgain_bit);

        }

    }

    return (get_bits_count(&gb) + 7) / 8;

}

typedef struct MetasoundProps {

    uint32_t tag;

    int      bit_rate;

    int      channels;

    int      sample_rate;

} MetasoundProps;

static const MetasoundProps codec_props[] = {

    { MKTAG('V','X','0','3'),  6, 1,  8000 },

    { MKTAG('V','X','0','4'), 12, 2,  8000 },

    { MKTAG('V','O','X','i'),  8, 1,  8000 },

    { MKTAG('V','O','X','j'), 10, 1, 11025 },

    { MKTAG('V','O','X','k'), 16, 1, 16000 },

    { MKTAG('V','O','X','L'), 24, 1, 22050 },

    { MKTAG('V','O','X','q'), 32, 1, 44100 },

    { MKTAG('V','O','X','r'), 40, 1, 44100 },

    { MKTAG('V','O','X','s'), 48, 1, 44100 },

    { MKTAG('V','O','X','t'), 16, 2,  8000 },

    { MKTAG('V','O','X','u'), 20, 2, 11025 },

    { MKTAG('V','O','X','v'), 32, 2, 16000 },

    { MKTAG('V','O','X','w'), 48, 2, 22050 },

    { MKTAG('V','O','X','x'), 64, 2, 44100 },

    { MKTAG('V','O','X','y'), 80, 2, 44100 },

    { MKTAG('V','O','X','z'), 96, 2, 44100 },

    { 0, 0, 0, 0 }

};

static av_cold int metasound_decode_init(AVCodecContext *avctx)

{

    int isampf, ibps;

    TwinVQContext *tctx = avctx->priv_data;

    uint32_t tag;

    const MetasoundProps *props = codec_props;

    if (!avctx->extradata || avctx->extradata_size < 16) {

        av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");

        return AVERROR_INVALIDDATA;

    }

    tag = AV_RL32(avctx->extradata + 12);

    for (;;) {

        if (!props->tag) {

            av_log(avctx, AV_LOG_ERROR, "Could not find tag %08X\n", tag);

            return AVERROR_INVALIDDATA;

        }

        if (props->tag == tag) {

            avctx->sample_rate = props->sample_rate;

            avctx->channels    = props->channels;

            avctx->bit_rate    = props->bit_rate * 1000;

            isampf             = avctx->sample_rate / 1000;

            break;

        }

        props++;

    }

    if (avctx->channels <= 0 || avctx->channels > TWINVQ_CHANNELS_MAX) {

        av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",

               avctx->channels);

        return AVERROR_INVALIDDATA;

    }

    avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO

                                                 : AV_CH_LAYOUT_STEREO;

    ibps = avctx->bit_rate / (1000 * avctx->channels);

    switch ((avctx->channels << 16) + (isampf << 8) + ibps) {

    case (1 << 16) + ( 8 << 8) +  8:

        tctx->mtab = &ff_metasound_mode0808;

        break;

    case (1 << 16) + (16 << 8) + 16:

        tctx->mtab = &ff_metasound_mode1616;

        break;

    case (1 << 16) + (44 << 8) + 32:

        tctx->mtab = &ff_metasound_mode4432;

        break;

    case (2 << 16) + (44 << 8) + 48:

        tctx->mtab = &ff_metasound_mode4448s;

        break;

    default:

        av_log(avctx, AV_LOG_ERROR,

               "This version does not support %d kHz - %d kbit/s/ch mode.\n",

               isampf, isampf);

        return AVERROR(ENOSYS);

    }

    avctx->block_align = (avctx->bit_rate * tctx->mtab->size

                                          / avctx->sample_rate + 7) / 8;

    tctx->codec          = TWINVQ_CODEC_METASOUND;

    tctx->read_bitstream = metasound_read_bitstream;

    tctx->dec_bark_env   = dec_bark_env;

    tctx->decode_ppc     = decode_ppc;

    return ff_twinvq_decode_init(avctx);

}

AVCodec ff_metasound_decoder = {

    .name           = "metasound",

    .long_name      = NULL_IF_CONFIG_SMALL("Voxware MetaSound"),

    .type           = AVMEDIA_TYPE_AUDIO,

    .id             = AV_CODEC_ID_METASOUND,

    .priv_data_size = sizeof(TwinVQContext),

    .init           = metasound_decode_init,

    .close          = ff_twinvq_decode_close,

    .decode         = ff_twinvq_decode_frame,

    .capabilities   = CODEC_CAP_DR1,

    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,

                                                      AV_SAMPLE_FMT_NONE },

};