cabac.h 1.67 KB
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/*
 * H.26L/H.264/AVC/JVT/14496-10/... encoder/decoder
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 *
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 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * 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
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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/**
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 * @file
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 * Context Adaptive Binary Arithmetic Coder.
 */

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#ifndef AVCODEC_CABAC_H
#define AVCODEC_CABAC_H
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#include <stdint.h>
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#include "put_bits.h"
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#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

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#define CABAC_BITS 16
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#define CABAC_MASK ((1<<CABAC_BITS)-1)

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typedef struct CABACContext{
    int low;
    int range;
    int outstanding_count;
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    const uint8_t *bytestream_start;
    const uint8_t *bytestream;
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    const uint8_t *bytestream_end;
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    PutBitContext pb;
}CABACContext;

void ff_init_cabac_encoder(CABACContext *c, uint8_t *buf, int buf_size);
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void ff_init_cabac_decoder(CABACContext *c, const uint8_t *buf, int buf_size);
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void ff_init_cabac_states(CABACContext *c);
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#endif /* AVCODEC_CABAC_H */