/*
  * Copyright (c) CMU 1993 Computer Science, Speech Group
  *                        Chengxiang Lu and Alex Hauptmann
  * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
  * Copyright (c) 2009 Kenan Gillet
  * Copyright (c) 2010 Martin Storsjo
  *

  * 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_G722_H
 #define AVCODEC_G722_H
 
 #include <stdint.h>

 #include "avcodec.h"

 #include "g722dsp.h"

 
 #define PREV_SAMPLES_BUF_SIZE 1024
 

 typedef struct G722Context {

     const AVClass *class;
     int     bits_per_codeword;

     int16_t prev_samples[PREV_SAMPLES_BUF_SIZE]; ///< memory of past decoded samples
     int     prev_samples_pos;        ///< the number of values in prev_samples
 
     /**
      * The band[0] and band[1] correspond respectively to the lower band and higher band.
      */
     struct G722Band {
         int16_t s_predictor;         ///< predictor output value
         int32_t s_zero;              ///< previous output signal from zero predictor
         int8_t  part_reconst_mem[2]; ///< signs of previous partially reconstructed signals
         int16_t prev_qtzd_reconst;   ///< previous quantized reconstructed signal (internal value, using low_inv_quant4)
         int16_t pole_mem[2];         ///< second-order pole section coefficient buffer
         int32_t diff_mem[6];         ///< quantizer difference signal memory
         int16_t zero_mem[6];         ///< Seventh-order zero section coefficient buffer
         int16_t log_factor;          ///< delayed 2-logarithmic quantizer factor
         int16_t scale_factor;        ///< delayed quantizer scale factor
     } band[2];
 
     struct TrellisNode {
         struct G722Band state;
         uint32_t ssd;
         int path;
     } *node_buf[2], **nodep_buf[2];
 
     struct TrellisPath {
         int value;
         int prev;
     } *paths[2];

 
     G722DSPContext dsp;

 } G722Context;
 
 extern const int16_t ff_g722_high_inv_quant[4];
 extern const int16_t ff_g722_low_inv_quant4[16];
 extern const int16_t ff_g722_low_inv_quant6[64];
 
 void ff_g722_update_low_predictor(struct G722Band *band, const int ilow);
 
 void ff_g722_update_high_predictor(struct G722Band *band, const int dhigh,
                                    const int ihigh);
 
 #endif /* AVCODEC_G722_H */