/*
  * 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 <inttypes.h>

 #include <math.h>
 #include <stdint.h>
 
 #include "libavutil/channel_layout.h"
 #include "libavutil/float_dsp.h"

 
 #define BITSTREAM_READER_LE

 #include "avcodec.h"
 #include "fft.h"

 #include "get_bits.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;

     const TwinVQModeTab *mtab = tctx->mtab;
     int channels              = tctx->avctx->channels;
     int sub;
     GetBitContext gb;

     int i, j, k, ret;

     if ((ret = init_get_bits8(&gb, buf, buf_size)) < 0)
         return ret;

     for (tctx->cur_frame = 0; tctx->cur_frame < tctx->frames_per_packet;
          tctx->cur_frame++) {
         bits = tctx->bits + tctx->cur_frame;

         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[tctx->cur_frame].window_type];

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

         if (bits->ftype != TWINVQ_FT_SHORT && !tctx->is_6kbps)

             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);
             }

         }

 
         // subframes are aligned to nibbles
         if (get_bits_count(&gb) & 3)
             skip_bits(&gb, 4 - (get_bits_count(&gb) & 3));

     }
 

     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 %08"PRIX32"\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) +  6:
         tctx->mtab = &ff_metasound_mode0806;
         break;
     case (2 << 16) + ( 8 << 8) +  6:
         tctx->mtab = &ff_metasound_mode0806s;
         break;

     case (1 << 16) + ( 8 << 8) +  8:
         tctx->mtab = &ff_metasound_mode0808;
         break;

     case (2 << 16) + ( 8 << 8) +  8:
         tctx->mtab = &ff_metasound_mode0808s;
         break;
     case (1 << 16) + (11 << 8) + 10:
         tctx->mtab = &ff_metasound_mode1110;
         break;
     case (2 << 16) + (11 << 8) + 10:
         tctx->mtab = &ff_metasound_mode1110s;
         break;

     case (1 << 16) + (16 << 8) + 16:
         tctx->mtab = &ff_metasound_mode1616;
         break;

     case (2 << 16) + (16 << 8) + 16:
         tctx->mtab = &ff_metasound_mode1616s;
         break;

     case (1 << 16) + (22 << 8) + 24:
         tctx->mtab = &ff_metasound_mode2224;
         break;
     case (2 << 16) + (22 << 8) + 24:
         tctx->mtab = &ff_metasound_mode2224s;
         break;

     case (1 << 16) + (44 << 8) + 32:
         tctx->mtab = &ff_metasound_mode4432;
         break;

     case (2 << 16) + (44 << 8) + 32:
         tctx->mtab = &ff_metasound_mode4432s;
         break;
     case (1 << 16) + (44 << 8) + 40:
         tctx->mtab = &ff_metasound_mode4440;
         break;
     case (2 << 16) + (44 << 8) + 40:
         tctx->mtab = &ff_metasound_mode4440s;
         break;
     case (1 << 16) + (44 << 8) + 48:
         tctx->mtab = &ff_metasound_mode4448;
         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, ibps);

         return AVERROR(ENOSYS);
     }
 
     tctx->codec          = TWINVQ_CODEC_METASOUND;
     tctx->read_bitstream = metasound_read_bitstream;
     tctx->dec_bark_env   = dec_bark_env;
     tctx->decode_ppc     = decode_ppc;

     tctx->frame_size     = avctx->bit_rate * tctx->mtab->size
                                            / avctx->sample_rate;

     tctx->is_6kbps       = ibps == 6;

 
     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   = AV_CODEC_CAP_DR1,

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