/* * 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 typedef struct ADXChannelState {    int s1,s2;} ADXChannelState; #define MAX_CHANNELS 6 typedef struct ADXContext {    int channels;    ADXChannelState prev[MAX_CHANNELS];    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); #endif /* AVCODEC_ADX_H */