/*
  * ADX ADPCM codecs
  * Copyright (c) 2001,2003 BERO
  *
  * 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
  */
 
 /**

  * @file

  * SEGA CRI adx codecs.
  *
  * Reference documents:
  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
  */
 

 #ifndef AVCODEC_ADX_H
 #define AVCODEC_ADX_H

 #include <stdint.h>
 
 #include "avcodec.h"
 

 typedef struct ADXChannelState {

     int s1,s2;

 } ADXChannelState;

 typedef struct ADXContext {

     int channels;

     ADXChannelState prev[2];

     int header_parsed;

     int eof;

     int cutoff;
     int coeff[2];

 } ADXContext;
 

 #define COEFF_BITS  12

 #define BLOCK_SIZE      18
 #define BLOCK_SAMPLES   32
 

 /**
  * Calculate LPC coefficients based on cutoff frequency and sample rate.
  *
  * @param cutoff       cutoff frequency
  * @param sample_rate  sample rate
  * @param bits         number of bits used to quantize coefficients
  * @param[out] coeff   2 quantized LPC coefficients
  */
 void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff);

 /**
  * Decode ADX stream header.
  * Sets avctx->channels and avctx->sample_rate.
  *
  * @param      avctx        codec context
  * @param      buf          header data
  * @param      bufsize      data size, should be at least 24 bytes
  * @param[out] header_size  size of ADX header
  * @param[out] coeff        2 LPC coefficients, can be NULL
  * @return data offset or negative error code if header is invalid
  */

 int ff_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
                          int bufsize, int *header_size, int *coeff);
 

 #endif /* AVCODEC_ADX_H */