libavcodec/twinvqdec.c - manifest_repos/ffmpeg - Git at Google

 /*
  * 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 <math.h>
 #include <stdint.h>

 #include "libavutil/channel_layout.h"
 #include "avcodec.h"
 #include "get_bits.h"
 #include "internal.h"
 #include "twinvq.h"
 #include "twinvq_data.h"

 static const TwinVQModeTab mode_08_08 = {
     {
         { 8, bark_tab_s08_64,  10, tab.fcb08s, 1, 5, tab.cb0808s0, tab.cb0808s1, 18 },
         { 2, bark_tab_m08_256, 20, tab.fcb08m, 2, 5, tab.cb0808m0, tab.cb0808m1, 16 },
         { 1, bark_tab_l08_512, 30, tab.fcb08l, 3, 6, tab.cb0808l0, tab.cb0808l1, 17 }
     },
     512, 12, tab.lsp08, 1, 5, 3, 3, tab.shape08, 8, 28, 20, 6, 40
 };

 static const TwinVQModeTab mode_11_08 = {
     {
         { 8, bark_tab_s11_64,  10, tab.fcb11s, 1, 5, tab.cb1108s0, tab.cb1108s1, 29 },
         { 2, bark_tab_m11_256, 20, tab.fcb11m, 2, 5, tab.cb1108m0, tab.cb1108m1, 24 },
         { 1, bark_tab_l11_512, 30, tab.fcb11l, 3, 6, tab.cb1108l0, tab.cb1108l1, 27 }
     },
     512, 16, tab.lsp11, 1, 6, 4, 3, tab.shape11, 9, 36, 30, 7, 90
 };

 static const TwinVQModeTab mode_11_10 = {
     {
         { 8, bark_tab_s11_64,  10, tab.fcb11s, 1, 5, tab.cb1110s0, tab.cb1110s1, 21 },
         { 2, bark_tab_m11_256, 20, tab.fcb11m, 2, 5, tab.cb1110m0, tab.cb1110m1, 18 },
         { 1, bark_tab_l11_512, 30, tab.fcb11l, 3, 6, tab.cb1110l0, tab.cb1110l1, 20 }
     },
     512, 16, tab.lsp11, 1, 6, 4, 3, tab.shape11, 9, 36, 30, 7, 90
 };

 static const TwinVQModeTab mode_16_16 = {
     {
         { 8, bark_tab_s16_128,  10, tab.fcb16s, 1, 5, tab.cb1616s0, tab.cb1616s1, 16 },
         { 2, bark_tab_m16_512,  20, tab.fcb16m, 2, 5, tab.cb1616m0, tab.cb1616m1, 15 },
         { 1, bark_tab_l16_1024, 30, tab.fcb16l, 3, 6, tab.cb1616l0, tab.cb1616l1, 16 }
     },
     1024, 16, tab.lsp16, 1, 6, 4, 3, tab.shape16, 9, 56, 60, 7, 180
 };

 static const TwinVQModeTab mode_22_20 = {
     {
         { 8, bark_tab_s22_128,  10, tab.fcb22s_1, 1, 6, tab.cb2220s0, tab.cb2220s1, 18 },
         { 2, bark_tab_m22_512,  20, tab.fcb22m_1, 2, 6, tab.cb2220m0, tab.cb2220m1, 17 },
         { 1, bark_tab_l22_1024, 32, tab.fcb22l_1, 4, 6, tab.cb2220l0, tab.cb2220l1, 18 }
     },
     1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
 };

 static const TwinVQModeTab mode_22_24 = {
     {
         { 8, bark_tab_s22_128,  10, tab.fcb22s_1, 1, 6, tab.cb2224s0, tab.cb2224s1, 15 },
         { 2, bark_tab_m22_512,  20, tab.fcb22m_1, 2, 6, tab.cb2224m0, tab.cb2224m1, 14 },
         { 1, bark_tab_l22_1024, 32, tab.fcb22l_1, 4, 6, tab.cb2224l0, tab.cb2224l1, 15 }
     },
     1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
 };

 static const TwinVQModeTab mode_22_32 = {
     {
         { 4, bark_tab_s22_128, 10, tab.fcb22s_2, 1, 6, tab.cb2232s0, tab.cb2232s1, 11 },
         { 2, bark_tab_m22_256, 20, tab.fcb22m_2, 2, 6, tab.cb2232m0, tab.cb2232m1, 11 },
         { 1, bark_tab_l22_512, 32, tab.fcb22l_2, 4, 6, tab.cb2232l0, tab.cb2232l1, 12 }
     },
     512, 16, tab.lsp22_2, 1, 6, 4, 4, tab.shape22_2, 9, 56, 36, 7, 72
 };

 static const TwinVQModeTab mode_44_40 = {
     {
         { 16, bark_tab_s44_128,  10, tab.fcb44s, 1, 6, tab.cb4440s0, tab.cb4440s1, 18 },
         { 4,  bark_tab_m44_512,  20, tab.fcb44m, 2, 6, tab.cb4440m0, tab.cb4440m1, 17 },
         { 1,  bark_tab_l44_2048, 40, tab.fcb44l, 4, 6, tab.cb4440l0, tab.cb4440l1, 17 }
     },
     2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44, 9, 84, 54, 7, 432
 };

 static const TwinVQModeTab mode_44_48 = {
     {
         { 16, bark_tab_s44_128,  10, tab.fcb44s, 1, 6, tab.cb4448s0, tab.cb4448s1, 15 },
         { 4,  bark_tab_m44_512,  20, tab.fcb44m, 2, 6, tab.cb4448m0, tab.cb4448m1, 14 },
         { 1,  bark_tab_l44_2048, 40, tab.fcb44l, 4, 6, tab.cb4448l0, tab.cb4448l1, 14 }
     },
     2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44, 9, 84, 54, 7, 432
 };

 /**
  * Evaluate a * b / 400 rounded to the nearest integer. When, for example,
  * a * b == 200 and the nearest integer is ill-defined, use a table to emulate
  * the following broken float-based implementation used by the binary decoder:
  *
  * @code
  * static int very_broken_op(int a, int b)
  * {
  *    static float test; // Ugh, force gcc to do the division first...
  *
  *    test = a / 400.0;
  *    return b * test + 0.5;
  * }
  * @endcode
  *
  * @note if this function is replaced by just ROUNDED_DIV(a * b, 400.0), the
  * stddev between the original file (before encoding with Yamaha encoder) and
  * the decoded output increases, which leads one to believe that the encoder
  * expects exactly this broken calculation.
  */
 static int very_broken_op(int a, int b)
 {
     int x = a * b + 200;
     int size;
     const uint8_t *rtab;

     if (x % 400 || b % 5)
         return x / 400;

     x /= 400;

     size = tabs[b / 5].size;
     rtab = tabs[b / 5].tab;
     return x - rtab[size * av_log2(2 * (x - 1) / size) + (x - 1) % size];
 }

 /**
  * Sum to data a periodic peak of a given period, width and shape.
  *
  * @param period the period of the peak divided by 400.0
  */
 static void add_peak(int period, int width, const float *shape,
                      float ppc_gain, float *speech, int len)
 {
     int i, j;

     const float *shape_end = shape + len;
     int center;

     // 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 = very_broken_op(period, i);
         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 = very_broken_op(period, i);
     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 min_period   = ROUNDED_DIV(40 * 2 * mtab->size, isampf);
     int max_period   = ROUNDED_DIV(40 * 2 * mtab->size * 6, isampf);
     int period_range = max_period - min_period;
     float pgain_step = 25000.0 / ((1 << mtab->pgain_bit) - 1);
     float ppc_gain   = 1.0 / 8192 *
                        twinvq_mulawinv(pgain_step * g_coef +
                                            pgain_step / 2,
                                        25000.0, TWINVQ_PGAIN_MU);

     // This is actually the period multiplied by 400. It is just linearly coded
     // between its maximum and minimum value.
     int period = min_period +
                  ROUNDED_DIV(period_coef * period_range,
                              (1 << mtab->ppc_period_bit) - 1);
     int width;

     if (isampf == 22 && ibps == 32) {
         // For some unknown reason, NTT decided to code this case differently...
         width = ROUNDED_DIV((period + 800) * mtab->peak_per2wid,
                             400 * mtab->size);
     } else
         width = period * mtab->peak_per2wid / (400 * mtab->size);

     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;

     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 / 4096);
             float st   = use_hist ? (1.0 - val) * tmp2 + val * hist[idx] + 1.0
                                   : tmp2 + 1.0;

             hist[idx] = tmp2;
             if (st < -1.0)
                 st = 1.0;

             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 twinvq_read_bitstream(AVCodecContext *avctx, TwinVQContext *tctx,
                                  const uint8_t *buf, int buf_size)
 {
     TwinVQFrameData     *bits = &tctx->bits[0];
     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;
     skip_bits(&gb, get_bits(&gb, 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[0].window_type];

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

     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;
 }

 static av_cold int twinvq_decode_init(AVCodecContext *avctx)
 {
     int isampf, ibps;
     TwinVQContext *tctx = avctx->priv_data;

     if (!avctx->extradata || avctx->extradata_size < 12) {
         av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");
         return AVERROR_INVALIDDATA;
     }
     avctx->channels = AV_RB32(avctx->extradata)     + 1;
     avctx->bit_rate = AV_RB32(avctx->extradata + 4) * 1000;
     isampf          = AV_RB32(avctx->extradata + 8);

     if (isampf < 8 || isampf > 44) {
         av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate\n");
         return AVERROR_INVALIDDATA;
     }
     switch (isampf) {
     case 44:
         avctx->sample_rate = 44100;
         break;
     case 22:
         avctx->sample_rate = 22050;
         break;
     case 11:
         avctx->sample_rate = 11025;
         break;
     default:
         avctx->sample_rate = isampf * 1000;
         break;
     }

     if (avctx->channels <= 0 || avctx->channels > TWINVQ_CHANNELS_MAX) {
         av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",
                avctx->channels);
         return -1;
     }
     avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
                                                  : AV_CH_LAYOUT_STEREO;

     ibps = avctx->bit_rate / (1000 * avctx->channels);
     if (ibps < 8 || ibps > 48) {
         av_log(avctx, AV_LOG_ERROR, "Bad bitrate per channel value %d\n", ibps);
         return AVERROR_INVALIDDATA;
     }

     switch ((isampf << 8) + ibps) {
     case (8 << 8) + 8:
         tctx->mtab = &mode_08_08;
         break;
     case (11 << 8) + 8:
         tctx->mtab = &mode_11_08;
         break;
     case (11 << 8) + 10:
         tctx->mtab = &mode_11_10;
         break;
     case (16 << 8) + 16:
         tctx->mtab = &mode_16_16;
         break;
     case (22 << 8) + 20:
         tctx->mtab = &mode_22_20;
         break;
     case (22 << 8) + 24:
         tctx->mtab = &mode_22_24;
         break;
     case (22 << 8) + 32:
         tctx->mtab = &mode_22_32;
         break;
     case (44 << 8) + 40:
         tctx->mtab = &mode_44_40;
         break;
     case (44 << 8) + 48:
         tctx->mtab = &mode_44_48;
         break;
     default:
         av_log(avctx, AV_LOG_ERROR,
                "This version does not support %d kHz - %d kbit/s/ch mode.\n",
                isampf, isampf);
         return -1;
     }

     tctx->codec          = TWINVQ_CODEC_VQF;
     tctx->read_bitstream = twinvq_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 + 8;
     tctx->is_6kbps       = 0;
     if (avctx->block_align && avctx->block_align * 8LL / tctx->frame_size > 1) {
         av_log(avctx, AV_LOG_ERROR,
                "VQF TwinVQ should have only one frame per packet\n");
         return AVERROR_INVALIDDATA;
     }

     return ff_twinvq_decode_init(avctx);
 }

 AVCodec ff_twinvq_decoder = {
     .name           = "twinvq",
     .long_name      = NULL_IF_CONFIG_SMALL("VQF TwinVQ"),
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = AV_CODEC_ID_TWINVQ,
     .priv_data_size = sizeof(TwinVQContext),
     .init           = twinvq_decode_init,
     .close          = ff_twinvq_decode_close,
     .decode         = ff_twinvq_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                       AV_SAMPLE_FMT_NONE },
 };
	/*
	* 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 <math.h>
	#include <stdint.h>

	#include "libavutil/channel_layout.h"
	#include "avcodec.h"
	#include "get_bits.h"
	#include "internal.h"
	#include "twinvq.h"
	#include "twinvq_data.h"

	static const TwinVQModeTab mode_08_08 = {
	{
	{ 8, bark_tab_s08_64, 10, tab.fcb08s, 1, 5, tab.cb0808s0, tab.cb0808s1, 18 },
	{ 2, bark_tab_m08_256, 20, tab.fcb08m, 2, 5, tab.cb0808m0, tab.cb0808m1, 16 },
	{ 1, bark_tab_l08_512, 30, tab.fcb08l, 3, 6, tab.cb0808l0, tab.cb0808l1, 17 }
	},
	512, 12, tab.lsp08, 1, 5, 3, 3, tab.shape08, 8, 28, 20, 6, 40
	};

	static const TwinVQModeTab mode_11_08 = {
	{
	{ 8, bark_tab_s11_64, 10, tab.fcb11s, 1, 5, tab.cb1108s0, tab.cb1108s1, 29 },
	{ 2, bark_tab_m11_256, 20, tab.fcb11m, 2, 5, tab.cb1108m0, tab.cb1108m1, 24 },
	{ 1, bark_tab_l11_512, 30, tab.fcb11l, 3, 6, tab.cb1108l0, tab.cb1108l1, 27 }
	},
	512, 16, tab.lsp11, 1, 6, 4, 3, tab.shape11, 9, 36, 30, 7, 90
	};

	static const TwinVQModeTab mode_11_10 = {
	{
	{ 8, bark_tab_s11_64, 10, tab.fcb11s, 1, 5, tab.cb1110s0, tab.cb1110s1, 21 },
	{ 2, bark_tab_m11_256, 20, tab.fcb11m, 2, 5, tab.cb1110m0, tab.cb1110m1, 18 },
	{ 1, bark_tab_l11_512, 30, tab.fcb11l, 3, 6, tab.cb1110l0, tab.cb1110l1, 20 }
	},
	512, 16, tab.lsp11, 1, 6, 4, 3, tab.shape11, 9, 36, 30, 7, 90
	};

	static const TwinVQModeTab mode_16_16 = {
	{
	{ 8, bark_tab_s16_128, 10, tab.fcb16s, 1, 5, tab.cb1616s0, tab.cb1616s1, 16 },
	{ 2, bark_tab_m16_512, 20, tab.fcb16m, 2, 5, tab.cb1616m0, tab.cb1616m1, 15 },
	{ 1, bark_tab_l16_1024, 30, tab.fcb16l, 3, 6, tab.cb1616l0, tab.cb1616l1, 16 }
	},
	1024, 16, tab.lsp16, 1, 6, 4, 3, tab.shape16, 9, 56, 60, 7, 180
	};

	static const TwinVQModeTab mode_22_20 = {
	{
	{ 8, bark_tab_s22_128, 10, tab.fcb22s_1, 1, 6, tab.cb2220s0, tab.cb2220s1, 18 },
	{ 2, bark_tab_m22_512, 20, tab.fcb22m_1, 2, 6, tab.cb2220m0, tab.cb2220m1, 17 },
	{ 1, bark_tab_l22_1024, 32, tab.fcb22l_1, 4, 6, tab.cb2220l0, tab.cb2220l1, 18 }
	},
	1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
	};

	static const TwinVQModeTab mode_22_24 = {
	{
	{ 8, bark_tab_s22_128, 10, tab.fcb22s_1, 1, 6, tab.cb2224s0, tab.cb2224s1, 15 },
	{ 2, bark_tab_m22_512, 20, tab.fcb22m_1, 2, 6, tab.cb2224m0, tab.cb2224m1, 14 },
	{ 1, bark_tab_l22_1024, 32, tab.fcb22l_1, 4, 6, tab.cb2224l0, tab.cb2224l1, 15 }
	},
	1024, 16, tab.lsp22_1, 1, 6, 4, 3, tab.shape22_1, 9, 56, 36, 7, 144
	};

	static const TwinVQModeTab mode_22_32 = {
	{
	{ 4, bark_tab_s22_128, 10, tab.fcb22s_2, 1, 6, tab.cb2232s0, tab.cb2232s1, 11 },
	{ 2, bark_tab_m22_256, 20, tab.fcb22m_2, 2, 6, tab.cb2232m0, tab.cb2232m1, 11 },
	{ 1, bark_tab_l22_512, 32, tab.fcb22l_2, 4, 6, tab.cb2232l0, tab.cb2232l1, 12 }
	},
	512, 16, tab.lsp22_2, 1, 6, 4, 4, tab.shape22_2, 9, 56, 36, 7, 72
	};

	static const TwinVQModeTab mode_44_40 = {
	{
	{ 16, bark_tab_s44_128, 10, tab.fcb44s, 1, 6, tab.cb4440s0, tab.cb4440s1, 18 },
	{ 4, bark_tab_m44_512, 20, tab.fcb44m, 2, 6, tab.cb4440m0, tab.cb4440m1, 17 },
	{ 1, bark_tab_l44_2048, 40, tab.fcb44l, 4, 6, tab.cb4440l0, tab.cb4440l1, 17 }
	},
	2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44, 9, 84, 54, 7, 432
	};

	static const TwinVQModeTab mode_44_48 = {
	{
	{ 16, bark_tab_s44_128, 10, tab.fcb44s, 1, 6, tab.cb4448s0, tab.cb4448s1, 15 },
	{ 4, bark_tab_m44_512, 20, tab.fcb44m, 2, 6, tab.cb4448m0, tab.cb4448m1, 14 },
	{ 1, bark_tab_l44_2048, 40, tab.fcb44l, 4, 6, tab.cb4448l0, tab.cb4448l1, 14 }
	},
	2048, 20, tab.lsp44, 1, 6, 4, 4, tab.shape44, 9, 84, 54, 7, 432
	};

	/**
	* Evaluate a * b / 400 rounded to the nearest integer. When, for example,
	* a * b == 200 and the nearest integer is ill-defined, use a table to emulate
	* the following broken float-based implementation used by the binary decoder:
	*
	* @code
	* static int very_broken_op(int a, int b)
	* {
	* static float test; // Ugh, force gcc to do the division first...
	*
	* test = a / 400.0;
	* return b * test + 0.5;
	* }
	* @endcode
	*
	* @note if this function is replaced by just ROUNDED_DIV(a * b, 400.0), the
	* stddev between the original file (before encoding with Yamaha encoder) and
	* the decoded output increases, which leads one to believe that the encoder
	* expects exactly this broken calculation.
	*/
	static int very_broken_op(int a, int b)
	{
	int x = a * b + 200;
	int size;
	const uint8_t *rtab;

	if (x % 400 \|\| b % 5)
	return x / 400;

	x /= 400;

	size = tabs[b / 5].size;
	rtab = tabs[b / 5].tab;
	return x - rtab[size * av_log2(2 * (x - 1) / size) + (x - 1) % size];
	}

	/**
	* Sum to data a periodic peak of a given period, width and shape.
	*
	* @param period the period of the peak divided by 400.0
	*/
	static void add_peak(int period, int width, const float *shape,
	float ppc_gain, float *speech, int len)
	{
	int i, j;

	const float *shape_end = shape + len;
	int center;

	// 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 = very_broken_op(period, i);
	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 = very_broken_op(period, i);
	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 min_period = ROUNDED_DIV(40 * 2 * mtab->size, isampf);
	int max_period = ROUNDED_DIV(40 * 2 * mtab->size * 6, isampf);
	int period_range = max_period - min_period;
	float pgain_step = 25000.0 / ((1 << mtab->pgain_bit) - 1);
	float ppc_gain = 1.0 / 8192 *
	twinvq_mulawinv(pgain_step * g_coef +
	pgain_step / 2,
	25000.0, TWINVQ_PGAIN_MU);

	// This is actually the period multiplied by 400. It is just linearly coded
	// between its maximum and minimum value.
	int period = min_period +
	ROUNDED_DIV(period_coef * period_range,
	(1 << mtab->ppc_period_bit) - 1);
	int width;

	if (isampf == 22 && ibps == 32) {
	// For some unknown reason, NTT decided to code this case differently...
	width = ROUNDED_DIV((period + 800) * mtab->peak_per2wid,
	400 * mtab->size);
	} else
	width = period * mtab->peak_per2wid / (400 * mtab->size);

	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;

	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 / 4096);
	float st = use_hist ? (1.0 - val) * tmp2 + val * hist[idx] + 1.0
	: tmp2 + 1.0;

	hist[idx] = tmp2;
	if (st < -1.0)
	st = 1.0;

	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 twinvq_read_bitstream(AVCodecContext avctx, TwinVQContext tctx,
	const uint8_t *buf, int buf_size)
	{
	TwinVQFrameData *bits = &tctx->bits[0];
	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;
	skip_bits(&gb, get_bits(&gb, 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[0].window_type];

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

	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;
	}

	static av_cold int twinvq_decode_init(AVCodecContext *avctx)
	{
	int isampf, ibps;
	TwinVQContext *tctx = avctx->priv_data;

	if (!avctx->extradata \|\| avctx->extradata_size < 12) {
	av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata\n");
	return AVERROR_INVALIDDATA;
	}
	avctx->channels = AV_RB32(avctx->extradata) + 1;
	avctx->bit_rate = AV_RB32(avctx->extradata + 4) * 1000;
	isampf = AV_RB32(avctx->extradata + 8);

	if (isampf < 8 \|\| isampf > 44) {
	av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate\n");
	return AVERROR_INVALIDDATA;
	}
	switch (isampf) {
	case 44:
	avctx->sample_rate = 44100;
	break;
	case 22:
	avctx->sample_rate = 22050;
	break;
	case 11:
	avctx->sample_rate = 11025;
	break;
	default:
	avctx->sample_rate = isampf * 1000;
	break;
	}

	if (avctx->channels <= 0 \|\| avctx->channels > TWINVQ_CHANNELS_MAX) {
	av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels: %i\n",
	avctx->channels);
	return -1;
	}
	avctx->channel_layout = avctx->channels == 1 ? AV_CH_LAYOUT_MONO
	: AV_CH_LAYOUT_STEREO;

	ibps = avctx->bit_rate / (1000 * avctx->channels);
	if (ibps < 8 \|\| ibps > 48) {
	av_log(avctx, AV_LOG_ERROR, "Bad bitrate per channel value %d\n", ibps);
	return AVERROR_INVALIDDATA;
	}

	switch ((isampf << 8) + ibps) {
	case (8 << 8) + 8:
	tctx->mtab = &mode_08_08;
	break;
	case (11 << 8) + 8:
	tctx->mtab = &mode_11_08;
	break;
	case (11 << 8) + 10:
	tctx->mtab = &mode_11_10;
	break;
	case (16 << 8) + 16:
	tctx->mtab = &mode_16_16;
	break;
	case (22 << 8) + 20:
	tctx->mtab = &mode_22_20;
	break;
	case (22 << 8) + 24:
	tctx->mtab = &mode_22_24;
	break;
	case (22 << 8) + 32:
	tctx->mtab = &mode_22_32;
	break;
	case (44 << 8) + 40:
	tctx->mtab = &mode_44_40;
	break;
	case (44 << 8) + 48:
	tctx->mtab = &mode_44_48;
	break;
	default:
	av_log(avctx, AV_LOG_ERROR,
	"This version does not support %d kHz - %d kbit/s/ch mode.\n",
	isampf, isampf);
	return -1;
	}

	tctx->codec = TWINVQ_CODEC_VQF;
	tctx->read_bitstream = twinvq_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 + 8;
	tctx->is_6kbps = 0;
	if (avctx->block_align && avctx->block_align * 8LL / tctx->frame_size > 1) {
	av_log(avctx, AV_LOG_ERROR,
	"VQF TwinVQ should have only one frame per packet\n");
	return AVERROR_INVALIDDATA;
	}

	return ff_twinvq_decode_init(avctx);
	}

	AVCodec ff_twinvq_decoder = {
	.name = "twinvq",
	.long_name = NULL_IF_CONFIG_SMALL("VQF TwinVQ"),
	.type = AVMEDIA_TYPE_AUDIO,
	.id = AV_CODEC_ID_TWINVQ,
	.priv_data_size = sizeof(TwinVQContext),
	.init = twinvq_decode_init,
	.close = ff_twinvq_decode_close,
	.decode = ff_twinvq_decode_frame,
	.capabilities = AV_CODEC_CAP_DR1 \| AV_CODEC_CAP_CHANNEL_CONF,
	.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
	AV_SAMPLE_FMT_NONE },
	};