/******************************************************************************

 *

 * Copyright (C) 2015 The Android Open Source Project

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at:

 *

 * http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 *

 *****************************************************************************

 * Originally developed and contributed by Ittiam Systems Pvt. Ltd, Bangalore

*/

/**

*******************************************************************************

* @file

*  ih264e_cabac_init.c

*

* @brief

*  Contains all initialization functions for cabac contexts

*

* @author

*  ittiam

*

* @par List of Functions

*  - ih264e_init_cabac_enc_envirnoment

*  - ih264e_init_cabac_table

*  - ih264e_init_cabac_ctxt

*

* @remarks

*  none

*

*******************************************************************************

*/

/*****************************************************************************/

/* File Includes                                                             */

/*****************************************************************************/

/* System Include Files */

#include <stdio.h>

#include <stddef.h>

#include <stdlib.h>

#include <string.h>

#include <limits.h>

#include <assert.h>

/* User Include Files */

#include "ih264e_config.h"

#include "ih264_typedefs.h"

#include "iv2.h"

#include "ive2.h"

#include "ih264_debug.h"

#include "ih264_macros.h"

#include "ih264_error.h"

#include "ih264_defs.h"

#include "ih264_mem_fns.h"

#include "ih264_padding.h"

#include "ih264_structs.h"

#include "ih264_trans_quant_itrans_iquant.h"

#include "ih264_inter_pred_filters.h"

#include "ih264_intra_pred_filters.h"

#include "ih264_deblk_edge_filters.h"

#include "ih264_cavlc_tables.h"

#include "ih264_cabac_tables.h"

#include "ih264_platform_macros.h"

#include "ime_defs.h"

#include "ime_distortion_metrics.h"

#include "ime_structs.h"

#include "irc_cntrl_param.h"

#include "irc_frame_info_collector.h"

#include "ih264e_error.h"

#include "ih264e_defs.h"

#include "ih264e_bitstream.h"

#include "ih264e_cabac_structs.h"

#include "ih264e_structs.h"

#include "ih264e_encode_header.h"

#include "ih264e_cabac.h"

#include "ih264e_statistics.h"

#include "ih264e_trace.h"

/*****************************************************************************/

/*  Function definitions .                                                   */

/*****************************************************************************/

/**

*******************************************************************************

*

* @brief Initialize cabac encoding environment

*

* @param[in] ps_cab_enc_env

*  Pointer to encoding_envirnoment_t structure

*

* @returns none

*

* @remarks none

*

*******************************************************************************

*/

static void ih264e_init_cabac_enc_envirnoment(encoding_envirnoment_t *ps_cab_enc_env)

{

    ps_cab_enc_env->u4_code_int_low = 0;

    ps_cab_enc_env->u4_code_int_range = 0x1fe;

    ps_cab_enc_env->u4_out_standing_bytes = 0;

    ps_cab_enc_env->u4_bits_gen = 0;

}

/**

*******************************************************************************

*

* @brief Initialize default context values and pointers. Called once at the

*  beginning of encoding.

*

* @param[in] ps_ent_ctxt

*  Pointer to entropy context structure

*

* @returns none

*

* @remarks none

*

*******************************************************************************

*/

void ih264e_init_cabac_table(entropy_ctxt_t *ps_ent_ctxt)

{

    cabac_ctxt_t *ps_cabac_ctxt = ps_ent_ctxt->ps_cabac;

    ps_cabac_ctxt->ps_mb_map_ctxt_inc = ps_cabac_ctxt->ps_mb_map_ctxt_inc_base + 1;

    ps_cabac_ctxt->ps_lft_csbp = &ps_cabac_ctxt->s_lft_csbp;

    ps_cabac_ctxt->ps_bitstrm = ps_ent_ctxt->ps_bitstrm;

    {

        /* 0th entry of mb_map_ctxt_inc will be always be containing default values */

        /* for CABAC context representing MB not available */

        mb_info_ctxt_t *ps_def_ctxt = ps_cabac_ctxt->ps_mb_map_ctxt_inc - 1;

        ps_def_ctxt->u1_mb_type = CAB_SKIP;

        ps_def_ctxt->u1_cbp = 0x0f;

        ps_def_ctxt->u1_intrapred_chroma_mode = 0;

        memset(ps_def_ctxt->i1_ref_idx, 0, sizeof(ps_def_ctxt->i1_ref_idx));

        memset(ps_def_ctxt->u1_mv, 0, sizeof(ps_def_ctxt->u1_mv));

        ps_cabac_ctxt->ps_def_ctxt_mb_info = ps_def_ctxt;

    }

}

/**

*******************************************************************************

*

* @brief Initialize cabac context: Initialize all contest with init values given

*  in the spec. Called at the beginning of entropy coding of each slice for

*  CABAC encoding.

*

* @param[in] ps_ent_ctxt

*  Pointer to entropy context structure

*

* @returns none

*

* @remarks none

*

*******************************************************************************

*/

void ih264e_init_cabac_ctxt(entropy_ctxt_t *ps_ent_ctxt)

{

    cabac_ctxt_t *ps_cabac_ctxt = ps_ent_ctxt->ps_cabac;

    slice_header_t *ps_slice_hdr = ps_ent_ctxt->ps_slice_hdr_base;

    const UWORD8 u1_slice_type = ps_slice_hdr->u1_slice_type;

    WORD8 i1_cabac_init_idc = 0;

    bin_ctxt_model *au1_cabac_ctxt_table = ps_cabac_ctxt->au1_cabac_ctxt_table;

    UWORD8 u1_qp_y = ps_slice_hdr->i1_slice_qp;

    ih264e_init_cabac_enc_envirnoment(&ps_cabac_ctxt->s_cab_enc_env);

    ps_cabac_ctxt->i1_prev_mb_qp_delta_ctxt = 0;

    if (ISLICE != u1_slice_type)

    {

        i1_cabac_init_idc = ps_slice_hdr->i1_cabac_init_idc;

    }

    else

    {

        i1_cabac_init_idc = 3;

    }

    memcpy(au1_cabac_ctxt_table,

           gau1_ih264_cabac_ctxt_init_table[i1_cabac_init_idc][u1_qp_y],

           NUM_CABAC_CTXTS * sizeof(bin_ctxt_model));

}