/*
  * 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
  */
 
 #ifndef AVCODEC_TWINVQ_H
 #define AVCODEC_TWINVQ_H
 
 #include <math.h>
 #include <stdint.h>
 
 #include "libavutil/common.h"
 #include "libavutil/float_dsp.h"
 #include "avcodec.h"
 #include "fft.h"
 #include "internal.h"
 
 enum TwinVQCodec {
     TWINVQ_CODEC_VQF,
     TWINVQ_CODEC_METASOUND,
 };
 
 enum TwinVQFrameType {
     TWINVQ_FT_SHORT = 0,  ///< Short frame  (divided in n   sub-blocks)
     TWINVQ_FT_MEDIUM,     ///< Medium frame (divided in m<n sub-blocks)
     TWINVQ_FT_LONG,       ///< Long frame   (single sub-block + PPC)
     TWINVQ_FT_PPC,        ///< Periodic Peak Component (part of the long frame)
 };
 
 #define TWINVQ_PPC_SHAPE_CB_SIZE 64
 #define TWINVQ_PPC_SHAPE_LEN_MAX 60
 #define TWINVQ_SUB_AMP_MAX       4500.0
 #define TWINVQ_MULAW_MU          100.0
 #define TWINVQ_GAIN_BITS         8
 #define TWINVQ_AMP_MAX           13000.0
 #define TWINVQ_SUB_GAIN_BITS     5
 #define TWINVQ_WINDOW_TYPE_BITS  4
 #define TWINVQ_PGAIN_MU          200
 #define TWINVQ_LSP_COEFS_MAX     20
 #define TWINVQ_LSP_SPLIT_MAX     4
 #define TWINVQ_CHANNELS_MAX      2
 #define TWINVQ_SUBBLOCKS_MAX     16
 #define TWINVQ_BARK_N_COEF_MAX   4
 

 #define TWINVQ_MAX_FRAMES_PER_PACKET 2
 

 /**
  * Parameters and tables that are different for each frame type
  */
 struct TwinVQFrameMode {
     uint8_t         sub;      ///< Number subblocks in each frame
     const uint16_t *bark_tab;
 
     /** number of distinct bark scale envelope values */
     uint8_t         bark_env_size;
 
     const int16_t  *bark_cb;    ///< codebook for the bark scale envelope (BSE)
     uint8_t         bark_n_coef;///< number of BSE CB coefficients to read
     uint8_t         bark_n_bit; ///< number of bits of the BSE coefs
 
     //@{
     /** main codebooks for spectrum data */
     const int16_t    *cb0;
     const int16_t    *cb1;
     //@}
 
     uint8_t         cb_len_read; ///< number of spectrum coefficients to read
 };
 
 typedef struct TwinVQFrameData {
     int     window_type;
     enum TwinVQFrameType ftype;
 
     uint8_t main_coeffs[1024];
     uint8_t ppc_coeffs[TWINVQ_PPC_SHAPE_LEN_MAX];
 
     uint8_t gain_bits[TWINVQ_CHANNELS_MAX];
     uint8_t sub_gain_bits[TWINVQ_CHANNELS_MAX * TWINVQ_SUBBLOCKS_MAX];
 
     uint8_t bark1[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX][TWINVQ_BARK_N_COEF_MAX];
     uint8_t bark_use_hist[TWINVQ_CHANNELS_MAX][TWINVQ_SUBBLOCKS_MAX];
 
     uint8_t lpc_idx1[TWINVQ_CHANNELS_MAX];
     uint8_t lpc_idx2[TWINVQ_CHANNELS_MAX][TWINVQ_LSP_SPLIT_MAX];
     uint8_t lpc_hist_idx[TWINVQ_CHANNELS_MAX];
 
     int     p_coef[TWINVQ_CHANNELS_MAX];
     int     g_coef[TWINVQ_CHANNELS_MAX];
 } TwinVQFrameData;
 
 /**
  * Parameters and tables that are different for every combination of
  * bitrate/sample rate
  */
 typedef struct TwinVQModeTab {

     struct TwinVQFrameMode fmode[3]; ///< frame type-dependent parameters

 
     uint16_t     size;        ///< frame size in samples
     uint8_t      n_lsp;       ///< number of lsp coefficients
     const float *lspcodebook;
 
     /* number of bits of the different LSP CB coefficients */
     uint8_t      lsp_bit0;
     uint8_t      lsp_bit1;
     uint8_t      lsp_bit2;
 
     uint8_t      lsp_split;      ///< number of CB entries for the LSP decoding
     const int16_t *ppc_shape_cb; ///< PPC shape CB
 
     /** number of the bits for the PPC period value */
     uint8_t      ppc_period_bit;
 
     uint8_t      ppc_shape_bit;  ///< number of bits of the PPC shape CB coeffs
     uint8_t      ppc_shape_len;  ///< size of PPC shape CB
     uint8_t      pgain_bit;      ///< bits for PPC gain
 
     /** constant for peak period to peak width conversion */
     uint16_t     peak_per2wid;
 } TwinVQModeTab;
 
 typedef struct TwinVQContext {
     AVCodecContext *avctx;

     AVFloatDSPContext *fdsp;

     FFTContext mdct_ctx[3];
 
     const TwinVQModeTab *mtab;

 
     int is_6kbps;

 
     // history
     float lsp_hist[2][20];           ///< LSP coefficients of the last frame
     float bark_hist[3][2][40];       ///< BSE coefficients of last frame
 
     // bitstream parameters
     int16_t permut[4][4096];
     uint8_t length[4][2];            ///< main codebook stride
     uint8_t length_change[4];
     uint8_t bits_main_spec[2][4][2]; ///< bits for the main codebook
     int bits_main_spec_change[4];
     int n_div[4];
 
     float *spectrum;
     float *curr_frame;               ///< non-interleaved output
     float *prev_frame;               ///< non-interleaved previous frame
     int last_block_pos[2];
     int discarded_packets;
 
     float *cos_tabs[3];
 
     // scratch buffers
     float *tmp_buf;
 

     int frame_size, frames_per_packet, cur_frame;
     TwinVQFrameData bits[TWINVQ_MAX_FRAMES_PER_PACKET];

 
     enum TwinVQCodec codec;
 
     int (*read_bitstream)(AVCodecContext *avctx, struct TwinVQContext *tctx,
                           const uint8_t *buf, int buf_size);
     void (*dec_bark_env)(struct TwinVQContext *tctx, const uint8_t *in,
                          int use_hist, int ch, float *out, float gain,
                          enum TwinVQFrameType ftype);
     void (*decode_ppc)(struct TwinVQContext *tctx, int period_coef, int g_coef,
                        const float *shape, float *speech);
 } TwinVQContext;
 
 extern const enum TwinVQFrameType ff_twinvq_wtype_to_ftype_table[];
 
 /** @note not speed critical, hence not optimized */
 static inline void twinvq_memset_float(float *buf, float val, int size)
 {
     while (size--)
         *buf++ = val;
 }
 
 static inline float twinvq_mulawinv(float y, float clip, float mu)
 {
     y = av_clipf(y / clip, -1, 1);
     return clip * FFSIGN(y) * (exp(log(1 + mu) * fabs(y)) - 1) / mu;
 }
 
 int ff_twinvq_decode_frame(AVCodecContext *avctx, void *data,
                            int *got_frame_ptr, AVPacket *avpkt);

 int ff_twinvq_decode_close(AVCodecContext *avctx);
 int ff_twinvq_decode_init(AVCodecContext *avctx);

 #endif /* AVCODEC_TWINVQ_H */