libavcodec/adx.h
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00001 /*
00002  * ADX ADPCM codecs
00003  * Copyright (c) 2001,2003 BERO
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00031 #ifndef AVCODEC_ADX_H
00032 #define AVCODEC_ADX_H
00033 
00034 #include <stdint.h>
00035 
00036 #include "avcodec.h"
00037 
00038 typedef struct {
00039     int s1,s2;
00040 } ADXChannelState;
00041 
00042 typedef struct {
00043     AVFrame frame;
00044     int channels;
00045     ADXChannelState prev[2];
00046     int header_parsed;
00047     int eof;
00048     int cutoff;
00049     int coeff[2];
00050 } ADXContext;
00051 
00052 #define COEFF_BITS  12
00053 
00054 #define BLOCK_SIZE      18
00055 #define BLOCK_SAMPLES   32
00056 
00065 void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff);
00066 
00078 int avpriv_adx_decode_header(AVCodecContext *avctx, const uint8_t *buf,
00079                              int bufsize, int *header_size, int *coeff);
00080 
00081 #endif /* AVCODEC_ADX_H */