xref: /aosp_15_r20/external/libhevc/encoder/vbr_storage_vbv.c (revision c83a76b084498d55f252f48b2e3786804cdf24b7)

/******************************************************************************
 *
 * Copyright (C) 2018 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 vbr_storage_vbv.c
*
* \brief
*    This file contain functions related to VBV buffer
*
* \date
*
* \author
*    ittiam
*
******************************************************************************
*/
/*****************************************************************************/
/* File Includes                                                             */
/*****************************************************************************/
/* System include files */
#include <stdio.h>

/* User include files */
#include "ittiam_datatypes.h"
#include "mem_req_and_acq.h"
#include "rc_common.h"
#include "rc_cntrl_param.h"
#include "var_q_operator.h"
#include "fixed_point_error_bits.h"
#include "cbr_buffer_control.h"
#include "rc_rd_model.h"
#include "est_sad.h"
#include "cbr_buffer_control.h"
#include "picture_type.h"
#include "bit_allocation.h"
#include "vbr_storage_vbv.h"
#include "trace_support.h"

#define MAX(x, y) ((x) > (y) ? (x) : (y))

typedef struct vbr_storage_vbv_t
{
    WORD32 i4_max_buf_size;
    WORD32 i4_cur_buf_size;
    WORD32 i4_max_bits_inflow_per_frm_period;
    /* Storing input variables */
    WORD32 i4_max_bit_rate;
    WORD32 i4_max_frame_rate;
    /* Error bits calculation module */
    error_bits_handle ps_error_bits;
} vbr_storage_vbv_t;

#if NON_STEADSTATE_CODE

WORD32 vbr_vbv_num_fill_use_free_memtab(
    vbr_storage_vbv_t **pps_vbr_storage_vbv, itt_memtab_t *ps_memtab, ITT_FUNC_TYPE_E e_func_type)
{
    WORD32 i4_mem_tab_idx = 0;
    static vbr_storage_vbv_t s_vbr_storage_vbv_temp;

    /* Hack for al alloc, during which we dont have any state memory.
      Dereferencing can cause issues */
    if(e_func_type == GET_NUM_MEMTAB || e_func_type == FILL_MEMTAB)
        (*pps_vbr_storage_vbv) = &s_vbr_storage_vbv_temp;

    /*for src rate control state structure*/
    if(e_func_type != GET_NUM_MEMTAB)
    {
        fill_memtab(
            &ps_memtab[i4_mem_tab_idx],
            sizeof(vbr_storage_vbv_t),
            MEM_TAB_ALIGNMENT,
            PERSISTENT,
            DDR);
        use_or_fill_base(&ps_memtab[0], (void **)pps_vbr_storage_vbv, e_func_type);
    }
    i4_mem_tab_idx++;

    i4_mem_tab_idx += error_bits_num_fill_use_free_memtab(
        &pps_vbr_storage_vbv[0]->ps_error_bits, &ps_memtab[i4_mem_tab_idx], e_func_type);
    return (i4_mem_tab_idx);
}
/******************************************************************************
  Function Name   : init_vbr_vbv
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
void init_vbr_vbv(
    vbr_storage_vbv_t *ps_vbr_storage_vbv,
    WORD32 i4_max_bit_rate,
    WORD32 i4_frm_rate,
    WORD32 i4_max_vbv_buff_size)
{
    ps_vbr_storage_vbv->i4_max_buf_size = i4_max_vbv_buff_size;
    ps_vbr_storage_vbv->i4_cur_buf_size = i4_max_vbv_buff_size;

    /* Calculate the max number of bits that flow into the decoder
    in the interval of two frames */
    X_PROD_Y_DIV_Z(
        i4_max_bit_rate, 1000, i4_frm_rate, ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period);

    /* init error bits */
    init_error_bits(ps_vbr_storage_vbv->ps_error_bits, i4_frm_rate, i4_max_bit_rate);

    /* Storing the input values */
    ps_vbr_storage_vbv->i4_max_bit_rate = i4_max_bit_rate;
    ps_vbr_storage_vbv->i4_max_frame_rate = i4_frm_rate;
}
#endif /* #if NON_STEADSTATE_CODE */
/******************************************************************************
  Function Name   : update_vbr_vbv
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
void update_vbr_vbv(vbr_storage_vbv_t *ps_vbr_storage_vbv, WORD32 i4_total_bits_decoded)
{
    WORD32 i4_error_bits = get_error_bits(ps_vbr_storage_vbv->ps_error_bits);
    /* In the time interval between two decoded frames the buffer would have been
       filled up by the max_bits_inflow_per_frm_period.*/
    overflow_avoided_summation(
        &ps_vbr_storage_vbv->i4_cur_buf_size,
        (ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period + i4_error_bits));

    if(ps_vbr_storage_vbv->i4_cur_buf_size > ps_vbr_storage_vbv->i4_max_buf_size)
    {
        ps_vbr_storage_vbv->i4_cur_buf_size = ps_vbr_storage_vbv->i4_max_buf_size;
    }

    ps_vbr_storage_vbv->i4_cur_buf_size -= i4_total_bits_decoded;

    /* Update the error bits state */
    update_error_bits(ps_vbr_storage_vbv->ps_error_bits);

#define PRINT_UNDERFLOW 0
#if PRINT_UNDERFLOW
    if(ps_vbr_storage_vbv->i4_cur_buf_size < 0)
        printf("The buffer underflows \n");
#endif
}
/******************************************************************************
  Function Name   : get_max_target_bits
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
WORD32 get_max_target_bits(vbr_storage_vbv_t *ps_vbr_storage_vbv)
{
    WORD32 i4_cur_buf_size = ps_vbr_storage_vbv->i4_cur_buf_size;
    WORD32 i4_error_bits = get_error_bits(ps_vbr_storage_vbv->ps_error_bits);

    /* The buffer size when the next frame is decoded */
    overflow_avoided_summation(
        &i4_cur_buf_size, (ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period + i4_error_bits));
    if(i4_cur_buf_size > ps_vbr_storage_vbv->i4_max_buf_size)
    {
        i4_cur_buf_size = ps_vbr_storage_vbv->i4_max_buf_size;
    }

    /* Thus for the next frame the maximum number of bits the decoder can consume
    without underflow is i4_cur_buf_size */
    return i4_cur_buf_size;
}

/****************************************************************************
Function Name : get_buffer_status
Description   : Gets the state of VBV buffer
Inputs        : Rate control API , header and texture bits
Globals       :
Processing    :
Outputs       : 0 = normal, 1 = underflow, 2= overflow
Returns       : vbv_buf_status_e
Issues        :
Revision History:
DD MM YYYY   Author(s)       Changes (Describe the changes made)
*****************************************************************************/
vbv_buf_status_e get_vbv_buffer_status(
    vbr_storage_vbv_t *ps_vbr_storage_vbv,
    WORD32 i4_total_frame_bits, /* Total frame bits consumed */
    WORD32 *pi4_num_bits_to_prevent_vbv_underflow) /* The curent buffer status after updation */
{
    vbv_buf_status_e e_buf_status;
    WORD32 i4_cur_buf;
    WORD32 i4_error_bits = get_error_bits(ps_vbr_storage_vbv->ps_error_bits);

    /* error bits due to fixed point computation of drain rate*/
    i4_cur_buf = ps_vbr_storage_vbv->i4_cur_buf_size;
    overflow_avoided_summation(
        &i4_cur_buf, (ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period + i4_error_bits));

    if(i4_cur_buf > ps_vbr_storage_vbv->i4_max_buf_size)
    {
        i4_cur_buf = ps_vbr_storage_vbv->i4_max_buf_size;
    }

    pi4_num_bits_to_prevent_vbv_underflow[0] = i4_cur_buf;

    i4_cur_buf -= i4_total_frame_bits;
    if(i4_cur_buf < 0)
    {
        e_buf_status = VBV_UNDERFLOW;
    }
    else if(i4_cur_buf > ps_vbr_storage_vbv->i4_max_buf_size)
    {
        e_buf_status = VBV_OVERFLOW;
    }
    else if(i4_cur_buf < (ps_vbr_storage_vbv->i4_max_buf_size >> 2))
    {
        e_buf_status = VBR_CAUTION;
    }
    else
    {
        e_buf_status = VBV_NORMAL;
    }

    return e_buf_status;
}
/******************************************************************************
  Function Name   : get_max_vbv_buf_size
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
WORD32 get_max_vbv_buf_size(vbr_storage_vbv_t *ps_vbr_storage_vbv)
{
    return (ps_vbr_storage_vbv->i4_max_buf_size);
}
/******************************************************************************
  Function Name   : get_cur_vbv_buf_size
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
WORD32 get_cur_vbv_buf_size(vbr_storage_vbv_t *ps_vbr_storage_vbv)
{
    return (ps_vbr_storage_vbv->i4_cur_buf_size);
}
/******************************************************************************
  Function Name   : get_max_bits_inflow_per_frm_periode
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
WORD32 get_max_bits_inflow_per_frm_periode(vbr_storage_vbv_t *ps_vbr_storage_vbv)
{
    return (ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period);
}

/******************************************************************************
  Function Name   : get_vbv_buf_fullness
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
WORD32 get_vbv_buf_fullness(vbr_storage_vbv_t *ps_vbr_storage_vbv, UWORD32 u4_bits)
{
    WORD32 i4_error_bits = get_error_bits(ps_vbr_storage_vbv->ps_error_bits);
    WORD32 i4_cur_buf_size = ps_vbr_storage_vbv->i4_cur_buf_size;

    overflow_avoided_summation(
        &i4_cur_buf_size, (ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period + i4_error_bits));

    if(i4_cur_buf_size > ps_vbr_storage_vbv->i4_max_buf_size)
    {
        i4_cur_buf_size = ps_vbr_storage_vbv->i4_max_buf_size;
    }

    i4_cur_buf_size -= u4_bits;

#if PRINT_UNDERFLOW
    if(i4_cur_buf_size < 0)
        printf("The buffer underflows \n");
#endif
    return (i4_cur_buf_size);
}
/******************************************************************************
  Function Name   : get_max_tgt_bits_dvd_comp
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
WORD32 get_max_tgt_bits_dvd_comp(
    vbr_storage_vbv_t *ps_vbr_storage_vbv,
    WORD32 i4_rem_bits_in_gop,
    WORD32 i4_rem_frms_in_gop,
    picture_type_e e_pic_type)
{
    WORD32 i4_dbf_max, i4_dbf_min, i4_dbf_prev, i4_vbv_size, i4_dbf_desired;
    WORD32 i4_max_tgt_bits;

    i4_vbv_size = ps_vbr_storage_vbv->i4_max_buf_size;
    i4_dbf_max = 95 * i4_vbv_size / 100;
    i4_dbf_min = 10 * i4_vbv_size / 100;
    i4_dbf_prev = ps_vbr_storage_vbv->i4_cur_buf_size;

    if(i4_rem_bits_in_gop < 0)
        i4_rem_bits_in_gop = 0;
    if(i4_rem_frms_in_gop <= 0)
        i4_rem_frms_in_gop = 1;

    if(e_pic_type == I_PIC)
    {
        i4_dbf_desired = i4_dbf_min;
    }
    else
    {
        i4_dbf_desired = (i4_dbf_max - i4_rem_bits_in_gop / i4_rem_frms_in_gop - i4_dbf_prev) /
                         i4_rem_frms_in_gop;
        i4_dbf_desired += i4_dbf_prev;
    }

    i4_dbf_prev += ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period;
    if(i4_dbf_prev > ps_vbr_storage_vbv->i4_max_buf_size)
    {
        i4_dbf_prev = ps_vbr_storage_vbv->i4_max_buf_size;
    }

    i4_max_tgt_bits = MAX(0, (i4_dbf_prev - i4_dbf_desired));
    return (i4_max_tgt_bits);
}

#if NON_STEADSTATE_CODE
/******************************************************************************
  Function Name   : change_vbr_vbv_frame_rate
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
void change_vbr_vbv_frame_rate(vbr_storage_vbv_t *ps_vbr_storage_vbv, WORD32 i4_frm_rate)
{
    /* Calculate the max number of bits that flow into the decoder
    in the interval of two frames */
    X_PROD_Y_DIV_Z(
        ps_vbr_storage_vbv->i4_max_bit_rate,
        1000,
        i4_frm_rate,
        ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period);

    /* update the lower modules */
    change_frm_rate_in_error_bits(ps_vbr_storage_vbv->ps_error_bits, i4_frm_rate);
    /* Storing the input values */
    ps_vbr_storage_vbv->i4_max_frame_rate = i4_frm_rate;
}
/******************************************************************************
  Function Name   : change_vbr_vbv_bit_rate
  Description     :
  Arguments       : ps_vbr_storage_vbv
  Return Values   : void
  Revision History:
                    Creation
*****************************************************************************/
void change_vbr_vbv_bit_rate(vbr_storage_vbv_t *ps_vbr_storage_vbv, WORD32 i4_max_bit_rate)
{
    /* Calculate the max number of bits that flow into the decoder
    in the interval of two frames */
    X_PROD_Y_DIV_Z(
        i4_max_bit_rate,
        1000,
        ps_vbr_storage_vbv->i4_max_frame_rate,
        ps_vbr_storage_vbv->i4_max_bits_inflow_per_frm_period);

    /* update the lower modules */
    change_bitrate_in_error_bits(ps_vbr_storage_vbv->ps_error_bits, i4_max_bit_rate);

    /* Storing the input values */
    ps_vbr_storage_vbv->i4_max_bit_rate = i4_max_bit_rate;
}
#endif /* #if NON_STEADSTATE_CODE */