uvg266/src/cabac.h

#ifndef CABAC_H_
#define CABAC_H_
/*****************************************************************************
 * This file is part of Kvazaar HEVC encoder.
 *
 * Copyright (C) 2013-2014 Tampere University of Technology and others (see
 * COPYING file).
 *
 * Kvazaar is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as published
 * by the Free Software Foundation.
 *
 * Kvazaar 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 Kvazaar.  If not, see <http://www.gnu.org/licenses/>.
 ****************************************************************************/

/*
 * \file
 * \brief The Content Adaptive Binary Arithmetic Coder (CABAC).
 */

#include "global.h"

#include "bitstream.h"


// Types
typedef struct
{
  uint8_t  uc_state;
} cabac_ctx;

typedef struct
{
  cabac_ctx *ctx;
  uint32_t   low;
  uint32_t   range;
  uint32_t   buffered_byte;
  int32_t    num_buffered_bytes;
  int32_t    bits_left;
  int8_t     only_count;
  bitstream *stream;
  
  // CONTEXTS
  cabac_ctx ctx_sao_merge_flag_model;
  cabac_ctx ctx_sao_type_idx_model;
  cabac_ctx ctx_split_flag_model[3]; //!< \brief split flag context models
  cabac_ctx ctx_intra_mode_model;    //!< \brief intra mode context models
  cabac_ctx ctx_chroma_pred_model[2];
  cabac_ctx ctx_trans_subdiv_model[3]; //!< \brief intra mode context models
  cabac_ctx ctx_qt_cbf_model_luma[3];
  cabac_ctx ctx_qt_cbf_model_chroma[3];
  cabac_ctx ctx_part_size_model[4];
  cabac_ctx ctx_cu_sig_coeff_group_model[4];
  cabac_ctx ctx_cu_sig_model_luma[27];
  cabac_ctx ctx_cu_sig_model_chroma[15];
  cabac_ctx ctx_cu_ctx_last_y_luma[15];
  cabac_ctx ctx_cu_ctx_last_y_chroma[15];
  cabac_ctx ctx_cu_ctx_last_x_luma[15];
  cabac_ctx ctx_cu_ctx_last_x_chroma[15];
  cabac_ctx ctx_cu_one_model_luma[16];
  cabac_ctx ctx_cu_one_model_chroma[8];
  cabac_ctx ctx_cu_abs_model_luma[4];
  cabac_ctx ctx_cu_abs_model_chroma[2];
  cabac_ctx ctx_cu_pred_mode_model;
  cabac_ctx ctx_cu_skip_flag_model[3];
  cabac_ctx ctx_cu_merge_idx_ext_model;
  cabac_ctx ctx_cu_merge_flag_ext_model;
  cabac_ctx ctx_cu_mvd_model[2];
  cabac_ctx ctx_cu_ref_pic_model[2];
  cabac_ctx ctx_mvp_idx_model[2];
  cabac_ctx ctx_cu_qt_root_cbf_model;
  cabac_ctx ctx_transform_skip_model_luma;
  cabac_ctx ctx_transform_skip_model_chroma;
} cabac_data;


// Globals
extern const uint8_t g_auc_next_state_mps[128];
extern const uint8_t g_auc_next_state_lps[128];
extern const uint8_t g_auc_lpst_table[64][4];
extern const uint8_t g_auc_renorm_table[32];


// Functions
void cabac_start(cabac_data *data);
void cabac_encode_bin(cabac_data *data, uint32_t bin_value);
void cabac_encode_bin_ep(cabac_data *data, uint32_t bin_value);
void cabac_encode_bins_ep(cabac_data *data, uint32_t bin_values, int num_bins);
void cabac_encode_bin_trm(cabac_data *data, uint8_t bin_value);
void cabac_write(cabac_data *data);
void cabac_finish(cabac_data *data);
void cabac_flush(cabac_data *data);
void cabac_write_coeff_remain(cabac_data *cabac, uint32_t symbol,
                              uint32_t r_param);
void cabac_write_ep_ex_golomb(cabac_data *data, uint32_t symbol,
                              uint32_t count);
void cabac_write_unary_max_symbol(cabac_data *data, cabac_ctx *ctx,
                                  uint32_t symbol, int32_t offset,
                                  uint32_t max_symbol);
void cabac_write_unary_max_symbol_ep(cabac_data *data, unsigned symbol, unsigned max_symbol);


// Macros
#define CTX_STATE(ctx) (ctx->uc_state >> 1)
#define CTX_MPS(ctx) (ctx->uc_state & 1)
#define CTX_UPDATE_LPS(ctx) { (ctx)->uc_state = g_auc_next_state_lps[ (ctx)->uc_state ]; }
#define CTX_UPDATE_MPS(ctx) { (ctx)->uc_state = g_auc_next_state_mps[ (ctx)->uc_state ]; }

#ifdef VERBOSE
  #define CABAC_BIN(data, value, name) { \
    uint32_t prev_state = (data)->ctx->uc_state; \
    cabac_encode_bin(data, value); \
    printf("%s = %d prev_state=%d state=%d\n", \
           name, value, prev_state, (data)->ctx->uc_state); }

  #define CABAC_BINS_EP(data, value, bins, name) { \
    uint32_t prev_state = (data)->ctx->uc_state; \
    cabac_encode_bins_ep(data, value, bins); \
    printf("%s = %d prev_state=%d state=%d\n", \
           name, value, prev_state, (data)->ctx->uc_state); }

  #define CABAC_BIN_EP(data, value, name) { \
    uint32_t prev_state = (data)->ctx->uc_state; \
    cabac_encode_bin_ep(data, value); \
    printf("%s = %d prev_state=%d state=%d\n", \
           name, value, prev_state, (data)->ctx->uc_state); }
#else
  #define CABAC_BIN(data, value, name) \
    cabac_encode_bin(data, value);
  #define CABAC_BINS_EP(data, value, bins, name) \
    cabac_encode_bins_ep(data, value, bins);
  #define CABAC_BIN_EP(data, value, name) \
    cabac_encode_bin_ep(data, value);
#endif

#endif