www.pudn.com > X264_20060729.rar > cabac.h


/*****************************************************************************
* cabac.h: h264 encoder library
*****************************************************************************
* Copyright (C) 2003 Laurent Aimar
* $Id: cabac.h,v 1.1 2004/06/03 19:27:06 fenrir Exp $
*
* Authors: Laurent Aimar <fenrir@via.ecp.fr>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
*****************************************************************************/

#ifndef _CABAC_H
#define _CABAC_H 1

typedef struct
{
/* context */
/* #436-459 are for interlacing, so are omitted for now */
uint8_t state[436];

/* state */
int i_low;
int i_range;

/* bit stream */
int i_bits_outstanding;
int f8_bits_encoded; // only if using x264_cabac_size_decision()
bs_t *s;

} x264_cabac_t;

/* encoder/decoder: init the contexts given i_slice_type, the quantif and the model */
void x264_cabac_context_init( x264_cabac_t *cb, int i_slice_type, int i_qp, int i_model );

/* decoder only: */
void x264_cabac_decode_init ( x264_cabac_t *cb, bs_t *s );
int x264_cabac_decode_decision( x264_cabac_t *cb, int i_ctx_idx );
int x264_cabac_decode_bypass ( x264_cabac_t *cb );
int x264_cabac_decode_terminal( x264_cabac_t *cb );

/* encoder only: */
void x264_cabac_encode_init ( x264_cabac_t *cb, bs_t *s );
void x264_cabac_encode_decision( x264_cabac_t *cb, int i_ctx_idx, int b );
void x264_cabac_encode_bypass( x264_cabac_t *cb, int b );
void x264_cabac_encode_terminal( x264_cabac_t *cb, int b );
void x264_cabac_encode_flush( x264_cabac_t *cb );
/* don't write the bitstream, just calculate cost: */
void x264_cabac_size_decision( x264_cabac_t *cb, int i_ctx, int b );
int x264_cabac_size_decision2( uint8_t *state, int b );
int x264_cabac_size_decision_noup( uint8_t *state, int b );

static inline int x264_cabac_pos( x264_cabac_t *cb )
{
return bs_pos( cb->s ) + cb->i_bits_outstanding;
}

#endif