FFmpeg4/libavcodec/cabac.h

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2023-07-02 12:20:28 +00:00
/*
* H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
* Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
*
* 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
* Context Adaptive Binary Arithmetic Coder.
*/
#ifndef AVCODEC_CABAC_H
#define AVCODEC_CABAC_H
#include <stdint.h>
#include "put_bits.h"
extern const uint8_t ff_h264_cabac_tables[512 + 4*2*64 + 4*64 + 63];
#define H264_NORM_SHIFT_OFFSET 0
#define H264_LPS_RANGE_OFFSET 512
#define H264_MLPS_STATE_OFFSET 1024
#define H264_LAST_COEFF_FLAG_OFFSET_8x8_OFFSET 1280
#define CABAC_BITS 16
#define CABAC_MASK ((1<<CABAC_BITS)-1)
typedef struct CABACContext{
int low;
int range;
int outstanding_count;
const uint8_t *bytestream_start;
const uint8_t *bytestream;
const uint8_t *bytestream_end;
PutBitContext pb;
}CABACContext;
void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
int ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
#endif /* AVCODEC_CABAC_H */