xref: /aosp_15_r20/external/libavc/encoder/ih264e_cabac_structs.h (revision 495ae853bb871d1e5a258cb02c2cc13cde8ddb9a)

/******************************************************************************
 *
 * 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_structs.h
*
* @brief
*  This file contains structure definitions necessary for cabac encoding
*
* @author
*  ittiam
*
* @remarks
*  none
*
*******************************************************************************
*/

#ifndef _IH264E_CABAC_STRUCTS_H_
#define _IH264E_CABAC_STRUCTS_H_


/*****************************************************************************/
/* Constant Macros                                                           */
/*****************************************************************************/

#define CABAC_INIT_IDC 2


/*****************************************************************************/
/* Structures                                                                */
/*****************************************************************************/

/**
*******************************************************************************
*  @brief     typedef for  context model
*******************************************************************************
*/

/* bits 0 to 5 :state
   bit 6       :mps */
typedef UWORD8 bin_ctxt_model;

/**
*******************************************************************************
*  @brief      MB info for cabac
*******************************************************************************
*/
typedef struct
{
    /* Neighbour availability Variables needed to get CtxtInc, for CABAC */
    UWORD8 u1_mb_type; /* !< macroblock type: I/P/B/SI/SP */

    UWORD8 u1_cbp; /* !< Coded Block Pattern */
    UWORD8 u1_intrapred_chroma_mode;

    /*************************************************************************/
    /*               Arrangnment of AC CSBP                                  */
    /*        bits:  b7 b6 b5 b4 b3 b2 b1 b0                                 */
    /*        CSBP:  V1 V0 U1 U0 Y3 Y2 Y1 Y0                                 */
    /*************************************************************************/
    UWORD8 u1_yuv_ac_csbp;

    /*************************************************************************/
    /*               Arrangnment of DC CSBP                                  */
    /*        bits:  b7  b6  b5  b4  b3  b2  b1  b0                          */
    /*        CSBP:   x   x   x   x   x  Vdc Udc Ydc                         */
    /*************************************************************************/
    UWORD8 u1_yuv_dc_csbp;

    WORD8 i1_ref_idx[4];
    UWORD8 u1_mv[4][4];

} mb_info_ctxt_t;


/**
*******************************************************************************
*  @brief      CSBP info for CABAC
*******************************************************************************
*/
typedef struct
{
    /*************************************************************************/
    /*               Arrangnment of Luma AC CSBP for leftMb                  */
    /*        bits:  b7 b6 b5 b4 b3 b2 b1 b0                                 */
    /*        CSBP:   X  X  X  X Y3 Y2 Y1 Y0                                 */
    /*************************************************************************/
    /*************************************************************************/
    /*  Points either to u1_y_ac_csbp_top_mb or  u1_y_ac_csbp_bot_mb         */
    /*************************************************************************/
    UWORD8 u1_y_ac_csbp_top_mb;
    UWORD8 u1_y_ac_csbp_bot_mb;

    /*************************************************************************/
    /*               Arrangnment of Chroma AC CSBP for leftMb                */
    /*        bits:  b7 b6 b5 b4 b3 b2 b1 b0                                 */
    /*        CSBP:   X  X  X  X V1 V0 U1 U0                                 */
    /*************************************************************************/
    /*************************************************************************/
    /*  Points either to u1_uv_ac_csbp_top_mb or  u1_uv_ac_csbp_bot_mb       */
    /*************************************************************************/
    UWORD8 u1_uv_ac_csbp_top_mb;
    UWORD8 u1_uv_ac_csbp_bot_mb;

    /*************************************************************************/
    /*               Arrangnment of DC CSBP                                  */
    /*        bits:  b7  b6  b5  b4  b3  b2  b1  b0                          */
    /*        CSBP:   x   x   x   x   x  Vdc Udc Ydc                         */
    /*************************************************************************/
    /*************************************************************************/
    /*  Points either to u1_yuv_dc_csbp_top_mb or  u1_yuv_dc_csbp_bot_mb     */
    /*************************************************************************/
    UWORD8 u1_yuv_dc_csbp_top_mb;
    UWORD8 u1_yuv_dc_csbp_bot_mb;

} cab_csbp_t;

/**
*******************************************************************************
*  @brief      CABAC Encoding Environment
*******************************************************************************
*/
typedef struct
{
    /**
     * cabac interval start L
     */
    UWORD32 u4_code_int_low;

    /**
     * cabac interval range R
     */
    UWORD32 u4_code_int_range;

    /** bytes_outsanding; number of 0xFF bits that occur during renorm
     *  These  will be accumulated till the carry bit is knwon
     */
    UWORD32  u4_out_standing_bytes;

    /** bits generated during renormalization
     *   A byte is put to stream/u4_out_standing_bytes from u4_low(L) when
     *   u4_bits_gen exceeds 8
     */
    UWORD32  u4_bits_gen;

} encoding_envirnoment_t;


/**
*******************************************************************************
*  @brief      CABAC Context structure : Variables to handle Cabac
*******************************************************************************
*/
typedef struct
{

    /**
     * Base pointer to all the cabac contexts
     */
    bin_ctxt_model au1_cabac_ctxt_table[NUM_CABAC_CTXTS];

    /**
     * left csbp
     */
    cab_csbp_t s_lft_csbp;

    /**
     * pointer to Bitstream structure
     */
    bitstrm_t *ps_bitstrm;

    /**
     * Pointer to mb_info_ctxt_t map_base
     */
    mb_info_ctxt_t *ps_mb_map_ctxt_inc_base;

    /**
     * Pointer to encoding_envirnoment_t
     */
    encoding_envirnoment_t s_cab_enc_env;

    /* These things need to be updated at each MbLevel */
    /**
     * Prev mb_qp_delta_ctxt
     */
    WORD8 i1_prev_mb_qp_delta_ctxt;

    /**
     * Pointer to mb_info_ctxt_t map
     */
    mb_info_ctxt_t *ps_mb_map_ctxt_inc;

    /**
     * Pointer to default mb_info_ctxt_t
     */
    mb_info_ctxt_t *ps_def_ctxt_mb_info;

    /**
     * Pointer to current mb_info_ctxt_t
     */
    mb_info_ctxt_t *ps_curr_ctxt_mb_info;

    /**
     * Pointer to left mb_info_ctxt_t
     */
    mb_info_ctxt_t *ps_left_ctxt_mb_info;

    /**
     * Pointer to top mb_info_ctxt_t
     */
    mb_info_ctxt_t *ps_top_ctxt_mb_info;

    /**
     * Pointer to csbp structures
     */
    cab_csbp_t *ps_lft_csbp;
    UWORD8 *pu1_left_y_ac_csbp;
    UWORD8 *pu1_left_uv_ac_csbp;
    UWORD8 *pu1_left_yuv_dc_csbp;

    /**************************************************************************/
    /*       Ref_idx contexts  are stored in the following way                */
    /*  Array Idx 0,1 for reference indices in Forward direction              */
    /*  Array Idx 2,3 for reference indices in backward direction             */
    /**************************************************************************/
    /**
     * Dimensions for u1_left_ref_ctxt_inc_arr is [2][4] for Mbaff:Top and Bot
     */
    WORD8 i1_left_ref_idx_ctx_inc_arr[2][4];
    WORD8 *pi1_left_ref_idx_ctxt_inc;

    /**
     * Dimensions for u1_left_mv_ctxt_inc_arr is [2][4][4] for Mbaff case
     */
    UWORD8 u1_left_mv_ctxt_inc_arr[2][4][4];
    UWORD8 (*pu1_left_mv_ctxt_inc)[4];

} cabac_ctxt_t;

#endif /* _IH264E_CABAC_STRUCTS_H_ */