/******************************************************************************
*
* 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 cbr_buffer_control.c
*
* \brief
* This file contains all functions needed for cbr buffer control
* \date
* 06/05/2008
*
* \author
* ittiam
*
* \List of Functions
* init_cbr_buffer
* cbr_buffer_constraint_check
* get_cbr_buffer_status
* update_cbr_buffer
*
******************************************************************************
*/
/*****************************************************************************/
/* File Includes */
/*****************************************************************************/
/* System include files */
#include <stdio.h>
/* User include files */
#include "assert.h"
#include "ittiam_datatypes.h"
#include "rc_cntrl_param.h"
#include "rc_common.h"
#include "mem_req_and_acq.h"
#include "fixed_point_error_bits.h"
#include "cbr_buffer_control.h"
#include "trace_support.h"
#include "var_q_operator.h"
#define MIN(x, y) ((x) < (y)) ? (x) : (y)
/*allow a maximum of 20 percent deviation when input is very large*/
#define VBR_MAX_BIT_DEV_SEC 50LL
typedef struct cbr_buffer_t
{
WORD32 i4_buffer_size; /* Buffer size = Delay * Bitrate*/
WORD32
i4_drain_bits_per_frame[MAX_NUM_DRAIN_RATES]; /* Constant drain rate */
WORD32 i4_ebf; /* Encoder Buffer Fullness */
LWORD64
i8_ebf_bit_alloc; /* current encoder buffer fulness that accounts precise bit consumption (not truncated to max buffer size at skip)*/
LWORD64 i8_credit_level;
WORD32 i4_upr_thr[MAX_PIC_TYPE]; /* Upper threshold of the Buffer */
WORD32 i4_low_thr[MAX_PIC_TYPE]; /* Lower threshold of the Buffer */
error_bits_handle
aps_bpf_error_bits[MAX_NUM_DRAIN_RATES]; /* For error due to bits per frame calculation */
WORD32
i4_is_cbr_mode; /* Whether the buffer model is used for CBR or VBR streaming */
/* Input parameters stored for initialisation */
WORD32 ai4_bit_rate[MAX_NUM_DRAIN_RATES];
WORD32 i4_max_delay;
WORD32 ai4_num_pics_in_delay_period[MAX_PIC_TYPE];
WORD32 i4_tgt_frm_rate;
UWORD32 u4_max_vbv_buf_size;
WORD32 i4_peak_drain_rate_frame;
WORD32 u4_num_frms_in_delay;
UWORD32 u4_vbr_max_bit_deviation;
rc_type_e e_rc_type;
WORD32 i4_vbr_no_peak_rate_duration_limit;
LWORD64 i8_tot_frm_to_be_encoded;
LWORD64
i8_num_frames_encoded; /*need to track the number of frames encoded to calculate possible deviaiton allowed*/
WORD32 i4_cbr_rc_pass;
WORD32 i4_inter_frame_int;
WORD32 i4_intra_frame_int;
WORD32 i4_capped_vbr_on;
float f_max_dur_peak_rate;
LWORD64 i4_ebf_estimate;
} cbr_buffer_t;
#if NON_STEADSTATE_CODE
WORD32 cbr_buffer_num_fill_use_free_memtab(
cbr_buffer_t **pps_cbr_buffer, itt_memtab_t *ps_memtab, ITT_FUNC_TYPE_E e_func_type)
{
WORD32 i4_mem_tab_idx = 0, i;
static cbr_buffer_t s_cbr_buffer_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_cbr_buffer) = &s_cbr_buffer_temp;
if(e_func_type != GET_NUM_MEMTAB)
{
fill_memtab(
&ps_memtab[i4_mem_tab_idx], sizeof(cbr_buffer_t), MEM_TAB_ALIGNMENT, PERSISTENT, DDR);
use_or_fill_base(&ps_memtab[0], (void **)pps_cbr_buffer, e_func_type);
}
i4_mem_tab_idx++;
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
{
i4_mem_tab_idx += error_bits_num_fill_use_free_memtab(
&pps_cbr_buffer[0]->aps_bpf_error_bits[i], &ps_memtab[i4_mem_tab_idx], e_func_type);
}
return (i4_mem_tab_idx);
}
static void set_upper_lower_vbv_threshold(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_bits_per_frm)
{
WORD32 i;
for(i = 0; i < MAX_PIC_TYPE; i++)
{
ps_cbr_buffer->i4_upr_thr[i] =
(WORD32)(((LWORD64)ps_cbr_buffer->i4_buffer_size >> 4) * UPPER_THRESHOLD_EBF_Q4);
if(ps_cbr_buffer->e_rc_type == VBR_STREAMING)
{
/*lower threshold can be zero as there is no problem of studffing in this mode (VBR STORAGE)*/
if(ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit)
ps_cbr_buffer->i4_low_thr[i] = 0;
else
ps_cbr_buffer->i4_low_thr[i] = ps_cbr_buffer->i4_inter_frame_int * i4_bits_per_frm;
}
else
{
if(ps_cbr_buffer->i4_inter_frame_int == 1)
ps_cbr_buffer->i4_low_thr[i] = 0;
else
{
ps_cbr_buffer->i4_low_thr[i] = ps_cbr_buffer->i4_inter_frame_int * i4_bits_per_frm;
}
}
/*For huge buffer low limit can be higher*/
if(ps_cbr_buffer->i4_low_thr[i] < (ps_cbr_buffer->i4_buffer_size >> 6))
ps_cbr_buffer->i4_low_thr[i] = (ps_cbr_buffer->i4_buffer_size >> 6);
if(ps_cbr_buffer->i4_low_thr[i] > (ps_cbr_buffer->i4_buffer_size >> 3)) //KISH_DEBUG
ps_cbr_buffer->i4_low_thr[i] = (ps_cbr_buffer->i4_buffer_size >> 3);
ASSERT(ps_cbr_buffer->i4_upr_thr[i] > ps_cbr_buffer->i4_low_thr[i]);
}
}
/* ******************************************************************************/
/**
* @brief Initialise the CBR VBV buffer state.
* This could however be used for VBR streaming VBV also
*
* @param ps_cbr_buffer
* @param i4_buffer_delay
* @param i4_tgt_frm_rate
* @param i4_bit_rate
* @param u4_num_pics_in_delay_prd
* @param u4_vbv_buf_size
*/
/* ******************************************************************************/
void init_cbr_buffer(
cbr_buffer_t *ps_cbr_buffer,
WORD32 i4_buffer_delay,
WORD32 i4_tgt_frm_rate,
UWORD32 u4_bit_rate,
UWORD32 *u4_num_pics_in_delay_prd,
UWORD32 u4_vbv_buf_size,
UWORD32 u4_intra_frm_int,
rc_type_e e_rc_type,
UWORD32 u4_peak_bit_rate,
UWORD32 u4_num_frames_in_delay,
float f_max_dur_peak_rate,
LWORD64 i8_num_frames_to_encode,
WORD32 i4_inter_frm_int,
WORD32 i4_cbr_rc_pass,
WORD32 i4_capped_vbr_flag)
{
WORD32 i4_bits_per_frm[MAX_NUM_DRAIN_RATES];
int i;
/* Initially Encoder buffer fullness is zero */
ps_cbr_buffer->i4_ebf = 0;
ps_cbr_buffer->i4_ebf_estimate = 0;
ps_cbr_buffer->i8_ebf_bit_alloc = 0;
ps_cbr_buffer->i8_credit_level = 0;
ps_cbr_buffer->e_rc_type = e_rc_type;
ps_cbr_buffer->i4_capped_vbr_on = i4_capped_vbr_flag;
/*If this is set to 1, it acts similar to storage VBR which allows peak rate to be sustained for infinite duration*/
ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit = 0;
ps_cbr_buffer->i8_num_frames_encoded = 0;
ps_cbr_buffer->i8_tot_frm_to_be_encoded = i8_num_frames_to_encode;
ps_cbr_buffer->i4_cbr_rc_pass = i4_cbr_rc_pass;
ps_cbr_buffer->i4_inter_frame_int = i4_inter_frm_int;
ps_cbr_buffer->i4_intra_frame_int = u4_intra_frm_int;
ps_cbr_buffer->f_max_dur_peak_rate = f_max_dur_peak_rate;
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
{
X_PROD_Y_DIV_Z(u4_bit_rate, 1000, i4_tgt_frm_rate, i4_bits_per_frm[i]);
/* Drain rate = bitrate/(framerate/1000) */
ps_cbr_buffer->i4_drain_bits_per_frame[i] = i4_bits_per_frm[i];
/* initialise the bits per frame error bits calculation */
init_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i], i4_tgt_frm_rate, u4_bit_rate);
}
/* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/
if(e_rc_type == CBR_NLDRC) /* This would mean CBR mode */
{
//buffer size should be independent of initial delay
//X_PROD_Y_DIV_Z(u4_bit_rate,i4_buffer_delay,1000,ps_cbr_buffer->i4_buffer_size);
ps_cbr_buffer->i4_buffer_size = (WORD32)u4_vbv_buf_size;
ps_cbr_buffer->i4_is_cbr_mode = 1;
ps_cbr_buffer->i4_peak_drain_rate_frame = i4_bits_per_frm[0];
/*In CBR the max file size deviaiton allowed is specified by buffer size*/
ps_cbr_buffer->u4_vbr_max_bit_deviation = ps_cbr_buffer->i4_buffer_size;
}
else if(e_rc_type == VBR_STREAMING)
{
/*this is raw vbv buffer size, also initilize the buffer window to bit alloc (credit limit)*/
ps_cbr_buffer->i4_buffer_size = (WORD32)u4_vbv_buf_size;
/*if there is no limit on duration for which peak bitrate can be sustained, bits can be moved from any region to other region
giving better quality*/
if(f_max_dur_peak_rate < 0)
ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit = 1;
/*To avoid file size deviation in case of VBR mode of rate control, clip the max deviaiton allowed based on number of frames to enode*/
{
ULWORD64 u8_vbr_max_bit_deviation;
ULWORD64 file_size = (ULWORD64)(
(((LWORD64)u4_bit_rate * 1000) / i4_tgt_frm_rate) * i8_num_frames_to_encode);
/*When f_max_dur_peak_rate is -ve, it implies user is not worried about duration for which peak is sustained, hence go with max possible value*/
if(f_max_dur_peak_rate > 0)
u8_vbr_max_bit_deviation = (ULWORD64)(f_max_dur_peak_rate * u4_bit_rate);
else
u8_vbr_max_bit_deviation = (ULWORD64)(VBR_MAX_BIT_DEV_SEC * u4_bit_rate);
/*when num frames to encode is negative is -ve it implies total frames data is not available (as in case of live encoding)*/
if(i8_num_frames_to_encode > 0)
{
/*allow atleast one second deviation or 12% of total file size whichever is higher*/
if(u8_vbr_max_bit_deviation > (file_size >> 3))
u8_vbr_max_bit_deviation = (UWORD32)(file_size >> 3);
/*allow atleast one second for shorter sequence*/
if(u8_vbr_max_bit_deviation < u4_bit_rate)
u8_vbr_max_bit_deviation = u4_bit_rate;
}
else
{
/*the data of number of frames to be encoded is not available*/
/*start off with one second delay, this will be later adjusted once large number of frames are encoded*/
u8_vbr_max_bit_deviation = u4_bit_rate;
}
ps_cbr_buffer->u4_vbr_max_bit_deviation = u8_vbr_max_bit_deviation;
}
ps_cbr_buffer->i4_is_cbr_mode = 0;
X_PROD_Y_DIV_Z(
u4_peak_bit_rate, 1000, i4_tgt_frm_rate, ps_cbr_buffer->i4_peak_drain_rate_frame);
}
else
{
/*currently only two modes are supported*/
ASSERT(e_rc_type == CONST_QP);
}
if(ps_cbr_buffer->i4_buffer_size > (WORD32)u4_vbv_buf_size)
{
ps_cbr_buffer->i4_buffer_size = u4_vbv_buf_size;
}
/* Uppr threshold for
I frame = 1 * bits per frame
P Frame = 4 * bits per frame.
The threshold for I frame is only 1 * bits per frame as the threshold should
only account for error in estimated bits.
In P frame it should account for difference bets bits consumed by I(Scene change)
and P frame I to P complexity is assumed to be 5. */
/*HEVC_hierarchy*/
if(e_rc_type != CONST_QP)
set_upper_lower_vbv_threshold(ps_cbr_buffer, i4_bits_per_frm[0]);
/* Storing the input parameters for using it for change functions */
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
ps_cbr_buffer->ai4_bit_rate[i] = u4_bit_rate;
for(i = 0; i < MAX_PIC_TYPE; i++)
{
ps_cbr_buffer->ai4_num_pics_in_delay_period[i] = u4_num_pics_in_delay_prd[i];
}
ps_cbr_buffer->i4_tgt_frm_rate = i4_tgt_frm_rate;
ps_cbr_buffer->i4_max_delay = i4_buffer_delay;
ps_cbr_buffer->u4_max_vbv_buf_size = u4_vbv_buf_size;
ps_cbr_buffer->u4_num_frms_in_delay = u4_num_frames_in_delay;
}
#endif /* #if NON_STEADSTATE_CODE */
/* ******************************************************************************/
/**
* @brief Condition check for constrining the number of bits allocated based on bufer size
*
* @param ps_cbr_buffer
* @param i4_tgt_bits
* @param e_pic_type
*
* @return
*/
/* ******************************************************************************/
WORD32 cbr_buffer_constraint_check(
cbr_buffer_t *ps_cbr_buffer,
WORD32 i4_tgt_bits,
picture_type_e e_pic_type,
WORD32 *pi4_max_tgt_bits,
WORD32 *pi4_min_tgt_bits)
{
WORD32 i4_max_tgt_bits, i4_min_tgt_bits;
WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC)
? ps_cbr_buffer->i4_drain_bits_per_frame[0]
: ps_cbr_buffer->i4_drain_bits_per_frame[1];
WORD32 i4_error_bits = (e_pic_type == I_PIC)
? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0])
: get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]);
/*trace_printf(" ebf = %d bebf = %d ",ps_cbr_buffer->i4_ebf,ps_cbr_buffer->i8_ebf_bit_alloc);*/
/* Max tgt bits = Upper threshold - current encoder buffer fullness */
i4_max_tgt_bits =
(WORD32)(ps_cbr_buffer->i4_upr_thr[e_pic_type] - ps_cbr_buffer->i4_ebf_estimate);
/* Max tgt bits cannot be negative */
if(i4_max_tgt_bits < 0)
i4_max_tgt_bits = 0;
/* Min tgt bits , least number of bits in the Encoder after
draining such that it is greater than lower threshold */
i4_min_tgt_bits = (WORD32)(
ps_cbr_buffer->i4_low_thr[e_pic_type] -
(ps_cbr_buffer->i4_ebf_estimate - i4_drain_bits_per_frame - i4_error_bits));
/*Min tgt bits cannot be negative*/
if(i4_min_tgt_bits < 0)
i4_min_tgt_bits = 0;
/* current tgt bits should be between max and min tgt bits*/
CLIP(i4_tgt_bits, i4_max_tgt_bits, i4_min_tgt_bits);
pi4_min_tgt_bits[0] = i4_min_tgt_bits;
pi4_max_tgt_bits[0] = i4_max_tgt_bits;
return i4_tgt_bits;
}
/* ******************************************************************************/
/**
* @brief constaints the bit allocation based on buffer size
*
* @param ps_cbr_buffer
* @param i4_tgt_bits
* @param e_pic_type
*
* @return
*/
/* ******************************************************************************/
WORD32 vbr_stream_buffer_constraint_check(
cbr_buffer_t *ps_cbr_buffer,
WORD32 i4_tgt_bits,
picture_type_e e_pic_type,
WORD32 *pi4_max_bits,
WORD32 *pi4_min_bits)
{
WORD32 i4_max_tgt_bits, i4_min_tgt_bits = 0;
/* Max tgt bits = Upper threshold - current encoder buffer fullness */
/*maximum target for a pic is amount of bits that can be transmitted to decoder buffer in delay assuming max drain rate
This above limit has to be constrained wrt a single frame being accomodated in the buffer*/
i4_max_tgt_bits = (WORD32)(
(ps_cbr_buffer->u4_num_frms_in_delay * ps_cbr_buffer->i4_peak_drain_rate_frame) -
ps_cbr_buffer->i4_ebf_estimate);
/*the below check is necessary to make sure that a single frame to be accomodated in encoder buffer*/
if(i4_max_tgt_bits > ps_cbr_buffer->i4_upr_thr[e_pic_type] - ps_cbr_buffer->i4_ebf_estimate)
{
i4_max_tgt_bits =
(WORD32)(ps_cbr_buffer->i4_upr_thr[e_pic_type] - ps_cbr_buffer->i4_ebf_estimate);
}
/*In VBR streaming though encoder buffer underflow is not a problem, at any point of time the bitrate underconsumption
cannot go below specified limit. Hence it is limited based on possible bitrate deviation allowed*/
/*Enabling movement of stuffing bits always*/
if(ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit)
{
/*If the content has underconsumed force it to consume atleast per frame bits so that end of encoding there wont be too much undersonsumption*/
if(ps_cbr_buffer->i8_ebf_bit_alloc < 0 && ps_cbr_buffer->i4_cbr_rc_pass != 2)
i4_min_tgt_bits = (ps_cbr_buffer->i4_drain_bits_per_frame[0] >> 1);
}
else
{
/*In this case buffer is always guranteed to be positive, to avoid stuffing give decent amount of min bits*/
i4_min_tgt_bits = (WORD32)(ps_cbr_buffer->i4_low_thr[0] - ps_cbr_buffer->i8_ebf_bit_alloc);
}
/*Clip min target bit*/
if(i4_min_tgt_bits < 0)
i4_min_tgt_bits = 0;
if(i4_tgt_bits < i4_min_tgt_bits)
i4_tgt_bits = i4_min_tgt_bits;
pi4_min_bits[0] = i4_min_tgt_bits;
/* Max tgt bits cannot be negative */
if(i4_max_tgt_bits < 0)
i4_max_tgt_bits = 0;
if(i4_tgt_bits > i4_max_tgt_bits)
i4_tgt_bits = i4_max_tgt_bits;
pi4_max_bits[0] = i4_max_tgt_bits;
return i4_tgt_bits;
}
/* ******************************************************************************/
/**
* @brief Verifies the buffer state and returns whether it is overflowing, underflowing or normal
*
* @param ps_cbr_buffer
* @param i4_tot_consumed_bits
* @param pi4_num_bits_to_prevent_overflow
* @param e_pic_type
*
* @return
*/
/* ******************************************************************************/
vbv_buf_status_e get_cbr_buffer_status(
cbr_buffer_t *ps_cbr_buffer,
WORD32 i4_tot_consumed_bits,
WORD32 *pi4_num_bits_to_prevent_overflow,
picture_type_e e_pic_type,
rc_type_e e_rc_type)
{
vbv_buf_status_e e_buf_status;
WORD32 i4_cur_enc_buf;
WORD32 i4_error_bits = (e_pic_type == I_PIC)
? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0])
: get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]);
WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC)
? ps_cbr_buffer->i4_drain_bits_per_frame[0]
: ps_cbr_buffer->i4_drain_bits_per_frame[1];
/* Add the tot consumed bits to the Encoder Buffer*/
i4_cur_enc_buf = ps_cbr_buffer->i4_ebf + i4_tot_consumed_bits;
/* If the Encoder exceeds the Buffer Size signal an Overflow*/
if(i4_cur_enc_buf > ps_cbr_buffer->i4_buffer_size)
{
e_buf_status = VBV_OVERFLOW;
i4_cur_enc_buf = ps_cbr_buffer->i4_buffer_size;
}
else
{
/* Subtract the constant drain bits and error bits due to fixed point implementation*/
i4_cur_enc_buf -= (i4_drain_bits_per_frame + i4_error_bits);
if(e_rc_type == VBR_STREAMING)
{
/*In VBR suffing scenerio will not occur*/
if(i4_cur_enc_buf < 0)
i4_cur_enc_buf = 0;
}
/* If the buffer is less than stuffing threshold an Underflow is signaled else its NORMAL*/
if(i4_cur_enc_buf < 0)
{
e_buf_status = VBV_UNDERFLOW;
}
else
{
e_buf_status = VBV_NORMAL;
}
if(i4_cur_enc_buf < 0)
i4_cur_enc_buf = 0;
}
/* The RC lib models the encoder buffer, but the VBV buffer characterises the decoder buffer */
if(e_buf_status == VBV_OVERFLOW)
{
e_buf_status = VBV_UNDERFLOW;
}
else if(e_buf_status == VBV_UNDERFLOW)
{
e_buf_status = VBV_OVERFLOW;
}
pi4_num_bits_to_prevent_overflow[0] = (ps_cbr_buffer->i4_buffer_size - i4_cur_enc_buf);
return e_buf_status;
}
/* ******************************************************************************/
/**
* @brief Based on the bits consumed the buffer model is updated
*
* @param ps_cbr_buffer
* @param i4_tot_consumed_bits
* @param e_pic_type
*/
/* ******************************************************************************/
void update_cbr_buffer(
cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tot_consumed_bits, picture_type_e e_pic_type)
{
WORD32 i;
WORD32 i4_error_bits = (e_pic_type == I_PIC)
? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0])
: get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]);
WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC)
? ps_cbr_buffer->i4_drain_bits_per_frame[0]
: ps_cbr_buffer->i4_drain_bits_per_frame[1];
ps_cbr_buffer->i8_num_frames_encoded++;
if(ps_cbr_buffer->e_rc_type == VBR_STREAMING && ps_cbr_buffer->i8_tot_frm_to_be_encoded < 0)
{
LWORD64 i8_max_bit_dev_allowed = ps_cbr_buffer->ai4_bit_rate[0];
LWORD64 approx_file_size = ps_cbr_buffer->i8_num_frames_encoded *
ps_cbr_buffer->ai4_bit_rate[0] * 1000 /
ps_cbr_buffer->i4_tgt_frm_rate;
if(i8_max_bit_dev_allowed < (approx_file_size >> 4))
i8_max_bit_dev_allowed = (approx_file_size >> 4);
/*have a max limit so that bit dev does not grow for very long sequence like 24 hours of encoding (max can be 20 second)*/
if(i8_max_bit_dev_allowed > (VBR_MAX_BIT_DEV_SEC * ps_cbr_buffer->ai4_bit_rate[0]))
i8_max_bit_dev_allowed = (VBR_MAX_BIT_DEV_SEC * ps_cbr_buffer->ai4_bit_rate[0]);
ps_cbr_buffer->u4_max_vbv_buf_size = (UWORD32)i8_max_bit_dev_allowed;
}
/* Update the Encoder buffer with the total consumed bits*/
if(ps_cbr_buffer->i4_is_cbr_mode != 0)
{
ps_cbr_buffer->i4_ebf += i4_tot_consumed_bits;
ps_cbr_buffer->i8_ebf_bit_alloc += i4_tot_consumed_bits;
/* Subtract the drain bits and error bits due to fixed point implementation*/
ps_cbr_buffer->i4_ebf -= (i4_drain_bits_per_frame + i4_error_bits);
ps_cbr_buffer->i8_ebf_bit_alloc -= (i4_drain_bits_per_frame + i4_error_bits);
}
else
{
ps_cbr_buffer->i4_ebf += i4_tot_consumed_bits;
ps_cbr_buffer->i4_ebf -=
((MIN(ps_cbr_buffer->i4_peak_drain_rate_frame, ps_cbr_buffer->i4_ebf)) + i4_error_bits);
ps_cbr_buffer->i8_ebf_bit_alloc += i4_tot_consumed_bits;
ps_cbr_buffer->i8_ebf_bit_alloc -=
(ps_cbr_buffer->i4_drain_bits_per_frame[0] + i4_error_bits);
ps_cbr_buffer->i8_credit_level += i4_tot_consumed_bits;
ps_cbr_buffer->i8_credit_level -=
(ps_cbr_buffer->i4_drain_bits_per_frame[0] + i4_error_bits);
/*To keep limit on duration for which peak rate can be sustained limit the accumulation of bits from simpler regions*/
if(!ps_cbr_buffer->i4_vbr_no_peak_rate_duration_limit)
{
if(ps_cbr_buffer->i8_ebf_bit_alloc < 0)
ps_cbr_buffer->i8_ebf_bit_alloc =
0; /*This will make VBR buffer believe that the bits are lost*/
}
}
/*SS - Fix for lack of stuffing*/
if(ps_cbr_buffer->i4_ebf < 0)
{
//trace_printf("Error: Should not be coming here with bit stuffing \n");
ps_cbr_buffer->i4_ebf = 0;
}
if(ps_cbr_buffer->i4_ebf > ps_cbr_buffer->i4_buffer_size)
{
//trace_printf("Error: Frame should be skipped\n");
ps_cbr_buffer->i4_ebf = ps_cbr_buffer->i4_buffer_size;
}
ps_cbr_buffer->i4_ebf_estimate = ps_cbr_buffer->i4_ebf;
trace_printf(
"VBR ebf = %d bebf = %d ", ps_cbr_buffer->i4_ebf, ps_cbr_buffer->i8_ebf_bit_alloc);
/* Update the error bits */
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
update_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i]);
}
/* ******************************************************************************/
/**
* @brief If the buffer underflows then return the number of bits to prevent underflow
*
* @param ps_cbr_buffer
* @param i4_tot_consumed_bits
* @param e_pic_type
*
* @return
*/
/* ******************************************************************************/
WORD32 get_cbr_bits_to_stuff(
cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tot_consumed_bits, picture_type_e e_pic_type)
{
WORD32 i4_bits_to_stuff;
WORD32 i4_error_bits = (e_pic_type == I_PIC)
? get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[0])
: get_error_bits(ps_cbr_buffer->aps_bpf_error_bits[1]);
WORD32 i4_drain_bits_per_frame = (e_pic_type == I_PIC)
? ps_cbr_buffer->i4_drain_bits_per_frame[0]
: ps_cbr_buffer->i4_drain_bits_per_frame[1];
/* Stuffing bits got from the following equation
Stuffing_threshold = ebf + tcb - drain bits - error bits + stuff_bits*/
i4_bits_to_stuff =
i4_drain_bits_per_frame + i4_error_bits - (ps_cbr_buffer->i4_ebf + i4_tot_consumed_bits);
return i4_bits_to_stuff;
}
/* ******************************************************************************/
/**
* @brief Change the state for change in bit rate
*
* @param ps_cbr_buffer
* @param i4_bit_rate
*/
/* ******************************************************************************/
void change_cbr_vbv_bit_rate(
cbr_buffer_t *ps_cbr_buffer, WORD32 *i4_bit_rate, WORD32 i4_peak_bitrate)
{
WORD32 i4_bits_per_frm[MAX_NUM_DRAIN_RATES];
int i;
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
{
X_PROD_Y_DIV_Z(i4_bit_rate[i], 1000, ps_cbr_buffer->i4_tgt_frm_rate, i4_bits_per_frm[i]);
/* Drain rate = bitrate/(framerate/1000) */
ps_cbr_buffer->i4_drain_bits_per_frame[i] = i4_bits_per_frm[i];
/* initialise the bits per frame error bits calculation */
change_bitrate_in_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i], i4_bit_rate[i]);
}
X_PROD_Y_DIV_Z(
i4_peak_bitrate,
1000,
ps_cbr_buffer->i4_tgt_frm_rate,
ps_cbr_buffer->i4_peak_drain_rate_frame);
/* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/
//if(i4_bit_rate[0] == i4_bit_rate[1]) /* This would mean CBR mode */
{
X_PROD_Y_DIV_Z(
i4_bit_rate[0],
ps_cbr_buffer->i4_max_delay,
1000,
ps_cbr_buffer->i4_buffer_size); //the delay term is supposed to remain constant
//ps_cbr_buffer->i4_is_cbr_mode = 1;
ps_cbr_buffer->u4_max_vbv_buf_size = ps_cbr_buffer->i4_buffer_size;
}
if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size)
{
ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size;
}
set_upper_lower_vbv_threshold(ps_cbr_buffer, i4_bits_per_frm[0]);
if(ps_cbr_buffer->e_rc_type == CBR_NLDRC)
{
ps_cbr_buffer->u4_vbr_max_bit_deviation = ps_cbr_buffer->i4_buffer_size;
}
else
{
/*DCB: the deviaiton must be altered for VBR case, when bitrate is lowered quality might be bad because of this*/
{
ULWORD64 u8_vbr_max_bit_deviation =
(ULWORD64)(ps_cbr_buffer->f_max_dur_peak_rate * i4_bit_rate[0]);
ULWORD64 file_size = (ULWORD64)(
(((LWORD64)i4_bit_rate[0] * 1000) / ps_cbr_buffer->i4_tgt_frm_rate) *
(ps_cbr_buffer->i8_tot_frm_to_be_encoded - ps_cbr_buffer->i8_num_frames_encoded));
/*When f_max_dur_peak_rate is -ve, it implies user is not worried about duration for which peak is sustained, hence go with max possible value*/
if(ps_cbr_buffer->f_max_dur_peak_rate > 0)
u8_vbr_max_bit_deviation =
(ULWORD64)(ps_cbr_buffer->f_max_dur_peak_rate * i4_bit_rate[0]);
else
u8_vbr_max_bit_deviation = VBR_MAX_BIT_DEV_SEC * i4_bit_rate[0];
/*when num frames to encode is negative is -ve it implies total frames data is not available (as in case of live encoding)*/
if(ps_cbr_buffer->i8_tot_frm_to_be_encoded > 0)
{
/*allow atleast one second deviation or 12% of total file size whichever is higher*/
if(u8_vbr_max_bit_deviation > (file_size >> 3))
u8_vbr_max_bit_deviation = (UWORD32)(file_size >> 3);
}
else
{
u8_vbr_max_bit_deviation = (UWORD32)(file_size >> 3);
}
/*allow atleast one second for shorter sequence*/
if(u8_vbr_max_bit_deviation < (ULWORD64)i4_bit_rate[0])
u8_vbr_max_bit_deviation = (ULWORD64)i4_bit_rate[0];
ps_cbr_buffer->u4_vbr_max_bit_deviation = u8_vbr_max_bit_deviation;
}
}
/* Storing the input parameters for using it for change functions */
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
ps_cbr_buffer->ai4_bit_rate[i] = i4_bit_rate[i];
}
/* ******************************************************************************/
/**
* @brief Update the state for change in number of pics in the delay period
*
* @param ps_cbr_buffer
* @param u4_num_pics_in_delay_prd
*/
/* ******************************************************************************/
void change_cbr_vbv_num_pics_in_delay_period(
cbr_buffer_t *ps_cbr_buffer, UWORD32 *u4_num_pics_in_delay_prd)
{
WORD32 i;
if(!ps_cbr_buffer->i4_is_cbr_mode)
{
ps_cbr_buffer->i4_buffer_size =
u4_num_pics_in_delay_prd[0] * ps_cbr_buffer->i4_drain_bits_per_frame[0] +
u4_num_pics_in_delay_prd[1] * ps_cbr_buffer->i4_drain_bits_per_frame[1];
if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size)
{
ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size;
}
for(i = 0; i < MAX_PIC_TYPE; i++)
{
ps_cbr_buffer->i4_upr_thr[i] =
ps_cbr_buffer->i4_buffer_size - (ps_cbr_buffer->i4_buffer_size >> 3);
}
/* Re-initilise the number of pics in delay period */
for(i = 0; i < MAX_PIC_TYPE; i++)
{
ps_cbr_buffer->ai4_num_pics_in_delay_period[i] = u4_num_pics_in_delay_prd[i];
}
}
}
/* ******************************************************************************/
/**
* @ modifies the ebf estimated parameter based on error
*
* @param ps_cbr_buffer
* @param i4_bit_error
*/
/* ******************************************************************************/
void cbr_modify_ebf_estimate(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_bit_error)
{
ps_cbr_buffer->i4_ebf_estimate = ps_cbr_buffer->i4_ebf + i4_bit_error;
if(ps_cbr_buffer->i4_ebf_estimate < 0)
{
ps_cbr_buffer->i4_ebf_estimate = 0;
}
else if(ps_cbr_buffer->i4_ebf_estimate > ps_cbr_buffer->i4_buffer_size)
{
ps_cbr_buffer->i4_ebf_estimate = ps_cbr_buffer->i4_buffer_size;
}
}
/* ******************************************************************************/
/**
* @ get the buffer size
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
WORD32 get_cbr_buffer_size(cbr_buffer_t *ps_cbr_buffer)
{
return (ps_cbr_buffer->i4_buffer_size);
}
#if NON_STEADSTATE_CODE
/* ******************************************************************************/
/**
* @brief update the state for change in target frame rate
*
* @param ps_cbr_buffer
* @param i4_tgt_frm_rate
*/
/* ******************************************************************************/
void change_cbr_vbv_tgt_frame_rate(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_tgt_frm_rate)
{
WORD32 i4_i, i4_bits_per_frm[MAX_NUM_DRAIN_RATES];
int i;
for(i = 0; i < MAX_NUM_DRAIN_RATES; i++)
{
X_PROD_Y_DIV_Z(ps_cbr_buffer->ai4_bit_rate[i], 1000, i4_tgt_frm_rate, i4_bits_per_frm[i]);
/* Drain rate = bitrate/(framerate/1000) */
ps_cbr_buffer->i4_drain_bits_per_frame[i] = i4_bits_per_frm[i];
/* initialise the bits per frame error bits calculation */
change_frm_rate_in_error_bits(ps_cbr_buffer->aps_bpf_error_bits[i], i4_tgt_frm_rate);
}
/* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/
if(!ps_cbr_buffer->i4_is_cbr_mode)
{
/* VBR streaming case which has different drain rates for I and P */
ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->ai4_num_pics_in_delay_period[0] *
ps_cbr_buffer->i4_drain_bits_per_frame[0] +
ps_cbr_buffer->ai4_num_pics_in_delay_period[1] *
ps_cbr_buffer->i4_drain_bits_per_frame[1];
}
if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size)
{
ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size;
}
for(i4_i = 0; i4_i < MAX_PIC_TYPE; i4_i++)
{
/* Uppr threshold for
I frame = 1 * bits per frame
P Frame = 4 * bits per frame.
The threshold for I frame is only 1 * bits per frame as the threshold should
only account for error in estimated bits.
In P frame it should account for difference bets bits consumed by I(Scene change)
and P frame I to P complexity is assumed to be 5. */
WORD32 i4_index;
i4_index = i4_i > 0 ? 1 : 0;
ps_cbr_buffer->i4_upr_thr[i4_i] =
ps_cbr_buffer->i4_buffer_size - (ps_cbr_buffer->i4_buffer_size >> 3);
/* For both I and P frame Lower threshold is equal to drain rate.
Even if the encoder consumes zero bits it should have enough bits to drain*/
ps_cbr_buffer->i4_low_thr[i4_i] = i4_bits_per_frm[i4_index];
}
/* Storing the input parameters for using it for change functions */
ps_cbr_buffer->i4_tgt_frm_rate = i4_tgt_frm_rate;
}
/* ******************************************************************************/
/**
* @brief update the state for change in buffer delay
*
* @param ps_cbr_buffer
* @param i4_buffer_delay
*/
/* ******************************************************************************/
void change_cbr_buffer_delay(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_buffer_delay)
{
WORD32 i4_i;
/* Bitrate * delay = buffer size, divide by 1000 as delay is in ms*/
if(ps_cbr_buffer->i4_is_cbr_mode)
{
X_PROD_Y_DIV_Z(
ps_cbr_buffer->ai4_bit_rate[0], i4_buffer_delay, 1000, ps_cbr_buffer->i4_buffer_size);
}
if(ps_cbr_buffer->i4_buffer_size > (WORD32)ps_cbr_buffer->u4_max_vbv_buf_size)
{
ps_cbr_buffer->i4_buffer_size = ps_cbr_buffer->u4_max_vbv_buf_size;
}
for(i4_i = 0; i4_i < MAX_PIC_TYPE; i4_i++)
{
/* Uppr threshold for
I frame = 1 * bits per frame
P Frame = 4 * bits per frame.
The threshold for I frame is only 1 * bits per frame as the threshold should
only account for error in estimated bits.
In P frame it should account for difference bets bits consumed by I(Scene change)
and P frame I to P complexity is assumed to be 5. */
ps_cbr_buffer->i4_upr_thr[i4_i] =
ps_cbr_buffer->i4_buffer_size - (ps_cbr_buffer->i4_buffer_size >> 3);
}
/* Storing the input parameters for using it for change functions */
ps_cbr_buffer->i4_max_delay = i4_buffer_delay;
}
/* ******************************************************************************/
/**
* @brief update the state for change in buffer delay
*
* @param ps_cbr_buffer
* @param i4_buffer_delay
*/
/* ******************************************************************************/
WORD32 get_cbr_buffer_delay(cbr_buffer_t *ps_cbr_buffer)
{
return (ps_cbr_buffer->i4_max_delay);
}
/* ******************************************************************************/
/**
* @brief get_cbr_ebf
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
WORD32 get_cbr_ebf(cbr_buffer_t *ps_cbr_buffer)
{
return (ps_cbr_buffer->i4_ebf);
}
/* ******************************************************************************/
/**
* @brief get_cbr_max_ebf
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
WORD32 get_cbr_max_ebf(cbr_buffer_t *ps_cbr_buffer)
{
return (ps_cbr_buffer->i4_upr_thr[0]);
}
/* ******************************************************************************/
/**
* @brief set_cbr_ebf
*
* @param ps_cbr_buffer
* @param i32_init_ebf
*/
/* ******************************************************************************/
void set_cbr_ebf(cbr_buffer_t *ps_cbr_buffer, WORD32 i32_init_ebf)
{
ps_cbr_buffer->i4_ebf = i32_init_ebf;
}
/* ******************************************************************************/
/**
* @brief update_cbr_buf_mismatch_bit
*
* @param ps_cbr_buffer
* @param i4_error_bits
*/
/* ******************************************************************************/
void update_cbr_buf_mismatch_bit(cbr_buffer_t *ps_cbr_buffer, WORD32 i4_error_bits)
{
ps_cbr_buffer->i4_ebf -= i4_error_bits;
ps_cbr_buffer->i8_ebf_bit_alloc -= i4_error_bits;
ps_cbr_buffer->i8_credit_level -= i4_error_bits;
}
/* ******************************************************************************/
/**
* @brief get encoded number of frames
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
LWORD64 get_num_frms_encoded(cbr_buffer_t *ps_cbr_buffer)
{
return ps_cbr_buffer->i8_num_frames_encoded;
}
/* ******************************************************************************/
/**
* @brief get num frames to encode
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
LWORD64 get_num_frms_to_encode(cbr_buffer_t *ps_cbr_buffer)
{
return ps_cbr_buffer->i8_tot_frm_to_be_encoded;
}
/* ******************************************************************************/
/**
* @brief get peak drain rate
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
/* The buffer limit in bit allocation should be according to peak bitrate */
WORD32 get_buf_max_drain_rate(cbr_buffer_t *ps_cbr_buffer)
{
if(ps_cbr_buffer->e_rc_type == VBR_STREAMING)
return ps_cbr_buffer->i4_peak_drain_rate_frame;
else if(ps_cbr_buffer->e_rc_type != CONST_QP)
{
ASSERT(
ps_cbr_buffer->i4_peak_drain_rate_frame == ps_cbr_buffer->i4_drain_bits_per_frame[0]);
return ps_cbr_buffer->i4_drain_bits_per_frame[0];
}
return ps_cbr_buffer->i4_drain_bits_per_frame[0];
}
/* ******************************************************************************/
/**
* @brief get excess bits by moving in VBV buffer to enable bitrate greater than peak rate for shorter duration in very
* complex contents
*
* @param ps_cbr_buffer
* @param i4_tgt_frm_rate
*/
/* ******************************************************************************/
WORD32 get_vbv_buffer_based_excess(
cbr_buffer_t *ps_cbr_buffer,
float f_complexity_peak_rate,
float f_cur_bits_complexity,
WORD32 bit_alloc_period,
WORD32 i4_num_gops_for_excess)
{
LWORD64 max_buffer_level = (LWORD64)((float)ps_cbr_buffer->i4_buffer_size * 0.8f);
LWORD64 i8_excess_bits;
/*LWORD64target_buf_level;*/
WORD32
num_frm_to_be_distributed; //Number of frames for which excess bits should be distributed, using number of frames corresponding to buffer size for now
if(ps_cbr_buffer->i4_upr_thr[0] <
max_buffer_level) /*choose max allowed level to min(upper_threshold,80% of buffer*/
max_buffer_level = ps_cbr_buffer->i4_upr_thr[0];
if(ps_cbr_buffer->e_rc_type == VBR_STREAMING)
max_buffer_level = (LWORD64)(
ps_cbr_buffer->i4_peak_drain_rate_frame * ps_cbr_buffer->u4_num_frms_in_delay * 0.8f);
if(f_cur_bits_complexity >
0.9f) /*clip current to max of 80% of buffer size to avoid dangerous buffer level by end of GOP*/
f_cur_bits_complexity = 0.9f;
if(f_cur_bits_complexity < f_complexity_peak_rate || f_cur_bits_complexity < 0.1f ||
ps_cbr_buffer->i4_buffer_size <
ps_cbr_buffer->ai4_bit_rate
[0]) //For buffer size less than 1 sec disable any contribution from buffer based for extra complex contents
{
/*For very low compleity content or Cavg do not allow buffer movement*/
return 0;
}
i8_excess_bits = (LWORD64)(
((f_cur_bits_complexity - f_complexity_peak_rate) / (0.9f - f_complexity_peak_rate)) *
(max_buffer_level - ps_cbr_buffer->i4_ebf));
if(i8_excess_bits < 0)
i8_excess_bits = 0;
num_frm_to_be_distributed = (WORD32)(
((float)ps_cbr_buffer->i4_buffer_size / ps_cbr_buffer->ai4_bit_rate[0] *
ps_cbr_buffer->i4_tgt_frm_rate / 1000) +
0.5);
/*Excess bits should be proportional to bit alloc period, shorter intra period should get in small incentives*/
if(bit_alloc_period < num_frm_to_be_distributed)
i8_excess_bits =
(LWORD64)((float)i8_excess_bits * bit_alloc_period / num_frm_to_be_distributed);
if(ps_cbr_buffer->e_rc_type == VBR_STREAMING)
{
if(i4_num_gops_for_excess > 1)
i8_excess_bits = i8_excess_bits * i4_num_gops_for_excess;
if(i8_excess_bits > (LWORD64)(
(float)ps_cbr_buffer->i4_peak_drain_rate_frame *
ps_cbr_buffer->u4_num_frms_in_delay * 0.8f))
i8_excess_bits = (LWORD64)(
(float)ps_cbr_buffer->i4_peak_drain_rate_frame *
ps_cbr_buffer->u4_num_frms_in_delay * 0.8f);
}
trace_printf(
"Excess bits %d %f %f num gops %d",
i8_excess_bits,
f_cur_bits_complexity,
f_complexity_peak_rate,
i4_num_gops_for_excess);
return ((WORD32)i8_excess_bits);
}
/* ******************************************************************************/
/**
* @brief get gop correction error bits for the current gop. This will be added to rbip.
*
* @param ps_cbr_buffer
* @param i4_lap_complexity_q7
* @param i4_bit_alloc_period
*/
/* ******************************************************************************/
WORD32 get_error_bits_for_desired_buf(
cbr_buffer_t *ps_cbr_buffer, WORD32 i4_lap_complexity_q7, WORD32 i4_bit_alloc_period)
{
if(ps_cbr_buffer->e_rc_type == CBR_NLDRC)
{
LWORD64 error_bits = 0, complexity_mov_buf_size = 0;
LWORD64 i8_default_bits_in_period, i8_max_additional_bits_in_period;
LWORD64 i8_buf_based_limit_red, i8_buf_based_limit_inc, i8_buf_diff_bits;
float buf_diff, abs_lap_complexity;
/*calculate default allocation*/
i8_default_bits_in_period = (LWORD64)ps_cbr_buffer->ai4_bit_rate[0] * 1000 *
i4_bit_alloc_period / ps_cbr_buffer->i4_tgt_frm_rate;
/*In case of VBR give additional bits according to peak bitrate*/
if(ps_cbr_buffer->e_rc_type == VBR_STREAMING)
{
i8_max_additional_bits_in_period =
((LWORD64)ps_cbr_buffer->i4_peak_drain_rate_frame * i4_bit_alloc_period) -
i8_default_bits_in_period;
ASSERT(i8_max_additional_bits_in_period >= 0);
if(i8_max_additional_bits_in_period > (i8_default_bits_in_period))
{
/*clip max bits that can be given to 2x bitrate since its too riskly to give more than that in single pass encoding
where long future is not known*/
i8_max_additional_bits_in_period = (i8_default_bits_in_period);
}
}
else
{
i8_max_additional_bits_in_period = i8_default_bits_in_period;
}
{
float X = ((float)i4_lap_complexity_q7 / 128);
float desired_buf_level;
/*For CBR VBV buffer size is "complexity_mov_buf_size" and In case of VBR it is determined by bit deviaiton*/
if(ps_cbr_buffer->e_rc_type == CBR_NLDRC)
{
complexity_mov_buf_size = (LWORD64)ps_cbr_buffer->i4_upr_thr[0];
}
else if(ps_cbr_buffer->e_rc_type == VBR_STREAMING)
{
complexity_mov_buf_size = ps_cbr_buffer->u4_vbr_max_bit_deviation;
}
abs_lap_complexity = X;
if(ps_cbr_buffer->i4_cbr_rc_pass == 2)
desired_buf_level = COMP_TO_BITS_MAP_2_PASS(X, complexity_mov_buf_size);
else
desired_buf_level = COMP_TO_BITS_MAP(X, complexity_mov_buf_size);
if(desired_buf_level < 0)
desired_buf_level = 0;
/*map complexity to buffer level*/
error_bits = (LWORD64)(desired_buf_level - ps_cbr_buffer->i8_ebf_bit_alloc);
i8_buf_diff_bits = error_bits;
/*For VBR its possible that i8_ebf_bit_alloc can go below 0, that the extent of giving should only be desired - cur( = 0 for cur < 0)*/
buf_diff = (float)error_bits / complexity_mov_buf_size;
/*clipping based on buffer size should depend on gop size. Assuming 7% of gop of gop = 32, calculate for other GOP intervals max 7% while giving from buffer and 10%
while stealing from buffer(for GOP of 32)*/
/*try to be conservative when giving extra bits to gop and limit while reducing bits to GOP needs to be higher inorder to be buffer compliant if necessary*/
i8_buf_based_limit_red =
((LWORD64)complexity_mov_buf_size * i4_bit_alloc_period * 12) >> 12;
i8_buf_based_limit_inc = ((LWORD64)complexity_mov_buf_size * i4_bit_alloc_period * 8) >>
12;
/*(shd be 7 even if GOP size goes lesser)*/
if(i8_buf_based_limit_red < (((LWORD64)complexity_mov_buf_size * 10) >> 7))
i8_buf_based_limit_red = (((LWORD64)complexity_mov_buf_size * 10) >> 7);
if(i8_buf_based_limit_inc < (((LWORD64)complexity_mov_buf_size * 10) >> 7))
i8_buf_based_limit_inc = (((LWORD64)complexity_mov_buf_size * 10) >> 7);
/*if error bits is too high it is given in stages so that buffer is utilized for entire complex content*/
/*error bits should not exceed ten 7% of buffer*/
/*error bits can be max equal to bitrate*/
if(error_bits > 0)
{
/*if lap compleixty is higher and buffer allows give the bits*/
error_bits = (WORD32)(abs_lap_complexity * i8_max_additional_bits_in_period);
/*if lap complexity is too simple do not give additional bits to make sure that simple scenes never get additional bits whatsoever*/
if(abs_lap_complexity < 0.2f && ps_cbr_buffer->i8_ebf_bit_alloc >= 0)
{
error_bits = 0;
}
if(error_bits > i8_buf_diff_bits)
error_bits = i8_buf_diff_bits;
if(error_bits > i8_buf_based_limit_inc)
{
error_bits = i8_buf_based_limit_inc;
}
/*If buffer is already half filled be conservative. Allocate 1.5 times bits
else allocate twice the bits*/
if(ps_cbr_buffer->i8_ebf_bit_alloc >
(LWORD64)(ps_cbr_buffer->i4_buffer_size * 0.75))
{
if(error_bits > (i8_max_additional_bits_in_period >> 1))
{
error_bits = (i8_max_additional_bits_in_period >> 1);
}
}
else
{
if(error_bits > i8_max_additional_bits_in_period)
{
error_bits = i8_max_additional_bits_in_period;
}
}
}
else
{
error_bits = (WORD32)(buf_diff * (i8_default_bits_in_period >> 1));
if(error_bits < -i8_buf_based_limit_red)
{
error_bits = -i8_buf_based_limit_red;
}
/*when buffer level needs to reduce bits in period*/
/*If current level is less than half min bits in period = 70% of constant bit in period else 50%*/
if(ps_cbr_buffer->i8_ebf_bit_alloc > (ps_cbr_buffer->i4_buffer_size >> 1))
{
if(error_bits < -(i8_default_bits_in_period >> 1))
{
error_bits = -(i8_default_bits_in_period >> 1);
}
}
else
{
if(error_bits < -((i8_default_bits_in_period * 5) >> 4))
{
error_bits = -((i8_default_bits_in_period * 5) >> 4);
}
}
}
}
return (WORD32)error_bits;
}
else
{
LWORD64 max_excess_bits, default_allocation_for_period, comp_based_excess = 0;
LWORD64 i8_excess_bits = 0, bit_dev_so_far, credit_limit_level;
LWORD64 Ravg_dur, num_intra_period_in_Ravg_dur,
num_intra_in_clip; //duration for which Ravg has to be met, for shorter slips this can be equal to clip duration
LWORD64 i8_buf_based_limit_red, i8_buf_based_limit_inc;
float comp_to_bit_mapped, X;
/*default allocation for period in absence of complexity based bit allocation*/
default_allocation_for_period =
ps_cbr_buffer->i4_drain_bits_per_frame[0] * i4_bit_alloc_period;
bit_dev_so_far = ps_cbr_buffer->i8_ebf_bit_alloc;
credit_limit_level = ps_cbr_buffer->i8_credit_level;
Ravg_dur =
ps_cbr_buffer->u4_vbr_max_bit_deviation * 5 / ps_cbr_buffer->i4_drain_bits_per_frame[0];
if(Ravg_dur > 20 * ps_cbr_buffer->i8_tot_frm_to_be_encoded / 100)
Ravg_dur = 20 * ps_cbr_buffer->i8_tot_frm_to_be_encoded / 100;
if(Ravg_dur <= 0)
Ravg_dur = 1;
/*map the complexity to bits ratio*/
X = (float)i4_lap_complexity_q7 / 128;
if(ps_cbr_buffer->i4_cbr_rc_pass == 2)
comp_to_bit_mapped = COMP_TO_BITS_MAP_2_PASS(X, 1.0f);
else
comp_to_bit_mapped = COMP_TO_BITS_MAP(X, 1.0f);
comp_to_bit_mapped *= 10; //mapping it to absolute peak bitrate
/*calculate the number of bit alloc periods over which the credit limit needs to build up*/
num_intra_in_clip = ps_cbr_buffer->i8_tot_frm_to_be_encoded / i4_bit_alloc_period;
num_intra_period_in_Ravg_dur = Ravg_dur / i4_bit_alloc_period;
//ASSERT(ps_cbr_buffer->i8_tot_frm_to_be_encoded > i4_bit_alloc_period);
if(ps_cbr_buffer->i8_tot_frm_to_be_encoded < i4_bit_alloc_period)
{
num_intra_period_in_Ravg_dur = 1;
num_intra_in_clip = 1;
}
if(num_intra_period_in_Ravg_dur <= 0)
{
num_intra_period_in_Ravg_dur = 1;
}
/*max excess bits possible according to given peak bitrate*/
{
max_excess_bits = (ps_cbr_buffer->i4_peak_drain_rate_frame -
ps_cbr_buffer->i4_drain_bits_per_frame[0]) *
i4_bit_alloc_period;
/*constrain max excess bits allocated to a region if buffer is already at critical level*/
/*assume room for 20% over-consumption due to mismatch between allocation and consumption*/
if(ps_cbr_buffer->i4_ebf >
(ps_cbr_buffer->i4_upr_thr[0] - (WORD32)(max_excess_bits * 0.2)))
{
max_excess_bits = (LWORD64)(max_excess_bits * 0.8);
}
}
/*clipping based on buffer size should depend on gop size. Assuming 7% of gop of gop = 32, calculate for other GOP intervals max 7% while giving from buffer and 10%
while stealing from buffer(for GOP of 32)*/
/*try to be conservative when giving extra bits to gop and limit while reducing bits to GOP needs to be higher inorder to be buffer compliant if necessary*/
i8_buf_based_limit_red =
((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * i4_bit_alloc_period * 12) >> 12;
i8_buf_based_limit_inc =
((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * i4_bit_alloc_period * 8) >> 12;
/*(shd be 7 even if GOP size goes lesser)*/
if(i8_buf_based_limit_red < (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7))
i8_buf_based_limit_red = (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7);
if(i8_buf_based_limit_inc < (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7))
i8_buf_based_limit_inc = (((LWORD64)ps_cbr_buffer->u4_vbr_max_bit_deviation * 10) >> 7);
/*The credit limit is not completly built, hence the average operating bitrate will be lesser than average*/
//if(ps_cbr_buffer->i8_ebf_bit_alloc >= 0)
//Disabling this to avoid under-consumption of bits since mostly contents will end with simpler sequence
if(1 != ps_cbr_buffer->i4_capped_vbr_on)
{
/*adjust the excess bits to account for deviation in bitrate
If bit deviation is positive then overconsumption, hence resuce the default bit allocation*/
/* In capped vbr mode this is not calculated as there is no constraint to meet the configured bitrate */
i8_excess_bits -= (bit_dev_so_far / num_intra_period_in_Ravg_dur);
}
/*allocate bits based on complexity*/
/*comp_to_bit_mapped less than 1 implies a content that requires less than average bitrate,
hence due to sign reversal we tend to steal bits*/
comp_based_excess = (LWORD64)((comp_to_bit_mapped - 1) * default_allocation_for_period);
if(1 != ps_cbr_buffer->i4_capped_vbr_on)
{
/*clip the complexity based on intra period and credit limit buffer size so that when credit limit is lower not everything is used for first GOP*/
if(comp_based_excess > i8_buf_based_limit_inc)
{
comp_based_excess = i8_buf_based_limit_inc;
}
else if(comp_based_excess < -i8_buf_based_limit_red)
{
comp_based_excess = -i8_buf_based_limit_red;
}
/*when the credit limit is fully used, stop giving extra*/
if(credit_limit_level > ps_cbr_buffer->u4_vbr_max_bit_deviation)
{
if(comp_based_excess < 0)
i8_excess_bits += comp_based_excess;
}
/*when credit limit is almost full (80 percent full)*/
else if(credit_limit_level > (LWORD64)(ps_cbr_buffer->u4_vbr_max_bit_deviation * 0.8f))
{
/*follow smooth transition, at 80% utilized the excess should be 100 percent, it should move to zero percent as it approaches 100% utlization*/
if(comp_based_excess > 0)
i8_excess_bits += (LWORD64)(
((ps_cbr_buffer->u4_vbr_max_bit_deviation - credit_limit_level) /
(0.2f * ps_cbr_buffer->u4_vbr_max_bit_deviation)) *
comp_based_excess);
else
i8_excess_bits += comp_based_excess;
}
else if(credit_limit_level > (LWORD64)(ps_cbr_buffer->u4_vbr_max_bit_deviation * 0.2f))
{
i8_excess_bits += comp_based_excess;
}
/*When credit limit is almost unutilized*/
else if(
credit_limit_level < (WORD32)(ps_cbr_buffer->u4_vbr_max_bit_deviation * 0.2f) &&
credit_limit_level > 0)
{
if(comp_based_excess < 0)
i8_excess_bits += (LWORD64)(
(credit_limit_level / (0.2f * ps_cbr_buffer->u4_vbr_max_bit_deviation)) *
comp_based_excess);
else
i8_excess_bits += comp_based_excess;
}
/*If the credit limit still uutilized stop drawing bits from simpler content*/
else if(credit_limit_level <= 0)
{
if(comp_based_excess > 0)
i8_excess_bits += comp_based_excess;
}
else
ASSERT(0);
}
else
{
/* In capped vbr mode excess bits will be based on complexity of content alone*/
i8_excess_bits = comp_based_excess;
}
/*Clip the excess bits such that it will never violate peak bitrate and also Rmin*/
if(i8_excess_bits > max_excess_bits)
i8_excess_bits = max_excess_bits;
/*assuming atleast 0.4 times average bitrate even for the simplest content*/
if(i8_excess_bits < -(default_allocation_for_period * 0.6f))
i8_excess_bits = (LWORD64)(-(default_allocation_for_period * 0.6f));
ASSERT(i8_excess_bits <= 0x7FFFFFFF);
return (WORD32)i8_excess_bits;
}
}
/* ******************************************************************************/
/**
* @brief get_rc_type.
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
rc_type_e get_rc_type(cbr_buffer_t *ps_cbr_buffer)
{
return (ps_cbr_buffer->e_rc_type);
}
/* ******************************************************************************/
/**
* @brief cbr_get_delay_frames
*
* @param ps_cbr_buffer
*/
/* ******************************************************************************/
UWORD32 cbr_get_delay_frames(cbr_buffer_t *ps_cbr_buffer)
{
return (ps_cbr_buffer->u4_num_frms_in_delay);
}
#endif /* #if NON_STEADSTATE_CODE */