text: /*
   * Real Audio 1.0 (14.4K)
   * Copyright (c) 2003 the ffmpeg project
   *
   * 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_RA144_H
  #define AVCODEC_RA144_H
  
  #include "lpc.h"
  
  #define NBLOCKS         4       ///< number of subblocks within a block
  #define BLOCKSIZE       40      ///< subblock size in 16-bit words
  #define BUFFERSIZE      146     ///< the size of the adaptive codebook
  #define FIXED_CB_SIZE   128     ///< size of fixed codebooks
  #define FRAMESIZE       20      ///< size of encoded frame
  #define LPC_ORDER       10      ///< order of LPC filter
  
  typedef struct {
      AVCodecContext *avctx;
      AVFrame frame;
      LPCContext lpc_ctx;
  
      unsigned int     old_energy;        ///< previous frame energy
  
      unsigned int     lpc_tables[2][10];
  
      /** LPC coefficients: lpc_coef[0] is the coefficients of the current frame
       *  and lpc_coef[1] of the previous one. */
      unsigned int    *lpc_coef[2];
  
      unsigned int     lpc_refl_rms[2];
  
      int16_t curr_block[NBLOCKS * BLOCKSIZE];
  
      /** The current subblock padded by the last 10 values of the previous one. */
      int16_t curr_sblock[50];
  
      /** Adaptive codebook, its size is two units bigger to avoid a
       *  buffer overflow. */
      uint16_t adapt_cb[146+2];
  } RA144Context;
  
  void ff_copy_and_dup(int16_t *target, const int16_t *source, int offset);
  int ff_eval_refl(int *refl, const int16_t *coefs, AVCodecContext *avctx);
  void ff_eval_coefs(int *coefs, const int *refl);
  void ff_int_to_int16(int16_t *out, const int *inp);
  int ff_t_sqrt(unsigned int x);
  unsigned int ff_rms(const int *data);
  int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold,
                int energy);
  unsigned int ff_rescale_rms(unsigned int rms, unsigned int energy);
  int ff_irms(const int16_t *data);
  void ff_subblock_synthesis(RA144Context *ractx, const uint16_t *lpc_coefs,
                             int cba_idx, int cb1_idx, int cb2_idx,
                             int gval, int gain);
  
  extern const int16_t ff_gain_val_tab[256][3];
  extern const uint8_t ff_gain_exp_tab[256];
  extern const int8_t ff_cb1_vects[128][40];
  extern const int8_t ff_cb2_vects[128][40];
  extern const uint16_t ff_cb1_base[128];
  extern const uint16_t ff_cb2_base[128];
  extern const int16_t ff_energy_tab[32];
  extern const int16_t * const ff_lpc_refl_cb[10];
  
  #endif /* AVCODEC_RA144_H */
  