yading@10: /*
yading@10:  * ADX ADPCM codecs
yading@10:  * Copyright (c) 2001,2003 BERO
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * SEGA CRI adx codecs.
yading@10:  *
yading@10:  * Reference documents:
yading@10:  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
yading@10:  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
yading@10:  */
yading@10: 
yading@10: #ifndef AVCODEC_ADX_H
yading@10: #define AVCODEC_ADX_H
yading@10: 
yading@10: #include <stdint.h>
yading@10: 
yading@10: #include "avcodec.h"
yading@10: 
yading@10: typedef struct ADXChannelState {
yading@10:     int s1,s2;
yading@10: } ADXChannelState;
yading@10: 
yading@10: typedef struct ADXContext {
yading@10:     int channels;
yading@10:     ADXChannelState prev[2];
yading@10:     int header_parsed;
yading@10:     int eof;
yading@10:     int cutoff;
yading@10:     int coeff[2];
yading@10: } ADXContext;
yading@10: 
yading@10: #define COEFF_BITS  12
yading@10: 
yading@10: #define BLOCK_SIZE      18
yading@10: #define BLOCK_SAMPLES   32
yading@10: 
yading@10: /**
yading@10:  * Calculate LPC coefficients based on cutoff frequency and sample rate.
yading@10:  *
yading@10:  * @param cutoff       cutoff frequency
yading@10:  * @param sample_rate  sample rate
yading@10:  * @param bits         number of bits used to quantize coefficients
yading@10:  * @param[out] coeff   2 quantized LPC coefficients
yading@10:  */
yading@10: void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff);
yading@10: 
yading@10: /**
yading@10:  * Decode ADX stream header.
yading@10:  * Sets avctx->channels and avctx->sample_rate.
yading@10:  *
yading@10:  * @param      avctx        codec context
yading@10:  * @param      buf          header data
yading@10:  * @param      bufsize      data size, should be at least 24 bytes
yading@10:  * @param[out] header_size  size of ADX header
yading@10:  * @param[out] coeff        2 LPC coefficients, can be NULL
yading@10:  * @return data offset or negative error code if header is invalid
yading@10:  */
yading@10: int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
yading@10:                              int bufsize, int *header_size, int *coeff);
yading@10: 
yading@10: #endif /* AVCODEC_ADX_H */